Altitudinal variation of community metrics in Italian small mammal assemblages as revealed by Barn Owl (Tyto alba) pellets

2019 ◽  
Vol 281 ◽  
pp. 11-15 ◽  
Author(s):  
Giuliano Milana ◽  
Corrado Battisti ◽  
Luca Luiselli ◽  
Giovanni Amori
Keyword(s):  
Small Mammal ◽  
Barn Owl ◽  
Tyto Alba ◽  
Altitudinal Variation ◽  
Community Metrics ◽  
Mammal Assemblages

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.

Diet of the Barn Owl, Tyto-Alba, in the Tanami Desert, Northern Territory

1989 ◽  
Vol 16 (6) ◽  
pp. 611 ◽  
Author(s):  
JDB Smith ◽  
J Cole
Keyword(s):  
Life History ◽  
Small Mammals ◽  
Small Mammal ◽  
Barn Owl ◽  
Northern Territory ◽  
Tyto Alba ◽  
Prey Biomass ◽  
Large Fluctuations ◽  
Prey Items ◽  
Owl Pellets

The diet of the barn owl was determined by analysing egested pellets collected from the Tanami Desert. These data were also used to examine the distribution of small mammals in the region. Rodents were the dominant prey items, forming more than 74% of prey biomass in all samples. The dominant rodent species were those that undergo large fluctuations in population size. Notomys alexis was the dominant prey item in 15 of the 17 samples. In all samples, one or two species of rodents formed 47-100% of prey biomass. Dasyurids were relatively minor prey items, forming less than 12% of prey biomass in all samples. It is suggested that this is a reflection of their abundance relative to rodents. Bats, birds, lizards and insects combined formed less than 14% of prey biomass in all but one sample (24%). Behavioural and life-history characteristics of prey appear to affect their susceptibility to predation. The analysis of pellets proved to be a useful supplementary technique to conventional methods of surveying small mammals. All species of small mammal that could be expected were identified in owl pellets. Notomys amplus was recorded in pellets but not collected by conventional techniques.

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.

scholarly journals Variation in the diet and breeding biology of the Common Barn-owl (Tyto alba) in a demographic cycle of Common Vole (Microtus arvalis) between two outbreaks

2020 ◽  
Vol 28 (2) ◽  
pp. 37-65
Author(s):  
Adrienn Horváth ◽  
László Bank ◽  
Győző F. Horváth
Keyword(s):  
Clutch Size ◽  
Small Mammal ◽  
Diet Composition ◽  
Common Vole ◽  
Barn Owl ◽  
Early Spring ◽  
Tyto Alba ◽  
Microtus Arvalis ◽  
Breeding Parameters ◽  
The Common

AbstractIn the present study, we analysed the variation of breeding parameters and the diet composition of the Common Barn-owl (Tyto alba) in three different demographic phases of the Common Vole (Microtus arvalis) in a complete population cycle between two outbreaks. The study was conducted in the south-eastern part of the Transdanubian region in South Hungary. For the analysis, we used data of 81 randomly selected first clutches from 2015 to 2019, a time period which represented a full demographic cycle of the Common Vole after the 2014 outbreak with an exceptionally high peak. We tested the impact of prey abundance and diversity of diet composition as continuous predictors as well as the demographic phase of Common Vole and the mesoregion as categorical explanatory variables on the measured reproductive outputs as response variables using Generalized Linear Models (GLM). Considering the breeding parameters, the number of fledglings, and fledging and reproductive success were significantly higher in the increase phase than during the vole crash phase. Based on GLM models, our results demonstrated that the clutch size of the Common Barn-owl is determined ultimately by the availability and consumption rate of the Common Vole as main prey, while other small mammal prey categories did not affect the clutch size. These results support the finding that the clutch size of vole-eating raptors and owls, which begin breeding periods in early spring predicts the vole abundance in this early spring period. Considering the other investigated small mammal prey groups, the alternative prey role was confirmed only in case of the Murid rodent prey categories (Apodemus spp., Muridae).

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 Applying abundance/biomass comparison curves to small mammals: a weak tool for detect urbanization-related stress in the assemblages?

2020 ◽  
Vol 47 (1) ◽  
pp. 10-15
Author(s):  
Ermellina di Bagno ◽  
Corrado Battisti ◽  
Francesco Zullo ◽  
Giovanni Amori
Keyword(s):  
Trophic Level ◽  
Small Mammal ◽  
Total Biomass ◽  
Tyto Alba ◽  
Synanthropic Species ◽  
Mosaic Landscapes ◽  
Related Stress ◽  
Mammal Assemblages ◽  
Almost All

AbstractUrbanization is a form of pervasive human-induced disturbance. We tested the effectiveness of Abundance/Biomass Comparisons (ABC) as an approach in detecting stress due to landscape urbanization in large small mammal assemblages obtained from pellets of Barn Owl (Tyto alba; Strigiformes). We compared three assemblages sampled in not urbanized contexts (agro-mosaic landscapes) with three assemblages preyed in highly urbanized contexts. In all assemblages, the role of strictly synanthropic species (in our case: rodents) emerged since almost all of total biomass was assigned to these species: indeed, everywhere (both in agro-mosaic and urbanized sites) species of low trophic level (i.e. omnivorous/herbivorous rodents) significantly prevail in biomass when compared to insectivorous species (i.e. shrews, Soricomorpha) linked to less anthropized habitats. This biomass dominance in rodent species is highlighted by the data on evenness, showing lower values in biomass when compared to abundance. This pattern did not match with the classic assumption expressed by the ABC model (i.e., species with higher biomass are typical of undisturbed assemblage) and could be wrongly interpreted. Our study evidenced as ABC approach is a not reliable tool to detect the effect of urbanization as landscape disturbance acting on small mammal assemblages. Therefore we suggest that the ABC assumptions are not universal but limited only to assemblages where high body mass species coincide to species of a higher trophic level.

scholarly journals Small mammals from barn owl Tyto alba pellets in a Mediterranean agroforestry landscape of central Italy

2021 ◽  
Vol 8 (2) ◽  
pp. 3-10
Author(s):  
Vincenzo Ferri ◽  
Paolo Crescia ◽  
Stefano Celletti ◽  
Christiana Soccini ◽  
Corrado Battisti
Keyword(s):  
Small Mammal ◽  
Central Italy ◽  
Detrended Correspondence Analysis ◽  
Habitat Diversity ◽  
Barn Owl ◽  
Tyto Alba ◽  
Almost Everywhere ◽  
Small Mammal Communities ◽  
One Year ◽  
Mammal Communities

In order to investigate diversity patterns and similarities in the small mammal communities of an agroforestry landscape in western central Italy (Maremma of Lazio), we analyzed, in a multivariate setting (Cluster analysis, DCA-Detrended Correspondence Analysis), the prey content of barn owl Tyto alba pellets collected along one year in five sampling sites. Small mammal communities were composed by guilds typical of habitats included in agroforestry landscapes (croplands and mosaics, forests and ecotones, wet habitats and synanthropic ones). Since landscape matrices were characterized almost everywhere by croplands, typical agro-ecosystem species (Apodemus cfr. sylvaticus, Microtus savii, Mus domesticus and Soricidae) dominated in the majority of the collecting sites. The statistical analyses show how small changes in land use and cover can explain the faunal differences between sites, with the occasional presence of Arvicola italicus in wet habitats, and of Muscardinus avellanarius and Sorex samniticus in sites dominated by forest or agroforestry ecotones. Communities recorded in sites characterized by wet and forest habitats showed a higher distance from the others, dominated by croplands. Communities occurring in landscapes with the lowest habitat diversity showed also the lowest species diversity.

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.

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