There is a considerable amount of literature on the diet and effect of feral American mink Mustela vison on the distribution and abundance of water voles Arvicola terrestris in Britain. Few recent studies, however, have attempted to examine the occurrence of water voles in the diets of native predators. Fox Vulpes vulpes scat and grey heron Ardea cinerea pellets were collected during winter 2003–2004 at a location known to contain a large number of water voles. These scats and pellets were subsequently analysed to determine the frequency of water vole occurrence in the diet of these opportunistic predators. Water vole remains were found in 30% of fox scats analysed and accounted for 13% of the total weight of scats. A total of 18% of heron pellets contained the fur of water voles in addition to the fur of four other rodent species. The potential role of native predators in the loss and fragmentation of site-specific populations of water voles in Britain is further discussed.

Many studies have concluded that territoriality is absent in male bushbuck Tragelaphus scriptus but a minority has suggested that some exclusive mechanisms act between adult males. This study provides indirect evidence for the existence of territorial structures between adult male bushbuck by comparing home-range overlap between adult and sub-adult males. The spatial organization of individuals in relation to each other was established by using numerical classification. Location fixes of 52 males, each individual distinguished by a characteristic coat pattern, were taken over a period of 3 years. Home ranges were estimated using the fixed kernel density estimator. Two indices (coefficient of overlap, index of overlap) were applied to compare home-range overlap between the different male age classes. There was a strong home-range overlap up to the 30% home-range core between sub-adult as well as between adult and sub-adult males, while adult male home ranges overlapped up to the 50% home-range core only. It could be shown that home ranges of adult males overlapped significantly less than those of sub-adult males and those between sub-adult and adult males indicating an exclusive use of central core areas (home sites). Sub-adult males form bachelor pools without being permanently associated. With increasing age, sub-adult males challenge territory holders and replace them in order to take over their exclusive areas. These maturing sub-adult males (young adults), often focused on a particular territory holder denoting the young adults as prospects or candidates.

Fundamental information on the ecology of the limbless tropical caecilians is needed for a well-founded conservation assessment. Here, essential life-history characters are presented for the oviparous caecilian Ichthyophis cf. kohtaoensis from a field site in South-east Asia (Mekong valley, north-eastern Thailand). Ichthyophis cf. kohtaoensis was found in a range of terrestrial macrohabitats including open scrubs, gallery forests and open secondary dipterocarp forests. In the dry season, caecilians were found mainly in soil but in the rainy season they were also detected in epigeic microhabitats (leaf litter or rotten vegetation). Ichthyophis cf. kohtaoensis were recorded in low densities (median 0.08 individuals/m2) and they share their habitat with a range of other terrestrial amphibians and reptiles. The population structure of I. cf. kohtaoensis varied seasonally. Records of late metamorphs were restricted to the cold dry season and occasionally to the onset of the rainy season. Females with clutches were only found in the rainy season. A life-history scenario of I. cf. kohtaoensis in north-eastern Thailand was set up. Reproduction and larval development is related to the rainy season. Mating and oviposition may start at the onset of the monsoon. Larvae hatch at the peak until the end of the rainy season and metamorphose until the end of the dry season. In the light of amphibian decline, this study may encourage further baseline work on the ecology of other caecilian species.

From May 1997 to July 1999, 24 gray foxes Urocyon cinereoargenteus were radio-marked and their fates monitored in a natural area of southern California to identify rates of survival and cause-specific mortality, and thus to assess population sustainability. Pup (0.4–1.0 years old) foxes had an 8-month (September–April) survival rate (0.34) that was lower than the 8-month (0.77) or 12-month (0.58) estimates for adult foxes. Interference competition was evident; 92% (11/12) of fox mortalities were the result of predation by sympatric coyotes Canis latrans or bobcats Felis rufus. Also, five of seven gray fox mortalities were outside of, or on the border of, the home range of the killed fox. Calculations indicated that the fox population would remain stable if survival of pups during their first 4 months of life was 0.68 (vs 0.75 for adults during these months and 0.58 for older pups for 4 other months). This seems reasonable, yet sympatric carnivores, mainly coyotes, clearly influence the gray fox population in southern California.

In this study the diet of otters Lutra lutra was examined following the establishment of a population of non-native ruffe Gymnocephalus cernuus in Loch Lomond, Scotland. Otter spraints (n=453) were collected at monthly intervals from four sites during 2002. Overall, 98% of spraints contained at least one species of fish, invertebrates were found in 49%, 17% contained amphibians, while mammals and birds were found in 9%. The most frequent prey from all sites were ruffe, which were found in 69% of spraints. Eel Anguilla anguilla, cyprinids (roach Rutilus rutilus, dace Leuciscus leuciscus and minnow Phoxinus phoxinus) and Salmo spp. were also relatively common and were recovered in 60%, 35% and 33% of spraints, respectively. Northern pike Esox lucius (14%), perch Perca fluviatilis (12%), stickleback Gasterosteus aculeatus (9%), powan Coregonus lavaretus (14%) and lampreys Lampetra spp. (2%) were less common. The fact that ruffe were the most frequent prey in otter spraints in all regions and in all seasons of the year indicated that they are one of the most important prey for otters in Loch Lomond at the present time.

Substrate reaction forces (SRFs) were quantified for 502 forelimb and hindlimb contacts in two primate species, Eulemur fulvus and Lemur catta. Three individuals of each taxon were encouraged to traverse a force transducer. Reaction forces were evaluated for linear locomotion on runway and simulated arboreal substrates. Preferred gaits differed between substrates: galloping on the runway and walking on simulated arboreal substrates. Unlike vertical and fore–aft (FA) forces, mediolateral (ML) forces during linear locomotion were relatively independent of speed, which suggests balancing the centre of body mass in the coronal plane was not speed related. Since peak ML forces occasionally exceeded peak FA forces, ML forces were not of trivial importance during primate quadrupedal locomotion. Both lemurids regularly experienced lower ML peak forces during ‘arboreal’ than ‘terrestrial’ quadrupedalism, probably to minimize side-to-side fluctuations of their centre of mass over the simulated arboreal branch supports. Eulemur fulvus encountered greater ML peak forces in their forelimbs, while L. catta encountered greater hindlimb peak ML forces. Lemurids most frequently exerted medially directed peak side-to-side forces during arboreal quadrupedalism and laterally directed peak side-to-side forces during terrestrial quadrupedalism. The direction of hindlimb ML peak force, however, was less consistent than forelimb ML peak force regardless of substrate. The lemurs experienced oscillations in the direction of the forelimb and hindlimb ML force over the duration of support phase, suggesting that both pairs of limbs contributed to balance. More frequent changes in ML force direction of the hindlimb support the predominance of these limbs in keeping side-to-side balance. The results of our study suggest that ML forces warrant consideration in locomotion studies, especially when evaluating joint moments and bending regimes of long bones.

Assessment of pinniped predation most often relies on analysis of the hard, undigested prey remains evident in faecal (scat) samples. For many prey species this method can yield valuable information on predator–prey interactions. For some genera, however, species diagnostic characteristics are lost during the process of prey digestion, thereby preventing morphological identification of fish prey species. Here, the feasibility of using faecal DNA to detect the presence of salmonids in pinniped scat samples and to distinguish reliably between sea trout Salmo trutta and Atlantic salmon S. salar was assessed. Novel salmonid mitochondrial DNA (mtDNA) primers were designed to amplify 162 bp of the 16S rDNA and a 327 bp section of the cytochrome b gene. Species-specific banding patterns were obtained by digestion of the cytochrome b PCR product with the restriction endonuclease AluI, and confirmed by the species-specific amplification of the 16S rDNA fragment from Atlantic salmon. Scats collected from captive grey seals Halichoerus grypus fed on known monospecific diets used to validate the PCR-RFLP assay indicated a probability of at least 95.8% (23 of 24 faecal extracts) of detecting salmonids using DNA extracted from the scat matrix. Implemented alongside conventional prey remains analyses, this technique presents a promising new method for examining prey composition and assessing pinniped predation on salmonids.

The primitive sheep of North Ronaldsay Island (Orkney), which feed almost exclusively on seaweed, have developed physiological features linked to that diet. The use of seaweed to feed domestic animals, attested for centuries in north-western Europe, may have appeared soon after the arrival of the first domestic herds during the 5th and 4th millennia BC. The use of isotope analysis of sheep tooth enamel as a means to investigate seaweed grazing in prehistoric times was tested. The teeth of five modern North Ronaldsay sheep were analysed for carbon (δ13C) and oxygen (δ18O) isotope ratios. Owing to differences in the δ13C of marine vs terrestrial plants, the seaweed-eating sheep have δ13C values clearly outside the range expected for terrestrial plant eaters. Results show that one group of individuals relied exclusively on seaweed throughout the year. In a second group, terrestrial plants provided about half the dietary carbon pool during the summer. In individuals relying exclusively on seaweed, the amplitude of seasonal change in the δ18O values of tooth enamel was low, possibly because of ingestion of marine water through fresh seaweed consumption. Analysis of a sheep tooth from the Neolithic site of Holm of Papa Westray (Orkney, Scotland), suggests that as early as at the beginning of the 4th millennium BC in the Orkney, seaweed contributed to the winter diet of domestic sheep.

The kinematics of each joint of the guinea pig Cavia porcellus were studied during the locomotor cycle at increasing speed by high-speed cinefluorography. The main objective was to reveal the functional specific features of these structural elements in each dynamic phase of the cycle and also which limb joints are important during the increase of animal speed. Most of the analysed angles in C. porcellus were affected as the speed increased, both in trot and gallop. However, only a few of them were correlated with speed. There were also differences with respect to symmetrical or asymmetrical gaits. Both pairs of limbs responded differently to the increase of speed; while the forelimb joints modified the duration of their action (frequency) more than the amplitude (stride length), the hindlimbs acted inversely. The movements of the joints during the stance phase changed dramatically with speed, particularly in the hindlimb. At knee level, the flexion amplitude increases to maintain the stiffness of the leg spring, a principle previously discussed as essential for the running process. In the swing phase, inertial effects are the main constraints and, as in the stance phase, the knee joint in the swing phase is correlated with speed both during trot and gallop, confirming the major importance of this joint to increasing speed.

Casts of forelimb elements of the Cretaceous theropod dinosaur Acrocanthosaurus atokensis were manually manipulated to determine range of motion and infer function. It was found that the humerus can swing posteriorly into a horizontal position but can neither swing laterally to glenoid height nor anteriorly much beyond the glenoid. The forearm can approach but not achieve full extension and right-angle flexion. Pronation and supination are precluded by immobility of the radius relative to the ulna. Motion also seems to be restricted at the wrist. The palm faces medially, and digital movement is subtransverse. All three digits are capable of extreme hyper-extension. Digits I and II converge during flexion. Only digit III can be abducted or adducted. The limited anterior range of brachial motion infers that Acrocanthosaurus first apprehended prey orally, using the forelimb afterwards to secure its grip or deliver fatal blows. Acrocanthosaurus could only manually grasp prey that was beneath its chest, towards which it may have used its mouth to move prey. Struggling prey would have impaled itself further upon the permanently and strongly flexed first ungual. The range of motion in the forelimb of Acrocanthosaurus resembles that of Herrerasaurus and Dilophosaurus, and exceeds that of Tyrannosaurus. Acrocanthosaurus exhibits a greater manual range of motion than ornithomimid and deinonychosaurian coelurosaurs, but less at the shoulder and elbow. Coelurosaurian theropods exhibit reduced digital flexion and hyper-extension, which suggests a change in the use of the manus in coelurosaurs.

While many animals respond to seasonal variation in their environment, animals such as pocket gophers Thomomys bottae that live below ground might seem to be buffered against such variation. In some areas, however, the patterns of burrowing activity by pocket gophers are tied to the seasons, one factor of which is rainfall. Variation in activity patterns may result from the ease of digging in moist soil or increased food availability during the wet season. Previous simulation modelling work suggests that food availability influences burrowing patterns, while soil conditions do not. Thus, field experiments were used to investigate how soil conditions and food availability influence seasonal burrowing activity. Results indicate that an increase in soil moisture initiates activity. After this initial increase in activity, mound production declines and reaches a steady rate, which can be supported by vegetation availability, in agreement with previous model results. Our findings support the idea that moist soil promotes a burst of digging activity, potentially for burrow maintenance when soil becomes easily workable, and the eventual growth of vegetation provides the food necessary to support continued activity.

Habitat selection was studied in two rhinolophid (Chiroptera) species, Rhinolophus mehelyi and R. euryale, breeding in the same roost in south-west Spain. The first analysis of habitat selection by R. mehelyi is provided, and the hypothesis explored that despite their close relatedness, in sympatry the two bat species showed different habitat preferences. For both species, the least preferred habitats were open habitats such as scrubland, grassland and arable land. As found elsewhere, R. euryale preferred broadleaved woodland. In addition, R. mehelyi also foraged in habitats characterized by loose trees, such as the ‘dehesa’, a semi-natural oak savanna. The progressive disappearance of the dehesa, jeopardized by land-use change, may not harm R. euryale, but could represent a threat to R. mehelyi, which would then be restricted to dense woodland, possibly competing with other bat species, including R. euryale. To conserve both species, the maintenance of a variety of wooded habitats of differing density is recommended.