ACTA THERIOLOGICA

Published by Springer Nature

Online ISSN: 2190-3743

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Print ISSN: 0001-7051

Articles


Histological changes in the gonads of the American mink during postnatal development
Article

June 1976

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11 Reads

Krystyna Zaleska-Freljan
Zbadano 79 norek amerykanskich, w tym osobniki 1-10 dniowe, 3-6 tygodniowe, 7-7,5 i 10 miesieczne oraz 11 miesieczne (tylko samice). Uzyskane wyniki wskazują, ze proces rozwoju gonad nie jest zakonczony w momencie urodzenia sie norek i trwa jeszcze u 10-11 miesiecznych zwierząt.
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Table 2 ). Observed heterozygosities (H O ) per locus ranged
The location of the sampling sites in the Łęgucki Młyn/Popielno hybrid zone: P Prawdowo (53°48′N, 21°32′E), LK Lisunie-Kulinowo (53°46′N, 21°33′E), L Lipowo (53°47′N, 21°25′E), NM Nowy Most (53°44′N, 21°31′E), KI Krutyń I (53°42′N, 21°26′E), KII Krutyń II (53°41′N, 21°26′E), ZL Zielony Lasek (53°40′N, 21°27′E), Z Zakręt (53°39′N, 21°26′E), KM Karwica Mazurska (53°37′N, 21°27′E)
A microsatellite study in the Łęgucki Młyn/Popielno hybrid zone reveals no genetic differentiation between two chromosome races of the common shrew (Sorex araneus)
ArticleFull-text available

April 2011

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76 Reads

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Anna Macierzyńska

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This study investigated a chromosome hybrid zone between two chromosomal races of the common shrew (Sorex araneus). Gene flow and genetic structure of the hybrid zone, located in the northeast of Poland, were studied using seven polymorphic autosomal microsatellite loci (L9, L14, L33, L45, L67, L68, L97) and a Y-linked microsatellite locus (L8Y). Seventy-five animals (46 of the Łęgucki Młyn race and 29 of the Popielno race) from nine different localities were examined and the data were analyzed using hierarchical AMOVA and F-statistic. The studied microsatellite loci and races (divided into nine geographical populations) were characterized by observed heterozygosity (H O), expected heterozygosities within (H S), and between (H T) populations, inbreeding coefficient (F IS), fixation index (F ST), and average allelic richness (A). We found that genetic structuring within and between the two chromosome races were weak and non-significant. This finding and unconstrained gene flow between the races indicates a high level of migration within the Łęgucki Młyn/Popielno hybrid zone, suggesting that evolutionarily important genetic structuring does not occur in interracial zones where races which are not genetically distinct come into contact.
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Stages of pregnancy of the bank vole

June 1976

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12 Reads

Przedstawiono sekwencje zmian zachodzących w narządach plciowych w trakcie ciązy oraz zmiany w ciezarze, dlugości i w morfologii zarodkow nornicy rudej, Clethrionomys glareolus (Schreber, 1780) pomiedzy 9 dniem ciązy a porodem. Stwierdzono, ze ciezar i dlugośc ciemieniowo-pośladkowa jest dobrą cechą dla ustalenia stadium zaawansowania ciązy pomiedzy 10 a 15 dniem ciązy (Tabela 1). Ustalono pewne cechy morfologiczne, ktore pozwalają na określenie wieku zarodka pomiedzy 9 a 16 dniem rozwoju (Tabela 2, Tablice V i VI).


Fig. 2 Partial correlation coefficients (r p ) between hare density and three variables describing landscape structure in relation to the average value of these variables in five study areas in Germany (G) and Poland (P) in 2006 (crop borders: r00.036, df03, p00.95; wild vegetation without trees: r 0−0.839, df 03, p 00.08; wild vegetation with trees: r0−0.658, df03, p00.2)
Distribution of subareas, spotlight count strips and surrounding zones within a study area
Partial correlation coefficients (rp) between hare density and three variables describing landscape structure in relation to the average value of these variables in five study areas in Germany (G) and Poland (P) in 2006 (crop borders: r = 0.036, df = 3, p = 0.95; wild vegetation without trees: r = −0.839, df = 3, p = 0.08; wild vegetation with trees: r = −0.658, df = 3, p = 0.2)
The effect of landscape structure on the distribution of brown hare Lepus europaeus in farmlands of Germany and Poland

January 2013

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165 Reads

Habitat management should be an important part of the brown hare (Lepus europaeus) conservation, but the habitat requirements of this species are not fully recognised. The aim of our research was to estimate these requirements by analysing the effect of various agricultural landscape structure features on the distribution of hares in five agricultural areas in Germany and Poland. The local density of hares was assessed in the spring and autumn of 2006 by using the method of spotlight-strip counts on 9-15 subareas in each research region. The structure of agricultural landscape has been described for each subarea: the share of grain, other crops and grasses as well as the density of crop edges and uncultivated places with wild vegetation. The density of hares was considerably higher in Germany than in Poland (18.8-48.4 vs. 4.1-9.5 indiv./km(2)). The hare density was positively correlated with non-grain crops in an area, with crop edges in two areas and with wild vegetation without trees in two areas, and negatively correlated with grassfields in two areas. The occurrence of wild vegetation without trees affected the hare density only in the study areas, where this habitat was relatively rare (<3 km/km(2)). It was suggested that proper projects aimed at habitat management for brown hares should be elastic, i.e. the projects should be modified depending on the structure of local landscapes. Moreover, the protection and creation of structures with wild vegetation among cropland seem to be considerable methods of brown hare or generally wildlife conservation; therefore, such measures should be an important part of agro-environmental packages.

Table 2 Species composition of wolf prey found between 2001 and 2005 in NE Hungary 
Diet of wolves Canis lupus returning to Hungary

April 2012

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575 Reads

At the end of the nineteenth century, the wolf Canis lupus was extinct in Hungary and in recent decades has returned to the northern highland area of the country. The diet of wolves living in groups in Aggteleki National Park was investigated using scat analysis (n = 81 scats) and prey remains (n = 31 carcasses). Throughout the year wolves (average, minimum two wolves per year) consumed mostly wild-living ungulates (mean percent of biomass consumed, B% 97.2%; relative frequency of occurrence, %O 74.0%). The wild boar Sus scrofa was the most common prey item found in wolf scat (%B 35.6%) and is also the most commonly occurring ungulate in the study areas. The second most commonly occurring prey item in wolf scat was red deer Cervus elaphus (B% 32.8%). Conversely, prey remain analyses revealed wild boar as the second most commonly utilised prey species (%O 16.1%) after red deer (%O 67.7%). The roe deer Capreolus capreolus that occurs at lower population densities was the third most commonly utilised prey species. The importance of low population density mouflon Ovis aries, livestock and other food types was low. The results are similar to those found in the northern part of the Carpathian Mountains.

The range of M. rossiaemeridionalis Ognev, 1924 (according to Shenbrot and Krasnov 2005) and capture sites in the Russian Far East: (1) Lososin rural settlement, (2) outskirts of Lososin rural settlement, (3) Sovetskaya Gavan City, Bunker port territory, (4) Bolshaya Okocha River, (5) Malaya Egge River, (6) left bank of lower reaches of the Bolshaya Egge River, (7) bank of Bukhta Egge, (8) northeast outskirts of Mayskii rural settlement
Average frequencies of main molar morphotypes in M. rossiaemeridionalis. See “Materials and methods” for morphotype abbreviations
Morphotype analysis of the sibling vole (Microtus rossiaemeridionalis) casually introduced to the Russian Far East

January 2013

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180 Reads

Here, we present the morphotypic variety of the m1 and M3 teeth diagnostics for the recently formed isolated population of the sibling vole in Far Eastern Russia. In the Far Eastern population, the prevalence of the individuals with m1 with a complicated crown of the forward unpaired loop of the paraconid is characteristic. Namely, m1 in these individuals shows well-expressed sixth exterior and fifth interior salient angles. The structure of the M3 morphotypes is also unique in the sibling voles in Far Eastern Russia. The dominant morphotypes were typica (47 %) and simplex (45 %), whereas the abundance of the duplicata morphotype was 0.08 %. The frequencies of various m1 and M3 morphotypes found in casually introduced sibling voles in the Far East are not typical of any previously studied Microtus rossiaemeridionalis population.

Drive counts as a method of estimating ungulate density in forests: Mission impossible?

July 2011

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1,380 Reads

Although drive counts are frequently used to estimate the size of deer populations in forests, little is known about how counting methods or the density and social organization of the deer species concerned influence the accuracy of the estimates obtained, and hence their suitability for informing management decisions. As these issues cannot readily be examined for real populations, we conducted a series of 'virtual experiments' in a computer simulation model to evaluate the effects of block size, proportion of forest counted, deer density, social aggregation and spatial auto-correlation on the accuracy of drive counts. Simulated populations of red and roe deer were generated on the basis of drive count data obtained from Polish commercial forests. For both deer species, count accuracy increased with increasing density, and decreased as the degree of aggregation, either demographic or spatial, within the population increased. However, the effect of density on accuracy was substantially greater than the effect of aggregation. Although improvements in accuracy could be made by reducing the size of counting blocks for low-density, aggregated populations, these were limited. Increasing the proportion of the forest counted led to greater improvements in accuracy, but the gains were limited compared with the increase in effort required. If it is necessary to estimate the deer population with a high degree of accuracy (e.g. within 10% of the true value), drive counts are likely to be inadequate whatever the deer density. However, if a lower level of accuracy (within 20% or more) is acceptable, our study suggests that at higher deer densities (more than ca. five to seven deer/100 ha) drive counts can provide reliable information on population size.

Observations on the electroejaculation in Red Deer

June 1974

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26 Reads

Metodą elektroejakulacji pobrano nasienie od ośmioletniego samca jelenia szlachetnego we wrześniu, bez stosowania trankwiliny. Uzyskano dwie porcje nasienia. Objetośc pierwszej wynosila 23,5 ml, koncentracja plemnikow 70 000/mm3. Objetośc drugiej wynosila 19 ml, koncentracja plemnikow 50 000/mm. Te samą metode stosowano dwukrotnie u piecioletniego samca jelenia szlachetnego w marcu.

The effects of sex, age, season and habitat on diet of the red fox Vulpes vulpes in northeastern Poland

July 2011

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692 Reads

The diet of the red fox Vulpes vulpes was investigated in five regions of northeastern Poland by stomach content analysis of 224 foxes collected from hunters. The red fox is expected to show the opportunistic feeding habits. Our study showed that foxes preyed mainly on wild prey, with strong domination of Microtus rodents, regardless of sex, age, month and habitat. Voles Microtus spp. were found in 73% of stomachs and constituted 47% of food volume consumed. Other food items were ungulate carrion (27% of volume), other mammals (11%), birds (9%), and plant material (4%). Sex- and age-specific differences in dietary diversity were found. Adult males and juvenile foxes had larger food niche breadths than adult females and their diets highly overlapped. Proportion of Microtus voles increased from autumn to late winter. Significant habitat differences between studied regions were found. There was a tendency among foxes to decrease consumption of voles with increasing percentage of forest cover. Based on our findings, red foxes in northeastern Poland can be recognized as a generalist predators, consuming easily accessible and abundant prey. However, high percentage of voles consumed regardless of age, sex, month, or habitats may indicate red fox specialization in preying on Microtus rodents.

A 13-year population study of the edible dormouse Glis glis in Britain

September 2010

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258 Reads

Edible dormice Glis glis Linnaeus, 1766 were monitored from 1996–2008 inclusive. This has been the first population study of this non-native species since its introduction to Britain in 1902. Dormice were present in nest boxes from May or June until October or November. Numbers recorded varied greatly from year to year, and breeding failure occurred in 6 of the 13 years, apparently in response to environmental cues such as food availability. Litter sizes declined with growth of the young but some of the largest litters resulted from females aggregating their offspring. Males used more nest boxes than females, some of whom showed clear site fidelity from year to year. Survival rates were high and some individual lifespans exceeded 9 years. Longevity, compensating for periodic reproductive failure, and an extremely short active season, make the life history of edible dormice exceptional among small rodents, perhaps unique. Population density, rate of population increase and evidence for local emigration in non-breeding years are discussed, issues of particular significance in populations of recently-established introduced species such as this. Key wordsdormice-Gliridae-introduced species-longevity-reproduction

Subspecies of the European beaver Castor fiber Linnaeus, 1758

January 2014

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511 Reads

Subspecific relationships of the European beaverCastor fiber have been obscured by failure to follow the rules of the International Code of Zoological Nomenclature and remain an open issue. Inconsequence in the use of subspecies names caused a nomenclatural as well as a taxonomic confusion. We discuss these controversial and incorrect nomenclatural decisions, and recognize 9 nominal subspecies of European beaver, bearing 9 available names:C. f. fiber Linnaeus, 1758,C. f. galliae Geoffroy, 1803, C. f. albicus Matschie, 1907,C. f. vistulanus Matschie, 1907,C. f. pohlei Serebrennikov, 1929,C. f. birulai Serebrennikov, 1929,C. f. tuvinicus Lavrov, 1969,C. f. belorussicus Lavrov, 1981, andC. f. orientoeuropaeus Lavrov, 1981. Key words Castor fiber -subspecies-systematics-nomenclature

Fig. 1 Location of study area, Águas Emendadas Ecological Station (AEES), Northern Federal District, Brazil. The highlighted area represents the cerrado biome extent, the square represents the city of Brasília, DF, and the star is the location of AEES
Fig. 2 Precipitation amount and population structure and reproductive condition of T. lasiotis Thomas 1916 in AEES, Federal District, Brazil
Natural history and demography of Thalpomys lasiotis (Thomas, 1916), a rare and endemic species from the Brazilian savanna

July 2011

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220 Reads

Hairy-eared cerrado mouse Thalpomys lasiotis is an endemic species of the cerrado biome. It can be found in open habitats, but its distribution is patchy and population numbers are unknown. In this paper, we describe, for the first time, aspects related to the ecology and natural history of T. lasiotis, detailing demographic parameters such as population densities, reproduction, home range, and longevity of this endemic and rare species. We captured, marked, and recaptured 55 individuals of T. lasiotis in Águas Emendadas Ecological Station, located in the northeast of the Federal District, Brazil. We found significant differences on population numbers and densities between the dry and wet seasons. Densities and population numbers apparently are affected by the seasonality of food resources. Moreover, the breeding season is seasonal, and both males and females were reproductively active during the wet season. T. lasiotis showed a permanence time ranging from 2–9months, which means that individuals can survive for at least 9months in natural habitats. The home ranges of males and females of T. lasiotis were not significantly different. However, males have larger home ranges than females and the mean distance moved by males was higher than the distance moved by females, which is consistent with the hypothesis that males belonging to polygynous species tend to move greater distances to avoid agonistic encounters and to search sexual partners. Keywords Thalpomys –Akodontini–Cerrado–Population parameters–Ecology

Red fox Vulpes vulpes density and habitat use in a rural area of western Poland in the end of 1990s, compared with the turn of 1970s

December 2002

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119 Reads

The red foxVulpes vulpes (Linnaeus, 1758) density and habitat use were studied in open farmland of western Poland, where forests covered only 6% of the area. During 1997-2000, nocturnal spotlight counts (in spring and early winter), the location of breeding sites and snow tracking were carried out, and the feeding habitat was described based on the stomach content of shot individuals. The average fox density estimated on the ground of spotlight counts was 1.02 individuals/km2 in spring and 1.63 ind./km2 in early winter, while the winter density obtained from the results of track counts was 1.26 ind./km2. The average breeding population density, calculated as the double density of breeding sites (mean 0.31/km2), amounted to 61% of the average total spring density, which indicates the occurrence of surplus individuals in the population. The searching intensity of farmland by foxes did not changed with the increasing distance from forests, but relatively larger number of individuals was observed <0.5 km than 0.5–1.0 km away from settlements. Out of 81 identified breeding sites, 17% were located in forests and 83% in farmland. The predominant ingredients of the fox’s diet were farm livestock and small rodents (44.4 and 43.8% of the stomach content volume, respectively). The fox density in the study area was 5.4 times higher, compared with the turn of the 1970s, and changes in the habitat use consisted of more intensive occupation of open farmland and the use of human-produced food. Thus, these changes may have been among reasons of the increase in the fox density in western Poland. Key words Vulpes vulpes -population density-habitat use-feeding habitat-farmland

Fig. 2. Skull measurements of the samples studied (see Material and methods for explanation of symbols).
Table 2 . Values of Nei's (1978) unbiased genetic distance (below diagonal) and identity (above diagonal), based on 21 gene loci, observed among three species of the genus Sorex from Italy.
Fig. 4. Distinction of Sorex arunchi and S. araneus on the basis of the Complex Index (A) and the Odonto-Rostral Index (B). 
Fig. 6. Linear correlation existing between the Odonto-Rostral Index (ORI) and the Complex Index (CI). #-Sorex arunchi, ´-S. araneus.
Genetic and morphometric comparison betweenSorex arunchi Lapini and Testone, 1998, and other shrews from Italy

December 2001

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248 Reads

The results of allozymic, morphologic and morphometric studies performed on three parapatric shrews of the genusSorex from northern Italy are presented. These data clearly indicate: (1)Sorex samniticus is genetically well differentiated from S. araneus andS. arunchi, displaying a high mean value of genetic distance in comparison with the other two species (D=0.463). (2)S. araneus andS. arunchi display low values of genetic distance (D=0.007) and the latter shows lower levels of genetic variability. Altough no fixed allele difference was observed, an exclusive allele (Lap-2 96) is present inS. arunchi at low frequence, another one (Pgm-1 96) is rare inS. araneus and quite frequent inS. arunchi, and several alleles (12) ofS. araneus are missing in S. arunchi. In S. araneus some of these alleles are quite frequent. (3) Strong morphometric differences betweenS. araneus andS. arunchi permit to distinguish these parapatric shrews with great accuracy, also in some cases of marginal sympatry. These evidences support the hypothesis thatS. arunchi might be a recent (end of Pleistocene-lower Holocene) relict of the subgenusSorex s. s.

Fig. 1. Number of carcasses removed by vertebrates at the Savannah River Site, SC, during the winter of 2000-2001. Sixty-two of 96 (65%) carcasses were removed during the course of this study; 26 were assigned to a specific scavenger species (A). Dark bars represent rats, hatched bars represent mice. The mean elapsed time for carcass removal was 5.6 days (B). Latin names are as follows: bobcat Lynx rufus, cotton mouse Peromyscus gossypinus, domestic dog Canis familiaris, Virginia opossum Didelphis virginiana, striped skunk Mephitis mephitis, red-tailed hawk Buteo jamaicensis, eastern coyote Canis latrans, eastern gray squirrel Sciurus carolinensis, feral pig Sus scrofa, gray fox Urocyon cinereoargenteus, raccoon Procyon lotor.
Fig. 2. Number of carcasses removed by scavengers per round in relation to average temperature (°C) during the round. The regression model was significant: R 2 = 0.95, p = 0.001, y = 4.91 + 0.76x.
DeVault, T. L. and O. E. Rhodes, Jr. 2002. Identification of vertebrate scavengers of small mammal carcasses in a forested landscape. Acta Theriologica

June 2002

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763 Reads

We identified vertebrate scavengers of small mammal carcasses at the 780-km2 Savannah River Site during the winter of 2000–2001. Rodent carcasses, differing in size and visual conspicuousness, were placed in upland pine forests and bottomland hardwood forests during six 2-week periods. Sixty-two of the 96 carcasses (65%) were removed by vertebrates. With the aid of remote photography, we identified 11 species of scavengers removing carcasses. RaccoonsProcyon lotor, gray foxesUrocyon cinereoargenteus, and feral pigsSus scrofa scavenged most frequently. The mean elapsed time for carcass removal was 5.6 days. The number of carcasses removed by vertebrates did not differ significantly with respect to carcass size, visual conspicuousness, or habitat type; however, air temperature was strongly correlated (positively) with carcass removal. Our study demonstrates that many mammal species are capable of utilizing small carrion items as a food resource, and suggests that scavenging may account for a higher proportion of the diet of some facultative scavengers than is now widely assumed. Key wordscarrion-diet-food habits-remote photography-scavenging


Fig. 2. Ventral (upper) and dorsal view (bottom) o f t h e skull o f (A) Octodon sp. MLP 12.VII.88.2 ( l . l x ) , (B) Abalosia castellanosi MMP 1439-M (1.2~1, (C) Tympanoctomys barrerae MACN 39949 ( 1 . 2 ~ ) .  
Fig. 6. External view of right mandible (A-C) and occlusal view of dP,-M, (D-E) of' (A) Octodon sp. MLP 12.VII.88.1 (1.3~1, (B) Abalosia caslellanosi MMP 1439-M ( 1 . 8 ~ 1 , (C) Tympanoclomys barrerae LP 213 ( 1 . 8 ~ 1 , (Dl T barrerae L P s/N"l2x), and (El Abalosia caslellanosi MMP 1439-M ( 1 2 ~ ) .  
Phylogenetic position of Abalosia and the evolution of the extant Octodontinae (Rodentia, Caviomorpha, Octodontidae)

September 2001

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132 Reads

South American octodontid rodents of the subfamily Octodontinae currently show low species richness but great morphological and chromosomal diversity. This diversity is interpreted alternatively as the remnant of a wider past radiation or as the result of saltational evolution. These hypotheses are discussed in relation to a phylogenetic analysis of the Late Pliocene octodontineAbalosia castellanosi. My results suggest thatAbalosia, together withTympanoctomys andOctomys, is part of a clade of desert specialist propalinal octodontids, which would have differentiated east of the Andes in the emergent semi-deserts of western Argentina. The presence ofAbalosia in the coastal region of central Argentina during the Upper Marplatan Age (Late Pliocene) suggests a pulse of expansion of such arid environments, probably coeval with the global climatic deterioration detected around the transition Gauss-Matuyama magnetic ages. The phylogenetic position ofA. castellanosi suggests that extinction events affected the clade of the octodontine desert specialists. Accordingly, regardless of how rough or gradual the differentiation of the octodontine’s diversity has been, the living representatives seem to be remnants of a wider radiation. Key wordsOctodontinae-rodents-morphology-phylogeny-biogeography

Habitat factors and the presence or absence of otters Lutra lutra in Denmark

June 2001

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779 Reads

The purpose of the present study was to examine the relative influence of different habitat factors on ottersLutra lutra (Linnaeus, 1758) and to develop a predictive model to better understand the distribution of the otter in Denmark. During the National Otter Survey in 1991 data were collected on 19 variables which reflected aspects of habitat structure, composition, organic pollution and human disturbance. Multiple logistic regression analysis was used to estimate probabilities of the presence of otters as a function of one or more explanatory variables. Six variables (county, pH, water depth, presence of trees, bottom substrate and Saprobien-Index) were identified. In Denmark, otter habitat typically consists of water courses with depths > 1 m over a varied bottom, with pH > 7.0, Saprobien-Index on II–III to III (indicating slight organic pollution) with no trees on the banks. Some of these variables reflect highly productive waters. The use of the otter as an indicator of good water quality and/or aquatic habitat should be used with care. Key words Lutra lutra -habitat structure-organic pollution-human disturbance-spraint survey

Differences in abundance and species richness between shrews and rodents along an elevational gradient in the Udzungwa Mountains, Tanzania

December 2007

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152 Reads

Small mammals (shrews and rodents) were surveyed along an elevational transect in the Udzungwa Scarp Forest Reserve, in the Udzungwa Mountains, Tanzania. Trap lines and pitfall lines were installed at 600, 910, 1460, and 2000 m a.s.l. In a total of 10341 sample nights (7448 trap-nights and 2893 bucket-nights) 343 specimens (148 shrews, 205 rodents) were captured representing 9 shrew and 14 rodent species for a total of 23 species. While overall species diversity generally increased with elevation, this pattern was not constant for each group sampled. For rodents, both species richness and abundance were lowest at 600 m and greatest at 2000 m a.s.l., and were significantly correlated with elevation. While the highest species number and abundance for shrews was at 2000 m, there was no correlation of these two values with elevation. Rainfall appears to have affected the capture of shrews, but not rodents, and capture success of individual buckets and traps indicated a lack of capture independence. Eastern Arc endemics such asCrocidura desperata Hutterer, Jenkins and Verheyen, 1991 andMyosorex kihaulei Stanley and Hutterer, 2000 were more abundant at 2000 m a.s.l., than at lower elevations. Implications of results of this survey for analyses of future biotic surveys are discussed. Key wordsEastern Arc Mountains-elevational transects-rodents-shrews-Tanzania-Udzungwa Mountains

Hunt sightings as a tool for monitoring the distribution and abundance of brown hare Lepus europaeus in UK agricultural landscapes

October 2011

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34 Reads

We examined the potential of hare sightings data, collected during hunts by the Association of Masters of Harriers and Beagles, as a possible monitoring tool for the European brown hare Lepus europaeus. The relationship between land use and both temporal trends, and spatial patterns, in brown hare sightings across England and Wales was examined using data collected between the 1985/86 and 2004/05 hunting seasons. Hare sightings increased significantly during this period, with an average increase of 2.81 hare sightings per hunting day across all hunts since 1985. Sightings were more frequent in eastern England, where arable land is abundant, than in the rest of England and Wales which is predominantly pastoral. There was no correlation between temporal trends in hare sightings and land use change. Patterns observed using the hunt sighting data are similar to those reported by other concurrent studies that used different methods. We conclude that hunt sightings could contribute useful data to a national monitoring scheme. KeywordsEuropean brown hare– Lepus europaeus –Hunt sightings–Population trends

Factors affecting wild boar abundance across an environmental gradient in Spain

September 2006

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911 Reads

The recent Europe-wide increase in wild boarSus scrofa, Linnaeus, 1758 abundance is undoubtedly due to many different factors, the relative importance of which differs from region to region. In Aragón (northeastern Spain), wild boar enlarged its distribution area eight times in the 1990s as compared with the century before, occupying the whole region. We studied wild boar abundance along an environmental gradient in Aragón to determine which factors are most responsible for its variation. Relative abundance of wild boars was estimated by catch-effort methods in 134 hunting estates (sampling units) for 5 consecutive hunting seasons. To characterise the environmental conditions, we quantified landscape composition and structure, topographical factors and climatic factors. Hunting pressure indices were also calculated for our sampling units. The average wild boar catch per hunting activity and per 100 km2 ranged from 0.72 to 16.31. Our results suggest thatwild boar abundances are affected by landscape structure, mainly by landscape diversity. In addition, lowland arid agrosystems (characterized by high temperatures and open juniper woodlands with little food availability) constrain the abundance of wild boar populations in spite of their wide plasticity to colonize new habitats. Key wordslandscape-fragstats-catch-effort-density-suids

Influence of herbaceous cover, shelter and land cover structure on wild rabbit abundance in NW Portugal

March 2004

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82 Reads

The European wild rabbitOryctolagus cuniculus (Linnaeus, 1758) populations in the Iberian Peninsula has suffered a serious decline. Therefore, the knowledge about the factors that influence rabbit distribution and abundance is of major interest for conservation and management programmes. Rabbit relative abundance was evaluated by pellet counting in relation to herbaceous ground cover, shelter availability (tall scrub cover and gaps in rocks) and land cover structure in the Peneda-Gerês National Park (PGNP), NW Portugal. Rabbit abundance was higher at intermediate levels of herbaceous cover, but no significant statistical differences were detected. A strong association between the abundance index and tall scrub cover was verified, and when this cover was rare, an association with gaps in rocks was observed. At the land cover level, rabbit abundance was associated with high interspersion sites of rocks with matorral and high interspersion sites of tall scrubland. Evidence from this study highlighted the importance of shelter and the interspersion of open/shelter habitats for rabbits. This pattern could be interpreted as an anti-predator strategy. Therefore, management actions should favour the growing and establishing of tall scrub patches and the selective cutting in highly continuous areas of tall scrub vegetation. Key words ctolagus cuniculus -shelter, abundance, food, interspersion

Fig. 2. Variations in Microtus arvalis abundance with distance from (a) hedgerows, (b) copses, and (c) forests. In these box-and-whisker plots, squares represent extreme data points; a box is drawn from the first and the third quartile; in the box the horizontal line represents the median and whiskers are located at 1.5´IQR (interquartile range) below the first quartile and at 1.5´IQR above the third quartile.
Influence of edge effects on common vole population abundance in an agricultural landscape of eastern France

March 2009

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208 Reads

Vole demographics are often modified close to wooded environments. Population monitoring in such settings reveals substantial edge effects, although these have seldom been quantified. This study compares the abundance of common voleMicrotus arvalis (Pallas, 1778) populations at various distances from three types of wooded environment (hedgerow, copse and forest) and in two types of habitat (temporary and permanent grassland). In temporary grassland, substantial edge effects were detected along the boundaries of forests and hedgerows. At 100 m from the forest edge, voles were twice more abundant than at 50 m, four times more than at 25 m and eight times more than at 5 m. In permanent grassland, the edge effect was such that voles were practically absent up to 100 m from the forest edge. For both types of grassland, the edge effect was more pronounced for forest habitat than for hedgerows, that is, for elements with a large surface area of wooded environment. Our results suggest that landscape context may greatly affect the local abundance of voles. Given the considerable damage done byM. arvalis, the presence of wooded patches in grassland areas leads to lower vole densities in adjacent areas and this might be an alternative method to controlM. arvalis as a pest species. Key wordsedge type-habitat quality-landscape ecology-landscape composition-predation risk