Sentinel behavior in captive meerkats (Suricata suricatta).

The social and cooperative behavior of meerkats (Suricata suricatta), specifically their sentinel behavior, has been intensively studied in free-ranging populations. This study focuses on whether guarding in captive meerkats exhibits a pattern similar to that described for wild groups. Sentinel behavior in captivity has been somewhat neglected because predation is usually not a critical factor. Nonetheless, observations in captivity might reveal whether individual or group experience influences this specific behavior pattern. We observed three captive meerkat groups (in outdoor as well as indoor enclosures) and analyzed the duration of guarding sequences, the number of established guards, the guard posture, and the individual guard positions. We also conducted playback experiments to investigate the reaction of the sentinel and the group to bird calls (songbird vs. predatory bird species). The results demonstrated that captive groups behave much the same as wild groups. Certain individuals performed the guard job more often than other group members. Accordingly, the "super sentinels" observed in the wild also exist in captive groups. Playbacks showed that the sentinels reacted more strongly to the calls of predatory bird species, indicating that captive meerkats are able to categorize bird calls. We also documented major differences in behavioral responses to the calls of specific predatory bird species. Our observations underline that sentinel behavior is probably a combination of an innate, imprinted pattern that is further affected by the experience. Future studies might further investigate this influence of experience, beyond innate behavior, on the group-specific sentinel behavior pattern in captive meerkats.

Per- and polyfluoroalkyl substances in plasma and feathers of nestling birds of prey from northern Norway.

Plasma samples from nestlings of two top predators, White-tailed eagle (Haliaeetus albicilla) and Northern goshawk (Accipiter gentilis) from northern Norway were analysed for a wide range of per- and polyfluoroalkyl substances (PFASs). Body feathers from the White-tailed eagles were also analysed and significant associations between specific PFASs in blood plasma and body feathers were found (0.36

Accumulation of microplastics in predatory birds near a densely populated urban area.

The pollution due to plastic and other anthropogenic particles has steadily increased over the last few decades, presenting a significant threat to the environment and organisms, including avian species. This research aimed to investigate the occurrence of anthropogenic pollutants in the digestive and respiratory systems of four birds of prey: Common Buzzard (Buteo buteo), Black Kite (Milvus migrans), Eurasian Sparrowhawk (Accipiter nisus), and Northern Goshawk (Accipiter gentilis). The results revealed widespread contamination in all species with microplastics (MPs) and cellulosic anthropogenic fibers (AFs), with an average of 7.9 MPs and 9.2 AFs per specimen. Every digestive system contained at least one MP, while 65 % of specimens exhibited MPs in their respiratory systems. This is the work reporting a high incidence of MPs in the respiratory system of birds, clearly indicating inhalation as a pathway for exposure to plastic pollution. The content of MPs and AFs varied significantly when comparing specimens collected from central Madrid with those recovered from other parts of the region, including rural environments, suburban areas, or less populated cities. This result aligns with the assumption that anthropogenic particles disperse from urban centers to surrounding areas. Additionally, the dominant particle shape consisted of small-sized fibers (> 98 %), primarily composed of polyester, polyethylene, acrylic materials, and cellulose fibers exhibiting indicators of industrial treatment. These findings emphasize the necessity for further research on the impact of plastic and other anthropogenic material contamination in avian species, calling for effective strategies to mitigate plastic pollution.

Mercury in the feathers of Golden eagle (Aquila chrysaetos) from Western Carpathian, Slovakia.

In this study, mercury (Hg) concentrations were detected in feathers of golden eagle (Aquila chrysaetos), a bird that typically inhabits alpine and forest areas. The mercury rates in feathers were compared in two groups of eagles: first, estimated home range (breeding, hunting, etc.) was located only in forest and lowland meadow habitats; second, the home range also included alpine habitats-rocks and meadows. Consequently, mercury concentration based on the feather typology were observed and the mercury levels in feathers were also compared among different Slovak Western Carpathian districts. It was found that there was no significant difference between groups classified by elevation level, which we attribute to the fact that eagle hunting territories are broad, so that alpine-dwelling and forest-dwelling eagles do not only reflect the pollution of the environments they typically inhabit. Non-significant differences were found also within different feather types, which means that the type of feather is not crucial for tracking mercury in eagle feathers. As the measurement of feather appears to be a simple and non-invasive method, the detection of non-significant differences in diverse types of golden eagle feathers provides useful knowledge for the future environment monitoring. The average mercury concentration measured in eagle samples was lower than the mercury concentration causing health complications among birds of prey. Our assumption that due to past mining activity in the Spis region, the highest concentration in this region would be observed was confirmed.

A comparative study on grasping-related muscles in five Accipitriformes species.

Accipitriformes are diverse in their prey preferences and use their grasping feet for hunting. Little is known about the architectural design of muscles related to grasping among species of different sizes, diets, and foraging behaviors. In the present study, we report quantitative data and analysis of the pelvic musculature of the Japanese sparrowhawk (Accipiter gularis), Eurasian sparrowhawk (Accipiter nisus), common buzzard (Buteo buteo), northern goshawk (Accipiter gentilis), and cinereous vulture (Aegypius monachus). As expected, mass and architecture of the considered muscles were very different between the cinereous vulture and the four other species. The cinereous vulture allocates more mass and physiological cross-sectional area (PCSA) to the proximally inserted flexor muscles, which indicates the rudimentary grasping ability of the foot and is a myological reflection of its carrion preference. Furthermore, in the cinereous vulture, muscles were built with the lowest architectural index (AI) compared with the other species, and the intrinsic foot muscles were short-fibered, which is disadvantageous for rapid manipulation and foot dexterity. The other four species, as a whole, featured large flexor hallucis longus (FHL) muscles and better development of distally inserted flexors, reflecting their predatory lifestyle. Some differences were also found between the species that consumed birds and those that consumed mammals. The two avivorous species were superior in AI and fiber length of the intrinsic foot muscles which are suitable for good hunting speed and digit flexibility, the prerequisition for hunting agile prey.

Biomonitoring of toxic metals in feathers of predatory birds from eastern regions of Hungary.

The aim of our study was to investigate the concentrations of toxic metals in the feathers of predatory birds in the Hortobágyi Madárpark (Bird Hospital Foundation). Samples were collected from different predatory birds originated from the eastern and north-eastern region of Hungary. Inductively coupled plasma optical emission spectrometry was used to determine the concentration of toxic metals. The mean values varied between bird species groups, their concentrations were between 0.29 ± 0.24 and 0.40 ± 0.30 mg/kg for arsenic (As), 0.09 ± 0.03 and 0.20 ± 0.18 mg/kg for cadmium (Cd), 1.15 ± 1.40 to 2.30 ± 1.52 mg/kg for lead (Pb) and 0.58 ± 0.31 to 2.19 ± 1.25 mg/kg for mercury (Hg), respectively. The measured values are not over the considered threshold values for these toxic metals and in accordance with similar concentrations of them recorded in similar species within Europe. No significant differences were found in their concentration between genders or age in the species. According to the detected concentrations of these metals, their levels accumulated in the feather of the investigated birds do not indicate the possibility of poisoning.

A case of cellulitis of the hands caused by a predatory bird attack.

Many species have been drastically affected by rapid urbanization. Harris's hawks from their natural habitat of open spaces and a supply of rodents, lizards and other small prey have been forced to change their natural environment adapting to living in open spaces in sub- and peri-urban areas. Specific areas include playgrounds, parks and school courtyards. The migration of this predatory species into these areas poses a risk to individuals, and especially the children are often attacked by claws, talons and beaks intentionally or as collateral damage while attacking rodent prey. In addition, the diverse micro-organisms harbored in the beaks and talons can result in wound infections, presenting a challenge to clinical management. Here we would like to present a case of an 80-year-old man with cellulitis of both hands after sustaining minor injuries from the talons of a Harris's hawk and review the management options. We would also like to draw attention to the matter that, even though previously a rarity, more cases of injuries caused by birds of prey may be seen in hospital settings.