Scarlet Macaw Diet

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Scarlet Macaw diets in Tambopata, Peru: 
studying wild parrots to improve captive bird nutrition 
 
January 2007 
 
Donald J. Brightsmith1
Schubot Exotic Avian Health Center 
College of Veterinary Medicine, Texas A&M University 
College Station, TX. Dbrightsmith@cvm.tamu.edu 
(979) 845-0563 
 
Debra McDonald 
Demac Wildlife Nutrition 
Dr. Mac’s Organic Origins 
PO Box 1004 
Healesville, Victoria, Australia 3777 
demacwildlifenutrition@yahoo.com.au 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1 Please address all correspondence about this proposal to Don Brightsmith 
Introduction 
 
The diets of most wild animals are poorly known, especially in comparison with domestic 
animals. Despite the facts that parrots have been kept in captivity for centuries (Colton 
1941, Greiser 1995) formulated diets are usually based on modifications of commercial 
poultry diets along with a mix of trial and error (Hess et al. 2002, Stanford 2005, 
McDonald 2006). However, diet requirements for poultry can differ significantly from 
those of parrots (Roudybush 1997) Additional research and education about diets for 
captive psittacines are sorely needed as most pet birds are being fed diets too high in fat 
and lacking in key nutrients (Hess et al. 2002). In this study, we will conduct detailed 
analyses of wild Scarlet Macaw chick diets to provide new insight in to the nutritional 
requirements of these birds. This information will be published in the scientific literature 
so that everyone—scientists, zoos, and commercial food producers—can work to 
improve the diets of psittacines in captivity. 
 
Over the past three years, the members of the Tambopata Macaw Project have studied 
diets of wild scarlet macaws and other psittacines (parrots, macaws, parakeets, etc.) at the 
Tambopata Research Center in southeastern Peru (Brightsmith et al. 2006). We have 
documented the wild foods eaten and conducted basic nutritional analyses. We have also 
been studying the large clay lick immediately adjacent to the research center (Brightsmith 
2004, Brightsmith 2006). One of the goals of the clay lick work has been to determine 
why the birds eat soil (Brightsmith and Aramburú 2004). Soil analyses and diet analyses 
have provided important information on the levels of nutrients available to the birds. For 
Calcium, Potassium, Magnesium, Copper, or Manganese the levels in the soil are lower 
than or the same as those in the diet, suggesting that birds do not eat soil to supplement 
their intake of these minerals (Table 1). Consumed soils have nearly twice as much iron 
as the average plant food. However, over 10% of the plants they eat have more available 
iron than the soil they eat. The soil could be providing an iron supplement, but there are 
other ways for the birds to get iron without eating dirt. As a result, we feel it is unlikely 
that the parrots desire to eat soil at the clay licks is being driven by the need for more 
iron. 
 
The clay lick soil has nearly 40 times more sodium (the attractive ingredient of salt) than 
the average plant food and much more sodium than any of the 89 plant resource tested, 
suggesting that clay lick soil is an extremely important source sodium for the birds (N= 
89 diet items tested, data from Brightsmith unpublished and Gilardi 1996). Sodium is 
scarce in many ecosystems and leaches easily from most soils in humid environments 
(Klaus and Schmid 1998). In addition, sodium is not needed by the vast majority of 
plants, so is not actively taken up by most vegetation (Klaus and Schmid 1998). Where 
plants do accumulate sodium, this often leads to animals eating the entire plant (Oates 
1978, Ohlson and Staaland 2001, Rothman et al. 2006). Parallel studies in Costa Rica 
show that the plants macaws eat can have as much as 120 times more sodium than the 
foods the birds eat in Peru (Costa Rica data from G. Matuzak and D. Brightsmith 
unpublished). In Costa Rica the birds do not eat soil, lending further support to the 
contention that the clay lick provides a significant source of dietary sodium for parrots in 
southeastern Peru (Brightsmith and Aramburú 2004). 
 
We have also analyzed the basic nutrient content of food samples collected from the 
crops of young Scarlet Macaws (age 13 – 77 days, N = 30 samples, Table 2). These data 
show that parents feed the young a great deal of clay, along with a variety of seeds, water, 
and the occasional insect larva (Brightsmith unpublished data). The nutrient analyses 
suggest that the chick’s diet has very low sodium content, well below that recommended 
for poultry and pet parrots (Table 3). Information on nutrient contents of hand feeding 
diets for parrots is scarce. One diet used by a private breeder had levels of total fat and 
total protein similar to the wild birds we studied, but the captive birds received 29% more 
Phosphorous, 63% less ash, 67% less Calcium, and 88% less fiber (Table 3, Abramson 
1995). The British Small Animal Veterinary Association (BSAVA) has published 
maintenance diet recommendations for pet birds and discuss the additional requirements 
for growing birds (Stanford 2005). These recommended values are very similar to the 
macaw chick diets in Peru for total protein, Phosphorous, Zinc and Copper but had much 
less fat, Potassium, and Magnesium. The BSAVA diet also has much higher sodium than 
the wild diet in Peru. The consequences of these differences between wild and captive 
diets are unknown. One interesting finding that highlights our general ignorance of parrot 
diets is that (Roudybush 1997) states that in diets for growing cage birds, Calcium should 
be limited to no more than 1.2%. However, our wild macaw chicks receive on average 
1.5% Calcium. A major source of fiber in the wild diet is the pieces of bark/wood chips 
that appear in nearly every crop sample that we have collected. These pieces do not come 
from inside the nest, suggesting that the parents make a conscious choice to feed these 
high fiber items to their young. These differences in captive and wild diets warrant 
further investigation and detailed data on diets of wild psittacines can help direct future 
lines of research in to the dietary needs of captive birds. 
 
Our previous research has provided great insight in to the general characteristics of 
macaw and parrot diets. It has aided us in understanding why birds eat soil and pointed 
out some gross differences between diets for captive and wild chicks. However, these 
analyses are too rough to use to formulate new diets for captive birds. To provide the 
information we need to truly understand the nutrient balance of wild diets, we need to 
know more than just the gross levels of fat, protein, etc. We need to know details about 
essential amino acids, essential fatty acids, vitamins, and even carotenoids (precursors of 
vitamin A). Lack of such detailed knowledge has led to the formulation of diets that can 
actually harm birds. For example Lories fed some commercial diets may suffer from 
Vitamin A toxicity, reproductive failure, poor health and even iron storage disease. This 
is due, in part, to the fact that in the wild, the birds consume mostly provitamin A 
carotenoids which they use to make only the amount of Vitamin A they need (McDonald 
2003). 
 
With the collaboration of Dr. Debra McDonald, we have the fortune of working with one 
of the emerging stars in the world of avian nutrition (McDonald 2003, McDonald 2004, 
McDonald 2006). Her original scientific research on wild birds has already provided 
great insight in to the dietary problems of Australian psittacines and other birds. With her 
help, our work in South America promises to provide many new insights in to the 
nutrition of wild macaws and many novel ways to use this information to help captivepsittacines. 
 
Table 1: Comparison of available mineral contents of soils and plants consumed by 
psittacines in southeastern Peru. Plant nutrient data from Gilardi (1996) and DJB 
unpublished. Soil data from Brightsmith (in preparation). 
 
 Consumed soils Plant resources 
Mineral Mean Stdev N Mean Stdev N p-value 
Ca 427 ± 209 12 5,233 ± 7512 90 < 0.0001 
Fe 119 ± 46 12 66 ± 48 90 0.002 
K 140 ± 24 12 16,977 ± 15543 90 < 0.0001 
Mg 259 ± 55 12 2,786 ± 2050 90 < 0.0001 
Na 1,360 ± 462 12 35 ± 32 89 < 0.0001 
Mn 17 ± 7.5 12 67 ± 125 33 > 0.1 
Cu 0.73 ± 0.57 12 10.7 ± 7 50 < 0.0001 
 
 
Table 2: Nutrient levels of crop samples collected from Scarlet Macaw crops at 
Tambopata Research Center, January – March 2005. The sampled chicks had a range of 
13 to 77 days. Mineral values are given in parts per million (ppm or mg / kg). “N” 
indicates the number of samples analyzed. This number varies because many of the 
samples were not sufficiently large to analyze for all nutrients. Nutrients for which the P 
is less than 0.05 indicates that the concentration of this nutrient in the chicks’ diets 
declined significantly as the bird aged. The R2 and P-values were generated using 
univariate linear regression (Sokal and Rohlf 1995). 
 
 Mean Stdev N R2 P 
Fiber % 34.21 7.58 19 0.06 0.31 
Ash % 11.76 8.76 15 0.00 0.96 
Fat % 28.60 8.58 24 0.11 0.11 
Protein % 23.46 5.56 30 0.10 0.09 
Soil % 5.20 11.44 30 0.004 0.73 
Ca ppm 14362 6112 29 0.08 0.14 
K ppm 7310 2229 29 0.34 0.00 
P ppm 4766 1327 29 0.05 0.27 
Mg ppm 3572 832 29 0.22 0.01 
Fe ppm 2457 5281 29 0.13 0.06 
Na ppm 242 311 30 0.32 0.00 
Zn ppm 44 13 29 0.06 0.19 
Cu ppm 15 5 29 0.01 0.64 
S ppm 0.18 0.05 29 0.00 0.80 
 
 
Table 3: Diet comparison of diets for wild and captive macaw chicks. The Raintree 
Macaw diet is a hand feeding formula used at a private breeding facility (Abramson 
1995). The BSAVA column represents the recommendations of the British Small Animal 
Veterinary Association. It is based on the adult diet recommendations (p. 137) and 
modified by the discussion presented under nutrition requirements for growing birds (p. 
138). 
 
 
Wild 
Mean 
Raintree 
Macaw1 BSAVA2
Fiber % 34.21 3.8 
Ash % 11.76 4.3 
Fat % 28.60 21.5 4 
Protein % 23.46 24 20 
Ca ppm 14362 4670 10,000 
K ppm 7310 4770 4,000 
P ppm 4766 4,000 
Mg ppm 3572 600 
Fe ppm 2457 80 
Na ppm 242 1,500 
Zn ppm 44 50 
Cu ppm 15 8 
1 Raintree Macaw Handfeeding Formula (Abramson 1995) 
2 (Stanford 2005) 
 
 
 
 
Budget 
The cost of the field work for this project and the salary for Dr. Brightsmith are being 
supported by previous grants from the Schubot Exotic Bird Health Center, Texas A&M 
University, the EarthWatch Institute, and Rainforest Expeditions. This represents 
“matching funds” in excess of $20,000. As a result, your contribution, no matter what the 
size, goes directly to support the analyses we need to allow us to improve captive parrot 
diets. If any individuals want to make additional contributions, all donations go through 
Texas A&M University and are completely tax deductible. 
 
Analysis Cost Units Total 
Mineral scan $53.57 5 $267.84 
Fiber $22.96 5 $114.79 
Fatty acid profile $68.87 5 $344.37 
Moisture $11.48 5 $57.39 
Sugar profile $114.79 5 $573.95 
Carotenoid profiles $114.79 5 $573.95 
Sample processing $22.96 5 $114.79 
 
Total request $2,047.08 
 
 
1 The minerals to be tested include P, K, S, Na, Ca, Mg, Cu, Zn, Mn, Fe, Bo, Se 
Donation details 
For more information or clarification, feel free to contact Donald Brightsmith at 
dbrightsmith@cvm.tamu.edu. 
 
Checks should be made payable to Texas A&M University and mailed to: 
Donald Brightsmith 
Schubot Exotic Bird Health Center 
Department of Vet Pathobiology 
Texas A&M University, TAMU 4467 
College Station, TX 77843-4467, USA 
 
Please put on the check “Brightsmith Diet Research” 
 
About the Researchers 
 
Donald Brightsmith is a Lecturer and Researcher in Avian Conservation at the Schubot 
Exotic Bird Health Center in the College of Veterinary Medicine at Texas A&M 
University. He has a Ph. D. in tropical ecology from Duke University. Since 1993 he has 
studied wild parrots in Peru, Indonesia, Florida, and Costa Rica. The results of these 
investigations have been published in numerous scientific journal articles and magazine 
articles. He is the Director of the Tambopata Macaw Project in Peru, a board member of 
Parrots International, an advisor on the Iguazu Macaw Reintroduction Project in Brazil, a 
consultant for the Indonesian Parrot Project, and a member of the Brazilian government’s 
Lear’s Macaw and Spix’s Macaw Conservation Advisory Groups. 
 
 
Debra McDonald is the Director of the zoo nutrition consultancy Demac Wildlife 
Nutrition and the Chief Nutritionist for Dr Mac's Organic Origins. She worked as 
Assistant Nutritionist at the Bronx Zoo and as Conservation Biologist at Healesville 
Sanctuary in Australia. Although an experienced zoo nutritionist, her work has focused 
on avian nutrition for the past 6 years, including extensive field research in Australia and 
overseas. She is currently establishing a research facility for studies of avian health 
and nutrition in Australia. 
Literature Cited 
 
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and J. B. Thomsen, editors. The large macaws: their care, breeding and 
conservation. Raintree Publications, Ft. Bragg, CA. 
Brightsmith, D. J. 2004. Effects of weather on avian geophagy in Tambopata, Peru. 
Wilson Bulletin 116:134 -145. 
Brightsmith, D. J. 2006. The psittacine year: what drives annual cycles in Tambopata's 
parrots? .in VI International Parrot Convention. Loro Parque Foundation, Loro 
Parque, Tenerife, Spain. 
Brightsmith, D. J., and R. Aramburú. 2004. Avian geophagy and soil characteristics in 
southeastern Peru. Biotropica 36:534-543. 
Brightsmith, D. J., D. McDonald, D. Matsufuji, and G. Matuzak. 2006. Diets of wild 
psittacines in Tambopata, Peru. A progress report to South Lakes Wildlife Animal 
Park. Duke University Dept. of Biolgy, Durham, NC. 
Colton, H. S. 1941. Prehistoric trade in the Southwest. Scientific Monthly 52:308-319. 
Gilardi, J. D. 1996. Ecology of Parrots in the Peruvian Amazon: Habitat Use, Nutrition, 
and Geophagy. Ph.D. dissertation. UC Davis, Davis, CA. 
Greiser, S. T. 1995. The sacred bird. Pages 497-510 in J. Abramson, B. L. Spear, and J. 
B. Thomsen, editors. The Large Macaws: Their Care, Breeding and Conservation. 
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Association of Avian Veterinarians. 
McDonald, D. L. 2006. Nutritional considerations: Section I. Pages 86-107 in G. L. 
Harrison and T. L. Lightfoot, editors. Clinical Avian Medicine, Vol I. Spix 
Publishing, Palm Beach, FL. 
Oates, J. F. 1978. Water-plant and soil consumption by guereza monkeys Colobus 
guereza: a relationship with minerals and toxins in the diet? Biotropica 10:241-
253. 
Ohlson, M., and H. Staaland. 2001. Mineral diversity in wild plants: benefits and bane for 
moose. Oikos 94:442-454. 
Rothman, J. M., P. J. Van Soest, and A. N. Pell. 2006. Decaying wood is a sodium source 
for mountaingorillas. Biology Letters 2. 
Roudybush, T. E. 1997. Chapter 3: Nutrition. Pages 27 - 44 in R. B. Altman, S. L. Clubb, 
G. M. Dorrestein, and K. E. Quesenberry, editors. Avian Medicine and Surgery. 
WB Saunders, London. 
Sokal, R. R., and F. J. Rohlf. 1995. Biometry. Freeman, New York. 
Stanford, M. 2005. Chapter 12: Nutrition and nutritional disease. Pages 136-154 in N. 
Harcourt-Brown and J. Chitty, editors. BSAVA Manual of Psittacine Birds, 
Second Edition. British Small Animal Veterinary Association, Quedgeley, UK. 
 
 
	Scarlet Macaw diets in Tambopata, Peru: 
	studying wild parrots to improve captive bird nutrition
	 Introduction
	 Budget
	Donation details
	About the Researchers
	Literature Cited