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Selection of calling sites by Pelophylax porosus porosus (Anura: Ranidae)

100%

Takahashi K., Takeuchi H.

Acta Biologica

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2021

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tom 28

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Intensity of melanin-based color and risk of predation in the Barn Swallow Hirundo rustica

86%

Galvan I., Nielsen J. T., Moller A. P.

Acta Ornithologica

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2014

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tom 49

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nr 1

Predators are supposed to exert strong selection pressures on their prey, especially when phenotypic traits such as secondary sexual characters promote mating success at the expense of costs in terms of natural selection. Signaling theory predicts that individuals of superior phenotypic quality will enjoy an advantage in term of mating success, but also in term of natural selection, if such individuals are in prime condition both before and after development of exaggerated secondary sexual characters. We tested this prediction in the Barn Swallow Hirundo rustica being preyed upon by the Eurasian Sparrowhawk Accipiter nisus, using extensive samples of feathers from prey and non-prey. We measured tail length and coloration of outermost tail feathers in the black area of the proximal and distal part of tail feathers, but also the white spot of the tail feathers. Prey had significantly less dark distal, but not proximal parts of their tails, while there was no difference in coloration of the white spot between prey and non-prey. Prey had significantly paler tail feathers than non-prey, especially among long-tailed individuals. These results suggest that Barn Swallows with long tails that fail to deposit large amounts of melanin in their tail feathers run an elevated risk of predation.

3

Summertime activity patterns of common weasels Mustela nivalis vulgaris under differing prey abundances in grassland habitats

72%

Brandt M. J., Lambin X.

Acta Theriologica

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2005

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tom 50

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nr 1

WeaselsMustela nivalis Linnaeus, 1766 in Kielder Forest, UK showed a diurnal rhythm of activity in summer and we argue that this is the prevailing rhythm found in weasels under natural conditions. Climatic conditions influenced weasel activity with weasels decreasing activity under rainy conditions, but we found no influence of month or weasel weight. In certain habitat types levels of weasel activity increased with increasing field voleMicrotus agrestis density. This result stands in contrast to results from studies carried out in the laboratory and may reflect a greater proportion of time spent in reproductive activity and intra-specific interactions in areas where vole density, and hence conspecific density is high.

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Dependence of nest mass on nest hole depth in the Great Tit Parus major

58%

Mazgajski T. D., Rykowska Z.

Acta Ornithologica

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2008

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tom 43

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nr 1

49-55

Predation is considered an important factor affecting the life histories and breeding strategies of hole nesting birds. Breeding losses in this group of birds are related to such nest site characteristics as entrance size, nest site depth and danger distance - the distance between the outer edge of the entrance to the centre of the nest's bottom, which determines how far a predator unable to enter the hole would have to reach to obtain its contents. It is suggested that birds assess predation risk and adjust their breeding investments accordingly. We tested the hypothesis that in shallow nest sites, birds build smaller nests to maintain the largest danger distance possible. During the experiment, two types of nestboxes were available to birds: those typical for small passerines (with a depth of 21 cm), and shallower ones (with a 16 cm depth). Breeding parameters were obtained by controlling nestboxes, the distances between eggs and entrances were measured, and nests were weighed just after the young fledged. Breeding phenology and clutch size did not differ between the types of nestboxes. Nest site depth influenced nest mass, and according to our assumptions, nests were significantly lighter in shallow nestboxes. A clear, negative relationship was found between nest mass and the danger distance — eggs in larger (heavier) nests were closer to the entrance. Breeding success (number of fledglings per eggs laid) was lower for shallow nestboxes compared to normal ones, and nest mass negatively influenced the number of fledglings and breeding success. The results of this study suggest that Great Tits perceive nest site depth and adjust nest building according to predation risks. Nest size (mass) in shallow sites may be limited by the danger distance, but it is also possible that the number of trips with nest material, which could lead to the detection of the site, is also important. However, both explanations are not mutually exclusive, and both are related to avoiding predator pressure.

5

Seed predation on the ground or in the tree? Size-related differences in behavior and ecology of granivorous birds

58%

Parea R., Venturas M., Gil L.

Acta Ornithologica

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2014

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tom 49

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nr 1

Seed-eating birds may consume seeds in the tree (pre-dispersal predation) as well as on the ground (post- dispersal predation), usually at contrasting microhabitat conditions. We examined the foraging behaviour and contribution to seed predation of a whole assemblage of seed-eating birds (mostly Fringillidae) at both dispersal phases (pre- and post-dispersal) in a wind-dispersed tree, the European White Elm Ulmus laevis. We found that most seed predators were tree-feeding birds that prey upon seeds for longer periods in the tree and spend shorter periods in larger flocks foraging on the ground. We also obtained significant differences in predation speed among the seed predator species. The overall number of seeds consumed by birds, as well as the amount of time spent foraging in the tree, increased with increasing feeding heights. Seed availability increases with height, which seems to be the main reason why birds spend more time foraging on higher branches. Birds strongly differed in their perching coefficient (PC, ration of feeding height to distance from crown edge). Small finches such as Serins Serinus serinus and Goldfinches Carduelis carduelis had a very high value of PC in comparison to large finches such as Greenfinches Carduelis chloris, Chaffinches Fringilla coelebs, and Hawfinches Coccothraustes coccothraustes. In general, finches showed much higher values of PC than non-fringillid species, indicating a greater adaptation to perch and feed on more flexible stems. Birds increased their overall seed predation and the time allocated to foraging on the ground when they were in flocks. Small finches tended to follow larger finches and flock in multispecies groups when foraging on the ground. We suggest that this behaviour increases both feeding efficiency and safety. Further studies should take into account possible differences in behavior of seed-eating birds throughout the dispersal season since it may have important implications for their adaptive behavior to select new niches.

6

Selected factors influencing the spatial relationship between latrines and burrows in rabbits Oryctolagus cuniculus (L.) in a suburban area of Madrid (Spain)

58%

Dominguez-Cebrian I., de Miguel F. J.

Polish Journal of Ecology

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2013

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tom 61

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nr 4

Latrines are a key element of maintenance behaviour in rabbits (Oryctolagus cuniculus), as well as a very important source of social and territorial information. On the other hand, its location probably carries significant costs associated with risk of predation. This study focuses on the factors involved in the spatial distribution of rabbit latrines in a suburban Mediterranean forest in Madrid (central Spain). In total, 167 latrines associated to 15 burrows were analyzed and the following information recorded: distance from each latrine to the burrow, ease of transit between each latrine and the burrow, visibility from the latrine and plant cover around the latrine. Our results show that, although all these factors are involved in the latrines disposition, their specific weight in the same was unequal, being ease of transit, visibility and plant cover more important than the distance between the latrines and the burrow.

7

Reproduction and behavior of plateau pikas [Ochotona curzoniae Hodgson] under predation risk: a field experiment

58%

Yang S., Yin B., Cao Y., Zhang Y., Wang J., Wei W.

Polish Journal of Ecology

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2007

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tom 55

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nr 1

The mixture of the feces and urine of the red fox (Vulpes vulpes Linnaeus) was used to increase the perception of predation risk of plateau pikas (Ochotona curzoniae Hodgson) in the field. The influence of the predation risk on the reproduction and behavior of plateau pikas was examined through comparing reproductive characteristics and five different kinds of behavior between treatment and control plots. The results showed that 1) the body weight of the pikas was not significantly different between treatment and control plots. 2) The reproductive period of the pikas extended from March to later August in both treatment and control plots. The pregnant ratio, developed testes ratio, reproductive success and sex ratio of the pikas were not significantly different between the treatment and control plots. 3) The pikas increased their observing and calling frequencies and decreased their moving and feeding frequencies when exposed to red fox’s feces and urine. 4) The increased red fox’s feces and urine had no influence on the behavior of the pikas when the number of their natural enemies increased; the pikas obviously increased the observing frequencies and sharply decreased the calling frequency so as to decrease the direct predation risk. 5) There were no significantly behavioral differences between males and females as well as between adults and young. 6) The results reject the hypothesis 1 that the red fox’s feces and urine as indirect predation risk suppresses the reproduction of the pikas and support the hypothesis 2 that the pikas can make decision by changing behavior to avoid the predation risk they encountered whenever.

8

The use of space by translocated edible dormice, Glis glis [L.], at the site of their original capture and the site of their release: radio-tracking method applied in a reintroduction experiment

58%

Jurczyszyn M.

Polish Journal of Ecology

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2006

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tom 54

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nr 3

A study was made of the use of space by two groups (each of 6 animals) of adult edible dormice (G. glis) at the sites of their origin and where they were released. The reintroduction took place in Szczeciński Landscape Park (north-western Poland; 53°17’N, 14°46’E). The source sites for the animals were in the Sie rakowski Landscape Park (western Poland; 52°38’N, 16°07’E) and a nature reserve “Buczyna Szprotawska” in south-western Poland (51°30’N, 15°40’E). All three sites had dense and extensive mixed forests. At release and source sites, dormice were radio-tracked during 10 successive nights between 20.00 and 05.00 at 1-hour intervals. At the source sites, the mean distance travelled per night and mean home range (95% Minimum Convex Polygon) (MCP) tended to be larger in males than in females but not significantly. At the release sites, the mean distance travelled per night and mean home range were significantly larger in females than in males. The mean distance travelled per night by males and their mean home range size did not differ significantly between source and release sites (although distances were larger at the source sites (source: 458 m; release: 265 m) and home ranges larger at the release sites (source: 1.3 ha; release: 1.8 ha). In contrast, the mean female distance travelled per night (source: 214 m; release: 404 m) and mean home range (source: 0.3 ha; release: 3.5 ha) were significantly larger at the release site than at the source sites.

Ograniczanie wyników

Selection of calling sites by Pelophylax porosus porosus (Anura: Ranidae)

Intensity of melanin-based color and risk of predation in the Barn Swallow Hirundo rustica

Summertime activity patterns of common weasels Mustela nivalis vulgaris under differing prey abundances in grassland habitats

Dependence of nest mass on nest hole depth in the Great Tit Parus major

Seed predation on the ground or in the tree? Size-related differences in behavior and ecology of granivorous birds

Selected factors influencing the spatial relationship between latrines and burrows in rabbits Oryctolagus cuniculus (L.) in a suburban area of Madrid (Spain)

Reproduction and behavior of plateau pikas [Ochotona curzoniae Hodgson] under predation risk: a field experiment

The use of space by translocated edible dormice, Glis glis [L.], at the site of their original capture and the site of their release: radio-tracking method applied in a reintroduction experiment