scholarly journals Study of small mammal populations within two Barn owl corridors at Folly Farm

2009 ◽  
Vol 2 (2) ◽  
pp. 155-163
Author(s):  
A. Keene
Keyword(s):  
Small Mammal ◽  
Barn Owl

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.

Prey selection by barn owls in relation to small-mammal community and population structure in a Sahelian agro-ecosystem

2007 ◽  
Vol 23 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Laurent Granjon ◽  
Mahamane Traoré
Keyword(s):  
Small Mammal ◽  
Prey Selection ◽  
Population Level ◽  
Tooth Wear ◽  
Barn Owl ◽  
Reproductive Period ◽  
Site Distribution ◽  
Barn Owls ◽  
Small Mammal Community ◽  
Major Shift

Barn owl pellet content was studied on seven occasions over a 2-y period during which terrestrial small-mammal populations were assessed via a capture-mark-recapture (CMR) programme in a Sahelian agro-ecosystem of the Inner Delta of Niger River in Mali. Rodents (especially Mastomys huberti representing 78.5% of the total number of prey) were the major prey of the barn owl on all but one occasion, when bats were dominant. This exception coincided with the period of lowest abundance of M. huberti at the study site. Distribution of M. huberti prey into four age classes was assessed through analysis of tooth wear in remains from the seasonal pellet samples. Comparisons with age structure of the CMR population indicate that the barn owl tended to prey on smaller-than-average (thus younger) individuals, especially when these are rare in the population (non-reproductive period between June and October). The spectrum of prey consumed is compared with data previously reported in Sahelian Africa, showing for the first time in this region a major shift in prey choice by the barn owl when its preferred prey becomes rare. At the rodent population level, the apparent choice of younger M. huberti prey at some periods is interpreted in the light of our knowledge on population dynamics of the species in this habitat.

scholarly journals Discovery of the bank vole (Myodes glareolus) on Ushant Island (Brittany, France)

Mammalia ◽  
2019 ◽  
Vol 83 (5) ◽  
pp. 496-500
Author(s):  
Olivier Lorvelec ◽  
Pascal Rolland ◽  
Patricia Le Quilliec ◽  
François Quénot ◽  
Alain Butet
Keyword(s):  
Small Mammal ◽  
Bank Vole ◽  
Ecological Monitoring ◽  
Barn Owl ◽  
Myodes Glareolus ◽  
Term Basis ◽  
Suitable Habitats ◽  
Bank Vole Myodes Glareolus ◽  
Owl Pellets

Abstract Ecological monitoring of small mammal occurrence on Ushant Island (Brittany, France) revealed the presence of the bank vole (Myodes glareolus) in September 2017. This was the first report of the bank vole on the island. Evaluation of previous small mammal monitoring and analysis of several batches of barn owl pellets allowed us to conclude that the arrival on the island is recent, sometime between 1995 and 2017. Further study is necessary to determine whether the current population, still incompletely distributed into suitable habitats of the island, will be self-sustaining on a long-term basis.

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 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.

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