Seasonal variation in coprophagic foraging in alpine choughs Pyrrhocorax graculus

The Alpine Chough Pyrrhocorax graculus is a social corvid which now uses food provided by tourist activities in mountain regions (e.g. at ski stations, refuse dumps, picnic areas). Foraging flock size, flock distribution and flock structure of Alpine Choughs were studied in the northern French Alps between 1988 and 1992. Flock size varied during the year, being larger in winter than in summer. Alpine Choughs were not evenly distributed in space, and their numbers depended principally on site‐specific factors, such as seasonal human presence. A significant positive correlation existed between Alpine Chough foraging flock size and the local human population. Immature birds gathered in winter in the largest flocks and principally frequented sites with the greatest food availability (e.g. refuse dump). In summer, immatures dispersed, joined small breeding groups and were more homogeneously distributed.

The fréquentation of a clumped food resource by a foraging flock of a social corvid species, the Alpine Chough Pyrrhocorax graculus was studied between November 1990 and May 1991 at a refuse tip according to sex and season. Site fréquentation, interactions and success rates were shown to vary with sex and season. Females were less aggressive than males, their success rate was lower, and they principally used low bird density areas where interaction rates were low. Female attendance increased in spring in parallel to their interaction success rate. Among females, those whose weight exceeded the median value were most frequently seen, especially in the area where highest interaction rates were observed. This suggests that alpine choughs use different foraging strategies in order to exploit clumped resources according to their social status (i.e. sex, physical caracteristics) and season.

The currently circulating high-pathogenicity avian influenza (HPAI) virus of the subtype H5 causes variable illness and death in wild and domestic birds and mammals, as well as in humans. This virus evolved from the Goose/Guangdong lineage of the HPAI H5 virus, which emerged in commercial poultry in China in 1996, spilled over into wild birds, and spread through Asia, Europe, Africa, and North America by 2021. Our objective was to summarize the spread and impact of the HPAI H5 virus in wild birds and mammals in South America, evaluate the risk of its spread and potential impact on Antarctic wildlife, and consider actions to manage the current and future HPAI outbreaks in wildlife. We obtained data on HPAI H5 virus detection and reported wildlife deaths from websites, newspaper articles, and scientific publications. The virus arrived in South America in October 2022. Thereafter, it spread widely and rapidly throughout the continent, where it infected at least 83 wild bird species and 11 wild mammal species and is estimated to have killed at least 667,000 wild birds and 52,000 wild mammals. The HPAI H5 virus spread to the Antarctic region by October 2023 and to mainland Antarctica by December 2023. This spread was associated with multiple mortality events in seabirds and marine mammals. The high spatial density of colonies of various Antarctic species of birds and mammals provides conditions for potentially devastating outbreaks with severe conservation implications. Ecosystem-level impacts may follow, and affected populations may take decades to recover. Although little can be done to stop the virus spread in wildlife, it is important to continue targeted surveillance of wildlife populations for HPAI H5 virus incursion and assessment of the spread and impact of disease to inform adaptation of conservation plans and to help policy makers mitigate and prevent future HPAI outbreaks.

The diets of the Chough Pyrrhocorax pyrrhocorax and the Alpine Chough Pyrrhocorax graculus coexisting in the western Italian Alps have been compared by faecal analyses. A total of 1581 fresh droppings (405 of the Chough and 1176 of the Alpine Chough) were collected in the pastures of the Rhêmes Valley, Aosta, Italy, from June to November 1992 and analysed in the laboratory, and a mean volume percentage for each item was calculated. Both species were omnivorous, including animal, vegetable and mineral dietary fractions. There was no overlap in the vegetable part of the diet since the Chough fed virtually exclusively on Yellow Gagea Gagea fistulosa bulbs (dug out from the soil), which were not taken at all by the Alpine Chough. Conversely, the Alpine Chough fed on berries and hips from September to November, but these were virtually ignored by the Chough. Even though animal items were collected by both species, their preferences were different. In June, Alpine Choughs largely collected cranefly (Tipula) larvae whilst Choughs mainly fed on Lepidoptera larvae. From July onward, Alpine Choughs mainly consumed grasshoppers while Choughs also collected Tipula pupae, Lepidoptera and fly (Bibionidae) larvae and beetles (Scarabaeidae and Staphylinidae). Interspecific morphological and behavioural differences may be partly responsible for the segregation observed. Chemical composition and caloric contents of the food items suggest that the balance between costs of collecting and benefits of consuming may also contribute to diet differentiation. Both species took a broad spectrum of food, and there was no clear indication that the different population densities of the two Choughs in the Alps were directly correlated with diet, even though some data suggest that during autumn the Alpine Chough might have a diet better adapted to the high mountain environment than the Chough.

Methods and devices specifically created for remote animal surveys and monitoring are becoming increasingly popular and effective. However, remote devices are also widely used in our societies for different, not scientific, goals. Ski resorts in the European Alps, for instance, use webcams to share panoramic views and promote themselves in the industry of winter recreational activities. We tested preinstalled webcam effectiveness as a remote tool for eco-ethological studies. Our target species was the Alpine ChoughPyrrhocorax graculus, a social and opportunistic corvid species of high mountain environments that attends ski resorts to feed on scraps discarded by high elevation bars and restaurants. We studied the effect of the winter presence of tourists and weather conditions on flocking behaviour at ski resorts. We used flock size and time spent at the ski resort as response variables, and assessed how strongly they were related to the number of tourists and weather conditions. We analysed about 13,500 pictures taken at 10 min intervals at three ski resorts sites in the European Alps in France, Italy and Switzerland. The number of birds was very different among the three study sites. Flock size and time spent were related to the same environmental drivers, but with different effect sizes in the three areas. The daily maximum flock size and the time spent at ski resorts increased with the number of tourists and decreased with temperature at two sites out of three. We also found that the presence of fresh snow caused a decrease in the maximum flock size in all ski resorts. In conclusion, Alpine Choughs modulated their presence at the ski resorts according to human presence and weather conditions, but these responses were context-dependent. Preinstalled webcams, despite a few caveats, can therefore be successfully employed in eco-ethological research. Webcams around the world are increasing in number and represent therefore a large potential resource. If webcam companies could be engaged to make some slight adjustments, without compromising their goals, then this could offer a new way to collect eco-ethological data.

The foraging behaviour of the Chough Pyrrhocorax pyrrhocorax and the Alpine Chough Pyrrhocorax graculus was studied during summer and autumn in the western Italian Alps. We assessed feeding times, feeding rates and foraging techniques associated with different foraging habitats. The Alpine Chough is mainly a ground surface feeder, stays for a rela‐tively short time at a feeding site (on average 2.1 min) and feeds quickly (on average 9.2 items/min). In contrast, the Chough is almost exclusively an undersurface feeder (digger and prober), stays at a feeding site twice as long as the Alpine Chough (5.4 min) and feeds four times as slowly (2.2 items/min). These differences suggest that the degree of actual ecological overlap is almost as low as possible for two species using the same Alpine pastures as foraging sites. Interspecific coexistence has occurred through a clear differentiation of foraging strategies and diets. The foraging efficiency (in terms of feeding rate)of the Alpine Chough was always higher than that of the Chough in all habitats where they occurred together. The Alpine Chough was more variable in the use of foraging techniques and more diversified in the use of foraging habitats than the Chough. In both species, juveniles fed less efficiently than adults; the foraging behaviour of the Chough is probably more difficult to learn than that of the Alpine Chough. Other data have also shown that the Alpine Chough is more opportunistic than the Chough in using seasonally available food. Considering the above, we suggest that the foraging behaviour of the Alpine Chough is more flexible and, perhaps, better adapted to the high mountain Alpine environment than that of the Chough. Two hypotheses concerning the ultimate reason why the Alpine Chough and the Chough have evolved divergent beak morphology are discussed.

Foraging strategy in a social bird, the alpine chough: effect of variation in quantity and distribution of food

This study investigates lead (Pb) contamination in wild animals in Japan. Pb is a known environmental toxin that can cause several issues in wildlife. Pb is still used in human society, and among Pb products, ammunition is reported to harm human and animal health. In Japan, few instances of Pb contamination in wild animals have been reported outside Hokkaido. Possible reasons for this include the absence of Pb contamination and insufficient investigation. This study aimed to understand the current state of Pb contamination in Japan and clarify the extent of Pb contamination related to ammunition. Blood lead concentrations (BLLs) were measured in wild birds and mammals from 25 municipalities, and an analysis was conducted based on ammunition-related factors. More than half of the avian and mammalian taxonomic groups were found to exhibit Pb contamination from environmental sources. Overall, this study suggests that Pb contamination is also present in wild birds and mammals living outside Hokkaido, Japan, and highlights the risks of mass mortality during infectious disease outbreaks as well as the potential health hazards of Pb exposure upon their consumption by humans. The results of this study highlight the importance of monitoring Pb contamination, particularly in hunting areas of Japan. Further, it indicates the need to reconsider the use of Pb-based ammunition for protecting the health and welfare of both humans and wildlife.

The literature on disease in lower animals offers very little information as to possible variations in resistance or susceptibility of different animal groups to the development of neoplasms. Observations on captive wild mammals and birds have indicated, however, that all taxonomic groups may not be equally affected and that there may be distinct differences in organ and tissue susceptibility to tumor growth. A review (1) of the autopsy records of more than 5000 wild mammals and birds dying in the Philadelphia Zoological Gardens has shown that tumors occurred in about 2 per cent of all specimens. Mammals were much more frequently affected than were birds, although the latter were much more numerous in this series. The incidence of tumors also varied widely for different taxonomic groups (orders) of both mammals and birds. The neoplasms found in these animals involved a variety of tissues, but the gastro-intestinal tract and related organs of mammals and the renal-adrenal-gonad tissues of birds, respectively, were more frequently the sites of tumor growth than other parts of the bodies. The skin of birds and the mucocutaneous junction of both birds and mammals were rarely affected by neoplasms. The present report is a second survey of all cases of tumors that have been found in wild birds and mammals dying in the Philadelphia Zoological Gardens from 1901 to 1932.2 Those instances discussed in earlier publications (1, 2) have been reexamined and included in the present discussion.

Food-storing bird species reside in environments with seasonal pulses of durable particulate food items, followed by periods of relative food scarcity. They have generalized diets and foraging repertoires, and show behavior (including territoriality) that helps storing individuals retain possession of stored items. Storing species occur in few families: woodpeckers, corvids, parids, and nuthatches. Less well developed storing occurs in shrikes and some predators because its evolution is constrained by rapid food item deterioration. Species in other families lack an ability to defend or retain cached food, do not feed on storable items, or lack sufficiently dense supplies of potential stored food. Storing increases food availability during periods of food scarcity, evolutionary leading to increased survival, longer life, and possibly to augmentation of a trend toward kin-selected social organizations. Storing species developed the trait in accord with the principle of economic defendability. A strategic analysis of the socioecological behavior of melanerpine woodpeckers and jays of the United States and Canada confirms expectations from an evolutionary model by showing that species utilize a single optimal strategy involving assessment of storable food availability. Individuals remain on a site and store food in favorable circumstances; in unfavorable conditions the selected behavior includes abandoning otherwise favorable habitat and opportunistically wintering where storable food is more abundant. Resident storers only opt for abandonment in very poor years, apparently because of benefits attending long-term residence. Fugitive storers only choose to remain when conditions in breeding areas are exceptionally favorable, i.e., when there is abundant storable food.

Syrphids feed on multiple patches in heterogeneous agricultural landscapes during the autumn season, a period of food scarcity

Today, the ecosystem is being rapidly destroyed due to habitat loss, animal hunting, road construction, raising of transmission lines, general pollution, and agricultural activities, in addition to many other factors, all of which directly and indirectly affect wildlife. By necessity, rehabilitation units are available for the care and treatment of wild birds and mammals in need of life support. This paper discusses data collected regarding the treatment and rehabilitation of wild mammals and birds brought to the Center for Wildlife Conservation and Rehabilitation at Van Yüzüncü Yýl University from 2009-2016. During the course of the present study, total 145 wild animals including 117 birds and 28 mammals. Out of the total treated, 96 wild birds and 21 wild mammals recovered, 12 birds and 4 mammals died without responding to treatments, whereas 9 birds and 3 mammals were euthanized. Additionally, of the 96 birds and 21 mammals that recovered, 15 birds and 6 mammals were determined to be unable to survive in their natural habitats, and were sent to zoo gardens or wildlife conservation and rehabilitation centers. The remaining 96 animals that fully recovered were released back into their natural habitats.

Avian gut microbial communities are complex and play a fundamental role in regulating biological functions within an individual. Although it is well established that diet can influence the structure and composition of the gut microbiota, foraging behaviour may also play a critical, yet unexplored role in shaping the composition, dynamics, and adaptive potential of avian gut microbiota. In this review, we examine the potential influence of coprophagic foraging behaviour on the establishment and adaptability of wild avian gut microbiomes. Coprophagy involves the ingestion of faeces, sourced from either self (autocoprophagy), conspecific animals (allocoprophagy), or heterospecific animals. Much like faecal transplant therapy, coprophagy may (i) support the establishment of the gut microbiota of young precocial species, (ii) directly and indirectly provide nutritional and energetic requirements, and (iii) represent a mechanism by which birds can rapidly adapt the microbiota to changing environments and diets. However, in certain contexts, coprophagy may also pose risks to wild birds, and their microbiomes, through increased exposure to chemical pollutants, pathogenic microbes, and antibiotic-resistant microbes, with deleterious effects on host health and performance. Given the potentially far-reaching consequences of coprophagy for avian microbiomes, and the dearth of literature directly investigating these links, we have developed a predictive framework for directing future research to understand better when and why wild birds engage in distinct types of coprophagy, and the consequences of this foraging behaviour. There is a need for comprehensive investigation into the influence of coprophagy on avian gut microbiotas and its effects on host health and performance throughout ontogeny and across a range of environmental perturbations. Future behavioural studies combined with metagenomic approaches are needed to provide insights into the function of this poorly understood behaviour.

Brain size varies dramatically between vertebrate species. Two prominent adaptive hypotheses – the Cognitive Buffer Hypothesis (CBH) and the Expensive Brain Hypothesis (EBH) – have been proposed to explain brain size evolution. The CBH assumes that brain size should increase with seasonality, as the cognitive benefits of a larger brain should help overcoming periods of food scarcity via, for example, increased behavioral flexibility. Alternatively, the EBH states that brain size should decrease with seasonality because a smaller brain confers energetic benefits in periods of food scarcity. Here, to test the two adaptive hypotheses by studying the effects of variation in temperature and growth season on variations in overall brain size and the size of specific brain regions (viz. olfactory nerves, olfactory bulbs, telencephalon, optic tectum and cerebellum) among Hylarana guentheri populations. Inconsistent with the predictions of both the EBH and the CBH, variation in temperature and growth season did not exhibit correlations with overall brain size and the size of brain regions across populations. Hence, our data do not provide support for either the EBH or the CBH to explain brain size variation in H. guentheri. Furthermore, brain size variation did not differ between males and females in this species. Our findings suggest that both the variation in temperature and growth season did not shape the variation in brain size in H. guentheri.

The volume of the hippocampal region (dorsomedial cortex) relative to body mass was measured in seven species of corvid (red-billed blue magpie, Cissa erythrorhyncha; European crow, Corvus corone; rook, C. frugilegus; jackdaw, C. monedula; jay, Garrulus glandarius; magpie, Pica pica; and Alpine chough, Pyrrhocorax graculus). The species studied differ in the extent to which they store food, and the results showed that there is a positive correlation between the estimated amount of food-storing behaviour and the relative volume of the hippocampus among the seven species. For two of the species, magpie and jackdaw, intraspecific variation was analysed. These two species show a sex difference in relative hippocampal volume (males larger than females), although there are no reports of sex differences in storing behaviour. In the magpie, which stores food regularly, hippocampal volume relative to body mass is positively related to relative volume of the rest of the telencephalon, whereas in the jackdaw, which rarely stores food, there is no relation.