A long-term study of food-niche dynamics in the Common Barn-Owl: comparisons within and between populations

1988 ◽  
Vol 66 (8) ◽  
pp. 1803-1812 ◽  
Author(s):  
Carl D. Marti
Keyword(s):  
Small Mammal ◽  
Niche Breadth ◽  
Barn Owl ◽  
Tyto Alba ◽  
Mammal Species ◽  
Long Term Study ◽  
Niche Differences ◽  
Niche Dynamics ◽  
Food Niche ◽  
Small Mammal Species

Food niches of Common Barn-Owl (Tyto alba) populations were studied for 8 years in Utah and Idaho. Small mammals dominated the diet as they do in most parts of the barn-owl's range. Mean prey weight was nearly identical between the two owl populations. Food-niche breadth, though, was significantly broader in Idaho than in Utah. Food-niche breadth was also more variable in Idaho than in Utah both within and between years. Voles (Microtus spp.) were predominant prey for both owl populations and were the only prey whose numeric variation in the diet significantly affected mean prey weight and food-niche breadth. Vegetative composition was less varied and more uniformly favorable to voles in Utah. The Idaho area contained a smaller poportion of good vole habitat but had a greater diversity of vegetation including deserts suitable for small mammal species not found in the Utah study area. These vegetative differences and their effects on small mammal species diversity and density were the most apparent causes of food-niche differences between the two owl populations.

An attempt to determine the size of the Common Barn-owl’s (Tyto alba) hunting area based on its prey composition

2021 ◽  
pp. 175815592110660
Author(s):  
Jenő J Purger ◽  
Dávid Szép
Keyword(s):  
Functional Groups ◽  
Small Mammals ◽  
Small Mammal ◽  
Barn Owl ◽  
Tyto Alba ◽  
Mammal Species ◽  
Open Forest ◽  
Prey Composition ◽  
Small Mammal Species ◽  
Owl Pellets

The relative abundance of small mammal species detected from Common Barn-owl pellets reflects the landscape structure and habitat pattern of the owl’s hunting area, but it is also affected by the size of the collected pellet sample and the size of the supposed hunting area. The questions arise: how many pellets should be collected and analyzed as well as how large hunting area should be taken into consideration in order to reach the best correspondence between the owl’s prey composition and the distribution of habitats preferred by small mammals preyed in supposed hunting areas? For this study, we collected 1045 Common Barn-owl pellets in a village in southern Hungary. All detected small mammal species were classified into functional groups (guilds) preferring urban, open, forest and wetland habitats. The proportion of functional groups was compared to the proportion of these habitats around the pellet collection site within circles of one, two, and three km radius. Saturation curves showed that at least 300 pellets or ca. 600 mammalian remains are required for the detection of the 19 small mammal species. The share of small mammals detected in the prey and their functional groups according to their habitat preference showed an increasing consistency with the distribution of real habitats in the potential hunting area of a radius of 3 km around the owl’s breeding or resting place.

scholarly journals The prey composition of the Barn Owl (Tyto alba) with respect to landscape structure of its hunting area (Zala County, Hungary)

2017 ◽  
Vol 25 (2) ◽  
pp. 51-64
Author(s):  
Dávid Szép ◽  
Ákos Klein ◽  
Jenő J. Purger
Keyword(s):  
Relative Abundance ◽  
Small Mammal ◽  
Landscape Structure ◽  
Barn Owl ◽  
Tyto Alba ◽  
Mammal Species ◽  
Prey Composition ◽  
Barn Owls ◽  
Landscape Patches ◽  
Small Mammal Species

Abstract The prey composition of the Barn Owl (Tyto alba) can be monitored indirectly by pellet analysis and we used this method to investigate less known small mammal species of Zala County. The number and abundance of small mammal species depend on the structure of the landscape of Barn Owls’ hunting area, therefore we analysed landscape features in the surrounding circles with 2 km radius around the sampling sites. In 2016 we collected 1106 pellets from 13 sampling localities. From the pellets we identified 21 species of 3022 individuals of small mammals (more than 98% of prey). Among the 21 species there was the rare Parti-colured Bat (Vespertilio murinus) and a new species for the county the Steppe Mouse (Mus spicilegus). Positive correlation was found between the diversity of the small mammal fauna of each sampling site and the landscape complexity (number of the landscape patches) of the Barn Owl hunting area. Relative abundance of the Wood Mouse (Apodemus sylvaticus) showed positive correlation with the number of landscape patches, while the abundance of the Lesser White-toothed Shrew (Crocidura suaveolens), the Miller’s Water Shrew (Neomys anomalus), the Striped Field Mouse (Apodemus agrarius) and the Harvest Mouse (Micromys minutus) was higher in hunting areas with more homogenous landscapes. Significant correlations were found between the relative abundance of some small mammal species and the landscape structure of the potential hunting area of owls that confirmed the consistency in habitat preference of some species. Our results proved that the prey-composition of Barn Owls reflects the land use through the distribution and abundance of small mammal species, therefore this method is suitable for ecological analyses of landscape.

scholarly journals Investigating the relationship between the prey composition of Barn Owls (Tyto alba) and the habitat structure of their hunting range in the Marcal Basin (Hungary), based on pellet analysis

2019 ◽  
Vol 27 (1) ◽  
pp. 32-43
Author(s):  
Dávid Szép ◽  
Ákos Klein ◽  
Jenő J. Purger
Keyword(s):  
Functional Groups ◽  
Small Mammal ◽  
Barn Owl ◽  
Habitat Types ◽  
Mammal Species ◽  
Open Forest ◽  
Prey Composition ◽  
Small Mammal Species ◽  
Wetland Habitats ◽  
Prey Items

Abstract Little was known about the small mammal fauna of the Marcal Basin to date, therefore we collected 1,144 Barn Owl pellets from 15 locations in 2017. After the analysis of the pellets, remnants of 3,063 prey items were identified, of which 97.5% were small mammals, belonging to 21 species, while the remaining 2.5% were birds, frogs and insects. Mammal prey items consisted of Cricetidae 41%, Muridae 31% and Soricidae 28%, and in some samples, we found the remnants of European Mole (Talpa europaea), Kuhl’s Pipistrelle (Pipistrellus kuhlii), Hazel Dormouse (Muscardinus avellanarius) and Least Weasel (Mustela nivalis). Small mammal species were classified into four functional groups based on their preferences for urban, open, forest or wetland habitats. We investigated whether their relative abundances match with the proportions of the four habitat types in the assumed Barn Owl hunting ranges (cca. 2 km radius circle) in five sample sites. The relative abundance of small mammal species preferring urban habitats showed concordance with the proportion of the appropriate habitat types in the hunting area in two samples, while such concordance was proved for species favouring open, forest and wetland habitats just in one out of five samples. Small mammal functional groups represented in the prey composition do not directly correspond to the proportion of their typical habitats. We conclude that the abundance of various prey types is not suitable for characterising the landscape within the Barn Owl’s hunting range.

scholarly journals Food-niche pattern of the Barn Owl (Tyto alba) in intensively cultivated agricultural landscape

2018 ◽  
Vol 26 (1) ◽  
pp. 27-40 ◽  
Author(s):  
Adrienn Horváth ◽  
Anita Morvai ◽  
Győző F. Horváth
Keyword(s):  
Land Use ◽  
Diet Composition ◽  
Niche Breadth ◽  
Local Level ◽  
Common Vole ◽  
Barn Owl ◽  
Tyto Alba ◽  
Barn Owls ◽  
Landscape Types ◽  
Food Niche

Abstract This study investigated the dietary niche of the Barn Owl (Tyto alba) in an intensively farmed landscape, based on pellet samples from 12 nesting pairs containing 25 animal taxa and 1,994 prey items after the breeding season in 2016. Based on land use categories of the buffer area around each nest, three landscape types (agricultural, mosaic, urban) were considered, to analyse the diet composition and food-niche parameters. Niche breadth was calculated at the local and landscape level. Small mammals were the most frequent in the diet than other prey in each of the landscape types. The Common Vole (Microtus arvalis), considered to be an important agricultural pest was the most numerous prey in all landscape groups. The trophic niche of Barn Owl varied between 0.69 – 0.86 at the local level, and the overall value of niche breadth was significantly higher in the urban than in the other two landscape types. Our results showed that the increase of Common Vole frequency lead to a decrease in niche breadth; significantly negative relationship was detected between these parameters. Despite differences in niche breadth, similarly high niche overlaps were detected by the randomisation test in the three landscapes. Our results suggest that the diet composition of Barn Owls, mainly their food-niche pattern, reflected prey availability in the comparison of the studied landscapes, which pointed out that it is necessary to examine the dietary difference of Barn Owls at the finer scale of land use.

scholarly journals Small mammals in diet of the barn owl (Tyto alba) in the Black Sea Biosphere Reserve

2020 ◽  
pp. 72-76
Author(s):  
Zoya Selyunina ◽  
Yuriy Moskalenko
Keyword(s):  
Black Sea ◽  
Small Mammals ◽  
Small Mammal ◽  
Dominant Species ◽  
Bird Species ◽  
Biosphere Reserve ◽  
Barn Owl ◽  
The Black Sea ◽  
Tyto Alba ◽  
Mammal Species

The barn owl (Tyto alba) formerly was one of the rarest vagrant bird species in the Black Sea Biosphere Reserve. Since 2018, this species has been wintering regularly in the Yahorlytskyi Kut division of the Black Sea Biosphere Reserve. We studied the barn owl’s diet in the reserve by analysing 20 pellets collected in the winter of 2018. A total of 69 specimens of 5 mammal species were identified from the pellets. Species of small mammals that dominate in open habitats prevail in the barn owl’s diet such as the social vole (Microtus socialis) (dominant species of steppe habitats; 43 % of identifiable small-mammal specimens) and the lesser white-toothed shrew (Crocidura suaveolens) (dominant species of salt marsh habitats; 42 % of identifiable small-mammal specimens). Remains of the southern vole (Microtus levis), the Ural field mouse (Sylvaemus cf. uralensis), and the Eurasian pygmy shrew (Sorex minutus) were non-abundant in the barn owl’s diet.

Long-term stress level in a small mammal species undergoing range expansion

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Adrien André ◽  
Johan Michaux ◽  
Jorge Gaitan ◽  
Virginie Millien
Keyword(s):  
Stress Level ◽  
Species Distribution ◽  
Small Mammal ◽  
Range Expansion ◽  
Mammal Species ◽  
Distribution Ranges ◽  
Northern Edge ◽  
Small Mammal Species ◽  
White Footed Mouse

Abstract Rapid climate change is currently altering species distribution ranges. Evaluating the long-term stress level in wild species undergoing range expansion may help better understanding how species cope with the changing environment. Here, we focused on the white-footed mouse (Peromyscus leucopus), a widespread small mammal species in North-America whose distribution range is rapidly shifting northward. We evaluated long-term stress level in several populations of P. leucopus in Quebec (Canada), from the northern edge of the species distribution to more core populations in Southern Quebec. We first tested the hypothesis that populations at the range margin are under higher stress than more established populations in the southern region of our study area. We then compared four measures of long-term stress level to evaluate the congruence between these commonly used methods. We did not detect any significant geographical trend in stress level across our study populations of P. leucopus. Most notably, we found no clear congruence between the four measures of stress level we used, and conclude that these four commonly used methods are not equivalent, thereby not comparable across studies.

Response of wildlife to forest herbicide applications in northern coniferous ecosystems

1993 ◽  
Vol 23 (10) ◽  
pp. 2286-2299 ◽  
Author(s):  
R.A. Lautenschlager
Keyword(s):  
Small Mammal ◽  
Growing Season ◽  
Sampling Techniques ◽  
Mammal Species ◽  
Growing Seasons ◽  
Disturbed Areas ◽  
Herbicide Treatments ◽  
Species Specific ◽  
Small Mammal Species ◽  
Coniferous Ecosystems

Reviewed studies of the effects of forest herbicide applications on wildlife often lacked replication, pretreatment information, and (or) were conducted for only one or two growing seasons after treatment. Because of these problems, as well as the use of dissimilar sampling techniques, study conclusions have sometimes been contradictory. A review of eight studies of the effects of herbicide treatments on northern songbird populations in regenerating clearcuts indicates that total songbird populations are seldom reduced during the growing season after treatment. Densities of species that use early successional brushy, deciduous cover are sometimes reduced, while densities of species which commonly use more open areas, sometimes increase. A review of 14 studies of the effects of herbicide treatments on small mammals indicates that like songbirds, small mammal responses are species specific. Some species are unaffected, while some select and others avoid herbicide-treated areas. Only studies that use kill or removal trapping to study small mammal responses show density reductions associated with herbicide treatment. It seems that some small mammal species may be reluctant to venture into disturbed areas, although residents in those areas are apparently not affected by the disturbance. Fourteen relevant studies examined the effects of conifer release treatments on moose and deer foods and habitat use. Conifer release treatments reduce the availability of moose browse for as long as four growing seasons after treatment. The degree of reduction during the growing season after treatment varies with the herbicide and rate used. Deer use of treated areas remains unchanged or increases during the first growing season after treatment. Eight years after treating a naturally regenerated spruce–fir stand browse was three to seven times more abundant on treated than on control plots (depending on the chemical and rate used). Forage quality (nitrogen, ash, and moisture) of crop trees increased one growing season after the soil-active herbicide simazine was applied to control competition around outplanted 3-year-old balsam fir seedlings.

scholarly journals Flea Communities on Small Mammals in Lowland Environment

2020 ◽  
Vol 39 (3) ◽  
pp. 260-269 ◽  
Author(s):  
Ivan Baláž ◽  
Martina Zigová
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Dominant Species ◽  
Mammal Species ◽  
Blood Sucking ◽  
Four Seasons ◽  
Small Mammal Species

AbstractThe landscape of south-western Slovakia is characterised by anthropogenous reshaping, while fragments of undisturbed, waterlogged habitats have been preserved in what remains of the meandering ancient Žitava River. These refuges are inhabited by various small mammal species and their blood-sucking ectoparasites. Between 2014 and 2018, research on them was carried out in Slovakia’s Danubian Lowland (Podunajská nížina) during three out of the four seasons (spring, summer and autumn). The small mammals were captured at 27 localities. The occurrence of nine flee species from the Hystrichopsyllidae, Ctenophthalmidae and Ceratophyllidae families was documented on 12 small burrowing mammals. During the course of all the seasons in which research was conducted, Ctenophthalmus agyrtes, C. assimilis, Megabothris turbidus a Nosopsyllus fasciatus were found, among the most dominant species to be seen on small burrowing mammals.

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