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BSAVA Manual of 
Psittacine Birds 
Second edition 
Published by: 
British Small Animal Veterinary Associat ion 
Woodrow House, 1 Telford Way, Waterwells 
Business Park, Quedgeley, Gloucester GL2 2AB 
A Company Limited by Guarantee in England. 
Registered Company No. 2837793. 
Registered as a Charity. 
Copyright © 2005 BSAVA 
All rights reserved. No part of this publication may be reproduced, stored 
in a retrieval system, or transmitted, in form or by any means, electronic, 
mechanical, photocopying, recording or otherwise without prior written 
permission of the copyright holder. 
The following figures are copyright Nigel Harcourt-Brown and are 
reproduced with his permission: 2.1—2.18, 4.1, 5.4, 9.1—9.25, 10.10, 
11.1—11.21, 11.23, 11.24, 13. 4, 13.6—13.10, 13.14, 13.16, 14.3, 
15.16, 18.4, 18.8. 
A catalogue record for this book is available from the British Library. 
ISBN 0 905214 76 5 
The publishers and contributors cannot take responsibility for information 
provided on dosages and methods of application of drugs mentioned in 
this publication. Details of this kind must be verified by individual users 
from the appropriate literature. 
E d i t o r s : 
Nigel Harcourt-Brown 
B V S c D i p E C A M S F R C V S 
3 0 C r a b L a n e , H a r r o g a t e , N o r t h Y o r k s h i r e H G 1 3 B E 
a n d 
John Chitty 
B V e t M e d C e r t Z o o M e d M R C V S 
S t r a t h m o r e V e t e r i n a r y C l i n i c , 6 L o n d o n R o a d , 
A n d o v e r , H a n t s S P 1 0 2 P H 
Typeset by Fusion Design, Wareham, Dorset, UK 
Printed by Replika Press Pvt. Ltd., India — 
Other titles in the 
BSAVA Manuals series: 
of Advanced Veterinary Nursing 
of Canine and Feline Behavioural Medicine 
of Canine and Feline Clinical Pathology 
of Canine and Feline Emergency and Critical Care 
of Canine and Feline Gastroenterology 
of Canine and Feline Haematology and Transfusion Medicine 
of Canine and Feline Infectious Diseases 
of Canine and Feline Nephrology and Urology 
of Canine and Feline Wound Management and Reconstruction 
of Canine and Feline Oncology 
of Canine and Feline Endocrinology 
of Companion Animal Nutrition and Feeding 
of Exotic Pets 
of Ornamental Fish 
of Rabbit Medicine and Surgery 
of Raptors, Pigeons and Waterfowl 
of Reptiles 
of Small Animal Anaesthesia and Analgesia 
of Small Animal Cardiorespiratory Medicine and Surgery 
of Small Animal Dermatology 
of Small Animal Diagnostic Imaging 
of Small Animal Endocrinology 
of Small Animal Fracture Repair and Management 
of Small Animal Neurology 
of Small Animal Ophthalmology 
of Small Animal Reproduction and Neonatology 
of Veterinary Care 
of Veterinary Nursing 
of Wildlife Casualties 
F o r t h c o m i n g T i t l e s : 
1 of Canine and Feline Abdominal Surgery 
1 of Canine and Feline Articular Surgery 
f of Canine and Feline Dentistry 
' of Canine and Feline Head, Neck and Thoracic Surgery 
' of Canine and Feline Lameness Diagnosis 
F o r i n f o r m a t i o n o n t h e s e a n d a l l B S A V A p u b l i c a t i o n s p l e a s e v i s i t o u r w e b s i t e : w w w . b s a v a . c o m 
ii 
Contents 
List of con t r ibu tors 
F o r e w o r d 
Pre face 
Part 1 S p e c i e s a n d h u s b a n d r y 
1 S p e c i e s a n d natura l h is tory 
Brian H. Coles 
2 
3 
4 
A n a t o m y a n d p h y s i o l o g y 
Nigel H. Harcourt-Brown 
H u s b a n d r y 
Alan K. Jones 
H a n d l i n g 
J. R. Best 
Part 2 Cl in ica l b a c k g r o u n d 
5 T h e initial p r e s e n t a t i o n : t r i age a n d cr i t ical 
Aidan Raftery 
6 Bas ic t e c h n i q u e s 
John Chitty 
7 Cl in ica l p a t h o l o g y a n d n e c r o p s y 
Gerry M. Dorrestein and Martine de Wit 
8 A n a e s t h e s i a a n d a n a l g e s i a 
Thomas M. Edling 
9 D iagnos t ic i m a g i n g 
Nigel H. Harcourt-Brown 
Part 3 S u r g e r y 
10 Sof t t i s s u e s u r g e r y 
Neil A. Forbes 
11 O r t h o p a e d i c a n d b e a k s u r g e r y 
Nigel H. Harcourt-Brown 
Part 4 Cl in ica l s y n d r o m e s 
12 Nutr i t ion a n d nutr i t ional d i s e a s e 
Michael Stanford 
13 
14 
S y s t e m i c in fec t ious d i s e a s e 
Michael Lierz 
Resp i ra to ry d i s e a s e 
Simon J. Girling 
15 Gast ro in tes t ina l d i s e a s e 180 
Deborah Monks 
16 Feather a n d sk in d i s o r d e r s 191 
John Chitty 
17 B e h a v i o u r a n d b e h a v i o u r a l d i s o r d e r s 2 0 5 
Kenneth R. Welle 
18 R e p r o d u c t i o n a n d paed ia t r i cs 2 2 2 
April Romagnano 
19 N e u r o l o g y a n d o p h t h a l m o l o g y 2 3 4 
Thomas N. Tully, Jr 
20 S y s t e m i c non - in fec t ious d i s e a s e 2 4 5 
Alistair Lawrie 
21 T h e s ick s m a l l ps i t tac id 2 6 6 
Ron Rees Davies 
Part 5 Lega l a s p e c t s 
22 Z o o n o t i c , legal a n d e th ica l a s p e c t s 2 8 0 
Peter Scott 
References a n d fur ther read ing 2 8 8 
A p p e n d i c e s 
1 Cl in ica l a p p r o a c h e s for s o m e c o m m o n p r e s e n t a t i o n s 2 9 4 
2 T h e c a g e f loor: in s i c k n e s s a n d hea l th 3 0 0 
3 F o r m u l a r y 3 0 3 
4 List of b i rd n a m e s 3 0 8 
5 C o n v e r s i o n tab les 3 1 0 
Index 311 
iv 
Contributors 
J R B e s t BVSc MRCVS 
Q u a n t o c k V i e w , S t e a r t , S o m e r s e t , T A 5 2 P X 
J o h n C h i t t y BVetMed CertZooMed MRCVS 
S t r a t h m o r e V e t e r i n a r y C l i n i c , 6 L o n d o n R o a d , A n d o v e r , H a n t s , S P 1 0 2 P H 
B r i a n H C o l e s B V S C D J P E C A M S Hon. F R C V S 
4 D o r f o l d W a y , U p t o n , C h e s t e r , C h e s h i r e , C H 2 1 Q S 
M a r t i n e D e W i t D V M 
W h i t e O a k C o n s e r v a t i o n C e n t e r , 5 8 1 7 0 5 W h i t e O a k R o a d , Y u l e e , F L 3 2 0 9 7 , U S A 
G e r r y M . D o r r e s t e i n DVM PhD DipVet Pathology Hon Memb ECAMS 
D e p a r t m e n t of P a t h o b i o l o g y , S e c t i o n P e t A v i a n , E x o t i c A n i m a l s a n d W i l d l i f e , U t r e c h t U n i v e r s i t y , 
Y a l e l a a n 1 , 3 5 8 4 C L U t r e c h t , N e t h e r l a n d s 
T h o m a s M . E d l i n g D V M M S P V M 
P E T C O A n i m a l S u p p l i e s Inc. , S a n D i e g o , C A 9 2 1 2 1 , U S A 
Nei l A . F o r b e s BVetMed CBiol MIBiol DipECAMS FRCVS 
RCVS Recognised Specialist in Zoo Animal and Wildlife Medicine 
G r e a t W e s t e r n R e f e r r a l s , Un i t 1 0 , B e r k s h i r e H o u s e , C o u n t y P a r k B u s i n e s s P a r k , S h r i v e n h a m R o a d , 
S w i n d o n , W i l t s , S N 1 2 N R 
S i m o n J G i r l i n g BVMS (Hons) DZooMed CBiol MiBiol MRCVS 
RCVS Recognised Specialist in Zoo Animal and Wildlife Medicine 
C a m b u s b a r r o n , S t i r l i n g s h i r e 
N i g e l H . H a r c o u r t - B r o w n B V S C D J P E C A M S F R C V S 
3 0 C r a b L a n e , H a r r o g a t e , N o r t h Y o r k s h i r e , H G 1 3 B E 
A l a n J o n e s BVetMed M R C V S 
T h e C o t t a g e , T u r n e r s Hi l l R o a d , W o r t h , C r a w l e y , W e s t S u s s e x , R H 1 0 4 L Y 
Al is ta i r M L a w r i e B V M S M R C V S 
T h e L a w r i e V e t e r i n a r y G r o u p , 2 5 Gr i f f i t hs S t r e e t , Fa l k i r k , F K 1 5 Q Y 
M i c h a e l L i e r z Dr med vet M R C V S 
Ins t i tu te fo r P o u l t r y D i s e a s e s , F re i e U n i v e r s i t a t B e r l i n , K o e n i g s w e g 6 3 , 1 4 1 6 3 B e r l i n , G e r m a n y 
D e b o r a h M o n k s BVSc (Hons) MACVSc CertZooMed MRCVS 
G r e a t W e s t e r n R e f e r r a l s , Un i t 1 0 , B e r k s h i r e H o u s e , C o u n t y P a r k B u s i n e s s P a r k , S h r i v e n h a m R o a d , 
S w i n d o n , W i l t s , S N 1 2 N R 
A i d a n R a f t e r y MVB CertZooMed CBiol MiBiol MRCVS 
A v i a n a n d Exo t i c A n i m a l C l i n i c , 2 2 1 U p p e r C h o r l t o n R o a d , M a n c h e s t e r , M 1 6 ODE 
R o n R e e s D a v i e s B V S C CertZooMed M R C V S 
T h e Exo t i c C e n t r e , 12 F i tz i l i an A v e n u e , H a r o l d W o o d , R o m f o r d , E s s e x , R M3 0 Q S 
A p r i l R o m a g n a n o PhD D V M D J P A B V P (Avian) 
5 5 0 0 Mi l i ta ry T r a i l , S u i t e 4 0 , J u p i t e r , F L 3 3 4 5 8 , U S A 
P e t e r W . S c o t t M S C B V S C F R C V S 
RCVS Specialist in Zoo Animal and Wildlife Medicine 
V e t a r k P r o f e s s i o n a l , P O B o x 6 0 , W i n c h e s t e r , S 0 2 3 9 X N 
M i c h a e l D. S t a n f o r d B V S C M R C V S 
Bi rch H e a t h V e t e r i n a r y C l i n i c , B i r c h H e a t h R o a d , T a r p o r l e y , C h e s h i r e , C W 6 9 U U 
T h o m a s N . T u l l y , J r DVM MS DipABVP (Avian) DipECAMS 
S c h o o l of V e t e r i n a r y M e d i c i n e , L o u i s i a n a S t a t e U n i v e r s i t y , B a t o n R o u g e , L A 7 0 8 0 3 - 8 4 1 0 , U S A 
K e n n e t h R. W e l l e D V M D J P A B V P (Avian) 
Al l C r e a t u r e s A n i m a l H o s p i t a l , 7 0 8 K i l l a rney , U r b a n a , IL 6 1 8 0 1 , U S A 
vi 
Foreword 
S i n c e t h e f i r s t e d i t i o n o f t h i s M a n u a l w a s p u b l i s h e d in 1 9 9 6 t h e r e h a v e 
b e e n m a n y a d v a n c e s in p s i t t a c i n e m e d i c i n e a n d s u r g e r y a n d t h i s e d i t i o n 
f u l l y a d d r e s s e s t h i s n e w i n f o r m a t i o n . A l t h o u g h p r i m a r i l y p r o d u c e d f o r 
v e t e r i n a r y s u r g e o n s in g e n e r a l p r a c t i c e , t h e m a n u a l w i l l a l s o b e v e r y 
u s e f u l f o r t h o s e w o r k i n g t o w a r d s a f u r t h e r q u a l i f i c a t i o n in z o o l o g i c a l 
m e d i c i n e o r w i s h i n g t o s t u d y t h e s u b j e c t in g r e a t e r d e p t h . 
P a r t 1 c o v e r s t h e i d e n t i f i c a t i o n , h u s b a n d r y , a n a t o m y a n d p h y s i o l o g y o f 
c o m m o n l y k e p t s p e c i e s . P a r t 2 g o e s o n t o a d v i s e o n t h e a p p r o a c h t o t h e 
c l i n i c a l c a s e a n d d e s c r i b e s t h e r e l e v a n t d i a g n o s t i c t e c h n i q u e s . P a r t 3 
c o v e r s h a r d a n d s o f t t i s s u e s u r g e r y . P a r t 4 t a k e s a s y s t e m a t i c a p p r o a c h 
t o c l i n i c a l s y n d r o m e s a n d t h e i r m a n a g e m e n t . O n e c h a p t e r o f t h i s s e c t i o n 
f o c u s e s o n p r o b l e m s l i k e l y t o b e p r e s e n t e d in g e n e r a l p r a c t i c e in 
c o c k a t i e l s a n d b u d g i e s a n d u s e f u l l y p r o v i d e s a d v i c e o n t r e a t m e n t t a k i n g 
i n t o a c c o u n t t h e f i n a n c i a l c o n s t r a i n t s o f t e n e n c o u n t e r e d in p r a c t i c e . 
In t h e f i n a l s e c t i o n , z o o n o t i c d i s e a s e s , a s p e c t s o f l e g i s l a t i o n i n c l u d i n g 
t r a d i n g a n d m e t h o d s o f i d e n t i f i c a t i o n , a n d e t h i c a l i s s u e s r e l a t i n g t o p e t 
b i r d k e e p i n g , a r e b r o u g h t t o t h e a t t e n t i o n o f t h e r e a d e r . 
T h e f o r m a t t i n g a n d c r o s s r e f e r e n c i n g t h r o u g h o u t t h e M a n u a l f a c i l i t a t e s 
q u i c k a n d e a s y a c c e s s i b i l i t y o f i n f o r m a t i o n . T h e p h o t o g r a p h s a n d l i ne 
d r a w i n g s a r e o f a t r u l y o u t s t a n d i n g q u a l i t y . 
T h e e d i t o r s a n d a u t h o r s h a v e t o b e c o n g r a t u l a t e d o n t h i s c o m p r e h e n s i v e 
M a n u a l . C l i n i c a l c a s e s in p s i t t a c i n e b i r d s m a y n o t b e e n c o u n t e r e d e v e r y 
d a y b y t h e g e n e r a l p r a c t i t i o n e r b u t a r e c h a l l e n g i n g c a s e s w h e n t h e y a r e . 
T h e M a n u a l c e r t a i n l y p r o v i d e s t h e b a s i s f o r t h e i r i m p r o v e d c a r e a n d 
t r e a t m e n t . 
A s u s u a l t h a n k s a r e d u e t o t h e P u b l i c a t i o n s C o m m i t t e e a n d t h e s ta f f a t 
W o o d r o w H o u s e f o r p r o d u c i n g a n o t h e r e x c e l l e n t a d d i t i o n t o t h e l i b r a r y o f 
B S A V A M a n u a l s . 
Ian MaSOn B V e t M e d P h D C e r t S A D D i p E C V D M R C V S 
BSAVA President 2004-2005 
Preface 
T h e p r i m a r y a i m o f t h i s M a n u a l is t o c o v e r t h e m e d i c i n e a n d s u r g e r y o f p s i t t a c i n e b i r d s f o r 
t h e g e n e r a l p r a c t i t i o n e r w h i l e a l s o a c t i n g a s a n i n t r o d u c t o r y t e x t f o r t h o s e w i s h i n g t o s t u d y 
t h i s s u b j e c t in g r e a t e r d e p t h . T h e r e h a v e b e e n m a n y a d v a n c e s in p s i t t a c i n e m e d i c i n e s i n c e 
t h e l as t e d i t i o n w a s p u b l i s h e d in 1 9 9 6 a n d t h e s e a r e r e f l e c t e d in t h e d i f f e r e n c e s b e t w e e n t h e 
t w o b o o k s . 
It is i m p o s s i b l e t o i d e n t i f y a n d t r e a t t h e s i c k b i r d p r o p e r l y w i t h o u t u n d e r s t a n d i n g t h e h e a l t h y 
p a r r o t in t h e w i l d a n d in c a p t i v i t y . T h e f i r s t t h r e e c h a p t e r s e n d e a v o u r t o p r o v i d e t h e r e a d e r 
w i t h t h i s i n f o r m a t i o n . In t h e c a s e o f n u t r i t i o n , b e h a v i o u r a n d r e p r o d u c t i o n t h e n o r m a l 
s i t u a t i o n is d i s c u s s e d a l o n g s i d e t h e a b n o r m a l in e a c h c h a p t e r . 
M a n y p s i t t a c i n e p a t i e n t s a r e p r e s e n t e d in a v e r y s i c k o r c r i t i c a l s t a t e ; in t h e s e c o n d p a r t o f 
t h e b o o k , b a s i c c l i n i c a l i n f o r m a t i o n o n h a n d l i n g a n d e x a m i n i n g t h e p a t i e n t a n d t h e t a k i n g o f 
c l i n i c a l s a m p l e s a r e d i s c u s s e d , a l o n g w i t h t h e in i t i a l s t a b i l i z a t i o n a n d h o s p i t a l i z a t i o n o f t h e 
p a t i e n t . S u b s e q u e n t c h a p t e r s c o v e r a n a e s t h e s i a , s u r g e r y , s y s t e m i c i l l n e s s e s a n d d i s e a s e 
b y i n d i v i d u a l o r g a n s y s t e m . T h e s e a r e d e s i g n e d t o b e r e a d in t h e i r e n t i r e t y o r t o b e r e f e r r e d 
t o a s n e e d e d . 
F o r g e n e r a l p r a c t i t i o n e r s t h e m o s t c o m m o n l y s e e n p s i t t a c i n e p a t i e n t s a r e t h e s m a l l e r 
p a t i e n t s . T h e s m a l l s i z e a n d l o w e c o n o m i c v a l u e o f t h e s e p a t i e n t s o f t e n m a k e t h e m t h e m o s t 
d i f f i cu l t t o e x a m i n e a n d t r e a t . W e h a v e , t h e r e f o r e , i n c l u d e d a c h a p t e r d e v o t e d t o t h e s i c k 
s m a l l p s i t t a c i d , w h i c h c o n c e n t r a t e s o n t h e c o m m o n p r e s e n t a t i o n s a n d s y n d r o m e s a n d 
p r o v i d e s a p r a c t i c a l a p p r o a c h t o t h e i r c a r e . 
T h e f i n a l c h a p t e r c o v e r s t h e l e g a l a n d e t h i c a l a s p e c t s o f o w n i n g a n d s e l l i n g p a r r o t s a s w e l l 
a s d i s c u s s i o n o f z o o n o t i c d i s e a s e a n d h o w t h i s r e l a t e s t o t h e v e t e r i n a r i a n . 
F o r m a n y p r a c t i t i o n e r s t h e a p p e a r a n c e in t h e s u r g e r y o f a s i c k p a r r o t is a s u d d e n a n d 
u n p l a n n e d e v e n t . A n a p p e n d i x o f d i a g n o s t i c a l g o r i t h m s is p r o v i d e d f o r v a r i o u s c o m m o n 
p r e s e n t a t i o n s . T h e s e a i m t o p r o v i d e a s t e p - b y - s t e p a p p r o a c h f o r t h e c l i n i c i a n t o f o l l o w a n d 
t o r e f e r t h e m t o t h e r e l e v a n t c h a p t e r f o r f u r t h e r i n f o r m a t i o n . O t h e r u s e f u l a p p e n d i c e s i n c l u d e 
a d r u g f o r m u l a r y , a l is t o f c o m m o n a n d t a x o n o m i c n a m e s , a n d a p i c t o r i a l g u i d e t o d r o p p i n g s . 
B o t h e d i t o r s d e v e l o p e d t h e i r i n t e r e s t s in a v i a n m e d i c i n e f r o m g e n e r a l p r a c t i c e a n d w eh o p e 
t h a t t h i s is r e f l e c t e d in a p r a c t i c a l , e a s y - t o - u s e a n d r e l e v a n t g u i d e t o p s i t t a c i n e m e d i c i n e . 
T h e e d i t o r s w o u l d l i ke t o t h a n k t h e c h a p t e r a u t h o r s n o t o n l y f o r t h e i r e x c e l l e n t c o n t r i b u t i o n s 
b u t a l s o f o r a d h e r i n g t o t h e p u b l i s h i n g d e a d l i n e s a n d m a k i n g t h e e d i t o r s ' j o b a s e a s y a s 
p o s s i b l e . W e w o u l d a l s o l i ke t o t h a n k M a r i o n J o w e t t a n d h e r t e a m a t B S A V A f o r t h e i r 
e n c o u r a g e m e n t t h r o u g h o u t t h i s p r o j e c t . 
L a s t l y , b u t b y n o m e a n s l e a s t , w e w o u l d l i ke t o t h a n k o u r w i v e s a n d f a m i l i e s f o r t h e i r s u p p o r t 
a n d t o l e r a n c e o f t h e t i m e s p e n t e d i t i n g t h i s b o o k . 
John Chitty 
Nigel H. Harcourt-Brown 
December 2004 
viii 
1 
Species and natural history 
Brian H. Coles 
of spec ies a re f o u n d in the m o r e t e m p e r a t e reg ions of 
Aus t ra l i a a n d N e w Z e a l a n d a n d foss i ls h a v e b e e n 
f o u n d in F rance a n d in Nor th A m e r i c a up to the C a n a ­
d ian border . 
Parrots range in s ize f r om the large Hyac in th Macaw , 
we igh ing up to 3 kg , to the p y g m y parro ts , wh i ch we igh 
on ly 10 g . Whi ls t sexua l d imo rph i sm occurs a m o n g s t 
m a n y Aust ra l ian a n d As ian parrots , th is is not as obv ious 
in t hose spec ies f ound in Af r ica or the N e w W o r l d . 
D i s t r i b u t i o n , h a b i t a t a n d s o u r c e s o f 
f o o d 
Dif ferent spec ies of par ro t o c c u p y a range of hab i ta ts 
at va ry i ng a l t i tudes, i nc lud ing t e m p e r a t e w o o d l a n d , 
s a v a n n a h , sc rub , sem i -dese r t a n d t rop ica l ra in forest 
(F igure 1.1). It is in t he lat ter t y p e of habi ta t (par t icu lar ly 
in t he Neo t rop i cs ) , w h e r e the re is a mul t ip l ic i ty of 
f ru i t ing t rees p r o d u c i n g a vas t r ange of d i f ferent t ypes 
of f ru i ts a n d f l owers , tha t the g rea tes t n u m b e r of parro t 
spec ies is f o u n d . 
Types of parrot commonly kept as cage birds, (continues) • 
I n t r o d u c t i o n a n d g e n e r a l 
c o n s i d e r a t i o n s 
Parrots are c lass i f ied into 3 5 3 spec ies in 8 4 g e n e r a . 
They are an unmis takab le g roup , w i th charac te r i s t i ­
cally large heads a n d power fu l h o o k e d b e a k s , a n d a re 
of ancient l ineage not c lose ly re la ted to any o the r g roup 
of birds. They have shor t necks a n d zygodac t y l or 
yoke-toed feet, so that d ig i ts II a n d III a re d i rec ted 
forward whi lst d ig i ts I a n d IV a re p laced b a c k w a r d s . 
This structure, toge ther w i th the beak ac t ing as a th i rd 
hand, makes these b i rds ve ry ag i le a rbo rea l c l imbe rs , 
often hanging ups ide d o w n wh i le f eed ing . 
The Ps i t tac i formes p robab ly e v o l v e d in the O l d 
World - possib ly Aus t ra l ia , w h e r e the o ldes t k n o w n 
fossil of a cocka too has b e e n f o u n d . Par ro ts p robab ly 
diverged f rom all o ther b i rds in the P a l a e o c e n e s o m e 
60 million years a g o a n d the o rder is spl i t into t w o ma in 
families: the Ps i t tac idae ( the vas t major i ty of par ro ts ) 
and the Caca tu idae ( the c o c k a t o o s , w i th 18 spec ies in 
five genera). T o d a y par ro ts mos t l y inhabi t t he t rop ica l 
and subtropical reg ions of the wo r l d , t h o u g h a n u m b e r 
1 
Chapter 1 S p e c i e s a n d n a t u r a l h i s t o r y 
Taxonomy and 
common names 
General characteristics Habitat Diet Breeding Taxonomy and 
common names 
General characteristics Habitat Diet 
No. eggs Incubation Fledge 
Subfamily 
Nymphicinae 
Cockatiel 
V 
Smallest representative of the 
cockatoos 
Species type mostly brownish grey 
with white wing covert feathers. 
Male forehead, crest, cheek 
patches and throat yellow, with 
prominent orange ear coverts 
Female smaller crest, same basic 
colouring but much less yellow, 
also feathering barred under wings 
(solid black in male) 
Immatures resemble female until 
sexual maturity at 6 months 
Over whole of Australia except 
coastal regions 
Feeds mainly on ground on 
grass seeds, fruits, berries 
(even mistletoe), grain crops 
(considered a pest by farmers) 
4-7 18-12 days c. 4-5 weeks 
Family Loriinae 
11 genera, 55 spp. 
Lories and lorikeets 
X 
Many have long tapering tails; in 
some, tails only medium length and 
more rounded 
Mostly medium size (c. 20-24 cm) 
but smallest 13 cm and largest 42 cm 
Most have glossy brilliant plumage 
in range of red, blue, violet, olive 
brown, green and yellow according 
to species 
Most well known is Rainbow 
Lorikeet (blue forehead, crown 
and cheeks; black underside of 
head; yellow collar; breast red 
barred with black; thighs yellow 
barred with green; upper parts green) 
Archipelago of SE Asia. Some 
species (e.g. Rainbow 
Lorikeet) also into N, E and 
S Australia 
Specialized brush-tongued 
feeding on pollen and nectar, 
also fruit and flowers 
1-5 
Smaller 
species tend 
to lay more 
than larger 
species 
23-30 days c. 42-90 days 
Smaller 
species fledge 
earlier than 
larger species 
Genus 
Cyanoramphus 
6 spp. (with 8 
subspp. in Red-
fronted Parakeet) 
Commonly called 
kakarikis 
V 
Small to medium, rather chunky, 
with long pointed tail 
Overall plumage green in most, 
slightly darker above than beneath. 
All tend to have violet-blue outer 
flight feathers. Most have reddish 
patch each side of rump; many 
have varying red markings on head 
Yellow-fronted Kakariki typical of 
genus: red above cere, yellow 
forehead 
23-26 cm, 50-113g 
New Zealand and neighbouring 
islands in polycarp forest and 
scrub 
Seeds, berries, shoots, 
flowers 
Invertebrates often an 
important part of diet 
5-9 c. 20 days c. 6 weeks 
Genus Platycercu 
8 spp. 
Rosellas 
s Medium size (25-36 cm, c. 
100-120 g) 
Long graduated tails; all show 
pronounced mottling or scalloped 
appearance of plumage on back 
Variety of species-specific 
markings in red, yellow, green and 
blue-violet 
Different species in various 
parts of Australia 
Predominantly seed eaters, 
spending much time on 
ground searching for food 
c. 4-7 19 days 13-14 weeks 
Genus Neophema 
7 spp. 
Grass parakeets 
\ 
Similar shape to Budgerigar but 
slightly larger (c. 20-21 cm, 44-61 g) 
Tendency to sexual dimorphism, 
particularly in Scarlet-chested and 
Turquoisine 
Except Bourke's (which has upper 
parts of body brown, abdomen 
pink), all have green upper plumage 
with yellow abdomen and species-
specific markings in red, blue and 
yellow on remainder of body 
Different species inhabit 
various parts of Australia; 
Bourke's and Scarlet-chested 
in large areas of central 
Australia 
Seeds of grasses and other 
seeds; fruit, berries, young 
shoots, small insects 
a 3-5 18-20 days c. 30-35 days 
(continued) Types of parrot commonly kept as cage birds, (continues) • 
9 
C h a p t e r 1 S p e c i e s a n d na tu ra l h i s to ry 
Taxonomy and 
common names 
General characteristics Habitat Diet Breeding Taxonomy and 
common names 
General characteristics Habitat Diet 
No. eggs Incubation Fledge 
Genus Melopsittacus 
one species: 
Budgerigar 
V 
Nominate race c. 18 cm and c. 30 g, 
but many captive-bred mutant 
strains larger (c. 26-29 cm) and 
heavier (c. 35-85 g) 
In wild, back of head, neck and 
body basically yellow barred black; 
forehead and throat yellow with row of 
black dots across throat; underparts 
greenish-yellow. Great variety of 
mutant colours bred in captive birds 
Across greater part of Australia 
away from coastal areas, and 
Tasmania 
Wide variety of habitats, from 
forest/woodland to open 
grassland, grain crops, dry 
scrub and acacia deserts 
Grass seeds (0.5-2.5 mm 
long), chenopod seeds 
Only feeds on or near the 
ground4-6 c. 18 days c. 30 days 
Genus Eclectus 
Eclectus Parrot 
1 sp., 9 subspp. 
(many of which 
breed in captivity) 
\ 
Stocky (355-615 g) 
Male brilliant green, flanks and 
underwing red, maxilla orange 
Female black bill, dark red on head, 
back and tail, bright purplish body, 
yellow tip to tail (see Figure 18.2) 
New Guinea, surrounding 
islands and N tip Australia 
Tend to live below 1000 m in 
woodland, parkland, even 
gardens 
Fruit, seeds, nuts, buds, 
blossoms 
2 26 days 12 weeks 
Family Psittacula 
14 spp. 
Ringneck 
parakeets 
Heavy beak; tapering tail longer 
than body 
Sexually dimorphic. 
Male usually red beak, well 
developed ring around neck or 
more striking head colour 
Ringneck Parakeet (95-143 g) 
1 subsp. Africa, another India: male 
green, with pink and black neck 
ring, red maxilla; female no ring, 
black tip to beak. Captive Ringneck 
Parakeets in many colour varieties 
Alexandrine Parakeet larger 
(200-250 g): male pink neck ring, 
red shoulders 
Moustached Parakeet (135-170 g): 
red beak, grey head, black chin, pink 
chest, green body; female duller 
Ringneck Parakeet N sub-
Saharan Africa, all India and 
Pakistan; deciduous habitats of 
all types 
Alexandrine Parakeet India to 
Thailand; lowland forest and 
wooded areas 
Moustached Parakeet N India 
and Indochina; deciduous 
forest 
Fruits, seeds, flowers 
Most spp. raid orchards, 
cultivated fields, gardens 
Ringneck Parakeet 
considered most destructive 
pest in India 
3-4 22-26 days 6-8 weeks 
Genus Loriculus 
10 spp. 
Hanging parrots 
\ 
Closely related to lovebirds and 
look similar except beaks much 
finer and more pointed. So named 
because roost hanging upside down 
Size c. 11-16 cm, c. 22-35 g 
Overall mostly green; most spp. 
have red upper tail and red crown. 
Species-specific markings of red, 
blue and yellow 
Colour of bills black or orange, 
depending on species 
Various parts of SE Asia and 
Indian subcontinent 
Woodland and forest 
Fruits, berries, nectar, seeds c. 2-4 c. 22 days c. 5 weeks 
Genus Agapomis 
9 spp. 
Lovebirds 
Most common: 
Peach-faced 
Lovebird (A. 
roseicollis) 
Small chunky, with relatively large 
bills and short rounded tails 
Most species not dimorphic but 
males tend to be slightly larger 
Size 15-18 cm, 43-63 g 
Species-specific phenotype: overall 
green plumage, rose-pink forehead 
and to just behind eyes, also 
cheeks and throat; rump bright blue 
Many captive mutant strains (e.g. 
Pastel Blue, Pied) 
Together with hanging parrots, the 
only two genera of parrots that 
collect nesting material held in 
plumage by female 
Sub-Saharan Africa 
Forest edge, woodland, 
savannah 
Cereal seeds, maize, 
cultivated sunflower seeds, 
fruit (e.g. figs, mango), buds 
and foliage 
3-6 c. 23 days c. 43 days 
(continued) Types of parrot commonly kept as cage birds, (continues) • 
Chapter 1 S p e c i e s a n d n a t u r a l h i s t o r y 
Taxonomy and 
common names 
General characteristics Habitat Diet Breeding Taxonomy and 
common names 
General characteristics Habitat Diet 
No. eggs Incubation Fledge 
Genus Psittacus 
Grey Parrot 
subsp.: Timneh 
Parrot 
Grey Parrot probably most familiar 
of all parrots 
c. 402-490 g 
Overall colour grey, lighter around 
eyes and over rump. Tail red, beak 
black 
Iris yellow in adult, mJack in young 
bird up to 3-4 months then 
yellowing up to 4 years 
Timneh subsp. slightly smaller 
(c. 350 g) with maroon instead of 
red tail, upper beak horn-coloured 
Nominate race across central 
Africa from Gulf of Guinea to 
W Kenya to Tanzania 
Timneh confined to Sierra 
Leone and Ivory Coast 
Feral populations in many 
African cities 
Edge of forest clearings, 
woodland, savannah, coastal 
mangroves, cultivated areas 
Seeds, figs, fruits (particularly 
the fleshy part of oil-seed palm 
surrounding inner stone) 
2-3 21-30 days c. 80 days 
Genus Poicephalus 
9 spp. 
Most common: 
Senegal Parrot and 
Meyer's Parrot 
V 
Thickset, with short squarish tails 
Senegal (21-23 cm, 120-161 g) 
green upper plumage and neck, 
yellow chest and abdomen yellow, 
grey head 
Meyer's brown upper plumage, 
yellow patch on crown and over 
carpal joint, bluish-green breast and 
abdomen 
Iris of Meyer's orange, of Senegal 
yellow 
Various species in different 
areas of sub-Saharan Africa 
Senegal C and W Africa 
Meyer's C and E Africa 
Both spp. woodland/savannah 
Seeds, grain, fruit, figs, leaf 
buds 
c. 2-4 c. 25-31 
days 
c. 63 days 
Macaws 
Genus Ara 
15 spp. 
Genus 
Anodorhynchus 
3 spp. (including 
Hyacinth Macaw) 
> 
All are slender elegant birds with 
long tapering tails 
Range in size from relatively small 
(e.g. Hahn's c. 34 cm, 150-180 g) 
to Hyacinth (100 cm, c. 1600 g) 
and popular Blue and Gold (c. 
86 cm, c. 1300 g) 
Most species have bare facial area 
devoid of most feathering (which 
may have been to prevent 
feathering becoming matted when 
feeding on fruit); in some species 
this area flushes pinkish, indicating 
change in mood 
Variety of colours in blue, red, yellow 
and green according to species 
Large areas of Amazon Basin, 
many species in same locality 
Some spp. found in Caribbean 
Species separation may be by 
altitude 
Variety of habitats include 
flooded forest, gallery forest, 
deciduous pine forest, 
mangrove swamps 
Seeds, fruit, palm nuts, figs, 
leaves, flowers, nectar 
c.1-3 c. 24-30 
days 
(longer for 
larger birds) 
13-14 weeks 
Conures: two main 
genera: 
Aratinga (19 spp.) 
Pyrrhura (18 spp.) 
All small to medium size, with long 
graduated tails 
Aratinga larger of the two genera 
(28-37 cm, 155-185 g); overall 
plumage green with species-specific 
red or brown or blue markings, 
except for Sun Conure (generally 
yellow but forehead and sides of 
head and abdomen tinged orange, 
mostly green wings, olive green tail) 
and Jandaya Conure (only head, 
breast and abdomen yellow) 
Pyrrhura (24-26 cm, 72-94 g): 
overall plumage dusky green, with 
species-specific other colour 
markings; most have red-brown 
tails, some a scaly or scalloped 
appearance of neck and breast 
plumage 
Mostly individual species 
restricted to various parts of 
Amazon Basin but some in 
Caribbean 
Seeds, fruits, nuts Usually 2-4 
(can be up to 
7) 
c. 4 weeks c. 8 weeks 
1.1 ( c o n t i n u e d ) T y p e s o f p a r r o t c o m m o n l y k e p t a s c a g e b i r d s , ( c o n t i n u e s ) 
4 
C h a p t e r 1 S p e c i e s a n d na tu ra l h is to ry 
Taxonomy and 
common names 
General characteristics Habitat Diet Breeding Taxonomy and 
common names 
General characteristics Habitat Diet 
No. eggs Incubation Fledge 
Genus Forpus 
7 spp. 
Parrotlets 
V 
Small chunky, with short pointed tail 
Most species c. 12-13 cm, 
c. 20-28 g; largest is Yellow-faced 
(c. 14.5 cm, 30-38 g) 
Some sexual dimorphism 
Overall plumage green with blue to 
violet-blue primary covert feathers 
in male; some species have blue 
rump. In most species, head and 
neck paler green (in Yellow-faced 
forehead and neck yellow) 
Celestial in drier parts along 
Pacific side of Andes 
Other species confined to 
various parts of Amazon Basin; 
Blue-winged inhabits very 
large part of this area 
Forest, woodland, scrub, 
pasture, town suburbs 
Fruits, berries, buds, seeds c.4-6 c. 17-22 
days 
c. 35-40 days 
Genus Pionites 
Caiques 
2 spp.: 
Black-headed and 
White-bellied 
Both medium size (23 cm, 
130-170 g) 
Bills rather narrow, upper beak 
markedly ridged 
Both species white breast and 
abdomen; most of wings and upper 
tail green, primary feathers 
violet-blue 
Black-headed black forehead and 
crown; White-bellied orange 
forehead and crown and yellow neck 
Black-headed N part of 
Amazon Basin 
White-bellied S part of 
Amazon Basin 
Black-headed eats seeds, 
fruit pulp, flowers and, 
occasionally, leaves 
2-4 27-29 days c. 10-11 
weeks 
Genus Pionus 
8 spp. 
Pionus parrots 
All medium size (c. 26-28 cm, 
170-275 g) 
All species relatively short squarish 
tails with red feathers under tail 
Overall plumage in many species 
dull green/dusky brownexcept in 
Blue-headed and Coral-billed 
Some species have scaly 
appearance to feathering on neck 
and other species-specific markings 
Individual species in various 
parts of Amazon Basin and 
Caribbean 
Forest/woodlands and 
cultivated areas 
Maximilian's eats seeds 
(70%), flowers (20%), corn 
(8%), fruit (2%) 
Blue-headed also eats 
bananas 
3-5 24-29 days c. 8-12 weeks 
Genus Amazona 
27 spp. 
Amazon parrots 
\ 
Stocky, with short rounded tail 
Overall plumage green in most, with 
species-specific markings in other 
colours 
Blue-fronted typical medium size 
(c. 400 g) with yellow crown, chin 
and throat, but blue forehead and 
above cere 
Orange-winged overall green, with 
prominent orange patch on 
underside of outer three secondary 
flight feathers 
c. 298-469 g 
Blue-fronted and Orange-
winged range over greater part 
of Amazon Basin, but Blue-
fronted as far as Paraguay and 
N Brazil, and Orange-winged 
further N and towards coast of 
NandE 
Both found in scrub, savannah, 
palm groves, gallery rainforest 
along water courses 
Fruits, flowers, leaf buds, 
seeds 
3-4 
Blue-fronted 
up to 8 
23-25 days 58-60 days 
(continued) Types of parrot commonly kept as cage birds. 
Parrots as a w h o l e a re pr imar i ly s e e d ea te rs (F igure 
1.1). The re fo re , w i th the excep t i on of s o m e of the 
macaws , s o m e c o c k a t o o s a n d Pesque t ' s Parrot , mos t 
of the par ro ts do not eat the f leshy ou te r part of t he frui t 
but are c o n c e r n e d wi th get t ing at t he h igh ly nut r i t ious 
kernel . T o ach ieve th is t he fruit a n d t h e n the nut is 
wedged by the t o n g u e aga ins t a r idge on the unde rs ide 
of the upper beak , whi ls t t he ch ise l - l i ke ac t ion of the 
lower beak str ips the husk a n d the f lesh a n d then exer ts 
cons iderab le p ressu re to c rack the nut (in m a c a w s th is 
may be a p ressu re of m o r e t han 2 0 0 ps i ) . Dur ing the 
whole p rocess of spl i t t ing the nut, the t o n g u e g radua l l y 
rotates the nut to app ly p ressu re to d i f ferent a reas . 
Some of the m a c a w s , bes ides ea t ing the fruit , a lso eat 
f lowers a n d ma tu re leaves a n d t ake nectar . M a c a w s 
wi l l s o m e t i m e s tack le unr ipe fruit that con ta ins p o t e n ­
t ial ly tox ic t ann ins . T o o v e r c o m e these harmfu l e f fec ts , 
t he b i rds eat c lay t a k e n f r o m river banks a n d a lso at t he 
s a m e t ime m a y ob ta in n e e d e d minera ls . 
A n o t h e r g roup of par ro ts inc ludes spec ia l is t nec ta r 
a n d po l len ea te rs . T h e s e a re the Lor i idae, a lso k n o w n 
as lor ies a n d lor ikeets a n d a lso ca l led the b r u s h -
t o n g u e d par ro ts . In t hese birds the t ongue is long a n d 
w h e n ful ly e x t e n d e d exh ib i ts a coat ing of erec t i le hair­
l ike e p i d e r m a l pap i l lae , wh i ch enab les the b i rd to b rush 
up po l l en . 
Parrots most ly feed in the t rees, w h e r e they are safer 
f rom predators , but they will a lso fo rage on the g round 
for fa l len fruit a n d seed . S o m e of the smal le r spec ies , 
such as the Budger igar , spend more t ime on the g round 
5 
Chapter 1 S p e c i e s a n d n a t u r a l h i s to ry 
and never, unl ike most parrots, use the foot to ho ld the 
food . Food of an ima l or ig in probab ly does not p lay a big 
part in the diet of most parrots , t hough they m a y take the 
larvae of s o m e beet les, insects a n d mo ths , a n d Hyac in th 
Macaws will eat app le snai ls . However , parrots a re 
opportunist feeders and very adap tab le b i rds. For m a n y 
years there has been athr iv ing populat ion of the Ringneck 
Parakeet in the London suburbs a n d in the sou thern 
count ies of Eng land , the surv ival of wh ich has been 
helped by bird-table feed ing dur ing the winter . M a n y 
cit ies wor ldw ide a lso have feral popu la t ions of th is 
parrot, wh ich visits gardens and orchards , inhabits w o o d ­
land and raids all k inds of cerea l c rops . It shou ld be no ted 
that a l though the parrots have a hooked beak rather l ike 
the raptors, their gape is smal ler . 
No spec ies of parrot is t ru ly m ig ra to ry but s o m e , 
such as the Grey Parrot , a re n o m a d i c a n d o f ten f ly 
cons iderab le d i s tances (up to 3 0 k m e a c h day) in 
search of f o o d , re turn ing to the i r t rad i t iona l roos t ing 
si tes at night. 
S o c i a l l i f e 
Parrots are socia l an ima ls and wel l recogn ized as be ing 
noisy. Voca l iza t ion is used in the wi ld to main ta in f lock 
cohes ion , to reinforce pair bonds and to g ive warn ing of 
danger. Most parrot spec ies live in f locks, s o m e of wh i ch 
can be very large and c o m p o s e d of severa l t h o u s a n d 
birds. Most parrots are a lso m o n o g a m o u s a n d fo rm pair 
bonds th roughout life. T h e pairs feed a n d roost a n d do 
most th ings together th roughout the year . Wi th in a f lock 
there are smal ler fami ly g roups wh ich wil l s tay toge ther 
until the next b reed ing s e a s o n . In the fami ly g roup the 
more juveni le bi rds learn by observ ing the more exper i ­
enced older birds as wel l as interact ing wi th their s ib­
l ings. In dry habi tats the older birds wil l know w h e r e the 
nearest wa te rho le is in t imes of drought , whi ls t t hose in 
tropical rainforest wil l know the t ime a n d locat ion of 
f ru i t ing t r ees . A b s e n c e of ear ly soc ia l i za t i on w i th 
conspeci f ics has been shown to have adve rse ef fects on 
f ledgl ings reared wi th an al ien spec ies . 
B r e e d i n g b i o l o g y 
With f ew excep t i ons , par ro ts a re ho le nes te rs . T h e y 
m a y nest e i ther in a natura l cav i ty in a su i tab le t ree or 
in the a b a n d o n e d nest of ano ther spec ies , s u c h as a 
woodpecke r . T h e or ig ina l hole m a y be en la rged or 
a l tered to mee t the requ i remen ts of the nes t ing par ro ts . 
A f e w spec ies nest in ho les in cl i f fs or b a n k s or in te rmi te 
m o u n d s . S o m e of t he m o r e adap tab le spec ies wi l l 
m a k e use of ho les in bu i ld ings or in o ld p ipes . Nes ts can 
be any th ing f r om 0.5 to 2 m in d e p t h . D a r k n e s s is 
be l i eved to s t imu la te Budge r i ga rs to c o m m e n c e egg 
lay ing a n d th is m a y be impor tan t for o the r spec ies as 
we l l . T h e nest m a y s o m e t i m e s be l ined w i th g rass but 
m o r e o f ten has jus t a bed of w o o d ch ips left f r om 
remode l l i ng of t he nest ho le . 
Possess ion of a su i tab le nest hole is probab ly the 
mos t impor tant part of the b reed ing cyc le . T h e fema le 
tends to be the m o r e aggress ive of the pair in de fend ing 
the nest. In mos t parrot spec ies terr i tor ia l ism is con f ined 
to the immed ia te a rea wi th in approx imate ly one met re of 
the nest dur ing the b reed ing per iod , t hough a f ew 
spec ies nest communa l l y , even wi th o ther spec ies in the 
s a m e t ree. Cour tsh ip in mos t spec ies is by food pass ing 
a n d a l lopreen ing (i.e. p reen ing of the c o m p a n i o n bird). 
Both ma le a n d f ema le birds usual ly p repare the nest, but 
genera l ly on ly the fema le incubates the eggs . 
T h e e g g s of all spec ies of par ro t a re wh i te a n d 
relat ive ly sma l l . T h e y a re genera l l y la id on a l te rna te 
d a y s but in s o m e of the larger s p e c i e s the in terva ls 
b e t w e e n e g g lay ing m a y be as long as 5 day s . C lu tch 
s ize c a n be up to e leven in the sma l le r s p e c i e s but on ly 
o n e to th ree in the larger b i rds (F igure 1.1). Incuba t ion 
s tar ts as s o o n as the f irst e g g is la id , so that ch i cks wil l 
be p rog ress i ve l y o lder a n d m o r e a d v a n c e d w h e n the 
w h o l e c lu tch has b e e n h a t c h e d . S o m e ch icks m a y be 
tw ice the s ize of the i r s ib l ings . 
T h e new ly h a t c h e d ch i cks a re usua l ly c o v e r e d in 
d o w n . Dur ing thef irst w e e k the f e m a l e wi l l s tay in t he 
nest to ha tch all t he e g g s a n d k e e p the h a t c h e d ch icks 
w a r m . T h r o u g h o u t th is t ime the ma le b i rd wi l l f eed her 
a n d s h e wil l in tu rn f e e d t he ch icks . In all spec ies , 
f eed ing of the ch i cks is car r ied ou t by regurg i ta t ion of 
f o o d f r o m the c rop , w i th t he y o u n g b i rd 's beak he ld in 
that of t he adu l t a n d the f o o d pass ing d o w n the f unne l ­
l ike g r o o v e of the lower b e a k into that of the youngs te r . 
F r o m the s e c o n d w e e k , w h e n all t he e g g s a re ha t ched 
a n d the ha tch l ings a re bet ter ab le to ma in ta in thei r 
body t e m p e r a t u r e , the f e m a l e wi l l l eave t he nest for 
shor t pe r iods a n d the m a l e wi l l s h a r e in f eed ing t he 
y o u n g . Af ter th is init ial pe r i od , bo th b i rds wi l l leave the 
nest u n a t t e n d e d for longer pe r iods wh i ls t they bo th 
f o rage for e n o u g h f o o d to m e e t the n e e d s of the i r 
g r o w i n g y o u n g s t e r s . C o m p a r e d wi th o the r spec ies of 
b i rd , par ro ts t e n d to g r o w a n d m a t u r e rather s lowly . 
A l t h o u g h Budge r i ga rs m a y be sexua l l y m a t u r e at 6 
m o n t h s , s o m e of the larger spec ies do not reach sexua l 
matur i ty for severa l yea rs . 
6 
2 
Anatomy and physiology 
Nigel H. Harcourt-Brown 
I n t e g u m e n t 
The outer sur face of a par ro t is c o v e r e d w i th f e a t h e r s . 
The feathers f o rm a c o n t i n u o u s layer tha t i nsu la tes , 
protects and e n a b l e s t he par ro t to f ly. T h e e p i d e r m i s 
is thinner (app rox ima te l y 13 m i c r o m e t r e s (jam) in 
the feathered a reas ) a n d m o r e f rag i le t h a n tha t of 
mammals but f o r m s a n d ke ra t i n i zes in a s im i la r 
manner. T h e i m m a t u r e n u c l e a t e d ce l ls nex t to t he 
basal layer con ta in oi l g l o b u l e s tha t a re p u s h e d ou t 
of the cell as it ke ra t i n i zes . T h i s c o v e r s t he s u r f a c e of 
the bird wi th a layer of oi l ( s e b u m ) tha t has a n t i m i c r o ­
bial proper t ies , as we l l as k e e p i n g t h e sk in s u p p l e 
and prevent ing d e h y d r a t i o n . 
In the major i ty of ps i t t ac i f o rms t h e r e is a u ropyg ia l 
gland on the dorsa l a s p e c t of t h e b a s e of t he ta i l . It is 
a bi lobed ho loc r ine g l a n d : t he g l a n d u l a r ce l l s b r e a k 
down comp le te ly to f o r m the s e c r e t i o n , w h i c h is w a t e r 
repellent, but it has m a n y o the r p rope r t i es . Usua l l y 
only 7 % of the s e b u m in t he p l u m a g e is f r o m t he 
uropygial g l and . V a r i o u s neo t rop i ca l pa r ro ts ( e .g . 
Amazons , Pionus pa r ro ts a n d Brotgeris p a r a k e e t s ) 
do not have a p r e e n g l a n d . B i rds h a v e no s w e a t 
glands and no t rue c u t a n e o u s g l a n d s . Hea t loss is 
accompl ished t h r o u g h t he resp i ra to ry t rac t a n d t h e 
feet, espec ia l ly wh i l s t f l y i ng . 
The dermis is th inner ( 8 0 - 2 0 0 j i m ) than that of 
mammals . It con ta ins t he fea ther fo l l ic les, s m o o t h 
muscle and elast ic t e n d o n s , w h i c h m o v e the fea the rs ; 
it also conta ins b lood vesse l s a n d ne rves . 
The subcu taneous layer con ta ins fat , o f ten as d is ­
crete fat bod ies . A m a z o n s a n d s o m e c o c k a t o o s s e e m 
to have more fat t han o ther par ro ts , a n d exh ib i t ion 
Budger igars have been b red se lec t ive ly to have large 
fat bodies on thei r ches t . Th i s c o m p l i c a t e d s u b c u t a n e ­
ous layer a lso con ta ins s t r ia ted m u s c l e s a n d is r e s p o n ­
sible for feather m o v e m e n t . 
The b rood pa tch is a por t ion of sk in on the cauda l 
half of the vent ra l a b d o m e n . In t he f e m a l e , t he hor­
mones that s t imu la te b reed ing c a u s e th is a r e a to lose 
all its feathers and d e v e l o p a p ro fuse b lood supp ly pr ior 
to laying. T h e b rood pa tch is in con tac t w i th t he e g g s 
and is wel l supp l ied wi th ne rves that s e n s e t e m p e r a ­
ture changes in the eggs , a l l ow ing the bird to con t ro l 
incubat ion by ei ther coo l ing e g g s that a re too hot or 
warming eggs that a re too co ld . It is a lso ab le to s e n s e 
nitric ox ide re leased by the egg in r e s p o n s e to t e m ­
perature c h a n g e a n d hypox ia . 
The distal por t ion of the leg is c o v e r e d w i th sca ly 
sk in . T h e sca les (scu tes) va ry in s ize . T h e sk in on the 
unde rs ide of the foot a n d d ig i ts is c lose ly a t tached to 
f l eshy pads that pro tec t t he pha langea l jo in ts a n d f lexor 
t e n d o n s ; th is a l l ows the b i rd to gr ip f i rmly w i th its foot . 
T h e ce re is a fea the r less por t ion of sk in at the base of 
the upper beak ; it is we l l d e v e l o p e d in par ro ts , a n d in 
s o m e spec ies (e .g . Budger iga rs ) it is co l ou red a n d can 
ind ica te gende r . 
Feathers 
T h e fea the r is a ve ry c o m p l i c a t e d ep ide rma l s t ruc ture . 
It is a t o u g h kera t in i zed ce l lu lar der iva t i ve of the ep ider ­
mis a n d is f o r m e d in a fo l l ic le that pene t ra tes d e e p into 
the d e r m i s . O n c e f o r m e d , it is ful l of a i r spaces as wel l 
as p i gmen t g ranu les a n d oi ls . T h e fea the rs a re ar­
r a n g e d in d is t inc t a r e a s k n o w n as fea the r t rac ts 
(pterylae). T h e fea the r less s p a c e s (apteria) m a y be 
ba re or c o v e r e d w i th s e m i p l u m e s a n d d o w n fea thers . 
T h e s e fea the r l ess t rac ts a re inv is ib le f r om genera l 
obse rva t i on , as the con tou r fea the rs f r om the pterylae 
c o v e r t h e m . 
T h e r e a re seve ra l t ypes of fea ther : 
• Contour feathers f o r m t he ma jo r i t y of t he 
ex te rna l p l u m a g e . E a c h f ea the r has a long 
cen t ra l s ta lk or rach is , o n e i the r s ide of w h i c h 
a re t he b a r b s . T h e b a r b s a re fu r the r d i v i ded into 
t h e p r o x i m a l a n d d is ta l b a r b u l e s , w h i c h ho ld on 
to the i r a d j a c e n t b a r b u l e s w i th hamu l i or 
h o o k l e t s . C o n t o u r f e a t h e r s c o v e r m o s t of t he 
b o d y ; t hey a r e a lso t h e f l ight a n d tai l f ea the r s 
(F i gu res 2.1 a n d 2 .2 ) . 
• Down feathers h a v e a shor t rachis a n d long soft 
ba rbs . T h e y a re f o u n d under the con tou r fea thers 
a n d f o r m an insu la t ing unde rcoa t . 
• Semiplumes a re a c o m b i n a t i o n of the a b o v e two 
t ypes , d o w n y at the b a s e a n d wi th a con tour 
fea the r at the t ip . T h e y are f o u n d a long the 
marg i ns of t he con tou r fea the r t rac ts . 
• Powder down feathers a re con t inua l l y g rowing 
wh i t e to g rey d o w n fea the rs . T h e barbs at the tip 
cons tan t l y b reak off, f o rm ing a f ine whi te dust 
tha t coa ts the w h o l e b i rd ( inc lud ing its beak) and 
its su r round ings ; th is is ve ry obv ious in whi te 
c o c k a t o o s . P o w d e r d o w n fea thers m a y be found 
in pa t ches on the body wal l under the w ing (e.g. 
cocka toos ) or m a y be only sca t te red feathers 
(e .g . P ionus par ro ts ) . 
• Filoplumes cons is t of a long spike with a tassel of 
7 
Chapter 2 A n a t o m y a n d p h y s i o l o g y 
Humerus 
Alular 
Ulna Radius digit Calamus 
Rachis 
Metapatagi 
Secondary feathers Primary feathers 
Ventral Dorsal 
External 
vane 
Downy 
barbs 
Ventral 
crest 
Cilia 
Hooklets 
Ventral wing of a 
Maximilian's Pionus 
Parrot. 
OTPS Two tail feathers (retrices), 
^BBV moulted on the same day by an 
Amazon, shown as a dorsal and a ventral 
view. The feathers were from each side of 
the tail and are a mirror-image pair. In the 
embedded feather, the dermis of the follicle 
projects into the proximal umbilicus and 
forms a small moundof pulp inside the 
calamus. This mound is stimulated (by 
trauma) to produce a new feather when the 
old calamus is lost. The umbilici mark the 
path of the blood vessel of the growing 
feather. On the inner vane of the remiges, the 
distal barbule has three hooklets and three 
ventral cilia. When the distal barbules are 
seen from the ventral aspect, the hooklets 
form a brush-like border. Each hooklet is 
able to hook round the C-shaped cross-
section of the proximal barbule. The proximal 
barbule's pennulum is bent round at the end 
and extends towards the outer margin of the 
feather. 
barbs at its t ip. T h e y are a s s u m e d to be sensory 
detectors, as they are c losely assoc ia ted wi th 
sensory Herbst corpusc les . T h e y probab ly assess 
the strains and m o v e m e n t of the con tour fea thers , 
wh ich is vital for f l ight. Each f l ight fea ther has up to 
10 c losely assoc ia ted f i lop lumes. 
• Bristle feathers a re the short sp iky fea thers a round 
the eye and loral reg ion (ear) . T h e y are protect ive. 
P l u m a g e co lour 
Parro ts h a v e co lour fu l p l u m a g e . T h e co lou r d e f i n e s 
the par ro t ' s s p e c i e s a n d is u s e d to e n h a n c e b e h a v ­
ioural s igna ls . It a l so p rov i des s e x u a l d i m o r p h i s m , 
c a m o u f l a g e , a n d j u v e n i l e or adu l t cha rac te r i s t i c s . 
T h e s e t ra i ts a re we l l d e v e l o p e d in c o m p a r i s o n w i th 
m a m m a l s (o ther t h a n p r i m a t e s ) , a n d b i rds h a v e ex­
ce l len t co l ou r v i s i o n . 
P l u m a g e co lo ra t i on is a c h i e v e d in s e v e r a l w a y s . 
C o l o u r s m a y be p r o d u c e d by p i g m e n t s : b r o w n , y e l l o w 
a n d b lack m e l a n i n s a re p r o d u c e d by m e l a n o c y t e s ; 
reds a n d y e l l o w s a r e p r o d u c e d f r o m c a r o t e n o i d s s u c h 
a s c a r o t e n e s a n d x a n t h o p h i l s . T h e s e d ie ta ry p ig ­
m e n t s a re d i s s o l v e d in fa t g l o b u l e s in t h e f ea the r ce l l s . 
W h i t e is d u e to re f lec t ion a n d re f rac t ion of al l w a v e ­
leng ths of l ight t h r o u g h a i r s p a c e s in u n p i g m e n t e d 
f e a t h e r s . B lue p i g m e n t is rare a n d t he br igh t b lue in 
8 
C h a p t e r 2 A n a t o m y a n d p h y s i o l o g y 
Budger iga rs is d u e to the T y n d a l l e f fec t , a sca t t e r i ng 
of l ight on par t i c les of less t h a n 0.6 jum a c r o s s (s imi la r 
to the ef fect tha t p r o d u c e s a b lue s k y ) . M o s t pa r ro t s 
have g reen f ea the rs tha t a re a m ix tu re of y e l l o w 
caro teno ids a n d t he b lue T y n d a l l e f fec t . Se lec t i ve 
breed ing has m a d e s o m e b i rds lack o n e or o the r of 
these ' co lou rs ' so tha t a b lue or y e l l o w f ea the r is t he 
result. U l t rav io le t l ight re f l ec tance o c c u r s in pa r ro t s ; it 
is based on t he s t ruc tu ra l cha rac te r i s t i c s of f e a t h e r s 
and not on p i g m e n t . 
Moult 
Adult a n d i m m a t u r e p l u m a g e a re usua l l y d i f fe ren t in 
both co lou r a n d s h a p e . F e a t h e r s t e n d to w e a r ou t 
and are r e p l a c e d annua l l y . T h e f i rst mou l t usua l l y 
c o m m e n c e s at 3 - 1 0 m o n t h s of a g e but t he rea f t e r 
parrots no rma l l y mou l t o n c e e a c h yea r , usua l l y s tar t ­
ing du r ing or jus t a f ter b r e e d i n g . T h e mou l t h a p p e n s 
as a p red i c tab le s e q u e n c e of f ea the r loss . W i n g a n d 
tail f ea the rs a re m o u l t e d as mi r ro r i m a g e pa i rs . T h e 
wings usua l l y t a k e l onger to mou l t t h a n t he tai l o r 
body f ea the rs : c o m p l e t e w i n g m o u l t i n g t a k e s 160 
days in a G a l a h . 
F e a t h e r g r o w t h t a x e s t h e b i rd ' s r e s o u r c e s , e s p e ­
cial ly in s m a l l p a r r o t s . M o u l t f r e q u e n t l y m a k e s b i rds 
less ac t i ve a n d t h e y a l s o r equ i r e su f f i c i en t p r o t e i n , 
espec ia l l y s u l p h u r - c o n t a i n i n g a m i n o a c i d s , t o re -
grow the i r f e a t h e r s . F e a t h e r s g r o w f r o m a b l o o d -
fi l led sha f t bu t w h e n t h e y a r e fu l l y f o r m e d t h e y a r e 
iso la ted f r o m the i r b l o o d s u p p l y a n d t h e f e a t h e r is 
dead . O l d f e a t h e r s a r e p u s h e d ou t of t h e fo l l i c l es by 
the n e w g r o w i n g f ea the r . 
Mou l t i ng is t r i gge red by m a n y ex te rna l f ac to r s tha t 
comb ine to s t imu la te t he t hy ro id a n d g o n a d s , w h o s e 
ho rmones in i t iate mou l t . O n c e t he mou l t has s ta r t ed 
other ( u n k n o w n ) loca l f ac to rs , s e c r e t e d by t h e g r o w ­
ing fea ther , c a u s e t he a d j a c e n t f ea the r to mou l t in 
sequence . T h i s is ve ry o b v i o u s in t he w i n g , w h e r e t h e 
first f ea the r to fal l ou t is usua l l y p r ima ry 6 a n d t he 
sequence m o v e s in e a c h d i rec t i on a l o n g t he w i n g . 
The d e v e l o p i n g f ea the r h a s a c o n s i d e r a b l e b l o o d 
supply a n d g r o w s out of t he d e r m i s s u r r o u n d e d by a 
corni f ied s h e a t h . A s the f ea the r g r o w s t h e s h e a t h 
ruptures, a l l ow ing the f ea the r to un fu r l , w h i c h is h e l p e d 
by no rma l g r o o m i n g us ing t he b e a k a n d a l so c l a w s . 
Once the fea the r is fu l ly g r o w n t h e b l o o d s u p p l y 
d i sappears but t he f ea the r is he ld in p l ace in its fo l l i c le 
by an e p i d e r m a l co l la r of l iv ing t i s sue . W h e n t he 
feather is abou t to be r e p l a c e d , th is co l la r s ta r ts to 
prol i ferate a n d p u s h e s t he o ld f ea the r ou t of its fo l l i c le . 
If the fea the r is pu l l ed ou t p r e m a t u r e l y t he e p i d e r m a l 
col lar is t o rn ; th is d a m a g e s t i m u l a t e s t he g r o w t h of a 
new fea ther . 
Beak and claws 
The beak is desc r i bed in deta i l in F igure 2 .3 . 
T h e c l a w s at t h e e n d of e a c h t o e a r e s im i l a r t o 
the b e a k in tha t t h e y a r e h e a v i l y k e r a t i n i z e d a n d 
m ine ra l i zed . T h e y a re m a d e of a th i cke r , h a r d e r a n d 
more rap id l y g r o w i n g d o r s a l po r t i on a n d a f la t so f t e r 
vent ra l p o r t i o n . A s the g r o w t h is g r e a t e s t in t h e 
dorsa l po r t i on t he c l a w c u r v e s ven t ra l l y , m a k i n g it 
ideal fo r g r a s p i n g . 
J P | | A sagittal section of the rostral portion of the 
WBBP head of a Grey Parrot. The horny beak or bill 
(rhamphotheca) is a hard, tough epidermal structure. The 
beak is attached to a bony base, either the mandible or 
maxilla, which acts as a form to produce the beak's 
shape. The bony base is overlain by periosteum that is 
bound to the dermis by a layer of collagen and elastin 
fibres. The typical layers of epidermis are modified and 
formed by keratin-filled cells, firmly held together by cell 
junctions that cannot break down. The stratum corneum is 
very thick and its keratinized cells are also mineralized 
with hydroxyapatite crystals. 
The beak has a well developed superficial innervation 
in some areas but mostly is completely inert. The beak 
grows continually through life from both a germinal layer 
corresponding to the coronary band and from the 
germinal layer overlying the supporting bone. It becomes 
thicker towards its rostral end as it grows. In a large 
macaw it takes at least 9 months for a mark made next to 
the cere to reach the rostral tip. The inner and outer 
surfaces of the beak are formed as separate plates. The 
inside of the upper beak appears to have two areas of 
beak growth that between them form a shelf in the horn. 
Grey Parrots make a loud click by flicking the tip of their 
mandible off this shelf. The rostral part has a lamellar 
appearance but is smooth if the beak is wearing correctly.The shape of the beak is maintained mainly by the lower 
beak grinding against the inner surface of the upper beak. 
This happens during chewing but resting parrots will also 
grind their lower beak against the upper in a side-to-side 
rasping motion. The outer layers of the beak (cuticle) are 
also rubbed away by the bird wiping its beak on perches. 
Baby parrots hatch using their egg-tooth on the dorsal 
aspect of the end of the beak. It is a cone of horny cells 
containing hydroxyapatite that is shed as the beak grows. 
S k e l e t o m u s c u l a r s y s t e m 
Like the fea the rs , the ske le ton (F igure 2.4) is l ight but 
' e n g i n e e r e d ' to be ve ry s t r ong . T h e medu l l a ry cav i ty of 
s o m e b o n e s is f i l led w i th air ra ther t han mar row . 
Skull 
T h e skul l is a l ightweight box wi th t w o huge orbits 
su r rounded in m a n y parrots by a comp le te bony r ing. 
T h e upper j a w is f o r m e d by the premaxi l la and nasal 
bones a n d can be m o v e d relat ive to the rest of the skull 
(F igure 2.5) . In large parrots there is a synovia l joint at 
the junc t ion of beak a n d skul l (F igure 2.3) ; in smal ler 
parrots this is c o m b i n e d wi th a f lexible elast ic zone. The 
9 
Chapter 2 A n a t o m y a n d p h y s i o l o g y 
Major digit 
Minor digit 
Carpometacarpus 
Scleral ossicles 
Pelvis 
Antitrochanter 
Pygostyle 
Pubis 
Hypotarsus 
Digit IV 
Sternum 
Femur 
Fibula 
Tibiotarsus 
Tarso metatarsus 
Phalanges 1 to 4 
D i g i t I 
M M A right lateral view of the skeleton of the Blue-headed 
W Pionus Parrot. The bird is illustrated in its normal 
standing position but for clarity the wing is elevated. The jaws 
are in normal resting occlusion. The orbit contains the scleral 
ossicles. Even though the skeleton is very light, the body of the 
bird is very strong. 
The true ribs have a joint between the sternal and vertebral 
portions of the rib; the body wall is strengthened by uncinate 
processes that overlap the caudally adjacent vertebral rib. The 
sternum is attached by flexible joints to the sternal ribs, there is a 
slightly flexible joint with the coracoid and strong fibrous 
attachment to the most ventral portion of the furcula. 
Bony external naris 
Upper jaw 
Rhamphotheca 
Mandibular 
process 
Quadrate bone 
| Palatine bone 
B Jugal arch 
| Pterygoid bone 
M M Lateral and ventral views of the skull of a 
V B V Blue-headed Pionus Parrot. Parrots have 
very mobile jaws. The lower beak can be moved 
rostrally, caudally and laterally in relation to the 
upper jaw - it is quite possible for a parrot to place 
the tip of the maxilla inside the lower jaw. All these 
movements are interrelated by the mobility of the 
jaw bones and the unique jaw musculature (parrots 
have an extra jaw muscle compared with other 
birds). The muscles move the jaw bones and the 
skeleton of the palate. The quadrate bone (pink) is 
highly mobile and forms the articulation (dark red) 
for the mandible. The rest of the palatoquadrate 
bridge and the jugal arch move in concert with the 
upper jaw to which they are connected. When the 
upper jaw elevates it moves the quadrate bone, and 
therefore the lower jaw, rostrally as well. The jaws of 
parrots are not only very mobile but also immensely 
strong. This strength is made possible by the 
craniofacial hinge. 
lower jaw consis ts of two fused mand ib les . T h e mand i ­
bles do not art iculate direct ly w i th the skul l . T h e comp lex 
movemen ts of the upper a n d lower j aws , relat ive to each 
other, a l low the beak to be used in m a n y subt le w a y s 
other than a basic sc issors m o v e m e n t . T h e l igaments 
and musc les of the j aw are a lso highly spec ia l i zed . T h e 
maxi l la has a hol low air-f i l led interior that connec ts wi th 
the upper respiratory sys tem. 
Vertebrae, ribs and thoracic girdle 
Parrots , l ike mos t o ther b i rds , have a ve ry f lex ib le neck . 
T h e ver tebrae over the lungs are k n o w n as the no ta r ium 
a n d , a l though not f u s e d , a re less f lex ib le . T h e rema in ­
ing thorac ic , l umbar a n d sacra l ve r teb rae a re c o m ­
pletely f used to fo rm the s y n s a c r u m . T h e c a u d a l 
ver tebrae a n d te rm ina l pygos ty le a re f ree ly m o v a b l e 
and suppor t the tai l f ea thers . 
T h e r ibs ar t icu la te w i th the thorac ic v e r t e b r a e p rox i -
mal ly a n d the we l l d e v e l o p e d s t e r n u m dista l ly . T h e 
ca r ina (keel ) f o r m s a bony s e p t u m , o n e i ther s ide of 
w h i c h a re the pec tora l m u s c l e s . T h e s t e r n u m suppo r t s 
t he thorac ic g i rd le , w h i c h cons i s t s of the scapu la , 
c lav ic le a n d co raco id b o n e s . T h e co raco id ac ts as a 
strut , ho ld ing the shou lde r a cons tan t d i s tance f r om the 
s t e r n u m . T h e s c a p u l a e lie ad jacen t to the r ibs a n d the 
left a n d r ight c lav ic les a re f u s e d into a s t ruc tu re k n o w n 
as the fu rcu la (it is a b s e n t in s o m e par ro ts , s u c h as 
loveb i rds a n d rose l las) . T h e fu rcu la ac ts as a spr ing 
a n d s to res ene rgy du r ing t he d o w n - b e a t as it is c o m ­
p r e s s e d . T h e s e th ree b o n e s a re j o i ned by l i gaments at 
the i r p rox ima l e n d s to ar t icu la te w i th t he h e a d of the 
h u m e r u s ; the i r j o i n ted ar t i cu la r s u r f a c e s f o r m the 
t r iossea l f o r a m e n t h rough w h i c h the t e n d o n of the 
s u p r a c o r a c o i d e u s m u s c l e p a s s e s . 
10 
C h a p t e r 2 A n a t o m y a n d p h y s i o l o g y 
Wing 
The wing bones (F igures 2.1 a n d 2.4) a re the h u m e r u s , 
radius and u lna, a n d the m a n u s (a s e m i - f u s e d th ree -
f ingered hand) . T h e r e a re sepa ra te radia l a n d u lnar 
carpal bones a n d the dista l ca rpa l s a n d m e t a c a r p a l s 
are fused into a c a r p o m e t a c a r p u s (see F igure 11 .10) . 
The alula digit ( t humb) has a g o o d range of m o v e m e n t ; 
the major and m inor d ig i ts f o rm an in tegra ted unit . T h e 
wing is very mob i le w h e n f l exed but w h e n e x t e n d e d it 
tends to m o v e at the shou lde r jo in t a n d o the rw ise 
resists dorsa l a n d vent ra l f o rces . T h e shaf ts of t he f l ight 
feathers are c lose ly a t t ached to the dorsa l aspec t of the 
ulna and m a n u s ; t he p r imary fea the rs a re m o r e f i rmly 
at tached than the s e c o n d a r y f ea the rs . 
The w i n g has its m a i n m u s c l e m a s s on the ster­
num (F igure 2 .6 ) . T h e pec to ra l m u s c l e con t r ac t s to 
cause the d o w n - s t r o k e of t he w i n g a n d f o r m s 1 5 - 2 0 % 
of the tota l b o d y w e i g h t of t he b i rd . Do rsa l (or d e e p ) to 
the pectora l m u s c l e is t he s u p r a c o r a c o i d e u s m u s c l e . 
Its t endon of inser t ion runs t h r o u g h t he t r i ossea l 
fo ramen a n d inser ts o n the d o r s o c r a n i a l e d g e of t h e 
humerus . Du r i ng n o r m a l f l a p p i n g f l ight , t he s u p r a ­
co raco ideus m u s c l e ro ta tes t he h u m e r u s , c a u s i n g t he 
wing to ra ise its l ead ing e d g e . T h i s a l l o w s the b i rd to 
mainta in its pos i t i on in t he ai r b e t w e e n d o w n - s t r o k e s . 
Dur ing s l ow f l ight a n d take-o f f , t he s h o u l d e r m u s c l e s 
e levate the w i n g . T h e p r o p a t a g i u m (a t r i angu la r por ­
t ion of sk in) is p resen t f r o m t he c ran ia l a s p e c t of t he 
shou lder to t he c a r p u s a n d c a u d a l l y to t he e l b o w . T h e 
leading e d g e of t he p r o p a t a g i u m is s u p p o r t e d inter­
nally by an e las t ic t e n d o n tha t is j o i n e d by v a r i o u s 
other m u s c l e s a n d t e n d o n s , al l of w h i c h m a i n t a i n t he 
aerofoi l s h a p e of t he w i n g . T h e e l b o w jo in t h a s a w i d e 
range of m o v e m e n t s w h e n f l e x e d , a n d t he radius a n d 
ulna p rona te a n d s u p i n a t e . 
Leg 
T h e leg of the parrot (F igure 2.7) has a femur , a 
t ib io tarsus (the t ib ia f used to the prox imal row of tarsal 
bones) a n d a shor t f ibula that does not ex tend be low the 
f ibular crest (F igure 2.4) . T h e ta rsometa ta rsus is a lso a 
shor t bone , f o r m e d by the distal row of tarsal bones 
c o m b i n e d wi th the fused s e c o n d , th i rd a n d four th me ta ­
tarsa l bones (see Figure 11.11) . T h e first metatarsa l 
bone is separa te . T h e parrot 's foot is zygodac ty l : digits 
II a n d III face cranial ly , digi ts I a n d IVcauda l l y . T h e pelvis 
is f o r m e d by fus ion of the i l ium, isch ium a n d pubis . T h e 
ace tabu lum is f o r m e d f rom a bony r im a n d a f ibrous cup. 
Caudodo rsa l to the ace tabu lum is the ant i t rochanter , 
wh i ch ar t icu lates wi th the t rochanter of the femur and 
prevents abduc t ion of the l imb w h e n the bird is in a 
norma l s tand ing pos i t ion. B e c a u s e of their foot shape 
a n d shor t t a rsometa ta rsus , parro ts a re very good at 
c l imb ing a n d man ipu la t ing their f ood , but w h e n wa lk ing 
on a flat sur face they have a typ ica l wadd l i ng or roll ing 
gait, espec ia l ly t hose (such as m a c a w s ) that wa lk on the 
cauda l t a rsometa ta rsus as wel l as the foot . 
L ike that of the w i n g , the ma in m u s c l e m a s s of the 
leg is c lose to the body a n d so m a n y m u s c l e s have long 
t e n d o n s of inser t ion . W h e n the toes a re f l exed a n d 
gr ipp ing the re is a lock ing m e c h a n i s m b e t w e e n the 
f lexor t e n d o n s a n d the i r s h e a t h that ma in ta ins gr ip w i th 
a m i n i m u m of m u s c l e act iv i ty . In par ro ts the long digi ta l 
ex tenso r m u s c l e e x t e n d s all four d ig i ts . 
Medullary cavit ies and medul lary bone 
In g row ing parrots the medu l la ry cavi t ies of most bones 
conta in act ive bone mar row. W h e n a bird s tops g row ing , 
m a n y bones b e c o m e pneuma t i zed : d iver t icu la f rom the 
air sacs invade a n d occupy the medul la ry cavi t ies of 
m a n y ver tebrae , the pelv is, s te rnum a n d humerus . 
Cut insertion of 
pectoral muscle 
Tensor muscles of 
the propatagium Elastic tendon of propatagium Origin of ventral aponeurosis 
Supracoracoideus 
muscle 
Biceps brachii muscle Minor digit 
Ventral metacarpal artery 
Interosseal metacarpal artery 
Major digit 
Cut and reflected 
ventral aponeurosis 
Superficial ulnar artery 
Long digital extensor muscle 
of the major digit 
Extensor carpi radialis muscle 
Ulna 
Deep ulnar vein 
M M Ventral view of the wing of a Grey Parrot. Arteries are red, veins blue and nerves green. The pectoral muscle has 
Vift^P been removed. The brachial artery gives rise to the radial and then ulnar arteries. The superficial ulnar artery 
gives rise to the ventral metacarpal and digital arteries. The deep ulnar vein is the major venous return from the distal wing. 
The supracoracoideus muscle can be seen entering the triosseal foramen in the shoulder. 
11 
Chapter 2 A n a t o m y a n d p h y s i o l o g y 
Femoral artery, vein and nerve 
lie beneath the iliotibial muscle Head of femur 
Antitrochanter 
Position of the 
uropygial gland 
Tibial cartilage caudal 
to the intertarsal joint 
Tarsometatarsus 
Digit IV 
Gastrocnemius 
muscle 
Knee 
Cranial tibial muscle 
Tibial cartilage 
Superficial 
plantar vein 
Digital flexor 
tendons 
Digit IV 
Ansa restraining cranial tibial muscle 
Long digital extensor tendon 
supplying all four digits 
Digital flexor tendon 
(b ) 
Digit I 
^REB ( a ) L a t e r a l v i e w o f 
W t h e le f t p e l v i c 
l i m b o f a G r e y P a r r o t . T h e 
l i m b , i n c l u d i n g t h e p e l v i s 
a n d s y n s a c r u m , h a s b e e n 
r e m o v e d f r o m t h e v e r t e b r a l 
c o l u m n , a n d t h e i n t e g u m e n t 
r e m o v e d , e x c e p t f o r d i g i t s I 
a n d I I . T o i l l u s t r a t e t h e 
c o u r s e o f t h e m a i n n e r v e s , 
a r t e r i e s a n d v e i n s , i l i o f i b u l a r 
a n d l a t e r a l i l i o t i b i a l m u s c l e s 
h a v e b e e n r e m o v e d , a n d 
l a t e r a l g a s t r o c n e m i u s 
m u s c l e a n d m i n o r f l e x o r s o f 
d i g i t s II a n d III h a v e b e e n 
s e c t i o n e d a t t h e i r o r i g i n s 
a n d r e f l e c t e d , ( b ) T h e d i s t a l 
p o r t i o n o f t h e l e g o f a G r e y 
P a r r o t h a s h a d t h e s k i n 
r e m o v e d , e x c e p t f o r d i g i t s 
III a n d IV . T h e m a j o r v e n o u s 
r e t u r n f r o m t h e d i s t a l l i m b i s 
t h e s u p e r f i c i a l p l a n t a r v e i n . 
T h e d i s t a l t h i r d o f t h e 
t i b i o t a r s u s is v i s i b l e a s it 
h a s v i r t u a l l y n o s o f t t i s s u e 
c o v e r i n g o n c e t h e s k i n i s 
r e m o v e d . 
T h e t e n d o n s o f i n s e r t i o n 
a r e l o n g a n d t h e r e a r e 
s e v e r a l a d a p t a t i o n s w h e r e 
t h e y r u n o v e r j o i n t s . T h e 
i l i o f i b u l a r m u s c l e ( a f l e x o r o f 
t h e k n e e ) a n d t h e c r a n i a l 
t i b i a l m u s c l e ( f l e x o r o f t h e 
i n t e r t a r s a l j o i n t ) a r e b o t h 
h e l d c l o s e t o t h e i r 
r e s p e c t i v e j o i n t s b y a s t r a p ­
l i k e a n s a . A l o n g s i d e t h e 
t e n d o n o f i n s e r t i o n t h e s e 
a n s a e c o n t a i n a 
n e u r o v a s c u l a r b u n d l e . T h e 
g a s t r o c n e m i u s m u s c l e s 
( e x t e n s o r s o f t h e i n t e r t a r s a l 
j o i n t ) i n s e r t o n t h e 
h y p o t a r s a l r e g i o n a n d t h e i r 
f i b r o u s i n s e r t i o n s c o v e r t h e 
t i b i a l c a r t i l a g e a n d t h e n t h e 
f l e x o r t e n d o n s o n t h e 
c a u d a l t a r s o m e t a t a r s u s . 
T h e t i b i a l c a r t i l a g e c o n t a i n s 
t h e m i n o r d i g i t a l f l e x o r 
t e n d o n s in s e v e r a l t u n n e l s ; 
t h e t w o m a j o r d i g i t a l f l e x o r 
t e n d o n s r u n t h r o u g h t h i s 
r e g i o n i n t u n n e l s i n t h e 
h y p o t a r s u s . T h e m i n o r 
f l e x o r s p r o v i d e m o s t o f t h e 
c o m p l i c a t e d t o e 
m o v e m e n t s , t h e m a j o r 
f l e x o r s i n s e r t o n t h e d i s t a l 
p h a l a n g e a l b o n e a n d 
p r o d u c e p o w e r f u l d i g i t a l 
f l e x i o n . T h e d i g i t a l e x t e n s o r 
t e n d o n is s h o w n in F i g u r e 
1 1 . 5 . T h e r e a r e s o m e s m a l l 
i n t r i n s i c m u s c l e s in t h e 
t a r s o m e t a t a r s a l r e g i o n t h a t 
a l s o m a k e f i n e m o v e m e n t 
p o s s i b l e . 
12 
Medul lary bone (F igure 2 .8 ; see a lso F igure 18.4) is 
labile bone that norma l l y occu rs on ly in f e m a l e b i rds in 
the reproduct ive phase . Its f o rma t i on is con t ro l led by 
oestrogens and a n d r o g e n s a n d so it c a n a lso be 
formed in non- lay ing b i rds w i th h o r m o n a l a b n o r m a l i ­
ties. It consists of i n te rconnec ted sp icu les , r esemb l i ng 
embryonic bone , that g r o w out f r om the endos tea l 
surface of the long b o n e s . Medu l l a ry b o n e has no 
Haversian sys tem a n d con ta ins less co l l agen t han 
normal bone. P h a s e s of fo rma t i on a n d des t ruc t ion 
alternate dur ing the lay ing cyc le . 
M J ^ M Medullary bone i s laid down in the medullary 
M 9 H P cavity of bones that are not pneumatized. It is 
most obvious in the long bones, and in this Pionus parrot, 
it is absent from the humerus but present in the femur. 
Two weeks after these radiographs were taken the bird 
laid a clutch of five eggs. 
Body c a v i t i e s 
Birds do not possess a d iaph ragm that can separa te the 
body into thoracic and abdomina l cavi t ies. In birds in 
general there are 16 body cavi t ies. Eight of t hese a re 
connected to the respiratory sys tem a n d are p n e um a ­
tized (air sacs) . T h e others , wh i ch are not pneuma t i zed , 
are the left a n d right p leura l cav i t ies , a per icard ia l 
cavity, four sepa ra te hepat ic per i tonea l cav i t ies a n d 
the intestinal per i tonea l cav i ty . T h e intest inal per i to ­
neal cavi ty con ta ins t he gas t ro in tes t ina l t ract f r o m 
proventr iculus to rec tum, t he g o n a d s , sp leen a n d a b ­
dominal air sacs ; the k idneys a n d rep roduc t i ve t rac ts 
are ext raper i toneal . 
Digestive system 
Oral cavity 
Parrots have a th ick b l un t -ended t o n g u e that has an 
intrinsic muscu la tu re , w h i c h is un ique a m o n g s t b i rds . 
This enab les m a n y par ro ts to p ick up f o o d s u c h as 
seeds and man ipu la te the f o o d aga ins t t he j a w s . T h e 
tongue a lso conta ins fat a n d c a v e r n o u s vascu la r t is­
sue. In lor ies a n d lor ikeets the t o n g u e is cu r led into a 
groove and carr ies severa l h u n d r e d br is t les that he lp to 
collect pol len and nectar . 
C h a p t e r 2 A n a t o m y a n d p h y s i o l o g y 
Sa l i vary g l ands a re n u m e r o u s a n d wide ly distr i ­
bu ted w i th in t he pa la te , t o n g u e , f loor a n d corner of 
the m o u t h , c h e e k s a n d pha rynx . T h e g lands are c o m ­
p o u n d tubu la r s t ruc tu res w i th mul t ip le lobu les . Each 
lobu le is c o m p o s e d of m a n y sec re to ry tubu les that 
o p e n into a c o m m o n cav i ty tha t t h e n d ra ins v ia a s ing le 
duc t . T h e s e duc t s a re n u m e r o u s a n d c a n be s e e n wi th 
the n a k e d eye as sma l l o p e n i n g s all ove r the m o u t h . 
T h e y a re s t imu la ted by the pa rasympa the t i c ne rves 
a n d sec re te ma in ly m u c u s . 
O e s o p h a g u s 
T h e o e s o p h a g u s l ies on the r ight s ide of the neck a n d 
is mod i f i ed at t he thorac ic inlet to f o rm the c rop (F igure 
2.9) . Peristal t ic w a v e s m o v e the food d o w n the oesopha ­
g u s a n d mix the con ten t s of the c rop . 
M M A lateral view of the right side of the neck of the 
BHB^P Grey Parrot. The thymus i s well developed in 
the young bird and is present on each side of the neck. It 
regresses as the bird gets older. The right jugular vein is 
usually the larger of the two. The oesophagus, heart and 
syrinx are all very close to each other. All the structures 
illustrated in the neck are subcutaneous. 
S t o m a c h 
T h e s t o m a c h is d i v ided into a p roven t r i cu lus a n d v e n -
t r icu lus (g izzard) (F igures 2 .10 a n d 2 .11) . Cran ia l l y the 
p roven t r i cu lus is g landu la r a n d con ta ins oxyn t i copep t i c 
cel ls that sec re te hydroch lo r ic ac id a n d peps in ; cauda l ly 
it is muscu la r . T h e in te rmed ia te z o n e o p e n s into the 
g i zza rd . In par ro ts t he g izza rd is ex t reme ly muscu la r 
a n d has in terna l a n d ex te rna l adap ta t i ons for g r ind ing 
f o o d w i th gri t (F igure 2 .11) . T h e in ternal su r face is 
c o v e r e d w i th the cut ic le (koi l in layer ) , w h i c h is a ca rbo ­
h y d r a t e - p r o t e i n c o m p l e x a n d not kera t in . T h e pylor ic 
part of t he s t o m a c h is b e t w e e n t he muscu la r part of the 
g i zza rd a n d the d u o d e n u m . It con ta ins endoc r ine cel ls. 
Rad iog raph i c s tud ies have s h o w n that the food is 
prope l l ed in a l te rna te d i rec t ions b e t w e e n the p roven­
t r icu lus a n d the g i zza rd in a ser ies of cyc les . 
1 3 
Chapter 2 A n a t o m y a n d p h y s i o l o g y 
Oesophagus 
Cloaca 
Gizzard (ventriculus) 
Left lateral view of the viscera of a Blue-headed 
Pionus Parrot. 
Crop Oesophagus Proventriculus 
Glandular I Intermedidiale 
part zone 
Ventriculus 
(gizzard) 
Koilin 
S 'aver 
Grit 
External and internal views of the alimentary 
tract from oesophagus (distal to the crop) to 
duodenum of a typical parrot (Pionus senilis). The 
glandular part of the proventriculus can be identified by its 
darker colour and a honeycomb pattern on its surface; the 
intermediate part is paler. The body of the gizzard has two 
thick muscles (1, 2) and two thinner areas (3, 4) that 
correspond to blind-ending sacs within the gizzard. The 
entrance to the pyloric part of the stomach (P) and 
duodenum (D) is in the cranial part of the gizzard. The 
koilin layer is well developed in parrots. If parrots have 
access to grit, the healthy gizzard will always contain it. 
In tes t ines 
T h e d u o d e n u m is a U-shaped loop of bowe l . T h e je ju ­
n u m a n d the i leum are a r ranged in a ser ies of U-shaped 
loops, or coi ls . At the junc t ion be tween the i leum a n d the 
j e j unum is the vi tel l ine d iver t icu lum (the remnan t of the 
yo lk sac a n d the yolk duct ) (F igure 7.7) . T h e intest inal 
wal l has th ree types of epi thel ia l cel ls: chief cel ls, wh ich 
have a brush border and are absorpt ive; goblet cells, wh ich 
are m u c u s secre t ing ; a n d endocr ine cel ls, wh i ch in 
comb ina t ion wi th those in the s t o m a c h a n d panc reas 
fo rm a di f fuse endocr ine o rgan . Chemica l d igest ion and 
absorp t ion of f ood take p lace in the smal l in test ine. T h e 
large bowe l is short ; the pa i red vest ig ia l caeca ar ise at 
the junc t ion be tween the j e j u n u m a n d the rec tum. T h e 
intest ine emp t ies into t he c loaca (F igure 2 .12) . T h e 
length of the intest ines of the Ec lec tus Parrot is near ly 
tw ice that of the o ther large parrots . 
P a n c r e a s 
T h e p a n c r e a s has th ree lobes . T h e dorsa l lobe l ies 
a b o v e t he ven t ra l lobe in the d u o d e n a l loop (F igure 
15 .16a) a n d a sma l l sp len ic lobe runs f r o m the cran ia l 
par t of the p a n c r e a s t o w a r d s the s p l e e n . T h e p a n c r e a s 
sec re tes the s a m e exoc r i ne d iges t i ve e n z y m e s as 
m a m m a l s : a m y l a s e , l ipase a n d p r o t e a s e s , inc lud ing 
t r yps in . It a lso p r o d u c e s insul in a n d g l u c a g o n s but 
insul in has little ef fect on g l ucose m e t a b o l i s m , w h i c h is 
ma in ly con t ro l led by s te ro id h o r m o n e s . 
Liver 
T h e l iver has r ight a n d left l obes ( the right lobe is 
larger ) . E a c h lobe is d ra i ned by a bi le duc t a n d t hese 
un i te . In mos t par ro ts (not cocka toos ) the gal l b ladder 
is absen t a n d the r ight lobe 's bi le duc t b e c o m e s the 
m a i n d ra i nage to the d u o d e n u m . 
Urinary system 
Parrot k i dneys lie in the left a n d r ight rena l f o s s a e of the 
s y n s a c r u m . E a c h k idney is d i v ided into c ran ia l , m idd le 
a n d cauda l d iv is ions (F igure 2 .13) . E a c h d iv is ion c o n ­
s is ts of m a n y lobu les , w h i c h m a y be s e e n as smal l 
l u m p s on t he renal su r face ; t he lobu le is t h e f u n d a m e n ­
tal unit of t he k idney . T h e b lood supp l y to the k idney is 
ve ry c o m p l e x . 
Ur ic ac i d ra ther t h a n u rea is t h e e n d po in t of a v i a n 
n i t r ogen m e t a b o l i s m . It is f o r m e d in t h e l iver. A l t h o u g h 
s o m e is e x c r e t e d t h r o u g h g l o m e r u l a r f i l t ra t ion , 9 0 % is 
ac t i ve l y s e c r e t e d by the rena l t u b u l e . Ur ic ac id m i x e d 
w i t h sa l t s f o r m s s p h e r e s a f e w m i c r o m e t r e s a c r o s s 
tha t m ix w i t h m u c u s to b e c o m e a co l lo ida l so l u t i on , 
w h i c h p r e v e n t s the i nso lub le u r a t e s f r o m p rec ip i ta t i ng 
in t he ure ter . 
Ur ic ac id exc re t ion is v i ta l for an e m b r y o deve lop ing 
in a she l led e g g . It is m o v e d to , a n d s to red in , t he 
a l lanto is as a crys ta l l ine a n h y d r o u s depos i t , a l l ow ing 
w a t e r f r o m exc re t i on to b e recyc led . A s it is inso lub le , 
ur ic ac id wi l l not po i son t he c l osed s y s t e m of the e g g 
(as w o u l d h a p p e n w i th u rea ) . Af ter ha tch ing