The European bitterling Rhodeus sericeus Pallas is a freshwater fish belonging to the Acheilognathinae, a subfamily that has an unusual spawning symbiosis with freshwater mussels. Female bitterling possess long ovipositors that they use to place their eggs onto the gills of a mussel through the mussels' exhalant siphon. Males fertilize the eggs by releasing sperm into the inhalant siphon of the mussel. The embryos develop inside the mussel for approximately a month, eventually leaving the mussel as actively swimming larvae. Because they use a discrete spawning site that can be readily manipulated they have recently been used in studies to understand oviposition choice with respect to mate and spawning site quality, host–parasite coevolution, alternative male mating tactics, and linking behavioural decisions with population dynamics. The current state of knowledge of bitterling reproductive ecology is reviewed and synthesized, and future directions for research on this species are proposed.

In 2001 and 2002, surveys of slender lorises were carried out in Sri Lanka, providing the first recent information on four taxa (Loris lydekkerianus nordicus, L. l. grandis, L. tardigradus tardigradus, and L. t. nycticeboides) endemic to the island. Thirty-one sites across five ecological zones were surveyed. Approximately 766 km were covered in 17 areas where no lorises were found; 192 km were walked or motored in 14 sites yielding 185 sightings of Loris: L. l. nordicus (n=111), L. t. tardigradus (n=69), L. l. grandis (n=4), and L. t. nycticeboides (n=1). Density estimates, based on sightings of animals/km, were: L. t. tardigradus (0.86–13 animals/km) and L. l. nordicus (0.33–50 animals/km). Significantly fewer sightings occurred within protected areas than were made outside of them. Animal densities varied across habitat type with the highest density of lorises occurring in the dry zone in monsoon forests. Presence of Loris is positively associated with insect presence, and negatively associated with primary forest with little undergrowth; taxa differ in their ability to thrive on the edge of human habitations. Human-induced threats include habitat loss, electrocution on live wires, road accidents, the pet trade, and use in traditional medicine. Further behavioural and ecological studies are needed to estimate the habitat requirements for the different taxa of slender loris.

During pair formation, cicadas produce acoustic signals that allow sexual partners to meet. The male is generally the emitter, producing calling songs at long range and courtship songs at short range, and the female generally the receiver. The male–female courtship behaviour of seven taxa belonging to the Palaearctic genus Tibicina is described here for the first time. Male courtship songs consisted of a succession of groups of pulses arranged in two sub-groups. They were short in duration with strong amplitude variations. In all taxa, courtship songs were preceded by a series of 1–5 audible wing-flicks. Differences in courtship song structure between two pairs of sympatric species, respectively T. corsica corsica/T. nigronervosa and T. corsica fairmairei/T. tomentosa, suggest that courtship signals could act as distinctive species mating recognition systems. In response to male acoustic signalling, females of T. c. corsica, T. c. fairmairei and T. nigronervosa produced audible wing-flicks such that both sexes established an acoustic duet ending in physical contact. In addition, males and females of T. tomentosa produced silent wing-flicks, a previously unknown behaviour, which could facilitate pheromone diffusion. Females did not exhibit a species-specific temporal pattern in acoustic reply to male courtship song and female wing-flick behaviour does not seem necessary for pair formation. Nevertheless, this strategy through male and female signalling ensured a reciprocal phonotactic approach that probably enhanced the likelihood for the two sexes to meet in complex habitats.

In 2003, the date for publication of the annual report for 2002 was postponed and it is therefore printed in this issue of the Journal. 2002 was, however, another very successful year during which we received 281 submissions and published 167 papers in volumes 256–258. The Journal continues to receive high-quality, original research papers and reviews from a wide range of taxa and a variety of disciplines. Our aim to attract a truly international set of contributors has been met once again, with papers from 41 countries being submitted during 2002.

For species conservation, defining seasons according to an animal's perception and consideration of seasonal differences in its use of space is required. First, a statistical approach was used to determine seasons based on rates of movement of radio-collared caribou Rangifer tarandus caribou. Using polynomial regression, five seasons were delineated by inflection points that demarcate changes in rates of movement. Male and female caribou did not differ in timing and number of seasons. Second, the seasons so defined were used to describe the use of space in 33 caribou in north-western Ontario, Canada. Greatest rates of movement occurred during spring and early winter migration when caribou had both the largest range size and largest distance between seasonal ranges. The general direction of movement was west in spring and east early in winter, although variation occurred among caribou and years. A drop in rate of movement lasting about 3 days may indicate calving. Caribou were most dispersed and occupied the smallest seasonal range during the calving season. The animals showed strong fidelity to calving areas in contrast to the highly variable year-to-year location of winter ranges. Understanding the seasons of animal movement patterns, and applying this understanding when developing plans for forest management, may help reduce adverse effects of forest harvesting on highly mobile animals such as woodland caribou.

A 40-species assemblage of jumping spiders inhabiting a small (0.6 ha) tropical suburban study site in Zimbabwe was studied over 4 years. It was hypothesized that marked habitat separation is one of the critical factors permitting the close coexistence of so many species from the same family (Salticidae). The 25 most common salticids (i.e. species with 10 or more records) were found to occupy six primary habitat types: tree trunks (with three salticid species), tree leaves (two species), shrubs (five species), walls (three species), low herbaceous plants and grasses (three species) and ground and litter (six species). The remaining three species, termed habitat generalists, frequented three or more of these habitats. Finer-scale microhabitat separation was also recorded in many species. The remaining 15 less common species (i.e. <10 records) could not be assigned to particular habitats with certainty. Twenty-one (84%) of the 25 common salticids showed a significant association with a single primary habitat type. Three-quarters of species were present for 3 or 4 years of this 4-year study. It was concluded that the narrow spatial niches occupied by most species, combined with the numerous microhabitats within the site, were conducive to the highly diverse salticid assemblage. Attention is drawn to the problems of long-term sampling of such a small area without undue disturbance to the fauna. The impacts of long-term weather cycles on habitats, ephemeral niches, age-dependent use of habitats, inter- and intraspecific associations of individuals within habitats, and the relationship between suburban and wild habitats are discussed. Suburban environments, by providing a wide range of microhabitats, can support a high diversity of salticid species and thus contribute to their conservation.

The facial region of moose Alces alces is highly divergent relative to other cervids and other ruminants. In particular, the narial region forms an expanded muzzle or proboscis that overhangs the mouth. The nose of moose provides a case study in the evolution of narial novelty within a phylogenetically well-resolved group (Cervidae). The function of the nasal apparatus of moose remains enigmatic, and new hypotheses are proposed based on our anatomical findings. Head specimens of moose and outgroup taxa were subjected to medical imaging (CT scanning), vascular injection, gross anatomical dissection, gross sectioning, and skeletonization. Moose noses are characterized by highly enlarged nostrils accompanied by specialized musculature, expanded nasal cartilages, and an increase in the connective-tissue pad serving as the termination of the alar fold. The nostrils are widely separated, and the rhinarium that encircles both nostrils in outgroups is reduced to a tiny central patch in moose. The dorsal lateral nasal cartilage is modified to form a pulley mechanism associated with the levator muscle of the upper lip. The lateral accessory nasal cartilage is enlarged and serves as an attachment site for musculature controlling the aperture of the nostril, particularly the lateralis nasi, the apical dilatators, and the rectus nasi. Bony support for narial structures is reduced. Moose show greatly enlarged nasal cartilages, and the entire osseocartilaginous apparatus is relatively much larger than in outgroups. The nasal vestibule of moose is very large and houses a system of three recesses: one rostral and one caudal to the nostrils, and one associated with the enlarged fibrofatty alar fold. As a result of the expanded nasal vestibule, osseous support for the nasal conchae (i.e. turbinates) has retracted caudally along with the bony nasal aperture. The nasoturbinate and its mucosal counterparts (dorsal nasal concha and rectal fold) are reduced. The upturned maxilloturbinate, however, is associated with an enlarged ventral nasal concha and alar fold. Moose are the only species of cervid with these particular characteristics, indicating that this anatomical configuration is indeed novel. Although functional hypotheses await testing, our anatomical findings and published behavioural observations suggest that the novel narial apparatus of moose probably has less to do with respiratory physiology than with functions pertaining specifically to the nostrils. The widely separated and laterally facing nostrils may enhance stereolfaction (i.e. extracting directional cues from gradients of odorant molecules in the environment), but other attributes of narial architecture (enlarged cartilages, specialized musculature, recesses, fibrofatty pads) suggest that this function may not have been the evolutionary driving force. Rather, these attributes suggest a mechanical function, namely, an elaborated nostril-closing system.

Spiders of the genus Argyrodes are kleptoparasites that steal prey from other web spiders. Recent studies have shown that in addition to stealing prey, they occasionally eat the silk of the host spider webs. How Argyrodes alters the two foraging tactics in the field is still unknown. The foraging behaviour of Argyrodes flavescens was observed in the south-western part of Japan where prey availability changes greatly with season. Silk-eating behaviour was commonly observed when insect prey availability on host webs was low, but when prey was abundant, only prey-stealing behaviour was observed. Spiders spent more time feeding on silk than on prey when prey was scarce. Moreover, in the season when most individuals fed on silk, only a small portion of individuals consumed prey. These results suggest that silk eating is an important alternative foraging tactic under seasonally changing environments.

Some studies of birds suggest that the development of the skeleton may invoke a constraint on the rate of postnatal growth. Other studies have shown that the eggshell is the major source of calcium for skeletal development of the embryo. To test whether avian growth rate is indeed associated with different patterns of skeletal development, we compared the degree of skeletal ossification of the long bones of the wing and the leg of one slowly growing precocial species (quail Coturnix japonica) with that of two rapidly growing altricial species (starling Sturnus vulgaris and fieldfare Turdus pilaris). The degree of skeletal ossification of the long bones of the wings and legs of lines of quails that had undergone long-term selection for high- and low-growth rate, respectively, also was compared with a non-selected control line. Next, the fine structure of the inner eggshell surface (mammillary layer) of both pre- and post-incubated eggs, i.e. before and after embryonic development/calcium removal was compared. The data show that the skeleton of the more rapidly growing species and lines was less ossified than that of the more slowly growing ones. This difference appeared to be associated with different rates of calcium removal from the eggshell. Removal was more extensive in eggs of quail than in eggs of starling and fieldfare, i.e. more extensive in shells with a high number of mammillary tips per unit of surface area than in shells with a lower number. It is therefore concluded that growth rate is of fundamental importance for the pattern of skeletal development. Moreover, the mammillary density varies between different bird species, it is suggested, in order to support the different rates of calcium removal by developing embryos.

The timing of birth and postnatal growth in lesser horseshoe bats Rhinolophus hipposideros were studied during 2000 and 2001 at three maternity roosts located in the provinces of Carinthia and Salzburg, Austria. Postnatal growth curves for length of forearm and body mass were determined separately for the different colonies and years. Cooler weather during June 2001 coincided with a median birth date that was 8 days later than in 2000, whilst the difference between colonies was 4 and 5 days, respectively, for the pooled data of both years. Cool temperatures in June also coincided with a longer duration of the parturition period. Postnatal growth rates were higher than in most other bat species but differences between years and colonies were considerable. These differences may be attributed to the ambient roost temperatures, whereby the young of two cooler roosts showed significantly reduced growth rate during 8 days of cool weather in 2000. Moreover, later born and therefore smaller pups were more strongly affected by low temperatures than earlier born and larger ones. The mean length of forearm of young lesser horseshoe bats at the beginning of September equalled that of adult bats, whilst their body mass was still lower. Non-volant juveniles did not cluster following the nightly emergence of adult females, and a preferred location within the roosts could not be identified. High and very low roost temperatures, however, did have an influence on the location of non-volant young in the colonies.

The variation in 10 morphometric characters and the degree of sexual dimorphism in size and shape was studied in pure and hybrid populations of smooth Triturus vulgaris and Montandon's T. montandoni newts. Multivariate analyses showed pronounced interspecific differences in both sexes. Females differed mainly in traits related to general size, whereas males differed mainly in body proportions. Triturus vulgaris males possessed a relatively longer trunk and tail. Sexual size dimorphism was much stronger in T. montandoni, the females being the larger sex. In hybrid zone populations a general correlation between morphometric traits and nuclear genotypes was found. This does not, however, fully explain the variation in size and shape. Whereas the majority of genetically identified hybrids fell into the range of morphologically pure species, many genetically pure individuals were classified as morphometric intermediates. The linear relationship between the morphometric and genetic variation suggested no strong differential selection on the molecular markers and loci responsible for morphometric differences between species. The differences in the level of sexual size and shape dimorphism, however, suggest that females of both species show dissimilar mate preferences, and thus hybrid males may experience reduced fitness resulting from lower mating success.

Frequency-modulated sweep calls of Otomops martiensseni were recorded from individuals as they emerged from nine different building roosts near Durban, South Africa. Multiple analyses of call features, including duration (ms), lowest frequency (kHz), highest frequency (kHz) and frequency with most energy (kHz), indicated significant inter-individual variation. Discriminant function analysis of call features correctly classified the calls of individuals from four roosts > 70% on 19 of 28 times. Although other species of molossids (Chaerephon pumilus, Tadarida aegyptiaca, and one unidentified species) produced social calls as well as frequency-modulated sweep calls, O. martiensseni produced just the latter vocalizations and they were longer and lower in frequency than those of the sympatric molossids. Other species of molossids, but not O. martiensseni, produced feeding buzzes as they attacked flying insects. The frequency-modulated sweep calls of O. martiensseni seem to serve a communication function, but they may not be used in echolocation unlike similar calls by other molossids. Individually distinct communication signals (frequency-modulated sweep calls) enhance communication in a species that lives in year-round social groups (one adult male, females and dependent young).

Costly anti-predatory defences are used in ecological time and maintained in evolutionary time by natural selection favouring individuals that survive through their use. Autotomy of expendable body parts is a striking example of a defence having multiple substantial costs, including loss of ability to use the same defence, loss of energy, and decreased growth, reproductive success and survival following autotomy, plus the energetic cost of replacing the lost body part in species capable of regenerating them. Our study shows that autotomy in the lacertid lizard Podarcis lilfordi reduces sprint speed, indicating decreased capacity to escape as well as the loss of energy. Autotomy carries substantial cost, and thus should be avoided except as a last resort. Ease of autotomy and post-autotomic movements were studied in three populations of lacertid lizards. Two were islet populations of P. lilfordi from Aire (lowest predation pressure) and Colom (intermediate predation pressure) off Minorca. The third was a mainland population of Podarcis hispanica, a closely related species from the mainland of the Iberian Peninsula where predation pressure is higher than on the islets. As predicted, a suite of autotomic traits increases the effectiveness of autotomy as a defence as predation pressure increases. With increasing predation pressure, the frequency of voluntary autotomy increases, latency to autotomy decreases, pressure on the tail needed to induce autotomy decreases, vigour of post-autotomic tail movements increases, and distance moved by the shed tail increases. Additional changes that might be related to predation pressure, but could have other causes, are the presence of tail coloration contrasting with body coloration except under the lowest predation pressure (Aire) and longer tails in the mainland species P. hispanica. Correspondence between predation pressure and the suite of autotomic traits suggests that autotomy is an important defence that responds to natural selection. Comparative data are needed to establish the generality of relationships suggested in our study of only three populations.

Caviomorph rodents (Rodentia: Caviomorpha) are an anatomically variable group with diverse ecological and morphological types, including cursorial, digging, fossorial and swimming forms. Their appendicular skeleton is rather generalized and extreme modifications or reductions in the long bones of limbs are not present. It is of special interest to evaluate functional adaptive variations of the appendicular skeleton within this group. Although much work has been devoted to study structure, function, and kinematics of legs in mammals, most studies do not consider particular functions and behaviour within different mammalian lineages. Morphometric and biomechanical studies were performed to test the relationship between adaptation and morphology of the bones of the proximal and middle limb segments in terrestrial caviomorph rodents. Fifty-four specimens belonging to 10 species with different limb adaptations and representing a wide range of body sizes were measured. Diameters and functional lengths of long bones were taken and nine functional indices were built. Humerus (HRI) and ulna (URI) robustness, humerus deltoid (SMI) and epicondyle (EI) development, olecranon proportion (IFA), femur (FRI) and tibia (TRI) robustness, and gluteal muscle insertion at femur (GI), were calculated. Only TRI and, to a lesser degree, SMI and EI, were significantly related to body mass. A functional sequence (cursorial–generalized–occasional digging–diggers) which seems to reflect an increase in force and muscular development in middle segments of the fore limb is recognized. The hind limb shows a decrease in the speed efficiency of the femur and an increase in limb robustness in the transition from cursorial to digging forms. Although overlapping of speed and force functions in the limbs is evident, functional differentiation for speed in the proximal, and force in the middle segments can be inferred.

Nearly all animals show altered musculo-skeletal phenotypes when subjected to captive conditions. Whether such changes affect biomechanical performance is for the most part unknown. In American alligators Alligator mississippiensis such modifications include shortened jaws, more robust body form, and broadened heads. Bite-force performance was assessed for a variety of sizes of wild-captured alligator specimens and the results correlated with morphological indices. Bite forces ranged from 217 to 13 172 N, with the latter being the highest value ever measured for a living animal. These data were statistically compared with those for long-term captive specimens using ANCOVA. Bite-force performance showed similar patterns of increase between captive and wild-reared animals, and bite forces with respect to snout–vent length and body mass were statistically indistinguishable. Nevertheless, with respect to head size, captive alligators were found to bite more forcefully than their wild counterparts. These findings illustrate the importance of considering biomechanical performance differences between wild and captive individuals if meaningful ecological ties are to be made. Furthermore, before concluding that wild-reared or captive animals show similar or different biomechanical performances, it is important to understand that standardization to different morphological parameters can reveal conflicting results. Consideration as to which measures are the most germane to the question at hand is essential.

The histological organization and the main growth trends of the periotic and tympanic bones are described in known-aged common dolphins. The maximum sizes of these bones are already acquired in new-born specimens, and their full mineralization (84.62% and 83.3%, respectively) is reached either at birth (tympanic) or within the first 6 months. Mass, compactness and density of the periotic and tympanic quickly rise during the first year of life, and remain stable afterwards. Mean values of compactness and density observed in adults are 94% and 2.65 g/cm3 for the periotic, and 98% and 2.66 g/cm3 for the tympanic. The periotic and tympanic are composed of a fibro-lamellar tissue, initially deposited as a loose spongiosa with hypermineralized trabeculae. Before the end of the first year, this spongiosa is made compact by the perivascular formation of primary osteons. The vascular network of bone, originally very extensive, is obliterated rapidly by the osteons. The collagen matrix is composed of very thin collagen fibrils (diameter: 10 to 30 nm) arranged in a dramatically reduced network compared to normal bone. Hence, the room available for the mineral phase is considerably increased. Whatever the age of the animals, there is no inner (Haversian) remodelling in the periotic and tympanic. Since the compactness and density of these bones augment during the nursing period, it seems likely that the full hearing capacities of the dolphins are not reached before weaning.

Earlier authors demonstrated that wetland species of the genus Brachinus (Coleoptera: Carabidae) are pupal ectoparasitoids of water beetles of the families Dytiscidae, Gyrinidae and Hydrophilidae. Here we demonstrate that the dryland species, Brachinus explodens and B. crepitans, develop on pupae of ground beetles of the genus Amara (Carabidae). As Brachinus and Amara species often occur together at high densities in crops, the rearing of both Brachinus species was followed in the laboratory. Females laid eggs in the soil and the first instar larva searched for a host. After finding an Amara pupa, a Brachinus larva bit it and then fed on haemolymph exuding from the wound. The second instar larva continued feeding in this way. The third instar larva attached the Amara pupa to its dorsum and ate it completely within c. 2 days. Feeding was followed by a resting phase and moulting to pupa and adult. The total post-embryonic development was completed within 20 days in B. explodens and 24 days in B. crepitans at 24.7 °C.

The parasite load of seven European bat species (Myotis daubentonii, Myotis emarginatus, Myotis myotis, Myotis mystacinus, Myotis nattereri, Nyctalus noctula, Pipistrellus pipistrellus) was compared and tested to see if there was a relationship between high parasite load and poor body condition in bats. Considerable variations of the parasite load between host species, ages and sexes were found, which can be attributed to roosting conditions and behavioural differences of the bats. Overall, male bats had the fewest parasites. Very different parasite population densities were found in different years, and also at the same time at different sites. A generally high parasite load during the nursing season was not observed. There was no strong trend of increasing parasite load in bats with decreasing condition. If weak bats had more parasites than other individuals, the high number of parasites seemed to be a symptom and not the direct cause of the bad condition.

Predictors used to calculate the body mass of extinct carnivorans often scale differently between different taxa, thus yielding body mass estimates that diverge considerably depending on which predictive equation is used. This requires the investigator to choose the ones most suitable, a procedure that is best avoided if possible. The carnivoran elbow joint is here explored with the aim of producing a single general body mass predictor that can be used over a broad range of terrestrial and arboreal carnivorans. The circumference of the distal humerus trochlea is found to be highly correlated with body mass, and trochlea circumference seems to scale similarly throughout the order Carnivora. This scaling is not as theoretically predicted by elastic similarity and is slightly higher than that predicted by geometric similarity, indicating a slight positive allometry for the latter. Some degree of differential scaling between carnivoran families and between animals of large and small size cannot be ruled out, but this result is inconclusive. A predictive model that allows mass estimations for a broad range of carnivorans is presented (a=0.601; b=2.552; r2=0.952, SEE=0.136, P<0001, n=92). Body mass for eight extinct carnivoran species are calculated and these generally conform to earlier mass predictions.

Monogamy in mammals is characterized by reduced sexual dimorphism in morphology and behaviour. Ten pairs of Eurasian beaver Castor fiber were radio-tracked to test how far this concept can be applied to movement behaviour by focusing on sex-related effects on territory sizes and movement patterns. Within monogamous pairs, males and females occupied territories of almost equal size during the whole radio-tracking period and more specifically after parturition. The territories of pair members overlapped on average by 81.6±14.0% SD while the territory overlap between residents and their neighbours was small to non-existent (on average between 0.5% and 2.2%). Males had larger 95% utility distributions than did females during the whole tracking period and after parturition. There was no significant difference between the 50% utility distributions for both sexes. Furthermore, males and females spent equal proportions of their time in territory border zones. There was a non-significant trend for males to move greater distances at night than females. Nightly distance moved correlated positively with territory size in females but not in males. Nightly distance moved correlated with neither body weight nor colony size. These results suggest that beavers show reduced sexual dimorphism in space use and movement patterns within adult monogamous pairs.