Volume 77, Issue 1

The correlates of species richness and conservation status of South American rodents were studied by analyzing the ranges of 791 species (belonging to 159 genera and 16 families). The distribution data (size of each species’ range in km 2 ) and the relative quantity of each macrohabitat type (in km 2 ) were obtained from the Global Mammal Assessment data bank of the International Union for Conservation of Nature (IUCN), and the Global Land Cover 2000, respectively. We excluded mainly island species from analyses but included those species that occur on both islands and the mainland. Habitats were grouped according to seven categories (shrubland, forest, grassland, savannah, wetlands, desert, and artificial). Mean range sizes varied significantly among families, with members of the family Cuniculidae having larger ranges than the species belonging to the rest of the families. Mean range size did not differ significantly between endemic and non-endemic taxa. There was a significant positive relation between total species richness and the availability of habitat types. Specialized species (i.e., those linked to a single habitat type) were found especially in forests, but shrublands and grasslands were also important. IUCN threatened species were distributed in a scattered way, and essentially in forests, grasslands, and shrublands. No region of the Neotropics housed more than two to three threatened taxa, apart from a spot in north-central Peru with five species. The richness of IUCN threatened species was higher in the montane forest ecosystems of the Andes, north-central Peru, than in other areas of South America. There was a mismatch between the hotspot maps for threatened and endemic species. The conservation implications of these patterns are discussed.

Raccoons ( Procyon lotor ) are highly adaptable meso-carnivores that inhabit many environments, including the Atlantic barrier islands, where their role as predators of declining, beach-nesting bird and turtle species is of particular interest. Population models that improve our understanding of predator-prey dynamics are receiving increasing attention in the literature; however, their effective application requires site-specific information on population parameters. We studied an unharvested raccoon population on the Outer Banks of North Carolina and evaluated spatial and seasonal differences in a number of population/demographic factors of raccoons inhabiting areas of high and low human activity. Raccoons denned and foraged primarily in salt marsh habitats but shifted their movements in response to changes in seasonal resource conditions. The population was skewed toward older animals and exhibited delayed breeding, typical of populations at high density with few sources of mortality. Diet and movement analysis indicated shorebird and turtle predation was attributed to a small number of individual raccoons. Although seasonal resources appeared adequate to sustain a high population density of raccoons, poor body condition and low recruitment suggested a population near carrying capacity.

Przewalski’s gazelle ( Procapra przewalskii ) is a rare species endemic to China. Only 200–300 individuals were estimated to survive around the Qinghai Lake by the 1990s. Recent work has revealed that the status of the species is less precarious than indicated by earlier reports; 602 individuals were recorded in 2003. Here, we describe detailed distributions for 9 of the 10 known subpopulations of the gazelle and update its population status. We tallied 1320 individuals, but found that one subpopulation first discovered in 2003 had declined since then and in 2008 was probably close to extirpation. Estimates using distance sampling conducted in a portion of the study area were higher than those that would have resulted from extrapolation of the raw observations underlying them (i.e., unadjusted counts), suggesting that the total population of Przewalski’s gazelle was larger than 1320. We conclude that our larger population estimates were mainly due to a more thorough survey protocol and consideration of detection probability, and did not reflect a true population increase.

The most important surviving colony of the critically endangered Mediterranean monk seal ( Monachus monachus ) inhabits the Atlantic Saharan coast. The population has not recovered despite the cessation of commercial sealing in the second half of the 20th century. We report the distribution of the monk seals within the region from 1940 to 1989 and their interactions with fisheries, from data gathered through interviews of fishermen. Our study shows a notable decrease in the seals’ range during the study period. Observations of seals on open beaches and exposed rocks decreased, while observations in caves increased. Important negative interactions between monk seals and fisheries were detected, with the most frequent interactions being bycatch in gillnets and bottom trawl nets. Reports obtained from fishermen clearly indicate that the seals were still being deliberately killed on land during the 20th century, which likely caused the extirpation of seal populations hauling out on beaches. We recommend that mortality due to fishery bycatch be added as a contributing factor to the decline of the monk seal populations in the region from 1940 to 1989. We also recommend conservation measures such as the establishment of a permanent marine reserve along the Atlantic Coast of the Cap Blanc Peninsula.

Faunal impoverishment and distorted species compositions are common phenomena in oceanic islands; however, many land-bridge islands are poorly inventoried, especially in the Neotropics. We sampled a small mammal community on a land-bridge island (Anchieta Island) along the Brazilian coast. We found only one marsupial Didelphis aurita (Wied-Neuwied, 1826) and two rodent species Oligoryzomys nigripes (Olfers, 1818) and Trinomys iheringi (Thomas, 1911) during 12 months of live trapping and 9195 trap-nights. The diversity of rodents and marsupials was not explained by species-area relations, indicating possible past extinctions. The abundance of D. aurita and O. nigripes was approximately three times higher, while the abundance of T. iheringi was approximately four times lower than abundances reported from other Brazilian Atlantic Forest sites. The population of D. aurita exhibited many phenotypic changes; males were on average 8% smaller and females produced 30% less litters than those from the mainland and other land-bridge islands. The long history of forest disturbance, habitat loss, reduction in forest productivity, and the recent introduction of mesopredators may be the major drivers that explain the small mammal community composition on this island.

This study evaluates a number of methodological aspects regarding the recording and analysis of social behaviour in mole rat colonies (Bathyergidae, Rodentia). Behavioural observations were carried out on a colony of wild-caught Fukomys micklemi , in order to define an efficient, standardised method for future research. First, durations of work behaviour were scored and compared with data expressed as frequencies (recording method used in previous research). Second, a comparison was made between a terrarium set-up and a set-up with a perspex tunnel system, including a digging unit. Third, observations were carried out at different times of the day in order to map daily activity patterns. Our results show that the set-up with the tunnel system evokes more work activity and increases behavioural resolution. Using frequencies showed to be a better proxy for activity than the labour-intensive scoring of durations. Interindividual variation in activity patterns over a 24-h period were shown to be highly variable, and the moment of peak activity was not consistent. Observations should thus be carried out randomly during the day to avoid any temporal bias.

Resource partitioning in syntopic bats is mainly studied through comparative ecomorphology and behavioural ecology. We used simultaneous radio-tracking of syntopic forest-dwelling bats, the western barbastelle ( Barbastella barbastellus ), Bechstein’s bat ( Myotis bechsteinii ) and the brown long-eared bat ( Plecotus auritus ) to analyse individual and species-specific foraging habitat and roost site selection. We estimated niche partitioning through Euclidean distance analyses to landscape elements and through Pianka’s niche overlap index for roost types. We analysed a total of 2278 fixes and 54 roosts of 15 bats. Western barbastelles and Bechstein’s bats foraged significantly closer to the forest than brown long-eared bats. Female barbastelles also foraged significantly closer to forest tracks, which were avoided by female brown long-eared and Bechstein’s bats. Female and male brown long-eared bats were found close to open habitats, which were avoided by the other two species. We found a high niche overlap in terms of roost height, but low overlap in terms of roost type and roost tree species among the three bat species. Individual niche variation may allow these specialised forest-dwelling bat species to minimise competition when foraging and roosting in syntopy.

We studied sexual size dimorphism (SSD) and testes size allometry in 97 natural populations, including 39 nominal species and 19 unnamed or undescribed forms, of tuco-tucos ( Ctenomys ) from Argentina, Bolivia, Chile, Paraguay, and Uruguay in order to gain insight on the existence of sperm competition in these solitary, territorial, and possibly polygynic subterranean rodents. Our results indicated that sex-biased SSD occurs within the genus and also within lower taxa. SSD conforms to Rensch’s rule. Testes size showed a strong negative allometry when compared with male body mass both across and within species, clearly suggesting the operation of sperm competition in this genus. Thus, within a Ctenomys population, small males would invest more than larger males in testes growth and thus in ejaculate quality, which would counterbalance their presumably lower chances of accessing females due to their smaller body size.

The five-toed jerboas of the genus Allactaga inhabit arid areas of Asia and North Africa and are widely distributed in deserts, semideserts, and steppe regions of Iran. Many morphological and morphometric studies have been carried out on this genus; however, there is little molecular data available on them. Therefore, their phylogenetic relationships need to be evaluated. Here, using sequences of 903 and 632 bp of two mitochondrial DNA genes, cytochrome b ( Cytb ) and cytochrome oxidase subunit I ( Cox1 ), the phylogenetic relationships of five nominal species of Allactaga were evaluated from the Iranian Plateau. Phylogenetic trees were constructed on the basis of maximum parsimony, maximum likelihood, and Bayesian analyses. The resulting trees supported seven major clades: (1) Allactaga firouzi and A. hotsoni , (2) A. williamsi , (3) A. euphratica , (4) A. elater from Esfahan and Tehran, (5) A. toussi , (6) A. elater from Golestan, and (7) A. elater from Kashmar and Golestan. On the basis of the results of current study, A. firouzi and A. hotsoni are synonymized, while A. elater could be considered a complex species with three subclades. In addition, the geographic distribution analysis of the species was clarified and as a result, A. euphratica is a new record for the Ilam region.

The systematics of the rodent genus Gerbillus still needs clarifications. Within this genus, Gerbillus nanus is a species often considered to have a wide geographic distribution ranging from northwest India to the Mauritanian coast. Some authors, however, have suggested that other species, namely Gerbillus amoenus and/or Gerbillus garamantis , may replace G. nanus over a part of, or over the whole of its African area of occurrence. Here, we bring together new karyological data and molecular analyses of cytochrome b mitochondrial gene sequences of G. nanus specimens from various parts of the alleged extended distribution of the species: Pakistan and Israel in Asia, and Libya, Mali, and Mauritania in Africa. The karyotypes of Asian and African specimens appear similar, while a rather important genetic distance was found between samples of specimens from the two continents. This last finding suggests that at least two distinct species exist, G. nanus being the species of Asian distribution, and G. garamantis and/or G. amoenus being the one(s) with African distribution(s). Similar comparative analyses on larger samples are now needed to determine the precise taxonomic situation in this group, as well as the distribution limits of each species.

The first record of Urosciurus spadiceus participating in mixed-species bird flocks is reported in the Pantanal biome. Three groups of U. spadiceus were seen participating in mixed-species bird flocks, with Cantorchilus guarayanus being the avian nuclear species. Observations were carried out in the riparian forest of the Paraguay River, municipality of Corumbá, in the north-west of the state of Mato Grosso do Sul, Brazil. Hypotheses about the association between the squirrels and mixed-species bird flocks in South America are considered.

We add new localities to the distribution of bats of the families Molossidae and Vespertilionidae in southern Argentina. We report the southernmost known record for any bat species of the family Molossidae in the world, which corresponds to a locality in the Argentine province of Santa Cruz, for Tadarida brasiliensis . Also, new records of this species are added to the provinces of Chubut and Río Negro. Additionally, we provide new localities that extend the distribution of some species of Vespertilionidae, by adding Histiotus magellanicus and Lasiurus varius to Chubut, and new records for Histiotus montanus to Santa Cruz and for Myotis chiloensis to Chubut and Tierra del Fuego.

A rhinoceros horn was presented to the French governor by the tribal chiefs of Togo in 1941. This nasal horn, referable to the black rhino Diceros bicornis , most likely originates from this West African country. No rhinoceros remains have been recorded in Togo thus far, which provides a good opportunity to update the historical distribution of all three African rhino species ( Diceros bicornis , Ceratotherium simum , and Ceratotherium cottoni ).