A new species of leptodactylid frog is described from Parque das Mangabeiras, in Belo Horizonte, Minas Gerais, south-eastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and is characterized by medium size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger and toe discs with well-developed scutes, a weakly developed stripe on the upper lip, dorsum, arm, leg, and foot dark brown with small irregular brown and black dots, and absence of red and yellow spots in live specimens. The descriptions of the tadpoles and vocalizations, and information on natural history are provided. Hylodes perplicatus (Miranda-Ribeiro), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.

The role of diet on the growth, survival and movement of red grouse Lagopus lagopus scoticus chicks was examined. We compared two areas of moorland in Scotland: a dry heath with a low density of red grouse and poor chick survival; and a wetter heath/bog with relatively higher red grouse numbers and higher rates of chick survival. There were no differences in clutch size or the proportion of eggs hatching between the two moors but brood survival was significantly lower on the dry heath. Radio-tagged hens with broods were monitored during the first 12 days following hatching; the chicks were captured, weighed and faecal samples collected. Invertebrate samples were collected within brood feeding ranges. Analysis of chick faeces was used to identify dietary components. Heather comprised the major dietary component on both moors. Invertebrates formed a higher component of diet on the wet moor, and this was positively correlated with growth rates, which in turn were positively correlated with chick survival. We present data from an experiment carried out in 1982, in which chicks showed higher growth rates with increasing insect availability. We also show that broods in which all the chicks survived (4–10 days) had smaller home-range areas than broods in which some of the chicks died during this period. We suggest that the differences in chick survival between the two populations were the result of variations in the abundance of invertebrates, particularly tipulids. The protein provided by a high invertebrate component in the diet is, therefore, an important determinant of the growth and survival of young red grouse chicks in some areas.

Results of a 4-year study in Sangay National Park, Ecuador, indicated that the mountain tapir Tapirus pinchaque, consumes a wide variety of woody and non-woody plant taxa primarily as a foliose browser, and has a preference for some nitrogen-fixing plants. The more closed-cover Andean forest and chaparral habitats contain a greater abundance of mountain tapir-favoured food than the more open grassland paramo, riverine meadow, and pampas vegetation types. Andean forests are considered the most critical habitat for the survival of this tapir because of their provision of cover and food. Field observations and results of faecal germination experiments show that the mountain tapir assists in the successful seed dispersal of many species of Andean plants. Significant regressions between: (1) seed germination and (2) both the natural logarithm (ln e) of the preference ratio and the dietary abundance of food species indicate a mutualism between the mid to high montane-dwelling mountain tapir and the plants it consumes. A significant relation during the past 2 to 3 million years is proposed between: (1) the crossing of the Panamanian Isthmus and the occupation of the mid to high northern Andes by ancestors of the mountain tapir, and (2) the rise of the Andes and formation of the montane forest and paramo ecosystems above c. 2000 m elevation.

The Editors decided, during the year, that there was really little need for a Short Communications Section and it would be more effective to incorporate short papers into the body of the Journal. Great thanks therefore go to Martyn Gorman for his many years as Editor of the Communications from the Mammal Society and latterly for his editing of the Short Communications.

By the end of 2000, the majority of the members of the Editorial Board had completed a five year term and an editorial decision was taken to replace the Board with a small team of international Editorial Consultants who would be asked to act as ambassadors for the Journal as well as giving advice on editorial matters. I should therefore like to thank all the retiring members of the Editorial Board for their work on the Journal and welcome the new Editorial Consultants whose names are given on the inside front cover of this issue.

During 2000, 160 papers were published in the twelve monthly parts of volumes 250–252 and there was approximately eleven months between acceptance of a paper and its publication. Our aim is to reduce this time to a maximum of ten months from now on.

Over the year, 286 manuscripts were submitted to the Journal and reports were written on them by 471 referees, whose names are listed below. As in previous years, I should like to make full acknowledgement of the generosity of these referees in both their time and expertise, without which the Journal could not survive. I should also like to thank all the authors who have sent in colour slides for possible reproduction on the covers.

The shell and anatomy of Nipponomysella subtruncata is described. The bivalve is attached singly or in groups of up to nine on Siphonosoma cumanense, a burrowing intertidal sipunculan in south-west Japan. The species is a protandrous hermaphrodite. Specimens 1.4–2.5 mm long are males, which between 2.1 and 3 mm in length reverse sex and remain females. Reproduction peaks in summer and the annual number of clutches is small. Ripe oocytes, 84–88 μm diameter, are spawned into the suprabranchial cavity where they develop into 107-μm-long straight-hinged veligers. Following a planktotrophic period of unknown duration, the c. 360-μm-long spat normally settle upon and attach to the shells of larger, predominantly female, individuals. At a length of 1–1.6 mm they detach again and live separately thereafter. Sperm are transferred in spermatophores and stored within paired, mushroom-shaped receptacles located posteriorly in the female's suprabranchial cavity. The receptacles first appear in large males or in specimens in the process of reversing sex. Stored sperm probably survive long enough to fertilize more than one clutch. The anatomy of Nipponomysella is characteristic of the Montacutidae, and is of especial interest because of the unique structure of the sperm receptacles.

An objective, non-invasive technique was developed for identifying individual black rhino from their footprints (spoor). Digital images were taken of left hind spoor from tracks (spoor pathways) of 15 known black rhino in Hwange National Park, Zimbabwe. Thirteen landmark points were manually placed on the spoor image and from them, using customized software, a total of 77 measurements (lengths and angles) were generated. These were subjected to discriminant and canonical analyses. Discriminant analysis of spoor measurements from all 15 known animals, employing the 30 measurements with the highest F-ratio values, gave very close agreement between assigned and predicted classification of spoor. For individual spoor, the accuracy of being assigned to the correct group varied from 87% to 95%. For individual tracks, the accuracy level was 88%. Canonical analyses were based on the centroid plot method, which does not require pre-assigned grouping of spoor or tracks. The first two canonical variables were used to generate a centroid plot with 95% confidence ellipses in the test space. The presence or absence of overlap between the ellipses of track pairs allowed the classification of the tracks. Using a new ‘reference centroid value’ technique, the level of accuracy was high (94%) when individual tracks were compared against whole sets (total number of spoor for each rhino) but low (35%) when tracks were compared against each other. Since tracks with fewer spoor were more likely to be misclassified, track sizes were then artificially increased by summing smaller tracks for the same rhino. The modified tracks in a pairwise comparison gave an accuracy of 93%. The advantages, limitations and practical applications of the spoor identification technique are discussed in relation to censusing and monitoring black rhino populations.

Utah Lake, Utah, U.S.A. harbours an endemic catostomid fish, the June sucker Chasmistes liorus, that is recognized as being endangered. Since 1981, post-1935 representatives of the June sucker have generally been considered to be examples of a self-propagating hybrid. Utah Lake has contained another endemic catostomid, the webug sucker Chasmistes fecundus that was regarded as a true species until 1981 when it was judged to be an extirpated sterile hybrid. Since then, fisheries biologists have not attempted to identify it. This review makes a comparative examination of the published descriptions of the internal and external anatomy of these two species, plus the third catostomid of Utah Lake, the Utah sucker Catostomus ardens. The Utah sucker purportedly crossed with a form of the June sucker that has supposedly since been expunged, to produce hybrids. On the basis of comparative morphology and the consideration of temporal changes in the habitat and piscifauna of Utah Lake, the authenticity of supposed hybridism in the webug sucker, and in the contemporary June sucker, is analysed. The conclusion is reached that there is insufficient evidence to deem these taxa hybrids, or the webug sucker, extinct.

Comparative studies show that variation in sperm morphometry across taxa is associated with the environment in which sperm function, and the species' mating pattern dictating the risk of sperm competition. Accordingly, sperm have evolved to function in a non-self environment (in contrast to somatic cells) and sperm morphometry is predicted to be optimized independently of the individual male producing them, but is the result of selective forces arising directly from the fertilization and competitive environment in which sperm will operate. Males within a population are therefore under stabilizing selection to produce an optimal distribution of sperm sizes. The nature of this distribution was explored using consistent techniques to measure detailed sperm morphometry for 10 species in a range of taxa from insects to humans. Although we expected variance in sperm morphometry to be optimized by every individual male through stabilizing selection at a population or species level, we found the exact opposite; for every species examined there was significant variation between individual males in the total lengths of the sperm they produced. A significant variation is reported between individual males for every species in the sizes of each sperm head, mid-piece and flagellum component. The between-male variation exists consistently in wild, domestic and human populations, subject to a wide range of levels of inbreeding. In gryllid crickets sperm length is shown to be male-specific and is repeatable between successive ejaculates. Between-female variation in ova size (data are presented for trout) is explainable by individual female fecundity optimization strategies; however, the adaptive significance of widespread between-individual variance in male gamete size is counter-intuitive and difficult to interpret, particularly as the limited evidence available shows that sperm morphometry is not condition-dependent or resource-constrained. The differences, however, do suggest negligible influences from haploid expression in the development of sperm morphometry – if haplotypic expression were manifested we would expect more profound variation within a male's sperm population (to reflect the inherent within-male variance in haplotypes derived from recombination) rather than the significant between-male differences we found that suggests the diploid control of spermatozoal phenotype

In this study we tested the nature of the phoretic relationship between the cosmopolitan mite Macrocheles merdarius and the dimorphic dung beetle Onthophagus binodis. We observed and experimentally manipulated the number of mites on individual beetles and tested how mite infestation affects male longevity. There was a significant effect of mites on male longevity: males in our mites-added treatment died on average 15 days earlier than males in our mites-removed treatment. Interestingly, the number of mites on males was significantly repeatable suggesting that individuals may differ in their susceptibility to infestation. Major males had more mites on them than minor males, and the proportion of mites on minor males was negatively density dependent.

The small population and limited range of the Samoan flying fox Pteropus samoensis has generated concern regarding the survival of this large, diurnally active bat. During 1995–96, surveys were conducted monthly in six study valleys on Tutuila Island, American Samoa, to assess population size. The amount of diurnal and nocturnal activity was investigated to gauge the accuracy of diurnal surveys, and territorial behaviours were observed to determine how they influenced local dispersion. Individuals showed long-term fidelity to a series of roosts and small core areas that were used both nocturnally and diurnally. Territorial defence was observed only of temporary feeding territories in fruiting or flowering trees. Bats defended food resources by aerial patrols and extended aerial chases in which intruders were frequently bitten. Foraging movements changed seasonally, with up to 80% of individuals observed bypassing study valleys. The mean density of bats observed within the study valleys was 6.1 bats/km2 (range = 0.9–18.5 bats/km2). Pteropus samoensis were active both nocturnally and diurnally with greatest activity in late afternoon and evening, 16:00–22:00. Because bats were most active at night, it is probable that daytime surveys of flying bats undercount the number of individuals present. Greatest densities were found in valleys that were contiguous with large tracts of forest inaccessible to people. Most observations of roosting bats were of solitary males on dead branches that jutted above the forest canopy, while females and dependant young roosted below the canopy, hidden within vegetation. Adult male–female pairs were rarely seen together other than during the mating period in August–January. The population has increased following a ban on hunting, but reliance on mature forest makes long-term species survival dependant on protection of the limited mature forest remaining and continued hunting restrictions.

The mode by which individuals disperse, and the cost of dispersal, are of great importance in attempts to understand variation in reproductive skew in animal societies. In this paper we report detailed information on dispersal and pack formation in banded mongooses Mungos mungo. Six pack fission events were recorded among 11 packs over 22 months. Pack fission occurred under two distinct circumstances. First, groups of individuals were evicted from their natal group as a result of intense aggression from other group members. A small fraction of group members was responsible for most of the aggression. Both sexes helped to attack and evict individuals from the group, and both males and females were driven out of their natal groups en masse. The second mode of pack fission occurred when groups of same-sex individuals left their natal group voluntarily to join dispersing individuals of the opposite sex, thereby forming new packs. Dispersing groups were more frequently involved in fights with rival packs of mongooses compared to established groups, and in one instance these fights seemed to be responsible for severe injury and increased mortality among members of a dispersing group. The observations of eviction provide one line of evidence that the presence of subordinates is sometimes detrimental to dominants, contrary to the assumptions of concession models of reproductive skew.

Many species of nymphalid butterflies only exceptionally visit flowers and feed instead on tree sap, juice of rotting fruits and other decaying substances. To investigate whether the proboscis morphology of these non-flower-visiting Nymphalidae differs from that of nectarivorous butterflies, representatives from 64 nymphalid species with known feeding preferences were examined. Morphometric comparison of the proboscis revealed characteristic differences in proboscis length, tip-region length, wall composition, and number and shape of proboscis sensilla between these two feeding guilds. The investigated non-flower-visiting species belonging to Apaturinae, Limenitidinae, Morphinae, Brassolinae, Nymphalinae and Satyrinae, possess a relatively short and light-coloured proboscis which has a long tip-region with a great number of club-shaped sensilla styloconica. Densely arranged, these sensilla form a flat brush located laterally from the openings into the food canal on the dorsal side of the tip-region. Among the non-flower-visiting species, a second type of proboscis was found in fruit-feeding Charaxinae the stout tip-region of which is equipped with more widely spaced sensilla styloconica. The investigated flower-visiting Heliconiinae, Nymphalinae, Satyrinae, Danainae and Ithomiinae are characterized by a slender, darker-coloured proboscis with a rather short tip-region bearing fewer sensilla styloconica in a loose arrangement. Discriminant analysis revealed that the tip-region length, the number of sensilla styloconica and the relative proboscis length are the most important discriminating variables between the flower-visiting and the non-flower-visiting species. The proboscis morphology of nymphalid butterflies corresponds with certain feeding habits and allow us to make predictions on their food preferences. The ‘brush-tipped’ proboscis seems to have a functional role in the accumulation of fluid and the uptake of liquid from wet surfaces such as rotting fruits or tree sap. We conclude from the phylogeny of the examined taxa that this derived proboscis tip morphology evolved several times independently as an adaptation to the exploitation of new food resources.

Effect of arboreal activity on nesting site selection in Apodemus argenteus was examined by using nest boxes, a footprint recording technique, and live-trapping. Although the breeding season of A. argenteus was from April to September, the use of nest boxes placed on the trunks of trees was observed only from late July to September when use of the arboreal habitat by A. argenteus became active. Nesting site selection of A. argenteus was closely associated with their spatial activity.

Most praying mantids possess a single tympanal ear located in the ventral midline between the metathoracic legs. The auditory system is generally most sensitive to ultrasound in the 25–50 kHz range. Flying males exhibit a short-latency, stereotyped, multi-component response to ultrasound that allows them to escape from attacking bats. This study describes a small subset of species that differs in three major respects from the majority of mantis species: (1) their auditory tuning is 1.5–2 times broader; (2) they are sensitive to frequencies above 60 kHz (up to 130 kHz in some species) with thresholds as low or lower than at 25–50 kHz; (3) the behavioural response of the broadly tuned (BT) species includes 10–50 times more flight cessations and can be far less stereotyped, i.e. more ‘evitable’, than that of narrowly tuned (NT) species. However, BT species do not differ from NT species in overall sensitivity. Two species from one subfamily, the Amelinae (family Mantidae), stand out because they are among the least sensitive of any hearing mantids so far tested. Although the two amelines differ from one another in tuning curve shape, they are both more broadly tuned than most mantids. The occurrence of BT species does not follow any obvious phylogenetic pattern; they are patchily distributed among the mantis families, and both BT and NT species can be found in the same subfamily or tribe. We suggest that BT species are responding to a shared ecological pressure. Based on their tuning, the nature of their behavioural response, and their geographic distribution, we hypothesize that high duty cycle (HDC) bats (Rhinolophidae and Hipposideridae) pose a special danger to BT mantids in addition to the threat that all flying mantids face from the more common and widely distributed low duty cycle (LDC) bats.

Colonies of the Mashona mole-rat Cryptomys darlingi are founded from a single reproductive pair of animals that are genetically unrelated by descent. All non-reproductive animals are the progeny of the reproductive pair. Non-reproductive colony members do not seem to be suppressed from reproduction at the level of the pituitary. In colonies in which the reproductive female is removed or dies, there is strict incest avoidance and the colony remains reproductively quiescent. Reinstatement of sexual activity in a queenless colony may be brought about in the laboratory by the introduction of unfamiliar and unrelated adult males. In the queenless colony under study, there was a marked change in the dominance hierarchy with an increase in Landau's index of linearity from 0.61 to 1.0 on the introduction of two unrelated males. The two new males became the most dominant within the colony. All previously non-reproductive females exhibited heightened urinary oestradiol 17β and progesterone concentrations on the introduction of the males. However, it was only the older and most dominant non-reproductive female that became the new reproductive female and produced a litter of three pups 70 days after the initial introduction.

A total eclipse of the sun is a very rare event for a given geographical location, and it is not easy to predict the reaction of animals to such events. On 11 August 1999, the reaction of some species of Saltatoria was quantitatively analysed in a long-term study area for which the normal diurnal song patterns are well established. The song activity of the grasshoppers and bushcrickets declined slowly during the partial eclipse, and stopped completely during the 2-min total eclipse. After a marked delay, song activity returned suddenly to normal. This suggests that light intensity is the main parameter controlling the diurnal song pattern in the species studied, and obviously overrides any internal rhythm.

Current theories of locomotor biomechanics are based largely on observations of extant terrestrial mammals. However, extant mammals are limited with respect to certain aspects of terrestrial locomotion, and this constraint has confounded interpretations of limb design in this group. Dinosaurs include a wide array of large and small bipeds, record several transitions between bipedalism and quadrupedalism, and show a unique covariation of cursoriality and body size. Thus, the wider applications of biomechanical theories may be tested by applying them to the limb bones of dinosaurs. A broad examination of hindlimb and forelimb bone scaling patterns in dinosaurs and mammals reveals several general similarities that provide insight into the general constraints acting on terrestrial locomotion, particularly in animals with parasagittally oriented limbs. Most limb bones scale with negative allometry in these two groups, and larger taxa tend to scale more negatively than smaller forms. However, the strongly negative scaling of large mammals is mostly restricted to ungulates, whose unusually short femora may be the result of constraints of cursoriality at large body sizes. Bipedal and quadrupedal dinosaurs scale very similarly, with most differences apparently resulting from size rather than posture. Bone curvature tends to decrease with increasing body size, while femoral midshaft eccentricity tends to increase. Femoral midshaft eccentricity is explained as a general adaptation to mediolateral bending on parasagittal limb bones. These trends are more pronounced in dinosaurs than mammals; additional morphological constraints present in the dinosaurian hindlimb may contribute to this distinction.

Tidarren argo sp. nov. is described from Yemen. As in its congeners, the male amputates one of his palps before maturation and enters his adult life with one palp only. The new species is shown to adopt exceptional copulatory behaviour. As soon as the male achieves genitalia coupling with his palp, the palp is torn off by the female. The separated gonopod remains attached to the female's epigynum for c. 4 h and apparently continues to function independently. Furthermore, it serves as a mating plug. In the meantime the female feeds on the palpless male. Emasculation synchronizes sexual cannibalism and sperm transfer, and may lengthen the interval between copulations. This unique mating behaviour probably allows continuation of insemination by the dismembered palp and is reported for the first time.

The highveld mole-rat Cryptomys hottentotus pretoriae exhibits an extreme reproductive division of labour. Reproduction in this seasonally breeding social mole-rat is restricted to a breeding pair. The non-reproductive females seem to be physiologically suppressed from reproducing, whereas the non-reproductive males are restricted from sexual activity through incest avoidance. Circulating basal concentrations of luteinizing hormone (LH) between reproductive and non-reproductive females were not significantly different, yet the response to an exogenous gonadotrophin-releasing hormone (GnRH) challenge was significantly lower in non-reproductive females when compared to reproductive females. The mean basal LH concentration in non-reproductive females was not significantly different in and out of the breeding season. However, the magnitude of the LH response in non-reproductive females out of the breeding season was greater than in the breeding season. The ovaries of reproductive females showed little change with respect to season. However, reproductive females had enhanced follicular activity in comparison to their non-reproductive counterparts. This suggests that non-reproductive females are under stricter control from the reproductive female when she is pregnant. The tropical African mole-rats exhibit a continuum of socially induced infertility with differing social species inhabiting regions of varying degrees of aridity. In this spectrum, a predominantly behavioural repression is found amongst non-reproductive females in social mesic-adapted species, whereas a strictly physiological suppression is operative amongst non-reproductive females in arid-adapted social species. Here we show that the mesic-adapted highveld mole-rat does not fit this trend in that the non-reproductive females seem to be physiologically suppressed. We discuss this in light of the seasonality of breeding and the ecological constraints that may operate during times of drought.

Recent studies show that the availability of prey influences the ecology of otters by regulating breeding, carrying capacity and mortality. Mediterranean habitats experience extreme seasonal variation in water flow – a stress period can occur in summer when water flows and levels are low with long periods of drought, while torrential floods usually occur in autumn and spring. Reservoirs can affect this situation by further influencing water flow regimes and acting as a barrier. Our data show the close relationship between the amount of food (fish) available to otters and their use of a stretch of water and the otter density there. The adjustment of the number of individuals (and carrying capacity) in an area can be seen from their mortality, a decrease in their reproductive success, or migration. Our results are consistent with the hypothesis that otters are food-limited. Torrential rains, summer droughts and dams for water management have repercussions for otter populations in as much as they affect their prey-species. Barbels Barbus spp. and, secondarily, nases Chondrostoma spp. are shown to be important to otter ecology and breeding in Mediterranean Iberian rivers. The conservation and management of the otter in these habitats must not ignore the management of food sources. In order not to affect otter populations, the effect of the reservoirs and their dams also must be considered. The release and cessation of floodwater from reservoirs must be progressive and mimic more closely the flow regime of natural rivers.