African Grey Research Articles

Development and validation of 2 probe-hybridization quantitative PCR assays for rapid detection of a pathogenic Coxiella species in captive psittacines.

Avian coxiellosis is an emerging cause of morbidity and mortality among captive psittacines, and the utility of a rapid detection test using easily obtained samples is paramount in a clinical setting. New sequences were obtained from 3 genes: groEL, dnaK, and rpoB. We developed probe-hybridization quantitative PCR (qPCR) assays using groEL and dnaK genes. Samples, including splenic aspirates, liver aspirates, whole blood, and choanal, conjunctival, and cloacal swabs, were collected from 4 psittacine species including 3 blue-and-gold macaws (Ara ararauna), 2 scarlet-chested parrots (Neophema splendida), 1 Timneh African grey parrot (Psittacus timneh), and 1 yellow-naped Amazon parrot (Amazona auropalliata). Retrospective review of postmortem findings from 3 of these psittacines included splenomegaly, hepatitis, and/or transmission electron microscopy confirmation consistent with previous reports of avian coxiellosis. There was 100% agreement between these assays and consensus PCR with sequencing. A Wilcoxon rank-sum test found a strong correlation between groEL and dnaK cycle threshold values (p < 0.001), validating these assays for detection of this avian Coxiella sp.

Domestic parrots as a potential source of Mycobacteriosis

The article presents the results of bacteriological examination of five samples of feces from grey parrots (Psittacus) (n = 3), cockatoo (Cacatua) (n = 1), yellow-crowned amazon (Amazona) (n = 1). Five cultures of mycobacteria were bacteriologically isolated from the five samples. According to biochemical and cultural-morphological characteristics, mycobacterial cultures are classified as Mycobacterium scrofulaceum (n = 1) and Mycobacterium genavense (n = 4). Isolated cultures of mycobacteria are important in human pathology. Infected exotic poultry pose a potential risk of mycobacterial infection in their owners, so it is necessary to conduct research on biological material

Avian Papilloma and Squamous Cell Carcinoma: a Histopathological, Immunohistochemical and Virological study

In this retrospective study, we describe the histopathological findings in seven papillomas and 45 squamous cell carcinomas (SCCs) from psittacine birds, raptors and domestic fowl. The age of affected birds ranged from 3 to 40 years, with median age significantly higher in psittacines (P=0.014). The majority of tumours were located in the skin (24/52, 46.2%) or uropygial gland (10/52, 19.2%). Thirty of the SCCs (66.7%) were well differentiated and 15 (33.3%) were poorly-differentiated. SCCs exhibited a significantly higher degree of nuclear pleomorphism (P=0.005) and a greater proportion were ulcerated (P=0.001) compared with papillomas; however, there was no significant difference in mitotic count (MC) or inflammation score. The expression of cyclo-oxygenase (COX)-2 and E-cadherin was investigated by immunohistochemistry. The COX-2 total score (TS) was significantly higher in SCCs compared with papillomas (P=0.002), but the difference between COX-2 TS of well- and poorly-differentiated SCCs was not significant. COX-2 labelling was predominantly cytoplasmic, but some tumours had concurrent membranous and/or perinuclear labelling. SCCs with membranous labelling had a significantly higher MC (P=0.028). A significantly higher proportion of SCCs were negative for E-cadherin compared with papillomas (P=0.042), but there was no significant difference between well- and poorly-differentiated SCCs. Fourteen papillomas and SCCs from psittacines were also tested by polymerase chain reaction for the presence of Psittacus erithacus papillomavirus 1 and Psittacid herpesvirus 1, but all samples tested negative. We demonstrate for the first time the expression of COX-2 and E-cadherin in avian tissues, and suggest that these markers may be useful in differentiating papillomas from SCCs, particularly when sample size is small.

Parrots Voluntarily Help Each Other to Obtain Food Rewards

Helping others to obtain benefits, even at a cost to oneself, poses an evolutionary puzzle [1]. While kin selection explains such "selfless" acts among relatives, only reciprocity (paying back received favors) entails fitness benefits for unrelated individuals [2]. So far, experimental evidence for both prosocial helping (providing voluntary assistance for achieving an action-based goal) and reciprocity has been reported in a few mammals but no avian species [3]. In order to gain insights into the evolutionary origins of these behaviors, the capacity of non-mammalian species for prosociality and for reciprocity needs to be investigated. We tested two parrot species in an instrumental-helping paradigm involving "token transfer." Here, actors could provide tokens to their neighbor, who could exchange them with an experimenter forfood. To verify whether the parrots understood the task's contingencies, we systematically varied the presence of a partner and the possibility for exchange. We found that African grey parrots voluntarily and spontaneously transferred tokens to conspecific partners, whereas significantly fewer transfers occurred in the control conditions. Transfers were affected by the strength of the dyads' affiliation and partially by the receivers' attention-getting behaviors. Furthermore, the birds reciprocated the help once theroles were reversed. Blue-headed macaws, in contrast, transferred hardly any tokens. Species differences in social tolerance might explain this discrepancy. These findings show that instrumental helping based on a prosocial attitude, accompanied but potentially not sustained by reciprocity, is present in parrots, suggesting that this capacity evolved convergently in this avian group and mammals.

Testing microsatellite loci for individual identification of captive African grey parrots (Psittacus erithacus): a molecular tool for parentage analysis that will aid in monitoring legal trade

Populations of wild African Grey parrots (Psittacus erithacus) are declining rapidly driven by the removal of individuals for the pet trade and accelerated habitat destruction and fragmentation. African Greys are currently listed as Endangered on the IUCN Red list and are on Appendix I of CITES, which prohibits all trade in wild-caught individuals. The demand for these parrots in the pet trade can, however, be met through legal trade in captive-bred birds. Determining which birds are captive-bred is often challenging. Genetic techniques have recently become established as a valuable tool in providing accurate information on the paternity of any offspring produced in captivity. Another advantage of using molecular data is that genotypes can also be used for measuring the genetic diversity and degree of relatedness within the captive population to prevent inbreeding. In this study, we test the utility of a suite of previously published microsatellite markers as a molecular tool for parentage analysis. The panel of 11 loci was found to have sufficient discriminatory power to be used in parentage assignment. In this study we present a set of markers that can be used with confidence to determine if a bird has been bred from captive parents and so can be legally traded. These molecular markers were also tested for use on low amounts of DNA extracted from feathers to aid law enforcement authorities to better control legal and illegal trade of this endangered parrot species.

Characteristic viral inclusion bodies in psittacine beak and feather disease in a juvenile African grey parrot (Psittacus erithacus erithacus)

A 10-week-old African grey parrot ( Psittacus erithacus erithacus ) presented with a two-day history of weakness, anorexia, vomiting and diarrhoea. Radiography and endoscopy revealed opacities within the lungs and...

Assessing African grey parrots' prosocial tendencies in a token choice paradigm.

Prosociality is defined as a voluntary, typically low-cost behaviour that benefits another individual. Social tolerance has been proposed as a potential driver for its evolution, both on the proximate and on the ultimate level. Parrots are an interesting species to study such other-regarding behaviours, given that they are highly social and stand out in terms of relative brain size and cognitive capacity. We tested eight African grey parrots in a dyadic prosocial choice test. They faced a choice between two different tokens, a prosocial (actor and partner rewarded) and a selfish (only actor rewarded) one. We found that the birds did not behave prosocially when one subject remained in the actor role; however, when roles were alternated, the birds’ prosocial choices increased. The birds also seemed to reciprocate their partner's choices, given that a contingency between choices was observed. If the food provisioned to the partner was of higher quality than that the actor obtained, actors increased their willingness to provide food to their partner. Nonetheless, the control conditions suggest that the parrots did not fully understand the task's contingencies. In sum, African grey parrots show the potential for prosociality and reciprocity; however, considering their lack of understanding of the contingencies of the particular tasks used in this study, the underlying motivation for the observed behaviour remains to be addressed by future studies, in order to elucidate the phylogenetic distribution of prosociality further.

Comparative physiology of glomerular filtration rate by plasma clearance of exogenous creatinine and exo-iohexol in six different avian species

Early diagnosis of kidney diseases in avian species is limited. Endogenous markers currently used in avian practice are not sensitive enough to identify early kidney failure. Consequently, alternative markers should be evaluated. To be able to evaluate these alternative markers, an accurate marker to estimate the GFR should be validated. This study determined the GFR, measured as clearance of exogenous creatinine and exo-iohexol, in six different bird species, i.e. broiler chickens, laying chickens, turkeys, Muscovy ducks, pigeons and African grey parrots (4♀/4♂). To be able to compare the six bird species, normalization to bodyweight (BW) of the GFR was performed, after a good correlation between BW and kidney weight was demonstrated (R² = 0.9836). Clearance of exo-iohexol normalized to BW (mL/min/kg) was determined in all bird species, i.e. 3.09 in broiler chickens; 2.57 in laying chickens; 1.94 in turkeys; 1.29 in pigeons; 2.60 in ducks and 1.11 in parrots. However, these results differed significantly with the clearance of exogenous creatinine: 8.41 in broiler chickens; 9.33 in laying chickens; 5.62 in turkeys; 14.97 in pigeons; 17.59 in ducks and 25.56 in parrots 25.56. Iohexol is preferred to measure the GFR, since it is not prone to tubular reabsorption nor secretion.

What Frege asked Alex the parrot: inferentialism, number concepts, and animal cognition

ABSTRACTWhile there has been significant philosophical debate on whether nonlinguistic animals can possess conceptual capabilities, less time has been devoted to considering ‘talking’ animals, such as parrots. When they are discussed, their capabilities are often downplayed as mere mimicry. The most explicit philosophical example of this can be seen in Brandom’s frequent comparisons of parrots and thermostats. Brandom argues that because parrots (like thermostats) cannot grasp the implicit inferential connections between concepts, their vocal articulations do not actually have any conceptual content. In contrast, I argue that Pepperberg’s work with Alex (and other African gray parrots) provides evidence that the vocal articulations of at least some parrots have conceptual content. Using Frege’s insight that numbers assert something about a concept, I argue that Alex’s ability to answer the question “how many?” depended upon a prior grasp of conceptual content. Developing this claim, I argue that Alex’s arithmetical abilities show that he was capable of using numbers as both concepts and objects. Frege’s theoretical insight and Pepperberg’s empirical work provide reason to reconsider the capabilities of parrots, as well as what sorts of tasks provide evidence for conceptual content.

Parrots do not show inequity aversion

Inequity aversion, the negative reaction to unequal treatment, is considered a mechanism for stabilizing cooperative interactions between non-kin group members. However, this might only be adaptive for species that switch cooperative partners. Utilizing a comparative approach, inequity aversion has been assessed in many mammalian species and recently also in corvids and one parrot species, kea, revealing mixed results. To broaden our knowledge about the phylogenetic distribution of inequity aversion, we tested four parrot species in the token exchange paradigm. We varied the quality of rewards delivered to dyads of birds, as well as the effort required to obtain a reward. Blue-headed macaws and African grey parrots showed no reaction to being rewarded unequally. The bigger macaws were less willing to exchange tokens in the “unequal” condition compared to the “equal high” condition in which both birds obtained high quality rewards, but a closer examination of the results and the findings from the control conditions reveal that inequity aversion does not account for it. None of the species responded to inequity in terms of effort. Parrots may not exhibit inequity aversion due to interdependence on their life-long partner and the high costs associated with finding a new partner.

Low abundance of the Endangered timneh parrot Psittacus timneh in one of its presumed strongholds

AbstractAlthough both the grey parrot Psittacus erithacus and the recently recognized timneh parrot Psittacus timneh are categorized as Endangered because of harvest for the pet trade and loss of habitat, the latter has a much smaller range and may be largely restricted to a few stronghold areas. In March–April 2018 we surveyed for a total of 114 hours in and around one of these presumed strongholds, the large and well-protected Gola Rainforest National Park, the Sierra Leonean portion of the Gola Transboundary Peace Park. Timneh parrots were encountered at a rate of 0.1 groups/h in the National Park and 0.3 in the buffer zone, indicating densities of 1–3 individuals per km2. These figures are similar to recent density estimates from the Liberian side of the Peace Park, suggesting that the transboundary population amounts to c. 2,400 individuals inside the Park and an unknown number in the surrounding areas. Densities of the timneh parrot may be generally low even in strongholds, its numbers may be declining steeply, and the global population size is probably lower than previously believed.

Stool pigeon parrots

Stool pigeon parrots

Comparison of Dorsoventral Erect and Ventrodorsal Supine Radiographic Views for the Evaluation of Intracoelomic Organs in Clinically Normal African Grey Parrots (Psittacus erithacus).

Standard positioning for radiographic evaluation may require sedation and can be deleterious in critically ill birds. A prospective crossover study was performed in 15 clinically normal African grey parrots (Psittacus erithacus) to describe an alternative, unrestrained radiographic view. Whole-body radiographs were obtained in unrestrained dorsoventral erect (DVE) views and in anesthetized ventrodorsal supine (VDS) views. Visualization of various anatomic items in each view was scored by 3 observers. The surface area of the air sacs and the width of the heart, liver, thorax, and cardiohepatic waist were measured in DVE and VDS views. Measurements were obtained by 3 observers, and 1 observer repeated the measurements twice. Intraobserver and interobserver agreement were assessed. Major rotation of the coelom and superimposition of the limbs over the coelom were, respectively, observed in 4 of 15 (27%) and 15 of 15 (100%) of the DVE views and not observed in VDS views. The evaluation of the respiratory tract structures was considered limited in DVE views compared with VDS views, and the surface areas of the air sacs were significantly smaller. The proventriculus and ventriculus were more visible in the DVE view. The visualization of the heart was not significantly different between the 2 views. The absolute measures of heart, liver, and cardiohepatic waist width were significantly larger in the DVE view compared with the VDS view. Moderate intraobserver and interobserver agreement was observed in the evaluation of the 2 views. In conclusion, the DVE view could be adequate to assess the heart and the upper digestive tract. This positioning is likely to provide clinically relevant information for cases in which general anesthesia or dorsal recumbency is contraindicated.

Parrots Voluntarily Help Each Other to Obtain Food Rewards

Helping others to obtain benefits, even at a cost to oneself (altruism), poses an evolutionary puzzle (Clutton-Brock 2009). While kin selection explains such ‘selfless’ acts amongst relatives, only reciprocity (paying back received favours) entails fitness benefits for unrelated individuals (Taborsky et al. 2016). So far, experimental evidence for both altruistic helping and reciprocal altruism has been reported in a few mammals but no avian species (Massen et al. 2015). In order to gain insights into the evolutionary origin of altruistic helping and reciprocity, the capacity for altruism of non-mammalian species needs to be investigated. We tested two parrot species in an instrumental helping paradigm involving ‘token transfer’. Here, actors could provide tokens to their neighbour, who could exchange them with an experimenter for food. To verify whether the parrots understood the task’s contingencies, we systematically varied the presence of a partner and the possibility for exchange. We found that African grey parrots voluntarily and spontaneously transferred tokens to conspecific partners, whereas significantly fewer transfers occurred in the control conditions. Additionally, transfers were affected by the strength of the dyads’ affiliation and partially by the receivers’ attention-getting behaviours. Furthermore, the birds reciprocated the help once the roles were reversed. Blue-headed macaws, in contrast, transferred hardly any tokens. Species differences in social tolerance might explain this discrepancy. These findings show that altruistic helping based on a prosocial attitude, accompanied but not necessarily sustained by reciprocity, is present in parrots, suggesting that this capacity evolved convergently in this avian group and mammals.

Palatal Biomechanics and Its Significance for Cranial Kinesis in Tyrannosaurus rex.

The extinct nonavian dinosaur Tyrannosaurus rex, considered one of the hardest biting animals ever, is often hypothesized to have exhibited cranial kinesis, or, mobility of cranial joints relative to the braincase. Cranial kinesis in T. rex is a biomechanical paradox in that forcefully biting tetrapods usually possess rigid skulls instead of skulls with movable joints. We tested the biomechanical performance of a tyrannosaur skull using a series of static positions mimicking possible excursions of the palate to evaluate Postural Kinetic Competency in Tyrannosaurus. A functional extant phylogenetic bracket was employed using taxa, which exhibit measurable palatal excursions: Psittacus erithacus (fore-aft movement) and Gekko gecko (mediolateral movement). Static finite element models of Psittacus, Gekko, and Tyrannosaurus were constructed and tested with different palatal postures using anatomically informed material properties, loaded with muscle forces derived from dissection, phylogenetic bracketing, and a sensitivity analysis of muscle architecture and tested in orthal biting simulations using element strain as a proxy for model performance. Extant species models showed lower strains in naturally occurring postures compared to alternatives. We found that fore-aft and neutral models of Tyrannosaurus experienced lower overall strains than mediolaterally shifted models. Protractor muscles dampened palatal strains, while occipital constraints increased strains about palatocranial joints compared to jaw joint constraints. These loading behaviors suggest that even small excursions can strain elements beyond structural failure. Thus, these postural tests of kinesis, along with the robusticity of other cranial features, suggest that the skull of Tyrannosaurus was functionally akinetic. Anat Rec, 303:999-1017, 2020. © 2019 Wiley Periodicals, Inc.

Congo Grey Parrot Psittacus erithacus densities in oil palm plantation, agroforestry mosaic and protected forest in Southwest Cameroon – ERRATUM

The Congo Grey Parrot Psittacus erithacus has experienced a severe population breakdown in recent decades. The rainforests of the Korup region in Southwest Cameroon may harbour a large population of this species, but density and population estimates from this area remain controversial. Before the 2016 breeding season, we surveyed Grey Parrots along transects (621.1 km survey effort) in three adjacent landscape types: primary forest in Korup National Park (KNP), smallholder agroforestry matrix (AFM), and industrial oil palm plantation (OPP). We also collected information on the trees used for nesting, feeding and roosting. Using Distance analysis, we estimated relatively low densities of stationary flocks, ranging from 0.30 ind./km2 in KNP, over 0.82 ind./km2 in OPP to 2.70 ind./km2 in the AFM. Parrots were observed feeding or roosting in 17 tree species, of which 15 were located in AFM alone. Feeding was most often observed on cultivated Elaeis guineensis and Dacryodes edulis, but never in maize. The detected parrot densities probably reflect declines within the period 2008–2016, suggesting that the species’ recent IUCN uplisting to ‘Endangered’ and transfer to CITES Appendix I was indeed justified. Our results also suggest that traditional smallholder agroforestry may play a role in habitat conservation strategies, since these forms of cultivation may maintain important breeding and feeding opportunities for Congo Grey Parrots.

Congo Grey Parrot Psittacus erithacus densities in oil palm plantation, agroforestry mosaic and protected forest in Southwest Cameroon*

SummaryThe Congo Grey Parrot Psittacus erithacus has experienced a severe population breakdown in recent decades. The rainforests of the Korup region in Southwest Cameroon may harbour a large population of this species, but density and population estimates from this area remain controversial. Before the 2016 breeding season, we surveyed Grey Parrots along transects (621.1 km survey effort) in three adjacent landscape types: primary forest in Korup National Park (KNP), smallholder agroforestry matrix (AFM), and industrial oil palm plantation (OPP). We also collected information on the trees used for nesting, feeding and roosting. Using Distance analysis, we estimated relatively low densities of stationary flocks, ranging from 0.30 ind./km2 in KNP, over 0.82 ind./km2 in OPP to 2.70 ind./km2 in the AFM. Parrots were observed feeding or roosting in 17 tree species, of which 15 were located in AFM alone. Feeding was most often observed on cultivated Elaeis guineensis and Dacryodes edulis, but never in maize. The detected parrot densities probably reflect declines within the period 2008–2016, suggesting that the species’ recent IUCN uplisting to ‘Endangered’ and transfer to CITES Appendix I was indeed justified. Our results also suggest that traditional smallholder agroforestry may play a role in habitat conservation strategies, since these forms of cultivation may maintain important breeding and feeding opportunities for Congo Grey Parrots.

Grey Parrot Anatomy Project—A study for science

The Grey Parrot Anatomy Project is a collaborative effort to define the anatomy of one bird (Psittacus erithacus erithacus), utilize and develop new imaging technology that can potentially be used on any species including humans, collaborate with multiple scientific disciplines and share the data. This presentation will highlight the Project, demonstrate some of the new technology developed and show how the information is being utilized to better understand anatomy and diagnose and treat disease in multiple species. The Project has been funded by private donations and has been centered at the University of Utah. Many collaborators at other institutions and clinical practices have contributed to and/or benefited from the Project. In addition to being informative, this presentation is an invitation to collaborate.Support or Funding InformationPrivate donationsThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Tricks of the trade—legal trade used to conceal Endangered African grey parrots on commercial flights

Tricks of the trade—legal trade used to conceal Endangered African grey parrots on commercial flights

Opportunities to boost protection of the grey parrot in Nigeria

Opportunities to boost protection of the grey parrot in Nigeria