Anthropogenic changes have strongly influenced the biodiversity of Europe. In the last 50 years electric power-line networks have become a conspicuous part of the European landscape, and have strongly influenced the survival of some bird species. When they were constructed it was known, at least locally, that these lines and their support structures would cause fatalities in the white stork Ciconia ciconia. Annually thousands of white storks die in collision with, and through electrocution by, power lines, and these are important causes of their mortality. Using data collected in central Poland we show that technical modifications to electricity poles are an effective way to assist stork conservation and may, at least locally, reduce mortality by electrocution to zero. Because the white stork is an icon of nature conservation, we believe that public utilities and power-line companies will more readily focus on protecting this species; while indirectly aiding wider bird conservation. Furthermore, since contact with power-lines results in a break in energy transmission, these modifications also positively benefit both energy consumers and power companies.
Whether Ca and other micronutrients are equally distributed in an avian eggshell over its longitudinal section and what portion of these local resources are utilized by developing embryos are unanswered questions in avian reproductive physiology. Here, we measured the thickness and concentrations of Ca and 16 other chemical elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Se, and Sr) in 4 shell regions (sharp pole, equator, shoulder, blunt pole) of White Stork (Ciconia ciconia) eggs representing different stages of embryonic development, from unresorbed eggshells to almost fully resorbed ones (with near-to-hatch embryos). We found that unresorbed eggshells displayed several significant differences in the concentrations of 15 elements (Al, As, Ca, Cd, Co, Cr, Fe, K, Hg, Mg, Mn, Na, Ni, Se, and Sr) between various regions of the same shell. Only 2 metals (As and Ca) showed a cross-sectional decrease in concentrations from the sharp pole to the blunt one. In particular, we observed that unresorbed eggshells at the blunt pole were less calcified (with 2.4% less Ca) compared to the sharp pole. In contrast, the concentrations of 6 other metals (Co, Fe, Mg, Mn, Na, and Se) peaked in the relatively less calcified region of the blunt pole, where concentrations (such as Se) were up to 10 times as high as in other regions of unresorbed eggshells. Our findings highlight that eggshells over their longitudinal sections are not chemically homogeneous. Surprisingly, however, and contrary to our expectations, we found that unresorbed eggshells were thinner (2.1–5.9% less depending on the region) and at the same time more strongly calcified than resorbed eggshells. This suggests that some modification has occurred in the shell structure and raises the question of thin-shelled eggs in populations of wild birds.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
The ongoing growth of the human population will increase the rate of wildlife–human interactions. High levels of animal tolerance and flexible responses towards human presence seem to be among the key mechanisms behind successful wildlife–human coexistence, but this behaviour remains unexplored for most populations and species of animals. Here, we investigate the escape behaviour (measured as flight initiation distance) of the Crimean population of a charismatic and declining bird species, the lesser grey shrike (Lanius minor). We examined its relationship with starting distance of the approaching human, directness of that approach (direct or tangential), habitat type (rural or suburban), and height of the perch used by shrikes. We found that the starting distance was significantly associated with escape responses of shrikes to approaching humans. In contrast, we found no significant association between escape responses and directness of approach, habitat type, or height of perch. Our results indicate that the lesser grey shrike may exhibit low flexibility in their escape responses towards humans which may have implications for their conservation management. Our results also indicate that the widely used 30 metres threshold for minimum starting distance may be insufficient for rural populations, even of small passerines.
Transformation of natural habitats into farming lands and spread of built up areas has a pervasive effect on wildlife, especially for birds. Also, plastic pollution is affecting wildlife on a global scale. Discarded plastic is ubiquitous and accessible for birds, which can be incorporated in the nest structure. By now, a large collection of studies has been published regarding the anthropogenic nest material incorporation by birds. However, studies are predominately biased to marine birds. To balance this disproportion, we describe here the differences in type, prevalence and the amount of anthropogenic nest materials between two populations of terrestrial, mainly farmland bird, the white stork Ciconia ciconia on a broad geographical scale, from two migratory divides – eastern in Poland and western in Spain (in total 303 nests). We detected significant differences in anthropogenic nest material incorporation between two populations in regard to human pressure reflected by Human Footprint Index (HFI) and urbanisation level measured by Impervious Surface Areas (ISA). In Spanish population, we found that probability of anthropogenic nest material incorporation was positively related to ISA, and amount of anthropogenic nest material was positively associated to HFI, in contrast to Polish one, where there was no significant relationship. Moreover, we showed that the prevalence of nests with anthropogenic nest material was two times higher in Spanish than in Polish white stork population. This study demonstrates that the vulnerability to solid waste pollution differs on a population scale within one species.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.