Comparative analysis of the digestive system’s anatomical parts in two zoophagous bird species: White Stork (Ciconia ciconia) and Common Buzzard (Buteo buteo)

Aristotle in his anatomical observations is marking the beginning of functional anatomy followed by Georges Cuvier that formulate the low of the correlation of parts. According with this we can expect that the digestive system structures tend to be similar between species that consume approximately the same type of food. In this study we chose to evaluate macroscopic the digestive system of two different zoophytophagous species, with similar body size but different life behavior and feeding strategies: White Stork (Ciconia ciconia) and Common Buzzard (Buteo buteo). Data were collected after the dissection of 10 carcass (5 White Stork and 5 Common Buzzard). The digestive tract and its structures were measured and weighed. In common buzzard the beak is strong and short adapted for the laceration of the prey. In white stork the beak is long, strong, straight adapted to capture prey like a harpoon. In both species, the esophagus is located on the right side of the neck, the length is different, proportional to the neck. In common buzzard the crop is present and absent in white storks. The cuticle or koilin layer is highlighted in white stork compared to common buzzard. In common buzzard, the small intestine is reduced in size, without marked transition between the duodenum and the ileum. The white storks have a long small intestine with many loops, with no transition between the segments. In both species, the cecum is reduced in size and has a vestigial appearance; the colon is reduced in size, and extends from the level of the ileo-colic junction to the cloaca. The digestive system is adapted to a strictly carnivorous diet and the differences identified between the anatomical structures of the digestive tract of the two species are correlated with the differences of their feeding behavior.

Novelty at dawn: Exploration, low neophobia and crepuscular activity in a wild Common Buzzard (Buteo buteo)

Raptor cognition has received limited research attention, despite the importance of comparative investigations for reconstructing the evolution of complex cognition. Field studies provide essential ecological context for cognition in the natural habitat, although this approach is often challenging due to extensive procedures involved in cognitive testing. One predisposition suggested to contribute to problem-solving behaviour is the response to novel stimuli. In this pilot study, a novel object test was conducted on an outdoor feeding platform to assess the neotic responses of a single wild free-ranging Common Buzzard ( Buteo buteo), a generalist/opportunist diurnal predator species. Additionally, data on its daily activity were collected. As predicted, the subject expressed low neophobia and some exploratory behaviours. Interestingly, it repeatedly arrived on the platform in low light conditions. This study highlights the influence of foraging ecology on cognitive predispositions and offers a field method for research on raptor cognition.

The Importance of Low-Intensive Agricultural Landscape for Birds of Prey

Low-intensive agricultural areas of Romania sustain high species diversity. Together with natural habitats, these areas are very important for European biodiversity. The ecosystem´s health is reflected in the predator status because of their position at the top of the trophic networks. The Common Buzzard (Buteo buteo) is the most common bird of prey species in Europe. During the first survey census conducted in Eastern Romania (2011–2012 breeding seasons), 8.55–10.35 breeding pairs/100 square km have been counted. The Common Buzzard density varies between breeding seasons and with differences in habitat structure. Their density is positively influenced by the density of forest edge and Simpson diversity index of habitats but is negatively influenced by the total habitat fragmentation and mean daily temperature. According to this analysis, the selection of breeding territories by common buzzards is positively influenced by a heterogeneous landscape in an area with low-intensive agriculture and with large areas of open habitats made up of natural or semi-natural vegetation.

A pesticide banned in the European Union over a decade ago is still present in raptors in Poland

SummaryThe prevalent pesticide carbofuran was banned in the European Union (EU) in 2008; however, the extent of its actual elimination from the environment has been little studied. The presence of this pesticide in the livers of the protected raptors the white-tailed eagle (Haliaeetus albicilla) and the common buzzard (Buteo buteo) was monitored in Poland from 2008 to 2019 using liquid chromatography with tandem mass spectrometry analysis and data from government institutions. Carbofuran residues were detected in the liver samples of the analysed raptors throughout the period studied. In total, carbofuran was detected in the livers of 33% of the eagles and 54% of the buzzards; concentrations were in the ranges of 11–699 and 14–1890 μg kg–1 of dry matter, respectively. Effective measures to eliminate banned pesticides from the market more efficiently are required.