bluuebunny/crossref_metadata_2025_split huggingface dataset:
Foraging in wild and captive colonies of the common mole‐rat Cryptomys hottentotus hottentotus (Rodentia: Bathyergidae)
Authors: Spinks Andrew C. , Branch Trevor A. , Croeser Shula , Bennett Nigel C. , Jarvis Jennifer U. M. 
Published: February 2006

AbstractThe foraging behaviour of wild and captive colonies of the common mole‐rat Cryptomys hottentotus hottentotus was investigated. Field studies were undertaken at Steinkopf, an arid site in the Northern Cape, South Africa. The resource biomass and the total available energy here were amongst the highest recorded for any bathyergids, but geophytes were sparse and widely distributed. The low probability of locating these widely dispersed resources should promote co‐operative foraging in these mole‐rats. All common geophyte species were consumed, probably because high burrowing costs favour dietary generalism. The mole‐rat biomass per metre of burrow system (0.5–1.5 g.m‐1) remains the lowest of any subterranean mammal. Burrow depths and diameters were positively correlated to the average mass of the mole‐rats in each colony, apparently minimizing energetic costs and maximizing foraging success. Bulbs were stored in central food caches, and both field and laboratory data indicated size‐based selectivity in their storage and consumption. As predicted by central place foraging theory, large bulbs were preferentially stored, and small bulbs preferentially consumed. However, factors other than energetic considerations may also influence these storage decisions. Total consumption time of bulbs was negatively correlated to animal size, and furthermore smaller bulbs were consumed more rapidly than larger ones. In addition to geophyte‐storing, C. h. hottentotus also exhibited an alternative foraging strategy, termed ‘geophyte farming’, in which large bulbs were left and eaten in situ, and served as a renewable resource. Together with these foraging specializations, the evolution of sociality in mole‐rats is a key factor which enables them to live in some of the most formidable habitats in Africa.
Genetic variation in Neotricula aperta, the snail intermediate host of Schistosoma mekongi in the lower Mekong Basin
Authors: Attwood S. W. 
Published: February 2006

AbstractRestriction fragment length polymorphism (RFLP) was studied for six populations of the polytypic snail Neotricula aperta using seven different restriction enzymes. Samples of all three strains of N. aperta from north‐eastern Thailand were examined, as well as topotypes from southern Laos and material from Kampuchea and central Laos. Genetic distances were estimated as Nei & Miller's (1990) distance ×100 (D). The samples were taken from the Mekong, Mul and Xé‐Bang‐Fai (XBF) rivers of the lower Mekong basin. The γ‐strain of Kampuchea and southern Laos has been shown to act as intermediate host for Schistosoma mekongi. The least amount of genetic divergence was found where the α‐strain was compared with other taxa (D, 2.1–3.7), and the largest values for comparisons involving samples of the XBF strain (D, 2.1–6.4). Large distances were apparent between the b‐strain and all the γ‐strain populations (D, 4.0–5.5). The β‐ and XBF‐strain may represent a pair of sibling species with respect to N. aperta. The γ‐strain population of north‐eastern Thailand comprised two cryptic taxa which were relatively well diverged (D= 1.6). Only one of these cryptic taxa showed close affinity with other γ‐strain taxa; this finding may be important in the control of Mekong schistosomiasis.
Foraging ecology of Leisler's bat (Nyctalus leisleri) at two sites in southern Britain
Authors: Waters Dean , Jones Gareth , Furlong Mick 
Published: February 2006

AbstractLeisler's bat Nyctalus leisleri was studied at sites around Bristol and Kent in southern Britain. Its diet was studied by faecal analysis, and habitat use was monitored by radio‐telemetry and time‐expanding bat‐detectors. The diet, which varied between the two sites and also with the season, consisted primarily of small Nematoceran Diptera plus smaller numbers of Coleoptera and Lepidoptera. Foraging ranges were relatively large – bats flew a mean maximum distance of 4.2 km from the roost. Minimum area convex polygons enclosed an average of 7.4 km2, but were up to 18.4 km2. Bats significantly preferred foraging in areas of woodland and along scrub‐lined roads in Kent, but over pasture around Bristol. Urban and arable areas were avoided at both sites. Bat‐detector transects showed a significant preference for bats to forage along woodland margins.
Variation of harp seal (Pagophilus groenlandicus) underwater vocalizations among three breeding locations
Authors: Perry Elizabeth A. , Terhune John M. 
Published: February 2006

AbstractWe compared the underwater vocalizations of harp seals Pagophilus groenlandicus Erxleben, 1777 recorded during the breeding season at three locations: Jan Mayen Island (north of Iceland); Gulf of St Lawrence; and the ‘Front’ ice east of Labrador. The three herds shared 17 call types. The Jan Mayen herd had one call type not found in the Gulf or Front. One of the Gulf and Front call types was not found at Jan Mayen. Based on ANOVA post hoc pairwise comparisons between locations, the three herds exhibited a similar number of within‐call type differences in duration, number of elements, start pitch and end pitch. There were no differences in proportional usage of call types between the Gulf and Front herds but both differed in a similar manner from those of the Jan Mayen herd. These findings support tagging studies that indicate that the Gulf and Front herds may be interbreeding and both are reproductively isolated from the Jan Mayen herd. We found no evidence of acoustic adaptation to the site‐specific ice and environmental conditions associated with the three study locations.
Ecological and histological aspects of tail loss in spiny mice (Rodentia: Muridae, Acomys) with a review of its occurrence in rodents
Authors: Shargal Eyal , Rath‐Wolfson Lea , Kronfeld Noga , Dayan Tamar 
Published: February 2006

AbstractMany individual nocturnal common spiny mice Acomys cahirinus and diurnal golden spiny mice A. russatus in the field are found missing all or part of their tails. Possibly, this is a predator avoidance mechanism. A 25‐month field study revealed that at Ein Gedi (Israel) percentage tail‐loss is 63% in male and 44% in female golden spiny mice, and 12% in male and 25% in female common spiny mice. Tail loss is significantly more common in golden spiny mice than in common spiny mice, possibly reflecting differences in predation risk or predator efficiency between the different microhabitats used by these species and in their different activity times. However, inter‐ and intraspecific aggressive interactions may also account in part for this pattern. Few significant differences in longevity, body mass, or reproductive condition were found between tailed and tail‐less spiny mice, suggesting an advantage to tail‐less individuals. Histological sections revealed a plane separating the skin layer from the underlying muscles and vertebrae, facilitating loss of the skin with little bleeding. The remainder (muscles and bone) is later chewed off by the mouse. A survey of published cases of tail loss in rodents revealed that this phenomenon occurs in at least 35 species and has evolved separately in eight rodent families, with no clear pattern in systematics, geography, or habitat use.
Taxonomic studies on some Australian Phidoloporidae (Bryozoa: Cheilostomatida)
Authors: Hayward P. J. 
Published: February 2006

AbstractFourteen species of erect, reticulate bryozoans are described and illustrated with SEM micrographs. Nine species introduced by P. H. MacGillivray and two by T. Hincks are included; their taxonomic status is stabilized by the selection of type specimens. A new species is described in each of the genera Triphyllozoon and Reteporellina. Dictyochasma gen. nov. is introduced for D. janus sp. nov.
Seasonal changes in the rumen morphology of Himalayan tahr (Hemitragus jemlahicus) in the Two Thumb Range, South Island, New Zealand
Authors: Forsyth D. M. , Fraser K. W. 
Published: February 2006

AbstractMale and female Himalayan tahr Hemitragus jemlahicus exhibit extreme sexual size dimorphism and are spatially segregated outside the winter mating season. Segregation results in a greater change in both habitat selection and diet of males relative to females. Since the structure of the ruminant digestive tract is closely related to feeding habit, the rumen morphology of male and female tahr should reflect these apparently important seasonal changes. We therefore hypothesized that the rumen morphology of male tahr would undergo greater change between winter (when the sexes are aggregated) and summer (when the sexes are segregated) compared to females. Samples of rumen wall mucosa were cut from the dorsal rumen wall, atrium ruminis, caudo‐ventral blindsac, and the ventral rumen wall of tahr collected during winter (eight male, 10 female) and summer Two Thumb Range, South Island, New Zealand. Although we recorded a significant seasonal increase in the mean surface enlargement factor (SEF) from winter to summer for both sexes, the SEF of females and males were not significantly different in winter (3.88 ± 0.55, se, and 4.95 ± 0.61, respectively) or summer (7.71 ± 0.55 and 6.86 ± 0.52). We conclude that the effects of inter‐sexual differences in habitat selection and diet on rumen morphology were insignificant relative to the extreme seasonal changes in forage quality and quantity that occur in the Two Thumb Range.
Ecological traits and conservation biology of five fossorial ‘sand‐swimming’ snake species (Simoselaps: Elapidae) in south‐western Australia
Authors: How Richard A. , Shine Richard 
Published: February 2006

AbstractAlthough small, nocturnal, fossorial snakes are a significant component of the reptile fauna in many parts of the world, their biology is poorly known. An 11‐year pit‐trapping study in urban bushland remnants near the city of Perth, Western Australia, provided data from >500 captures of small fossorial snakes of the genus Simoselaps. The five species differed in relative abundances and in distribution, both among localities and among habitats within a single locality. For example, three saurophagous taxa (Simoselaps bertholdi, S. bimaculatus, S. calonotos) were most abundant in Banksia woodland, whereas two species that feed on reptile eggs (S. semifasciatus, S. fasciolatus) were most abundant in coastal heath. Capture rates for most species were low (for three of the five species, <one specimen captured per 1000 trapdays), and these taxa may be genuinely rare in most of the habitats that we surveyed. Activity patterns were highly seasonal, with little activity in winter or in midsummer. The two oophagous species showed a more restricted activity period (late spring–early summer) than did species with broader dietary habits. In the most abundant taxon (Simoselaps bertholdi), males were active mainly during spring (the mating season) and females during autumn, after oviposition. Capture rates and body condition of the captured snakes varied substantially among seasons and across years. Low capture rates mean that very prolonged surveys are needed to determine reliably whether or not a taxon occurs on any given site.
Developmental and territorial aspects of suckling behaviour in the domestic pig (Sus scrofa f. domestica)
Authors: Puppe B. , Tuchscherer A. 
Published: February 2006

AbstractThe suckling behaviour of 327 piglets from 39 litters of primiparous domestic sows Sus scrofa f. domestica was analysed regarding the development of territorial suckling consistency during a 5‐week suckling period. Additionally, the consistent use of a certain teat pair (1–7) during the whole suckling period was related to weight gain within the suckling period and to social dominance after weaning and mixing of the piglets. The piglets increased their suckling stability consistent with a three‐parametric exponential model delivering a time‐dependency that is typical for learning curves and which may be a useful methodological approach for studies on behavioural ontogeny. Thus, the development of suckling stability can be regarded as a continuous learning process. After extremely rapid learning within the first 4 days of life a moderate increase of suckling consistency with final stabilization occurred within the second week. After this time, the piglets maintained a high suckling consistency of about 95% up to the end of the observed suckling period. The anterior teats were preferred, whereas piglets suckling at the posterior teats showed a tendency to have lower weight gains and poorer dominance values. However, the lowest suckling stability (consistency) was found with piglets occupying the middle teats. The study shows that individual differences (e.g. weight gain, position in a social hierarchy) have their roots in early ontogenetic characteristics of the neonates (e.g. suckling behaviour, physical strength). The results are discussed with regard to findings and interpretations of behavioural ontogeny in pigs.
Life histories of the Insectivora: the role of phylogeny, metabolism and sex differences
Authors: Symonds Matthew R. E. 
Published: February 2006

AbstractLife‐history data for 63 species from the mammalian order Insectivora have been collated from the literature. These data were analysed for covariation and for correlations with body mass, brain mass and mass‐specific resting metabolic rate. An independent contrasts method has been used to remove the effect of phylogeny. Due to uncertainties surrounding their evolutionary relationships, 22 different phylogenies of insectivores have been used as a basis for comparative analysis. The results show that several key correlations between life‐history variables are only significant when certain phylogenies are used, highlighting the problems of such analyses when the phylogeny used is inaccurate. After removing the effect of phylogeny, relatively few significant correlations remain. Insectivores that have a high body mass have relatively lower metabolic rates, longer lifespans and longer gestation lengths. There is some support for a fast–slow continuum in insectivore life‐history evolution: there are some significant positive correlations between measures of growth rates (e.g. gestation length and age at weaning) and lifespan, and some negative correlations between growth rates and measures of reproductive output. It is suggested that the seasonality of life of many insectivores may have played an influential role in the evolution of the group, in particular in delaying the onset of sexual maturity. There is little indication that brain size influences life‐history evolution in this order, but metabolism may play an important role. The energetic requirements of maintaining high metabolic rates in small mammals such as insectivores may be constraining life histories to a greater extent than occurs in larger mammals. This effect may have obscured the relationship between metabolic rate and life histories in wider inter‐order analyses. Finally, there is considerable evidence that sex differences play a large role in shaping insectivore evolution, and it is suggested that this factor must be considered more often in future studies of mammalian life histories in general.
The fighting technique of male fallow deer (Dama dama): an analysis of agonistic interactions during the rut
Authors: Mattiangeli Valeria , Mattiello Silvana , Verga Marina 
Published: February 2006

AbstractA population of 560 individually recognizable European fallow deer (Dama dama) was studied in Phoenix Park, Dublin, Ireland, during the rut in order to examine buck fighting technique in relation to age and rank. The percent usage and association among behavioural elements used were analysed in 162 fights and 82 sparrings. During fight sequences, high‐ranking bucks tend to use a higher percentage of low‐risk behaviours (all behaviours which do not involve antler contact), especially when they interact with lower‐ranking deer. Fights between combatants of the same rank class show a higher use of high‐risk behaviours (characterized by antler contact), and cluster analysis of a preceding–following matrix revealed that high‐risk behaviours are closely associated with each other in these interactions. During sparrings, the low intensity of the interaction allows the deer to test their ability and strength using a higher percentage of behaviours which are generally considered high‐risk, without risking injury. The data suggest that the percent usage and the sequences of behavioural elements performed in agonistic interactions are affected by deer rank, probably in relation to the different risks and benefits that different hierarchical positions can offer.
Seasonal changes in the foraging behaviour of Leisler's bats (Nyctalus leisleri) in Ireland as revealed by radio‐telemetry
Authors: Shiel C. B. , Shiel R. E. , Fairley J. S. 
Published: February 2006

AbstractLeisler's bats Nyctalus leisleri, from two nursery colonies were radio‐tracked from April to August in 2 years. They commuted directly to foraging sites up to 13.4 km away at speeds often exceeding 40 km h‐1. Except during lactation, individuals occasionally day‐roosted away from the nursery in buildings or hollow trees. These were also sometimes used as night roosts, especially during rain, which also stimulated return to the nursery. On most nights the first flight lasted the longest. During preparturition, when distances from roost to foraging site were greatest, and time spent flying per night (tF) was least, there was often only one flight, with a second towards dawn on warmer nights, and occasionally a third. After parturition, in June, tF and the number of flights (NF) increased up to weaning, corresponding to rising energy demands. But distances to foraging sites fell, rising only slightly in postlactation, presumably because insects, and thus feeding patches, were more abundant than in preparturition. NF fell to preparturition levels after lactation. Exploratory behaviour by juveniles intensified with time – distances to feeding sites, tF and the total distance flown each night all increased; the distance flown each night was eventually greater than any recorded for adults. Roosting away from the nursery was also more common. Before dispersal, there were extended migrations by juveniles outside the summer range of the adults. Distances moved by two dispersed juveniles exceeded 34 km. Two‐thirds of the recorded foraging time was over pasture or drainage canals. Foraging over other habitats, particularly lake and conifer forest, was greatest in preparturition. Other habitats foraged included lights, estuary, stream, beach and dunes.
Echolocation signal design in Kerivoulinae and Murininae (Chiroptera: Vespertilionidae) from Malaysia
Authors: Kingston Tigga , Jones Gareth , Akbar Zubaid , Kunz Thomas H. 
Published: February 2006

AbstractEcholocation signal design in nine syntopic vespertilionid bats from the Malaysian rain forest understorey was studied. Four species of Kerivoula, two species of Phoniscus (Kerivoulinae) and three species of Murina (Murininae) all emitted calls that are typical of species that glean insects from surfaces: broadband, frequency‐modulated (FM) calls of low intensity and short duration. However, calls were highly distinctive in the use of very large bandwidths (range: 89–123 kHz) and extremely high frequencies (start frequency 152–180 kHz; end frequency 43–86 kHz). Furthermore, calls were produced in groups of 2–15 at very high pulse repetition rates (37–105 Hz). The functional significance of these characteristics with respect to foraging strategy is discussed. Large signal bandwidths facilitate highly accurate target localization in terms of both range and angle estimation and can thus be interpreted as an adaptation to foraging in the highly cluttered environment of the forest understorey. The use of high frequencies so far in excess of those seen in other FM gleaning bats of the same size is less easily explained, but may represent a mechanism by which these species distinguish prey items using echolocation alone, without recourse to visual or auditory cues. Species exhibited differences in echolocation parameters, particularly the end frequency and the number of calls per group of calls. The two subfamilies differed from each other in multivariate space derived from echolocation parameters; calls of the Murininae were of lower frequency than the Kerivoulinae and were typically produced in smaller groups or singly. Within the subfamilies there was considerable overlap between species of Murina, but the Kerivoula spp. were clearly distinct from one another but not from the two Phoniscus spp.
Body size and clutch size in the European pond turtle (Emys orbicularis) from central Italy
Authors: Zuffi M. A. L. , Odetti F. , Meozzi P. 
Published: February 2006

AbstractThe reproductive biology and ecology of the European pond turtle Emys orbicularis is little known, and available information was previously mainly anecdotal. Morphological data on E. orbicularis are now well documented in most of the known distribution area. Body size in northern populations tends to be larger than in southern populations. There are also indications that clutch size may be larger in northern than in southern European pond turtle populations. Clutch size and reproductive status of a central Italy population were detected by radiography and palpation, respectively, and comparative data were obtained by direct count of intact nest eggs. Reproductive females averaged 13.9 cm and rarely exceeded 15.5 cm carapace length. They produced a clutch size of six, the same number found in intact nests. Nest egg‐size averaged 32 mm in length. Egg number was positively associated with female body size, and especially with carapace height.
Variation and constraint in the shells of two sibling species of intertidal rough periwinkles (Gastropoda: Littorina spp.)
Authors: Clarke R. K. , Grahame J. , Mill P. J. 
Published: February 2006

AbstractShell shape in gastropods is generated by the spiral path of shell material laid down at the aperture. Many aspects of shape will therefore be associated. Such associations may indicate constraints, limiting the range of variation seen in populations as a response to different environmental pressures. Associations of shell variables were studied using the sibling species Littorina saxatilis and Littorina arcana. The same closely associated subset of three variables was found in both species, related to the maintenance of a constant aperture shape, despite variation in overall morphology. These closely associated variables describe similar variation in the two species. The less closely associated variables may contribute more to inter‐specific differences.
Morphological correlates of substrate use in didelphid marsupials: implications for primate origins
Authors: Lemelin Pierre 
Published: February 2006

AbstractThe ability of some mammals to forage on vines or terminal branches depends upon their grasping extremities. This study tests the functional link between use of small‐diameter supports and grasping abilities by comparing hand and foot proportions in didelphid marsupials. Metapodials and phalanges were measured for the hands and feet of six didelphid taxa characterized by different patterns of substrate use. Comparisons of hand and foot proportions demonstrate that Marmosa and Caluromys, didelphids that rely on vines or terminal branches, possess more prehensile extremities than Monodelphis, Didelphis, and Philander, which travel and feed mainly on the ground. Moreover, the proportions of the hand and foot of Marmosa and Caluromys are more similar to those of cheirogaleid primates than those of other didelphids. These morphological data corroborate the suggestion that the use of branches of small diameter was an important factor in the development of prehensile hands and feet in early primates.