Volume 75, Issue 1

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We explored the alpha and gamma patterns in species richness of non-volant small mammals on Mt. Snežnik (sea level: 1796 m) on the northern edge of the Mediterranean Basin. A total of 2871 individuals were sampled belonging to 23 different species of rodents and soricomorphs. Two estimates of true species richness (sample-based rarefaction and abundance-based coverage estimator of species richness, ACE) yielded very similar values to empirical data. The empirical number of species varied between 4 and 11 per station in alpha-richness and between 5 and 17 per 200 m elevational interval in gamma-richness. The 95% confidence intervals for ACE overlapped between elevations in both data sets, hence not a single sampling site or elevational interval emerged statistically richest or poorest in the number of species. The two patterns responded to elevation in a very different way but any of the curves was decidedly humped. The mid-domain effect predictions failed to reproduce the pattern of observed or estimated species richness, and hence the ranges were located non-randomly along the elevational gradient. The pattern of distribution and diversity is supposedly generated by the environmental variables correlated to the elevation, which vary in a non-random manner with elevation.

Population parameters, body mass and diet of Apodemus sylvaticus were compared in two nearby study sites in south-western Iceland: open grassland and mixed woodland. Live trapping was conducted at approximately 5 week intervals from September 2004 to October 2005. In addition, mice were caught in snap-traps every month to estimate food composition from stomach contents. Estimated population density was up to 10 times higher in the woodland than in grassland but seasonal dynamics were the same, with peak density in autumn and low density in spring. Apparent monthly survival varied greatly throughout the winter in the grassland, ranging from 39% to 78%, but was stable at around 60% in the woodland. Mice fed predominantly on seeds in all seasons, with an exception during the spring when arthropod larvae were the most common food type. Food varied more by seasons than by habitats, but evidently mice from the woodland were less likely to feed on green material and showed more seasonal fluctuations in seed consumption. During mid-winter, woodland mice of both sexes were heavier than mice in the grassland. To some extent, the observed differences in density, survival, weight and diet could be reflecting differences in habitat quality in the two contrasting habitat types.

The selection, characteristics and use of 72 resting sites and 3 dens corresponding to 16 adult common genets ( Genetta genetta ) in a Mediterranean habitat were studied. Over a 3-year period, the common genets each had at least 3–8 resting sites, which were reused with varying frequency. There was a positive correlation between the number of resting sites and the size of the resting home range. They used the resting sites during the day and also at night. The sites were located in thickets and trees. The females preferred thickets, and the males used trees more often than the females. The core areas of individuals revealed a higher number of resting sites than expected in relation to their size. When deciding on where to locate their resting sites, genets selected ravines, seeking the protection and safety that these places offered, with very dense vegetation that was practically inaccessible to any potential predators and thus also sheltering them from human activities. The highest probabilities of resting site presence are found in places near to torrents and away from roads and tracks.

The study of the nocturnal activity pattern of Iranian jerboa showed that this species stayed out of the burrow nests for a large part of the night during the first and last weeks of the lunar month, whereby their nocturnal activities markedly decreased from a half to a full moon. The scale of activity was higher when the moon was low than when it was high. Additionally, activity shifted somewhat from open to vegetation cover when the moon was high. The higher predation risk in brighter nights is supposed to be the main reason for such an activity pattern.

Habitat use, abundance and population dynamics of the woolly hare ( Lepus oiostolus ) were investigated in an alpine shrub-covering valley near Lhasa, Tibet. Counts of fecal pellets indicated that habitats outside the valley with heavily degraded shrub vegetation supported a small hare population, compared with habitats inside the valleys where vegetation was undisturbed, agricultural and hunting were lacking, and predators and herbivore competitors rare. Three types of shrub habitats with intermediate cover levels along with alpine meadow inside the valley were equally preferred by the hares, whereas willow-rhododendron, with the densest cover, was avoided. Transect surveys showed that the hare population density in the preferred habitats was 13 ind./km 2 in spring and 27 ind./km 2 in autumn. Out of seven years observations from 1995 to 2004, massive spring mortality of hares occurred only in 2000, leading to a marked population decline that year.

Growth patterns are nearly unknown in free-ranging rodents. Here, we analyse growth patterns (in body length) in relation to sex, year and population density in a population of bank voles, Myodes glareolus , studied by the capture-mark-recapture method at a mountainous site in central Italy during a 12-year period. In our study, (i) male and female bank voles had very similar growth rates and growth trajectories as described by von Bertalanffy growth functions; (ii) growth rates strongly varied interannually; and (iii) growth rates were independent on population densities, i.e., there was no density-dependence mechanism following individual growth rates in bank voles. The general implications of these patterns are discussed.

This study aimed to compare the efficacy of different trapping methodologies for sampling small mammals, consisting of trap type (pitfall, Sherman, and wire traps) and position (ground and understorey) in the Cerrado biome of Brazil. Five fragments of woodland savannah were selected for the study. We captured a total of 364 individuals of 14 species of small mammals. Pitfall traps sampled all 14 species (100%), whereas ground cage traps sampled 8 species (57%), and arboreal traps sampled 5 species (36%). The sampling methodologies gave significantly different results, particularly between pitfall and cage traps, and between ground and arboreal cage traps. However, the comparison between Sherman and wire traps indicated no significant difference, although abundance has been higher for wire cages. Our study confirms the high success rate for pitfall traps now in the Cerrado biome and suggests combinations of trapping methodologies for surveying mammalian diversity.

Many uncertainties remain regarding our knowledge of sigmodontine rodent distributions in Northwestern Argentina. Most of the available information has never been critically evaluated. By reviewing the published literature and overlaying this information with other spatial layers (political, environmental, infrastructure, protected areas, and topographic layers), we identified information gaps and added new localities. The new records were obtained through field surveys, including captures and owl pellet samples. In the literature, we found 561 localities, most of them published in the past decade. These records come mainly from low-altitude areas in Salta province, as well as some higher-altitude belts in Yungas, and strongly associated with roads. Records from protected areas were scarce. Akodon , Calomys , Oligoryzomys , and Phyllotis were recorded for most of the localities. We add 18 new localities for 14 species, including the first records of Akodon dolores in Tucumán province, Necromys lasiurus in Santiago del Estero and Tucumán, and Calomys lepidus in Catamarca. We add records for poorly known species such as Andalgalomys olrogi in the Capital department (Catamarca) and Auliscomys sublimis and Neotomys ebriosus in Cochinoca (Jujuy) and La Poma (Salta). We emphasize the need for more surveys to obtain an adequate knowledge of the distribution of most sigmodontines.

We studied the diet, habitat use and biology of Rousettus madagascariensis , a relatively small (∼55–77 g) fruit bat endemic to Madagascar, between July 2004 and May 2005. Faecal analysis revealed few seeds in the diet, suggesting that the bats either feed extensively on nectar, flowers and leaves or on fruits with seeds too large to ingest. However, bats were captured near fruiting Ficus sp. inside relatively intact forest and Ficus sp. seeds were found in the faeces during March and April. Defecated Ficus rubra seeds germinated significantly faster than seeds from ripe fruits under controlled conditions, but germination rates were similar. Radio tracking and observations of light-tagged individuals revealed that R. madagascariensis travelled a straight line distance of at least 8 km between the roost and feeding locations, with round trip foraging routes of up to 27 km. Most juveniles were trapped between March and July and we infer that weaning of young started before 8 weeks of age. The features used to distinguish juveniles from adults were no longer evident in December and it appears therefore that R. madagascariensis reaches somatic maturity within a single year. Pregnancy, lactation and weaning in this species coincide with the austral summer when food availability is higher.

We report on the development of an approximately 85-g beaded collar for dual micro GPS/VHF transmitter attachment to semi-aquatic nutria ( Myocastor coypus ). Prototype collars were tested on captive nutria and refined during field trials. Central to the design was novel use of the VHF transmitter antenna as a collar. A circular collar was formed by passing the 44-cm antenna cable through a pre-made hole in the transmitter, leaving an approximately 16-cm upright antenna. GPS units were mounted separately via a hole in the base of each unit. For good satellite contact, GPS units (∼28 g) were maintained at the nape of the neck by counterbalance of the heavier VHF transmitters (∼50 g) positioned under the neck. To reduce friction, we lined the collar with alternate-sized plastic and, later, more durable nylon beads. The final collar configuration was worn for approximately 1 month deployments with only minor neck abrasion; one collar was worn successfully for 5 months. Foot entanglement remained the greatest risk of injury from the collar. By fitting collars tightly, we reduced the incidence of foot entanglement to 2 of 33 deployments (6%). Successful GPS tracks were acquired on 29 of 33 deployments (88%).

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