Volume 74, Issue 1

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The fossil and subfossil mammal scenario of the oceanic islands of Macaronesia – the Azores, Madeira, and the Savage Islands (Portugal), the Canary Islands (Spain) and Cape Verde – is disconcertingly scant, consisting almost exclusively of the same taxonomic groups characterised by a homogeneous composition of species. The very few endemites can be referred essentially to three species of chiroptera in addition to three murids, which became extinct on the Canaries in historical times, and one representative of the taxonomic group of the Soricomorpha, the Canarian shrew, Crocidura canariensis Hutterer, Lopez-Hurado and Vogle 1987. It is the sole non-volant mammal still dispersed on the Canary Islands, where its occurrence is reported from Fuerteventura, La Graciosa, Lanzarote, and possibly from the two islets of Lobos and Montaña Clara. Owing to its vicinity to continental Africa, the Canary archipelago is the only one in the Eastern Atlantic islands to have been characterised by a non-volant mammalian fauna, whereas such elements do not appear to have been diffused in either the Azores or Cape Verde throughout the entire recent Quaternary. The current mammalian composition of these islands is characterised by the presence of species of almost entirely continental and anthropochorous origin. Evidence shows that the extant occurrence of non-volant mammals appears to be almost exclusively a result of human introduction during the late Holocene. The timing of such processes and the biological success of certain introductions (i.e., naturalisation) raise questions about the proper use of terms such as “natural” or “artificial” when dealing with expansions of anthropochorous range.

In this study we systematically examined species-specific exploration behaviour and behavioural acclimatisation of a black rhino Diceros bicornis founder group post-translocation. The study was carried out in a fenced region, approximately 350 km 2 in size and directly adjacent to Etosha National Park in Namibia. Rhinos were radio-tracked and movement data were complemented by detailed habitat descriptions at the centres of rhino activity with vegetation plot sampling. Rhinos used both geological formations of the study area: Otavi dolomite and Etosha calcrete substrate. The latter was dominated by Acacia spp. due to former land use for livestock farming. The size of total and seasonal home ranges and core areas, as well as home range establishment patterns and habitat use, are highly variable among individual rhinos. Home ranges of most individuals from our study are among the largest recorded for the species. We found age class specific patterns of home range establishment, typical mating and social behaviour, seasonal changes of home range and core area size, and clear shifts in spatial behaviour over time. The results provide our best estimate to date for the natural exploration behaviour and behavioural acclimatisation of black rhinos in a semi-arid savannah ecosystem.

The ecology of Asian rainforest mongooses is very poorly known. The short-tailed mongoose ( Herpestes brachyurus ) is found in rainforests throughout Southeast Asia and very little is documented about its natural history and ecology. Here, we present results from the first radio telemetry study of this species. We captured seven short-tailed mongooses in Krau Wildlife Reserve, Peninsular Malaysia and radio-tracked five adults (three males and two females). Our observations confirmed that this is a solitary, territorial species. The mean home range size of males (233 ha, 95% MCP) was larger than females (132 ha). Females had exclusive home ranges (mean overlap was 3.7%), and male home ranges overlapped more than one female's range. Short-tailed mongooses showed a diurnal activity pattern: mean activity between 06:00 and 17:59 h was 84.7%. The mean minimum distance covered during a 24-h period by males (842 m) was significantly greater than females (468 m). Short-tailed mongooses were mainly found in lowland forest. Deforestation and pollution of watercourses could have serious impacts on this species across its range.

Cetacean diversity and occurrence has never been investigated in the Union of the Comoros, located in the northern Mozambique Channel. Small boat-based surveys were conducted during the austral winter of 2002, primarily to assess the occurrence of humpback whales ( Megaptera novaeangliae ) and whether the area represents a wintering ground where the species reproduce. All other cetacean species were also recorded. Opportunistic sighting records were used to provide information on the diversity of cetaceans occurring in the area. Between 2000 and 2003, 12 cetacean species were recorded around the Comoros, including: Megaptera novaeangliae , Stenella longirostris , Peponocephala electra , Stenella attenuata , Tursiops truncatus , Globicephala macrorhynchus , Mesoplodon densirostris , Physeter macrocephalus , Lagenodelphis hosei , Grampus griseus , Mesoplodon pacificus and possibly Tursiops aduncus . During the dedicated surveys, the humpback whale was the most commonly encountered species (72% of sightings) followed by the spinner dolphin (15%). Humpback whale group composition was heterogeneous, but mother-calf pairs were the most commonly sighted (49%). This study demonstrates that the Union of the Comoros is an important site for migrating humpback whales in the southwest Indian Ocean and for a wide variety of toothed cetacean species.

The first density estimates of a peripheral guanaco population and its habitat use at different spatial scales are presented for a protected area of Monte desert, Argentina. Transects were surveyed in the wet and dry seasons of 2005. All guanaco herds observed during systematic surveys using roads and tracks were GPS located and their habitat use was identified. Herd size differed significantly between the dry and wet seasons. Population densities differed between wet (0.10–0.12 individuals/km 2 ) and dry seasons (0.60–0.75 individuals/km 2 ). The population estimates ranged from 75 individuals (dry season) to 388 individuals (wet season). Guanacos showed differential habitat use, the first determinant being abiotic factors, such as topography, soil characteristics or microclimate conditions, animals being detected in rougher rocky substrata in the dry season and in open flat terrain in the wet season, followed by a mesoscale selection defined by plant communities. At the latter scale, guanaco preferentially used mixed creosote bushland and saltbush more intensively during the wet season, and open scrub and columnar-cactus slopes in the dry season. The estimated population of this protected area was small but its population density was within the range of other populations and was relatively high for this dry and unproductive area.

We present the results of the first survey of the fruit bats of the Lesio-Louna Reserve in the Republic of Congo, an area representative of the larger Bateke Plateau region of the country. Mist-netting was conducted in 2002 during four seasonal sampling periods: late wet season, early dry season, late dry season and early wet season. Five species were recorded. Two were frequently trapped, Micropteropus pusillus (n=102 individuals) and Epomops franqueti (n=57). The remaining three were captured only occasionally, Myonycteris torquata (n=5), Hypsignathus monstrosus (n=2) and Megaloglossus woermanni (n=2). In agreement with studies of other fauna, our results confirm that the Bateke Plateau supports species associated with both forest and savanna habitats. However, species typical of forested habitats were also netted in forest edge and neighbouring savanna, suggesting that these species utilise surrounding habitat within the forest-savanna mosaic characteristic of the study area. We found statistically significant seasonal variation in juvenile body mass and forearm length in E. franqueti and in adult female nipple length in M. pusillus , suggesting breeding seasonality in both these species in the reserve.

The seasonal diet and size of fish prey of the otter Lutra lutra were studied in an almost pristine river of North Portugal (Paiva river) through the analysis of spraints collected during 1 year. To identify Iberian freshwater fish species ( Salmo trutta , Micropterus salmoides , Lepomis gibbosus , Luciobarbus bocagei , Cyprinus carpio , Carassius auratus , Pseudochondrostoma polylepis , Achondrostoma arcasii , and Iberocypris alburnoides ) consumed by the otter keys based on scales and vertebrae were first developed and tested. Both keys allowed identification of all fish species, although three Cyprinidae species could not be discriminated ( P. polylepis , A. arcasii , and I. alburnoides ). Regression equations were calculated to estimate the dimensions of preyed fish. Highly significant linear relationships were obtained for the standard length versus vertebrae measurements, for all fish species, except for C. carpio . Fish was the predominant prey category in autumn and winter, but the otter also preyed on amphibians, reptiles, mammals, and birds, particularly during spring and summer. In general, the otter consumed high proportions of small size fish (3–12 cm for the three indiscriminate Cyprinidae, 3–9 cm for C. carpio , and 6–12 cm for S. trutta ).

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