Feeding ecology of the Red-and-green Macaw (Ara chloropterus; Gray 1859) in a habitat mosaic from Cerrado

In the Brazilian Cerrado, the Red-and-green Macaw (Ara chloropterus) populations are facing an accelerated rate of habitat loss. Despite this, their feeding areas and primary food sources remain poorly understood. In this study, I assessed the relationship between the diet of the Red-and-green Macaw and available food resources in a habitat mosaic from the fragmented Cerrado in Mato Grosso do Sul State, Brazil. Red-and-green Macaws fed on 20 native and five exotic species, mainly in dry habitats (Cerrado, dry forest, and an urban area along the Maracaju Cliffs) during the dry season, while year-round foraging in the riparian vegetation (Aquidauana River and streams). Then, the number of feeding macaws paralleled variations in food abundance and diversity, besides the number of food species. On the other hand, by using a wide variety of abundant foods, macaws' diet breadth presented high values throughout the year. The seasonal consumption of large-seeded fruits across the habitat mosaic displayed a gradient ranging from the urban area to dry habitats, along which macaws ate from exotic to Cerrado species. In this respect, Terminalia catappa seeds and Mangifera indica fruit pulp were important for Red-and-green Macaws in the urban area during the wet season, while Caryocar brasiliense seeds comprised the same in the Cerrado. At this site, both Dipteryx alata and Buchenavia tomentosa seeds composed much of the Red-and-green Macaws' diet during the dry season. Between those habitats, in the watercourse vegetation, macaws frequently foraged on palm fruits across seasons. Therefore, throughout the year, the abundance and variety of food resources strongly influenced the number of foraging Red-and-green Macaws across the habitat mosaic. Understanding the effect of varying seed availability on the spatial and temporal abundance patterns of Red-and-green Macaws, which primarily feed on large-seeded species, is central to developing effective conservation strategies. Due to the accelerated habitat loss, the Maracaju Cliffs emerge as crucial for the Red-and-green Macaw among the Cerrado remnants of Mato Grosso do Sul.

Nutritional Considerations for Juvenile Exotic Companion Animals

Pediatric exotic companion animal nutrition is a broad topic, spanning small mammals, reptiles, and birds. Little research has been performed focusing on the juvenile life stages of these species because they are largely acquired by clients at the young adult stage. The information that does exist has been compiled by wildlife rehabilitators, commercial breeders, and/or exotic captive breeding programs, such as those that exist in zoologic facilities. In this article, we discuss natural history, feeding strategies, energy requirements, digestive physiology and diet digestibility, and key nutrients of concern as factors for determining an appropriate diet for pediatric exotic species.

Assessing the predictive value of morphological traits on primary lifestyle of birds through the extreme gradient boosting algorithm

The relationship between morphological traits and ecological performance in birds is an important area of research, as it can help us to understand how birds are able to adapt and how they are affected by changes in their environment. Many studies have investigated the relationship between morphological traits and certain aspects of the performance and ecological niche of these animals. However, the relationship between morphological traits and the primary lifestyle of birds has not previously been explored. This paper aims to evaluate the predictive potential of morphological data to determine the primary lifestyle of birds through a tree-based machine learning algorithm. By doing this, it is also possible to evaluate these artificial categories that we used to split up birds and know whether they are suitable for dividing them in function of shared morphological characteristics or need a redefinition under more discriminant criteria. Supplementary dataset 1 of the AVONET project was used, which comprises the 11 morphological predictors used in this work and the classification according to the primary lifestyle for more than 95% of the existing bird species. For all morphological traits used, statistically significant univariate differences were found between primary lifestyles. The three fitted machine learning models showed high accuracy, in all cases above 78% and superior to the ones achieved through traditional approaches used as contrasts. The results obtained provide evidence that primary lifestyle can be predicted in birds based on morphological traits, as well as more insights about the relevance of functional traits for ecological modeling. This is another step forward in our mechanistic understanding of bird ecology, while exploring how birds have adapted to their environments and how they interact with their surroundings.

Key Nutritional Factors and Obesity Prevention in Companion Psittacine Birds

Proper nutrition and feeding management are the foundation of good health. Nutrition is one area the veterinary health care team can affect. Optimal feeding practices of companion birds are constantly being evaluated. It is critical that health care team members understand the key nutritional factors in avian nutrition, as this allows for the proper recommendation and education of nutrition to bird owners. Depending on the species, today's pet birds may live decades, so it is imperative that proper nutrition habits be adopted by the owner for their avian pet. Educating the owner on proper nutrition and prevention of obesity is one of the most important roles of the veterinary health care team.

Parrot Dietary Habits and Consumption of Alternate Foodstuffs

Inappropriate diets cause many of the health problems commonly reported in parrots by psittaculturists and veterinarians. The dietary management of captive parrots would benefit from information derived from studies of dietary habits of wild parrots; however, it is unclear how complete this body of knowledge is at this time. Documentation of parrots' dietary habits appears to have grown dramatically over the past century. Reports of parrots consuming a number of foodstuffs beyond the reproductive parts of plants (alternate foodstuffs) have increased. The extent of alternate foodstuffs in parrot diets is currently unknown. We used Google search engines (ie, Scholar, Videos, Images) to determine how well psittaciform dietary habits have been studied to date and to quantify reports of alternate foodstuffs consumption among genera of Psittaciformes. We found that the dietary habits of over 43% of parrot species are poorly resolved. The dietary habits of 71.5% of parrot species classified by the International Union for Conservation of Nature as at risk of extinction are not well resolved. Parrots' consumption of alternate foodstuffs occurred at the following rates at the genus level: 91.2% foliage, 76.9% terrestrial invertebrates and fine earthen materials, 74.7% wood, 44% pure minerals, 34.1% vertebrates (9.9% dung), 29.7% sap, 19.8% roots, 17.6% charcoal, 18.7% epiphytes, 16.5% coarse earthen materials, 8.8% algae, and 6.6% aquatic invertebrates. Of these reports, 79.1% involved observations of wild parrots. Many parrot species may be more omnivorous than previously realized. Alternate foodstuffs are generally absent from current veterinary-based dietary recommendations for captive parrots. Future studies are needed to determine whether providing alternate foodstuffs to captive parrots can be used as a means to improve their diets and thus their health, welfare, and reproductive success.

Nutritive Support for Critical Exotic Patients

Malnutrition and need for nutritive support are both very common in exotic animals requiring critical care. Assessment and monitoring of body condition, weight, protein absorption, and catabolic loss is recommended to help guide restorative therapy. Several critical care diets are available based on digestive strategy. Fluid requirements and evaporative water loss can vary based on taxa; ectoderms suffer evaporative losses at a greater magnitude than endotherms. Enteral and parenteral nutrition strategies can be appropriate for patients, with natural history and anatomic and physiologic differences considered as much as possible.

Variable evidence for convergence in morphology and function across avian nectarivores

Nectar-feeding birds provide an excellent system in which to examine form-function relationships over evolutionary time. There are many independent origins of nectarivory in birds, and nectar feeding is a lifestyle with many inherent biophysical constraints. We review the morphology and function of the feeding apparatus, the locomotor apparatus, and the digestive and renal systems across avian nectarivores with the goals of synthesizing available information and identifying the extent to which different aspects of anatomy have morphologically and functionally converged. In doing so, we have systematically tabulated the occurrence of putative adaptations to nectarivory across birds and created what is, to our knowledge, the first comprehensive summary of adaptations to nectarivory across body systems and taxa. We also provide the first phylogenetically informed estimate of the number of times nectarivory has evolved within Aves. Based on this synthesis of existing knowledge, we identify current knowledge gaps and provide suggestions for future research questions and methods of data collection that will increase our understanding of the distribution of adaptations across bodily systems and taxa, and the relationship between those adaptations and ecological and evolutionary factors. We hope that this synthesis will serve as a landmark for the current state of the field, prompting investigators to begin collecting new data and addressing questions that have heretofore been impossible to answer about the ecology, evolution, and functional morphology of avian nectarivory.

Comparison of Some Behavioural Responses in Budgerigars (Melopsittacus undulatus) Raised in Cages Enriched with Coloured LED Lights

Simple Summary

In this study, the environment of hand-raised budgerigars in captivity (people’s homes) was simulated. We investigated the effect of coloured LED lights in addition to natural light on the behaviour of the birds. For birds raised by humans, the light in houses is significantly different from the lighting conditions in a bird’s natural habitat. This may lead to behavioural and health problems in birds, adversely affecting their wellbeing. This study investigated how white, blue, yellow, and red LED lights applied at the beginning of the dark cycle of the photoperiod affected the behaviours of budgerigars. The results indicated that when offered the opportunity, the birds chose yellow light. The open field tests (OFT I and II) were used to assess the locomotion and exploratory behaviour of birds. The results of the OFT I test, which was performed with an unfamiliar object, indicated that the group experiencing yellow light was more self-confident. The birds in cages with blue light felt more comfortable and displayed more social behaviour. People will be able to use this new information to improve the living conditions of their pet budgerigars.

Abstract

This study examined the effects of exposure to coloured LED lights on some behavioural responses, food and water consumption, and live weight in budgerigars kept in captivity using behavioural tests to compare different lighting conditions. Budgerigars’ feeding, comfort, social, fear, and resting behaviours and behavioural reactions to a new environment were studied. Twelve male birds were assigned to four groups, with three birds in each group. They were provided with food and water ad libitum in wire cages at 25 ± 2 °C in a room. The study was conducted with 10 h of natural light, 6 h of LED light (white, blue, yellow, and red LED lights), and 8 h of darkness. Their behaviours in the cages were observed. Home cage avoidance (HCA) and two open field tests (OFT) were performed. No difference was observed in the LW and food consumption, but the blue and yellow groups consumed less water. The blue group displayed more comfort and social behaviours. In the HCA test, the red group demonstrated higher reactions. Furthermore, the birds in the yellow group stayed closer to the centre of the platform in the OFT I test, and they chose the compartment simulating their familiar environment in the OFT II test. Consequently, it was concluded that first yellow and then blue lights may be used to prevent stress-related problems for these birds. Our findings could be used to improve the hand-rearing conditions of captive budgerigars.

Nutrition of free-living Neotropical psittacine nestlings and implications for hand-feeding formulas

Psittacidae is one of the most endangered families of birds in the world. Knowledge of their nutrition is important for understanding their survival and productivity in the wild, as well as for their adequate husbandry under human care. Hand-rearing is a common practice for psittacines, however research on their nutrition is limited. We analysed the predicted metabolisable energy, crude protein, crude fat, minerals and the essential amino acid profiles of the crop contents from free-living nestlings of scarlet macaws (Ara macao) and red-and-green macaws (Ara chloropterus) from southeastern Peru, Cuban Amazons (Amazona leucocephala bahamensis) from the Bahamas, lilac-crowned Amazons (Amazona finschi) from northwestern Mexico and thick-billed parrots (Rhynchopsitta pachyrhyncha) from northern Mexico. The crop content of the different parrot species displayed remarkably similar nutritional profiles, considering their diversity in habitats, geographic ranges and food sources. The crude protein and crude fat concentrations in crop samples were particularly similar for the Ara and Amazona species, while the thick-billed parrot stood out for its higher crude fat and lower crude protein content. Wider variations were found among the concentrations of sodium (Na) and iron (Fe), proline and tryptophan. Compared with the requirements of 6-12 weeks leghorn chickens, all free-ranging parrot diets contained lower crude protein, calcium (Ca), potassium (P) and Na concentrations. The hand-feeding formulas contained lower crude fat, magnesium (Mg), arginine, valine and phenylalanine concentrations, as well as much higher levels of Ca and zinc (Zn), in comparison with parrot crop samples. Our data suggest that a single formulation could be used to hand-rear Ara and Amazona sp. of 3 weeks of age and older, while a different formulation would likely be more appropriated for Rhynchopsitta sp. Experimental studies should evaluate if increasing the concentration of crude fat, Mg, arginine, valine and phenylalanine enhances psittacine chick growth and health.

Bird Welfare in Zoos and Aquariums: General Insights across Industries

Animal welfare is a priority across accredited zoological institutions; however, historically, research has been prioritized for mammals. Bird-focused studies accounted for less than 10% of welfare research in zoos and aquariums over the last ten years. Due to the lack of scientific publications on bird welfare, zoo scientists and animal practitioners can look to other industries such as agriculture, laboratories, and companion animal research for insight. This qualitative review highlights findings across industries to inform animal care staff and scientists on the welfare needs of birds within zoos and aquariums. Specifically, the review includes an overview of research on different topics and a summary of key findings across nine resources that affect bird welfare. We also highlight areas where additional research is necessary. Future welfare research in zoos and aquariums should prioritize studies that consider a diversity of bird species across topics and work to identify animal-based measures with empirical evidence. Moving forward, research from other industries can help develop innovative research on bird welfare within zoos and aquariums.

Tracking Changes of Hidden Food: Spatial Pattern Learning in Two Macaw Species

Food availability may vary spatially and temporally within an environment. Efficiency in locating alternative food sources using spatial information (e.g., distribution patterns) may vary according to a species’ diet and habitat specialisation. Hypothetically, more generalist species would learn faster than more specialist species due to being more explorative when changes occur. We tested this hypothesis in two closely related macaw species, differing in their degree of diet and habitat specialisation; the more generalist Great Green Macaw and the more specialist Blue-throated Macaw. We examined their spatial pattern learning performance under predictable temporal and spatial change, using a ‘poke box’ that contained hidden food placed within wells. Each week, the rewarded wells formed two patterns (A and B), which were changed on a mid-week schedule. We found that the two patterns varied in their difficulty. We also found that the more generalist Great Green Macaws took fewer trials to learn the easier pattern and made more mean correct responses in the difficult pattern than the more specialist Blue-throated Macaws, thus supporting our hypothesis. The better learning performance of the Great Green Macaws may be explained by more exploration and trading-off accuracy for speed. These results suggest how variation in diet and habitat specialisation may relate to a species’ ability to adapt to spatial variation in food availability.

Impact of Dietary Fructose on the Lipid Profile in Six Macaws

Atherosclerosis is frequently diagnosed in captive parrots. Recent studies have highlighted the potential role of high fructose intake in the development of human cardiovascular disease. The objective of this study was to investigate the effects of dietary fructose on the lipid profile in psittacine birds. Six macaws, composed of 3 green-winged macaws (Ara chloropterus, 2 females, 1 male), and 3 blue-and-gold macaws (Ara ararauna, 1 female, 2 males), ranging from 15 to 26 years of age, were used as subject animals for this dietary investigation. Initially, fruits were removed from the diet and replaced with vegetables lower in fructose for a month. Then, with a crossover study design, each bird was randomly selected to receive either 34 kcal of a fructose solution daily for 5 days then an equivalent volume of water for 5 days, or water in the first 5 days followed by the 34 kcal fructose solution. Lipid profiles were repeatedly performed over the course of the study at specific intervals. Serum cholesterol (3.01-5.55 mmol/L), triglycerides (0.27-2.70 mmol/L), high-density lipoprotein-cholesterol (1.43-4.79 mmol/L), low-density lipoprotein-cholesterol (0.02-0.85 mmol/L), and very low density lipoprotein-cholesterol (0.12-1.22 mmol/L) levels were not statistically significantly different over time and treatment. Although no significant effect could be demonstrated in this study, further studies are needed to investigate the effect of a high fructose intake in psittacine birds, because it could have a deleterious influence on their cardiovascular health if proven to be linked with dyslipidemia as reported in humans. Higher amounts of fructose and longer periods of administration should be considered for future studies.

Medical Causes of Feather Damaging Behavior

Feather damaging behavior (FDB), also referred to as feather picking, feather plucking, or pterotillomania, is one of the most common and frustrating clinical presentations in captive psittacines. The clinical approach to identify underlying medical conditions associated with FDB is reviewed. Primary feather or skin diseases as well as systemic diseases may lead to this syndrome. This article focuses on the medical causes of FDB documented in the current avian literature. Medical causes are presented using the VITAMIN D algorithm. Key components of the multifaceted therapeutic approach in managing FDB of medical origin are discussed.

Fatty acid profiles of crop contents of free-living psittacine nestlings and of commercial hand-feeding formulas

Research on psittacine nutrition is limited, and nestling requirements are poorly understood. This study analysed fatty acid (FA) profiles of crop contents of free-living scarlet macaws (Ara macao, n = 18), red-and-green macaws (Ara chloropterus, n = 5), Cuban parrots (Amazona leucocephala bahamensis, n = 27), lilac-crowned Amazons (Amazona finschi, n = 33) and thick-billed parrots (Rhynchopsitta pachyrhyncha, n = 32). The same analysis was carried out on 15 commercial parrot hand-feeding formulas. The mean FA concentration of the crop samples of each species ranged from 15% to 53% DM for crop samples and ranged from 6% to 22% for hand-feeding formulas. Long-chain FA represented over 92% of all FA in the crop samples and over 81% of all FA in the commercial formulas. Parrot species shared similarities in saturation profiles of crop samples, ranging between 13%-29% saturated fatty acids (SFA), 12%-40% monounsaturated fatty acids (MUFA) and 39%-58% polyunsaturated fatty acids (PUFA). All studied psittacines, except for the red-and-green macaw, were within the range of values for hand-rearing formulas. Palmitic acid was the most common SFA in scarlet macaws, red-and-green macaws, Cuban parrot, thick-billed parrot and in all but one commercial formula. Palmitic and stearic acids dominated the SFA in the samples of the Lilac-crowned Amazon. Oleic acid was the most common MUFA in all hand-feeding formulas as well as in the crop samples, except for the lilac-crowned amazon and the thick-billed parrot where vaccenic acid dominated. Linoleic acid was by far the most common PUFA found in the crop samples as well as in the hand-feeding formulas. PUFA were largely dominated by the n6 family, both in the crop samples and the formulas. The data presented on nestling diets of free-living parrot species provide a foundation for future researchers to test whether increasing FA concentration in hand-feeding formulas improves nestling development or if species-specific formulas will be advantageous.

Land Sparing Can Maintain Bird Diversity in Northeastern Bangladesh

One of humanity’s most significant challenges in the process of attaining the established sustainability goals is balancing the growing human demand for food and the need to conserve biodiversity. This challenge requires appropriate land uses that are able to conserve biodiversity while ensuring ample food supply. This study compares bird species diversity and abundance in areas undergoing land sharing and land sparing in northeastern Bangladesh (West Bhanugach Reserved Forest). Birds serve as useful biologic indicators because of their presence within different trophic levels and their well-studied ecology. To survey birds, we selected a total of 66 sampling sites within land-sharing (33) and land-sparing (33) land-use areas. Between May and June 2017, we observed and recorded bird calls within a 50-m radius around each sampling site. We counted 541 individuals from 46 species of birds. The Shannon bird diversity was higher in the land-sparing sites (1.52) than in the land-sharing sites (1.23). We found approximately 30% more bird species (39 vs. 30) and 40% more individuals (318 vs. 223) in the land-sparing areas than land-sharing areas. Three bird species, Arachnothera longirostra, Micropternus brachyurus and Copsychus malabaricus, were significantly associated with the land-sparing sites. This study shows that land sharing negatively affects bird diversity, richness and abundance compared to land-sparing. The use of chemical fertilizers and the lack of food, such as insects, for birds can explain the lower diversity, richness and abundance of birds in the land-sharing areas. Although land sharing is an effective means of producing food, land sparing is the most effective land-use practice for preserving bird diversity in northeastern Bangladesh.

Assessment of Three Diet Types on Constitutive Immune Parameters in Captive Budgerigar (Melopsittacus undulatus)

Proper diet and nutrition are essential for maintaining the health of captive birds, but specific nutritional requirements can vary by species. Our knowledge of avian nutrition is predominantly based on data collected from gallinaceous birds, which is the primary basis for the dietary recommendations for companion birds, such as budgerigars (Melopsittacus undulatus) and other psittacine birds, potentially leading to a higher risk of malnutrition. In the wild, budgerigars eat predominantly Australian grass seed of the Astrebla genus, which may not be similar to the commercially available food fed to captive budgerigars, both in nutrient content and in their physiologic effects. In this study, we examined the relationship between diet type and immune function by separating 36 budgerigars into 3 dietary treatments: 1) Roudybush formulated pellet diet (Roudybush BirdFood Inc, Woodland, CA, USA), 2) Kaytee Forti-Diet Pro Health seed mix (Kaytee Products Inc, Chilton, WI, USA), and 3) a natural seed diet containing fresh canary grass, flax, nyger, oat groats, and white millet seeds. We monitored body weight, measured the microbial killing ability of whole blood by Escherichia coli and Candida albicans, and collected blood smears to assess white blood cell counts during a period of 8 weeks. Overall, we observed no significant effects of the 3 different diets on bird microbial killing ability or on white blood cell counts, suggesting similar health outcomes for budgerigars that consume mixed seed and those that receive pellet-based diets during this relatively short-term study.

Chick growth and nutrient requirement during rearing period on eclectus parrot (Eclectus roratus, Müller 1776)

Nutrition is an important aspect of the successful breeding of wild birds in captivity. This research aims to find out nestling growth of Eclectus parrot (Eclectus roratus, Müller 1776) by parent-reared and nutrient requirement during rearing season. This research used a pair of Eclectus parrot with a male chick at first and fifth clutch, and female chick at the second, third, and fourth clutch. This research was conducted from July 2016 to June 2018. The bodyweight of chick was measured every week and feed intake was observed since the age of one week until the chick can eat independently. Feed was provided ad libitum and cafeteria. The chick was the altricial type. Feathers began to cover all bodies at weeks 9. Fledging time was approximately at weeks 10-11. Chick could be separated from its parents at 20 weeks of age. Feed intake tends to be increased along with the increasing age of chick. Eclectus favorites feed is sunflower seed. Nutrient consumption when rearing male chick is more than rearing the female chick.

Whole organism concentration ratios of radionuclides and metals in terrestrial vertebrates of an Australian tropical savanna environment

Preliminary values of whole organism concentration ratio (CR_wo-soil) were derived for terrestrial vertebrates of an Australian tropical savanna environment. Wildlife groups included bird, bat, ground-dwelling mammal and reptile. Sample data for some of the wildlife groups (bird and bat in particular) were limited. The bird and bat CR_wo-soil values were generally lower than the ground-dwelling mammal and reptile CR_wo-soil values based on the available data. Arithmetic mean CR_wo-soil values for two species of native marsupial and two species of non-native placental were not significantly different (p < 0.05) when tested using a one-way analysis of variance. The results hinted at possible sampling efficiencies for terrestrial vertebrates. However, verification with additional data was recommended. Used cautiously, the CR_wo-soil values may assist in environmental assessments of Australian uranium mining sites. They also enhance the available data on radionuclide transfer to wildlife for use internationally.

Inclusion of Madagascar cockroach (Gromphadorhina portentosa) meal in the diet of cockatiels (Nymphicus hollandicus) in captivity: Influences on offspring development

The use of unconventional food for animals is becoming more common. The objective was to evaluate the inclusion of Madagascar cockroach (Gromphadorhina portentosa) meal in the diet of cockatiel (Nymphicus hollandicus) chicks in captivity. Twenty-eight cockatiel chicks were used during 90 days of experiment. The animals were divided into two groups: a control group (receiving commercial feed + seed mixture) and a test group (receiving a control diet supplemented with Madagascar cockroach meal). The cockroach meal was mixed into commercial feed at a ratio of 14:1 (commercial feed: cockroach meal; 6.6% inclusion). Parents of the chicks were fed the experimental diets 30 days before egg laying to evaluate the influence of the cockroach meal on offspring development in the nest (1 to 30 days of age). Body development of the birds was evaluated every three days from the first to the 30th day of age and then every 15 days from the 31st to the 90th day of age. The cockroach meal did not influence (P > .05) the growth characteristics, body weight, total length or length of the animal's beaks, wings or tails, but increased seed consumption from the 31st to the 90th day of age. It is concluded that the cockroach meal can be used in the diet of growing cockatiels at an addition level of 6.6%.

Reproductive Characteristics of Cockatiels (Nymphicus hollandicus) Maintained in Captivityand Receiving Madagascar Cockroach (Gromphadorhina portentosa) Meal

The aim of this study was to evaluate the use of a Madagascar cockroach (Gromphadorhina portentosa) meal in the feed of cockatiels (Nymphicus hollandicus) in captivity and its influence on the reproductive characteristics of these birds. Twelve pairs of birds were used during two subsequent reproductive cycles of 130 days each, with time divided into four phases: laying, incubation, rearing of chicks until 30 days of age, and return to the new laying phase. The pairs were divided into two groups: a control group, which received a commercial diet for psittacines + a mixture of seeds, and a test group, which received the same diet as the control group except for the addition of a Madagascar cockroach meal in a ratio of 14 g of commercial food to 1 g of cockroach meal (6.6%). After hatching, chicks remained with their parents until 30 days of age. Subsequently, the chicks were transferred to another room and monitored until the 90th day of life. The inclusion of cockroach meal did not influence (p > 0.05) the intake of commercial food and mixture of seeds during the reproductive phases evaluated, except for feed intake, which was increased relative to control values (p = 0.02) in the return-to-laying phase. Yolk cholesterol content, egg width and egg shape index were increased with the inclusion of the cockroach meal, whereas the number of days to return to the new laying phase was reduced compared to the control (p = 0.02). The number of eggs laid decreased (p < 0.05) with the inclusion of the cockroach meal; however, the percentage of hatching was higher in the test group than in the control group (p < 0.05). No significant effect (p > 0.05) of dietary treatment was observed on the number of viable chicks at 1, 30 and 90 days of age or on the contents of most fatty acids present in the yolk. The findings of this study indicate that a Madagascar cockroach meal can be used as an alternative feedstuff in the diets for cockatiels and can lead to minor improvements in reproductive characteristics when replacing 6.6% of the commercial pelleted diet.

A Guide to Using Compound-Specific Stable Isotope Analysis to Study the Fates of Molecules in Organisms and Ecosystems

The measurement of stable isotopes in ‘bulk’ animal and plant tissues (e.g., muscle or leaf) has become an important tool for studies of functional diversity from organismal to continental scales. In consumers, isotope values reflect their diet, trophic position, physiological state, and geographic location. However, interpretation of bulk tissue isotope values can be confounded by variation in primary producer baseline values and by overlapping values among potential food items. To resolve these issues, biologists increasingly use compound-specific isotope analysis (CSIA), in which the isotope values of monomers that constitute a macromolecule (e.g., amino acids in protein) are measured. In this review, we provide the theoretical underpinnings for CSIA, summarize its methodology and recent applications, and identify future research directions. The key principle is that some monomers are reliably routed directly from the diet into animal tissue, whereas others are biochemically transformed during assimilation. As a result, CSIA of consumer tissue simultaneously provides information about an animal’s nutrient sources (e.g., food items or contributions from gut microbes) and its physiology (e.g., nitrogen excretion mode). In combination, these data clarify many of the confounding issues in bulk analysis and enable novel precision for tracing nutrient and energy flow within and among organisms and ecosystems.

Feeding cluster preferences in four genera of Lories and Lorikeets (Loriinae) that should be considered in the diet of nectarivorous psittacine species in captivity

Lories and lorikeets are popular birds in the pet bird trade, captured from the wild and exported worldwide. Their captive propagation has not been so successful for many species due to health issues, low breeding success and reduced longevity. As a result, uptake from the wild is currently the only way to meet the market's demand. Field studies on Asian species of loris and lorikeets are limited; therefore, dietary recommendations are based on the well-studied Australian species such as the rainbow lorikeet (Trichoglossus moluccanus). We aimed to provide an ad libitum diet to diverse Loriinae species at Jurong Bird Park (Singapore) which allowed for them to select between a low and moderate protein diet to compare their nutrient and energy intake with other Loriinae species. We measured the following variables: daily dry matter (DM) intake, nectar-to-fruit energy intake ratio (NF ratio), metabolisable energy (ME), protein and non-protein energy (NPE)-to-protein energy (PE) ratio intake (all by kg metabolic body weight MBW, kg^0.75 ) for 36 pairs over a 1-month period. A Kruskal-Wallis test revealed every genus had significantly different intakes of DM, NF ratio, NPE-to-PE ratio, ME and protein than each other. Post hoc Mann-Whitney U tests confirmed that the majority of variables were ingested in different amounts for each genus except for NF ratio, NPE/PE ratio which Lorius spp. are not different to Charmosyna sp. or Trichoglossus spp. and protein intake of Eos spp. does not differ from Trichoglossus spp. Our conclusion is that no species should be used as a model for a species from another genus of Loriinae; future studies should be species-specific for each genus to increase captive propagation success.

Feed processing effects on digestibility, palatability, excreta fermentation products and blood parameters in blue-fronted amazon parrots (Amazona aestiva)†

Captive parrots show a high incidence of obesity and other metabolic disorders due to the consumption of unbalanced diets. Therefore, this study evaluated the digestibility and metabolic effects of transitioning blue-fronted amazons from a high fat diet (sunflower seeds) to processed diets with three degrees of starch gelatinization (SG). The same feed formulation was processed to obtain pelletized feed (PEL) at 27.1% SG; low-cooked extruded feed (EXT_L ) at 81.6% SG; and high-cooked extruded feed (EXT_H ) at 98.5% SG. Thirty adult parrots were fed sunflower seeds for 90 days, then were distributed in a completely randomized design with 10 repetitions per treatment, and fed one of the three prepared diets for 160 days. Feed palatability, apparent digestibility, excreta concentrations of volatile fatty acids, lactate and ammonia, initial and final radiographic examinations, blood cell counts and glucose, triglycerides, cholesterol, total protein, albumin, aspartate aminotransferase (AST) and uric acid levels were evaluated. The data were analysed by an analysis of variance and compared by Tukey's test (p < 0.05). Sunflower seed was more digestible than processed feeds (p < 0.05). Diet processing interfered with fat and starch digestibility (p < 0.001), being higher in the PEL than in the EXT_H and EXT_L respectively. Transitioning from sunflower seeds to balanced diets reduced serum glucose, triglycerides, cholesterol and AST (p < 0.05) and increased red blood cell, haemoglobin, lymphocyte, monocyte and leucocyte counts (p < 0.01). Radiographs indicated a decreased hourglass (p = 0.015) and a reduced heart-liver ratio after ingesting the processed feeds (p < 0.05). Feed processing did not affect blood cell counts, serum biochemistry or radiographic examinations. In conclusion, parrots preferred the extruded diet and did not require an extensive SG to properly digest the feed. Consuming the processed diets improved the birds' metabolism and health.

IRON STORAGE DISEASE IN AFRICAN GREY PARROTS ( PSITTACUS ERITHACUS) EXPOSED TO A CARNIVOROUS DIET

Within a 2-wk period, three African grey parrots ( Psittacus erithacus) presented for emergency treatment. All three parrots had depressed behavior, an inability to fly, and significant weight loss. Plasma chemistry abnormalities included severe hypoproteinemia and elevated liver enzymes in all parrots. Two of the parrots died, and histologic examination with hematoxylin and eosin and Prussian blue stains revealed severe hepatic iron storage. Quantitative analysis confirmed high hepatic iron concentrations. Iron accumulation was attributed to ingestion of a carnivorous bird diet or selectively eating too much fruit and vegetables high in ascorbic acid. Management entailed husbandry changes including switching the remaining parrots to a low-iron diet. Psittacine species exposed to carnivorous bird diets are at risk of developing iron storage disease.

Isotope (δ13C, δ15N, δ2H) diet-tissue discrimination in African grey parrot Psittacus erithacus: implications for forensic studies

Diet-tissue isotopic relationships established under controlled conditions are informative for determining the dietary sources and geographic provenance of organisms. We analysed δ¹³C, δ¹⁵N, and non-exchangeable δ²H values of captive African grey parrot Psittacus erithacus feathers grown on a fixed mixed-diet and borehole water. Diet-feather Δ¹³C and Δ¹⁵N discrimination values were +3.8 ± 0.3 ‰ and +6.3 ± 0.7 ‰ respectively; significantly greater than expected. Non-exchangeable δ²H feather values (-62.4 ± 6.4 ‰) were more negative than water (-26.1 ± 2.5 ‰) offered during feather growth. There was no positive relationship between the δ¹³C and δ¹⁵N values of the samples along each feather with the associated samples of food offered, or the feather non-exchangeable hydrogen isotope values with δ²H values of water, emphasising the complex processes involved in carbohydrate, protein, and income water routing to feather growth. Understanding the isotopic relationship between diet and feathers may provide greater clarity in the use of stable isotopes in feathers as a tool in determining origins of captive and wild-caught African grey parrots, a species that is widespread in aviculture and faces significant threats to wild populations. We suggest that these isotopic results, determined even in controlled laboratory conditions, be used with caution.

Water requirements and drinking rates of homing pigeons: A consideration for exposure risk of migratory birds

Access to water along a bird's migratory flyway is essential during the vital process of migration. Because of the scarcity of water in some environments, there is potential for migratory birds to encounter and drink from contaminated bodies of water. Ingestion of contaminated water may cause injury and compromise flying ability, leading to a disruption of migration. To determine injury to birds from potential exposure, it is essential to know not only the concentration of a given contaminant in the water but also the quantity and rate of water consumption by the birds. Homing pigeons (Columba livia) were used in a series of experiments to determine differences in drinking behavior after various flights and after periods of resting. Results from the present study demonstrate that homing pigeons' water consumption is dramatically different when assessed according to activity, flight distance, and time elapsed after flight. This suggests that the drinking rates of birds during migration are extremely important and much greater than estimated using traditional exposure assessment procedures. Thus, exposure to contaminants via drinking water may be greatly underestimated, and the rate of water consumption should be considered when estimating potential exposure risk to avian species. Integr Environ Assess Manag 2017;13:870-876. © 2017 SETAC.

Use of collard green stalks as environmental enrichment for cockatiels ( Nymphicus hollandicus ) kept in captivity

ABSTRACT The objective of this study was to evaluate the influence of collard green stalks as environmental enrichment on the behavior of cockatiels (Nymphicus hollandicus) maintained in captivity. Sixteen birds were housed individually in cages and fed a commercial diet for parrots and seed mix, with water ad libitum during 12 days in climatic chamber with temperature and relative humidity simulating tropical conditions. The animals (n = 8) were divided into two groups, control and enriched, and the experimental period was divided into two phases (during and after enrichment) of four days each. The collard green stalks were used as enrichment only during the first period of the experiment, daily changed and maintained only during the day. The stalks increased the feed intake and decreased the sleep activities. No effect was observed on the body surface temperature, locomotion, maintenance and other resting activities. Small undesirable activities were detected. It was concluded that collard green stalks can be used as environmental enrichment, becoming part of food preferences of cockatiels. However, its use does not significantly alter the behavior of birds kept in captivity

Food preferences of cockatiel chicks ( Nymphicus hollandicus ) in captivity

ABSTRACT In order to improve the management and maintenance of the quality of life of captive wild birds, this study aimed to assess the food preferences of cockatiel chicks (Nymphicus hollandicus) kept in captivity. Thirty-two cockatiel chicks, three to 12 months of age, were kept in a galvanized, wire-netted vivarium with six ceramic feeders, two for an extruded diet, two for a dry-mashed diet and two for a seed mixture. Both extruded and dry-mashed food are commercial psittacine diets. Three round ceramic pots were used to provide water. The birds were exposed to 12 hours of artificial light (40 W incandescent lamps) during the experimental period of 27 days. The birds were observed by video filming, daily, through an ad libitum observation technique. The food consumption was 3.34±0.42g/bird/day of extruded feed, 1.58±0.44g/bird/day of dry-mashed diet and 3.73±0.10g/bird/day of seed mixture. In conclusion, the cockatiel chicks preferred the seed mixture and the extruded food over the dry-mashed diet.

Frequent fires reduce the nutritional quality of Sorghum stipoideum seed, a keystone food resource for the Gouldian finch (Erythrura gouldiae)

Fire is a pervasive feature of the tropical savannas of northern Australia. Increasingly extensive and intensive fires have had an adverse effect on grass layer diversity. Reduced grass species diversity and abundance are important correlates of the decline of granivores in these tropical savannas. The Gouldian finch (Erythrura gouldiae), an endangered species that is endemic to northern Australia, is particularly vulnerable to changes to the grass layer as its diet comprises only grass seed, and it relies mostly on Sorghum stipoideum during the breeding season. Although this annual grass species is abundant at breeding sites, the finches do not always choose to breed at these sites, raising the possibility that seed quality may vary from year to year. This study examines the effect of fire (time since last fire; fire frequency) on soil fertility and seed nutritional quality. We hypothesise that recently burnt sites produce a flush of soil nutrients and Sorghum stipoideum seed at these sites is of higher nutritional quality. Furthermore, we posit that frequently burnt sites become depleted of soil nutrients and their seeds are of lower nutritional quality. There was a significant increase in inorganic nitrogen in soils following a fire, but no notable change in other soil nutrients. Contingent on this increase in soil inorganic nitrogen, seed nutrient levels, particularly essential proteins, were greater at sites that were recently, but infrequently burnt. Fires appear to affect soil nitrogen and in turn seed nutrition, providing a plausible explanation for why Gouldian finches choose recently, but infrequently burnt breeding sites.

Effect of feeding graded levels of crude protein on nutrient utilization and feather growth in Lady Amherst's pheasants

In order to find out the optimum level of crude protein (CP) in the diet of captive Lady Amherst's pheasants (LAP) on molt, 18 male birds were randomly distributed into three groups of six each in an experiment based on completely randomized block design. The CP content of the diets of birds in groups I, II, and III was 13.4, 16.5, and 19.1%, respectively. Intake and apparent balance of nitrogen increased linearly (P < 0.001) as CP content of the diet increased. Intake and utilization of energy, calcium, and phosphorous were similar among groups. Body mass change and growth rate of feathers were significantly (P < 0.01) lower in group I as compared to groups II and III. There was a positive co-relationship between ME intake and change in body weight (R(2) = 0.89, F = 126.4, P < 0.001). Regression analysis indicates that LAP can maintain body mass when ME supply is 122.2 Kcal/kg BW(0.75)/d. Linear relationships between intake and apparent retention of N, Ca, and P as expressed on mg/kg BW(0.75)/d were all significant. Apparent nitrogen retention, and mean feather growth rate was lower in birds fed diet containing 13.4% CP. Feeding of the diets containing 16.5% CP resulted in improved retention of nitrogen, and mean feather growth rate. Further increase in dietary concentration of CP to 19.1% showed no further improvement. It was concluded that a diet containing 16.5% CP would be optimum for Lady Amherst's pheasants during molt.

Psittacine wellness management and environmental enrichment

The goal of this article is to present practical ways to provide a healthier lifestyle to the commonly kept companion psittacine pets. Necessary information for bird owners to provide for the physical and mental health of their bird is presented. This information is exquisitely important for people keeping birds as pets to know and apply. It is the exotic veterinarian's responsibility to educate clients on how to provide properly for the pet's mental and physical well-being.

Cockatiel Transition From a Seed-based to a Complete Diet

To determine the effects of diet transition in cockatiels ( Nymphicus hollandicus ), 14 cockatiels were transitioned over a 12-day period from a seed diet to one of 2 commercial diets advertised as nutritionally complete. Before the transition, cockatiels were fed a seed-based diet for 30 days. The transition strategy consisted of gradually increasing the ratio of complete diet : seed-based diet over the 12-day period. True amino acid digestibility determined on each complete diet (diets A and B) demonstrated that both diets contained highly digestible amino acids. Diets differed in ingredient composition and particle size, analyzed nutrients, and method of processing (baked or extruded). Daily feed intake of seed-based and complete diets was measured. Periodically throughout and after transition, body weights were measured, and blood samples were collected for hematologic testing and plasma biochemical analysis. All cockatiels accepted the transition strategy irrespective of complete diet. Cockatiels transitioned to diet A consumed significantly more of the complete diet and less of the seed-based diet during periods of measurement throughout transition. Total feed intake was significantly greater for cockatiels fed diet B for 33% of the measurement periods (P < .05). Body weight was generally not affected during or after transition (P > .05). Hematologic and plasma biochemical values did not differ between cockatiels fed the 2 complete diets (P > .05). It may be speculated that cockatiels were more accepting of diet A during transition, and diet A more efficiently maintained body weight.

Oxidative stress, activity behaviour and body mass in captive parrots

Many parrot species are kept in captivity for conservation, but often show poor reproduction, health and survival. These traits are known to be influenced by oxidative stress, the imbalance between the production of reactive oxygen species (ROS) and ability of antioxidant defences to ameliorate ROS damage. In humans, oxidative stress is linked with obesity, lack of exercise and poor nutrition, all of which are common in captive animals. Here, we tested whether small parrots (budgerigars, Melopsittacus undulatus) maintained in typical pet cages and on ad libitum food varied in oxidative profile, behaviour and body mass. Importantly, as with many birds held in captivity, they did not have enough space to engage in extensive free flight. Four types of oxidative damage, single-stranded DNA breaks (low-pH comet assay), alkali-labile sites in DNA (high-pH comet assay), sensitivity of DNA to ROS (H2O2-treated comet assay) and malondialdehyde (a byproduct of lipid peroxidation), were uncorrelated with each other and with plasma concentrations of dietary antioxidants. Without strenuous exercise over 28 days in a relatively small cage, more naturally 'active' individuals had more single-stranded DNA breaks than sedentary birds. High body mass at the start or end of the experiment, coupled with substantial mass gain, were all associated with raised sensitivity of DNA to ROS. Thus, high body mass in these captive birds was associated with oxidative damage. These birds were not lacking dietary antioxidants, because final body mass was positively related to plasma levels of retinol, zeaxanthin and α-tocopherol. Individuals varied widely in activity levels, feeding behaviour, mass gain and oxidative profile despite standardized living conditions. DNA damage is often associated with poor immunocompetence, low fertility and faster ageing. Thus, we have candidate mechanisms for the limited lifespan and fecundity common to many birds kept for conservation purposes.

Clinical avian nutrition

Psittacine birds eat plant-based foods. Birds in the wild seem to be able to balance their energy needs, amino acids, and calcium. Companion birds in captivity do not do as well when self-selecting, and balanced diets are needed to improve their general health. A nutritional history is important to determine whether the avian patient is in balance nutritionally. Understanding the various sources of the fat-soluble vitamins, calcium, and protein will help guide clients to provide nutritious foods for their birds. Owners need to learn to use foraging as a major source of their bird's diet and techniques.

Feather loss and feather destructive behavior in pet birds

Feather loss in psittacine birds is a common and frustrating clinical presentation. Causes include medical and nonmedical causes of feather loss with and without overt feather destructive behavior. Underlying causes include inappropriate husbandry and housing; parasitic, viral and bacterial infections; metabolic and allergic diseases; and behavioral disorders. Prior to a diagnosis of a behavioral disorder, medical causes of feather loss must be excluded through a complete medical work-up including history, physical examination, and diagnostic testing. This article focuses on common medical and nonmedical causes of feather loss and feather destructive behavior and approaches to diagnosis and treatment.

Experimental evidence of impacts of an invasive parakeet on foraging behavior of native birds

Invasive rose-ringed parakeets caused behavioral changes in native garden birds that reduced their feeding rates. Understanding how invasive species impact native species can be complex, especially in urban environments where many other factors are also at play. We therefore used an experiment to disentangle these factors and demonstrate that parakeets are more disruptive than a dominant native competitor.

Resource competition is one potential behavioral mechanism by which invasive species can impact native species, but detecting this competition can be difficult due to the interactions that variable environmental conditions can have on species behavior. This is particularly the case in urban habitats where the disturbed environment can alter natural behavior from that in undisturbed habitats. The rose-ringed parakeet (Psittacula krameri), is an increasingly common invasive species, predominantly associated with large urban centers. Using an experimental approach, we tested the behavioral responses of native garden birds in response to the presence of a rose-ringed parakeet versus the presence of a similarly sized and dominant native bird, the great spotted woodpecker (Dendrocopos major). Parakeet presence significantly reduced feeding rates and increased vigilance among native birds compared with our control treatments. Of visits made by native birds in the presence of a parakeet, feeding was more likely to occur in sites within the parakeet range compared with sites outside, suggesting some habituation of native birds has occurred following prior exposure to parakeets but overall foraging behavior is still disrupted. The results of our study suggest that nonnative species can have complex and subtle impacts on native fauna and show that a nonnative competitor can impact native species simply through their presence near resources.

Nutritional and physical characteristics of commercial hand-feeding formulas for parrots

Hand-rearing is a common practice for the propagation of captive psittacines, however, research on their nutrition is limited and the requirements of growing chicks are not well understood. The nutrition of 15 commercially available parrot hand-feeding formulas was compared with the average content of the crops of free living Scarlet Macaw (Ara macao) chicks, as well as with the requirements of 6- to 12-week-old leghorn chickens. When the formulas were prepared for a 1-week-old chick, all except three maintained >90% of solids in suspension after 15 min and >60 after 30 min. On average the formulas had a similar metabolizable energy density as wild macaw crop samples. The concentration of crude protein in the formulas was higher than that of the crop sample average, while the crude fat was lower than the average crop samples. More than 50% of the formulas had concentrations of K, Mg, and Mn less than the crop sample average, and Ca and Na concentrations below the requirements established for 6- to 12-week-old leghorn chickens. For >45% of the formulas the concentrations of arginine, leucine, and methionine + cystine were below the requirements of 6- to 12-week leghorns. When commercial formulas were prepared according to the manufacturer's instructions, the different dilutions greatly magnified the nutritional differences among them. Overall, the inconsistency in the nutrient concentrations among the formulas suggests that there is no consensus among manufacturers of the correct nutrition for growing psittacines and the industry could benefit from continued research in this area.

Pine as fast food: foraging ecology of an endangered cockatoo in a forestry landscape

Pine plantations near Perth, Western Australia have provided an important food source for endangered Carnaby’s Cockatoos (Calyptorhynchus latirostris) since the 1940s. Plans to harvest these plantations without re-planting will remove this food source by 2031 or earlier. To assess the impact of pine removal, we studied the ecological association between Carnaby’s Cockatoos and pine using behavioural, nutritional, and phenological data. Pine plantations provided high densities of seed (158 025 seeds ha⁻¹) over a large area (c. 15 000 ha). Carnaby’s Cockatoos fed throughout these plantations and removed almost the entire annual crop of pine cones. Peak cockatoo abundance coincided with pine seed maturation. Pine seed had energy and protein contents equivalent to native food sources and, critically, is available in summer when breeding pairs have young offspring to feed. This strong and enduring ecological association clearly suggests that removing pine will have a significant impact on this endangered species unless restoration strategies, to establish alternative food sources, are implemented.

Means-end comprehension in four parrot species: explained by social complexity

A comparative approach is required to investigate the evolutionary origins of cognitive abilities. In this paper, we compare the performance of four parrot species, spectacled parrotlets (Forpus conspicillatus), rainbow lorikeets (Trichoglossus haematodus), green-winged macaws (Ara chloroptera) and sulphur-crested cockatoos (Cacatua galerita triton) in standardized string-pulling and string-choice paradigms. We varied the spatial relationship between the strings, the presence of a reward and the physical contact between the string and the reward to test different cognitive skills requiring means-end comprehension. The species tested showed a high individual and inter-specific variation in their ability to solve the tasks. Spectacled parrotlets performed best among the four species and solved the most complex choice tasks, namely crossed-string task and broken-string task, spontaneously. In contrast, macaws and cockatoos failed to identify the correct string in these two tasks. The rainbow lorikeets were outperformed by the parrotlets, but outperformed in turn the macaws and the cockatoos. The findings can be best explained by the variation in social complexity among species, rather than in their ecology.

Ventricular diverticula formation in captive parakeet auklets (Aethia psittacula) secondary to foreign body ingestion

A captive parakeet auklet at the North Carolina Zoo evaluated for weight loss, lethargy, and dyspnea had radiographic evidence of a distended, stone-filled ventriculus (bird 1). Multiple stones (n = 76) were removed surgically, but the bird died and a large ventricular diverticulum was diagnosed at necropsy. This bird and seven other parakeet auklets had been transferred 3 yr earlier from a zoo in Ohio. Radiographic investigation revealed that 6 of 7 Ohio birds had stones in their ventriculus (n= 2-26), but only 1 of 7 radiographed North Carolina Zoo auklets had one small stone. Further diagnostic imaging (survey and contrast radiographs, fluoroscopy, CT scans [n = 2]) of six Ohio and two North Carolina birds was conducted to determine if other birds had ventricular abnormalities (birds 2-9). No ventricular diverticula were diagnosed using imaging techniques, although two Ohio birds (birds 6 and 7) required surgical intervention to remove 12-26 stones. A small ventricular diverticulum was identified in bird 6 during surgery. That bird died of unrelated causes 11 mo after surgery, but bird 7 remains clinically normal more than 4 yr later, along with four other auklets with stones (n = 2-15; birds 2-5). It is possible that without surgical intervention, these birds may develop ventricular disease, presumably due to chronic mechanical trauma to the thin-walled ventriculus. It was hypothesized that the Ohio birds ingested stones in their previous exhibit, with a loose stone substrate, and retained them for at least 3 yr. Possible causes for stone ingestion include trituration (for grinding, mixing coarse ingesta), gastric parasite reduction, hunger suppression, accidental ingestion while feeding, or behavioral causes, but the underlying cause in these birds was not determined. Based on these results, parakeet auklets and other alcids should not be housed, or at least fed, on a loose stone substrate.