bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of marginal radular teeth in Conoidea (Neogastropoda) and the evolution of the hypodermic envenomation mechanism
Authors: Kantor Yuir I. , Taylor John D.
Published: February 2006

Four main types of radula are found within the gastropod superfamily Conoidea. Type 1, the Clavidae type has five teeth in each row with comb‐like laterals and flat pointed marginals. Type 2, the Turridae type has two or three teeth in a row with the marginals comprised of teeth with the duplex or wishbone form. Type 3, the Pseudomelatomidae/Pervicaciinae type has two or three teeth in a row with the marginals curved and solid. Type 4, the hypodermic type has two hollow, enrolled, marginal teeth in each row with the radular membrane reduced or absent. Study of the maturing teeth along the radular membrane in gastropods with the Type 2 radula shows that the duplex teeth are not formed from two separate elements but develop from a flat plate, by thickening of the tooth edges and elevation of the posterior edge from the membrane. Semi‐enrolled and enrolled teeth of Pilsbryspira, Imaclava and Toxiclionella develop in a similar way. In Conidae where a vestigial radular membrane is attached only at the base of the teeth, the teeth are enrolled from first formation in the radular sac. This study demonstrates that duplex and enrolled teeth develop by a similar process, allowing the possibility of deriving hypodermic teeth from duplex clades as has been suggested by previous phylogenetic analysis.
Spatial and temporal dynamics of wild boar (Sus scrofa) rooting in a mosaic landscape
Authors: Welander Jonas
Published: February 2006

Contrary to large‐scale disturbances, animals constantly create small‐scale patches of various kinds during the course of their daily life. For example, rooting by wild boars is a recurrent disturbance regime, which varies in frequency and extent. Rooting by wild boars (Sus scrofa L.) in south‐central Sweden was therefore studied by censusing three times per year during 1992–1995 along fixed transects in the Tullgarn Nature Reserve. Significant differences were found in soil surface area being rooted by wild boar between year, season, habitat type and soil category. The amount of surface being rooted varied between 2.4 and 14.2 ha on 226 ha censused. The rooted surface in relation to the ground available was higher in deciduous compared to coniferous forests and grassland. Furthermore, the rooted surface in relation to available ground to root was much higher in damp soil than in dry soil. Mesic soil was used according to availability. Rooted patches showed large variation in size between year, season, habitat type and soil category. Within the three habitat types the largest patches were found in deciduous forests and the smallest in grasslands while in the different soil categories, the largest patches were found in damp soils and the smallest in dry soils. Results are discussed in terms of plant species diversity on a regional scale.
The effects of wound site and blood collection method on biochemical measures obtained from wild, free‐ranging red deer (Cervus elaphus) shot by rifle
Authors: Bateson Patrick , Bradshaw Elizabeth L.
Published: February 2006

Three groups of factors which might affect the blood biochemistry of red deer (Cervus elaphus) were examined. These were the wounding site (head/neck versus chest), the stalker who collected the blood (coupled with the geographical area where each deer was shot), and the sex and nutritional status of the deer. The activities of muscle enzymes, creatine kinase, aspartate amino transferase, and lactate dehydrogenase, were markedly higher in the plasma of deer shot in the chest as compared with those shot in the head or neck; the plasma also looked different, being deep cherry red in colour in the chest‐shot deer. Other biochemical measures were unaffected by the wounding site. Blood collected by one stalker from the chest cavity had higher activity of the liver enzyme, glutamate dehydrogenase, higher concentration of potassium and lower concentrations of sodium and chloride than blood collected by another stalker from a knife wound in the base of the neck. Otherwise the method of collecting blood had very little effect on blood biochemistry. Cortisol was unaffected by the wound site nor, probably, by the method of collecting blood, but was highest in the stags living in a more mountainous region and in those deer that had to be shot twice before they died. Stags, which were shot in the rutting season and were probably fasting, had significantly higher concentrations of free fatty acids than hinds. Lactating hinds had significantly less fat on their kidneys than non‐lactating hinds and stags. All hinds, which were shot in winter, had lower concentrations of urea than stags, which were shot in the autumn.
Net evolutionary trajectories of body shape evolution within a microgeographic radiation of threespine sticklebacks (Gasterosteus aculeatus)
Authors: Walker Jeffrey A. , Bell Michael A.
Published: February 2006

Following deglaciation of the Cook Inlet region of Alaska approximately 16 000 years ago, anadromous threespine stickleback (Gasterosteus aculeatus) rapidly colonized emerging lakes and rivers forming resident, freshwater populations. Although the precise body shape of the ancestral marine population is unknown, marine sticklebacks sampled from both Pacific and Atlantic sites present remarkably little body shape variation among populations, which suggests that the morphology of any of the marine populations could be used to represent the ancestral phenotype. To infer the net evolutionary trajectories of body shape change in the Cook Inlet radiation, derived body shapes of lacustrine samples were compared to the presumptive, primitive body shape, represented by the mean shape of two anadromous samples from Cook Inlet. In general, some derived body shape traits are shared by all freshwater populations but many traits evolved in opposite directions. The principal axes of shape variation among freshwater sample means were computed using Principal Components Analysis. The strong correlation between the direction of the principal component axes and lake habitat variables suggest that populations evolved toward selection peaks that are biased along the component axes due to biotic and abiotic features of the lakes.
Molecular phylogeny of viviparous Australian elapid snakes: affinities ofEchiopsis atriceps(Storr, 1980) andDrysdalia coronata(Schlegel, 1837), with description of a new genus
Authors: Keogh J. Scott , Scott Ian A. W. , Scanlon John D.
Published: February 2006

The rare Australian venomous elapid snake ‘Echiopsis’atricepshas been the subject of considerable taxonomic instability with the five known specimens assigned to four genera by various authorities. Phylogenetic affinities of the rareElapognathus minoralso are poorly understood and have been the subject of some disagreement. To examine the phylogenetic affinities of these two rare taxa, a molecular data set comprising 1680 base pairs of mtDNA was assembled from a representative of each of the terrestrial Australian viviparous elapid genera and two species ofDrysdalia, a genus about which there also has been phylogenetic controversy. A total of 936 base pairs of 12S rRNA, 454 base pairs of 16S rRNA and 290 base pairs of cytochromebmtDNA were sequenced for 15 species. The Asian elapidNaja najawas used as the outgroup. These mtDNA regions provided 195, 38 and 72 parsimony informative sites, respectively, for a total of 315 parsimony informative characters. Unweighted phylogenetic analyses were performed under both parsimony and neighbour‐joining criteria. Parsimony analyses of the unweighted, combined data set resulted in a single fully resolved most parsimonious tree 1225 steps long. The neighbour‐joining tree differed by only a single weakly supported branch. These data strongly support a sister group relationship between ‘Echiopsis’atricepsand the Australian broadheaded snakes of the genusHoplocephaluswith a bootstrap value of 99%. Templeton tests soundly reject all previous taxonomic arrangements for this species. Our data also strongly support a sister group relationship betweenElapognathus minorandDrysdalia coronatawith a bootstrap value of 98%. Importantly,Drysdalia coronataandDrysdalia coronoidesdo not form a monophyletic group, supporting some previous studies. Based on our results, we allocate ‘Echiopsis’atricepsto a new monotypic genus and re‐describeElapognathusto include ‘Drysdalia’coronata.
A deep‐sea octopus (Graneledone cf. boreopacifica) as a shell‐crushing hydrothermal vent predator
Authors: Voight Janet R.
Published: February 2006

The gut contents of a female specimen of Graneledone cf. boreopacifica collected from the caldera wall of Axial Volcano, near an active hydrothermal vent in the Northeast Pacific Ocean are reported. At least 30 individual gastropods and 46 individual polychaetes are represented in the gut contents by hard parts. Shell fragments and shells removed from the gut allow ready identification of the gastropods Provanna variabilis and Lepetodrilus fucensis, both of which are known only from North Pacific hydrothermal vents. Jaws of polychaete worms are identified as those of the nereidid, Nereis piscesae, and the predatory polynoids, Levensteiniella kincaidi and an unidentified species in the subfamily Branchinotogluminae. Not only was a considerable volume of prey hard parts ingested, the gastropod shells had been crushed before being ingested. The large size of the beaks in this genus of octopus and the increased area they offer for insertion of the superior mandible muscle, the prime mover in beak closure, support the hypothesis that these beaks exert sufficient force to crush the gastropod shells. Although cephalopods had been reported to be absent from hydrothermal vents, the data presented here demonstrate that not only do they occur in vent habitats, they actively prey on vent fauna.
The diet of stoats (Mustela erminea) and weasels (Mustela nivalis) in Great Britain
Authors: McDonald Robbie A. , Webbon Charlotte , Harris Stephen
Published: February 2006

The diet of 789 stoats Mustela erminea and 458 weasels M. nivalis collected in Great Britain between 1995 and 1997 is described from analyses of their gut contents. As a percentage frequency of occurrence, stoat diet consisted of 65% lagomorphs, 16% small rodents and 17% birds and birds' eggs. Weasel diet consisted of 25% lagomorphs, 68% small rodents, mainly Microtus agrestis, and 5% birds and birds' eggs. Male stoats ate a greater proportion of lagomorphs than females, which ate more small rodents. No differences in diet between the sexes of the weasels were detected. The proportion of lagomorphs in the diet of both species was greatest in the spring. Both species ate more lagomorphs in the 1990s than in the 1960s as a result of increasing rabbit populations following recovery from myxomatosis. The importance of small rodents had decreased for stoats and increased for weasels. Both species had a dietary niche that was more specialized than in the 1960s. The implications of these findings for stoat and weasel conservation are discussed.
Arable habitat use by wood mice (Apodemus sylvaticus). 3. A farm‐scale experiment on the effects of crop rotation
Authors: Macdonald D. W. , Tew T. E. , Todd I. A. , Garner J. P. , Johnson P. J.
Published: February 2006

We investigated the effects of crop type on numbers and movements of wood mice Apodemus sylvaticus in field edges and in arable fields containing either winter wheat, winter barley or oil‐seed rape, grown on a 3‐year rotation. We also investigated the effect of habitat (field centre vs edge), and of season and year. This was done at the individual level using radio‐tracking, and at the population level using live‐trapping. Wood mouse population size (estimated as minimum number alive) was significantly affected by season. Wood mouse numbers also differed between crop types. Rape field centres and edges had significantly lower numbers than did barley or wheat field centres and edges. Populations were largest from April to July, when the crop was tall. In winter, significantly more mice were found in field edges compared with field centres. The patterns of movement of individual mice also showed differences between habitats and between seasons. Mice were found to move more quickly when they were tracked through rape compared with the other crops. When the crop was growing, they moved faster through field edges bordered with hedgerow than they did through wood. This pattern was reversed later in the year when the crop was tall. The distances moved during a session of tracking showed differences which paralleled those for speed of movement. Also, males tended to move faster than females. Differences between the sexes in movement patterns were affected by season; when the crop was down (in winter) females moved further than males during a session of tracking, but when the crop was growing and tall, this was reversed.
Life‐history strategies in basal snakes: reproduction and dietary habits of the African thread snake Leptotyphlops scutifrons (Serpentes: Leptotyphlopidae)
Authors: Webb Jonathan K. , Shine Richard , Branch William R. , Harlow Peter S.
Published: February 2006

Information on the biology of ‘primitive’ blind snakes can help clarify the origin of ecological traits typical of ‘higher’ snakes. We examined and dissected 360 museum specimens to obtain information on morphology, dietary habits, and reproduction of two subspecies of an African thread snake, Leptotyphlops s. scutifrons and L. s. conjunctus. These small (to 225 mm long), slender‐bodied (body diameters < 5 mm) burrowing snakes are common throughout southern Africa. In both subspecies, females grow larger than males and have relatively shorter tails. Reproduction is seasonal, with vitellogenesis in spring (October), oviposition in summer (December–February), and hatching in autumn (April–May). Clutch sizes are small (1–3 eggs), and hatchling thread snakes are large relative to maternal body size. Despite the abundance of termites on the African continent, L. scutifrons feeds almost entirely on the larvae and pupae of small ants. Both races fed infrequently, and took large numbers of prey (up to 350 items) in a single meal. A shift from ‘lizard‐like’ to ‘snake‐like’ trophic biology is evident within the Scolecophidia: two species of North American thread snake feed frequently on a taxonomically diverse array of small prey; African L. scutifrons feed infrequently on small prey, but take large meals composed of numerous prey items; and one highly derived Melanesian typhlopid (Acutyphlops subocularis) feeds infrequently on large elongate prey. In contrast to popular theory, our data suggest that the evolutionary shift to infrequent feeding among snakes did not initially require a change from small to large prey.
Habitat‐related microgeographic body size variation in two Mediterranean populations of red fox (Vulpes vulpes)
Authors: Gortázar C. , Travaini A. , Delibes M.
Published: February 2006

The habitat‐related microgeographical body size variations in red foxes Vulpes vulpes living in two separated areas of Mediterranean Spain, the Central Ebro Valley (CEV) and Doáana National Park (DNP) are analysed. In both areas, samples taken from good and bad fox‐habitats were compared regarding body weight and head and body length. In the Ebro Valley, foxes collected in the good habitat were heavier (14%, P < 0.001 for males; 9%, P < 0.01 for females) and larger (4%, P < 0.01 for males; 1%, P < 0.05 for females) than those collected in the bad habitat. In Doáana, males from the good habitat were 19% heavier (P < 0.01) and 3% longer (P < 0.05) than those from the poorer one. The average weight and size of DNP vixens did not show significant differences, although both are higher in the good habitat. It is shown that body size of adult foxes can vary, linked to habitat change even across short geographic distances. Some tentative explanations for these results are discussed.
Early development of neural tissues and mesenchyme in the Australian lungfish Neoceratodus forsteri (Osteichthyes: Dipnoi)
Authors: Kemp A.
Published: February 2006

Analysis of early development of the head of the Australian lungfish Neoceratodus forsteri indicates that no mesenchyme cells in this species enter the embryo as neurectoderm cells, originally positioned between presumptive ectoderm and primordial neural tissue of the embryo. Neural tissue in N. forsteri forms initially as a plate of columnar cells, flanked by raised folds of ectoderm, that sinks below the level of the ectoderm and forms a deep trough. Neural tissue separates from ectoderm, and fuses below the ectoderm to form a neural tube with cells arranged around a small central cavity. Subsequently, ectoderm unites to form a complete cover over the neural tissue. No migrating cells leave the ectodermal–neural junction during this process. No unsegmented column of cells appears dorsal to the neural tissue, before migration, as in teleosts and lampreys of equivalent stages. Neuromeres and tracts of cells leaving the central nervous tissues can be demonstrated in the developing neurula, but these are derived from neural tissue alone and appear after the formation of the neural keel is complete and neural structures have begun to develop. Mesenchyme cells are already present in large numbers, and are apparently derived from enterotomy or enter the embryo by involution at the blastopore. This finding explains previous experimental results in embryos of N. forsteri, which demonstrated that removal of cells from the margin of the neural folds, where higher vertebrate neural crest cells appear, apparently has little influence on the development of pigment cells or of skeletal and dental structures of the head.
Winter selection of habitats within intertidal foraging areas by mink (Mustela vison)
Authors: Bonesi Laura , Dunstone Nigel , O'Connell Mark
Published: February 2006

Patterns of habitat selection by American minkMustela visonwithin foraging areas located on the shore, were studied in a coastal environment of Scotland from November to March in 1983/84, 1984/85 and 1994/95. The abundance of prey in the intertidal zone was modelled in relation to abiotic environmental characteristics. Four factors were found to be important predictors of prey abundance: the position within the tidal zone, the abundance and size of rockpools, the nature of the substratum and the presence of fresh water streams. The model was used to predict prey abundance in different areas of the shore. We then investigated whether mink were choosing areas with higher prey abundance at different tidal levels and within, as opposed to between, core areas (areas with a relatively high density of fixes, encompassing usually one or more dens). Only when foraging at low or mid‐tide and within core areas were mink found to behave selectively. They showed no significant preference for areas rich in prey when foraging at high tide and between core areas. Mink were also found to avoid areas with fresh water streams and to prefer foraging in the mid‐tide zone. The findings are discussed in relation to prey abundance and competition with the otterLutra lutra.
Diet composition of badgers (Meles meles) in a pristine forest and rural habitats of Poland compared to other European populations
Authors: Goszczyński Jacek , Jedrzejewska Bogumiła , Jedrzejewski Włodzimierz
Published: February 2006

Diets of the Eurasian badger Meles meles were studied by scat analysis in three localities of eastern and central Poland, representing pristine forests and rural landscapes with little wood cover. In spring, earthworms constituted 82–89% of biomass consumed by badgers in all localities. In summer and autumn, the proportion declined to 56% in the pristine forest, and to 24% in the mosaic of forests, fields, and orchards. Supplementary resources at this time were amphibians (in forests) or garden fruits (in a rural landscape). Literature on badger diet composition in Europe showed that earthworms and vegetable matter were the dominant food types of badgers, but their roles changed with latitude. The share of earthworms grew from nil at 37–40°N to 40–70% at 55–63°N; the opposite trend was observed for vegetable food. Also, of two major supplementary resources, vertebrates were taken by badgers more often at northern latitudes, and insects in the south. In consequence, the food niche of badgers was broadest at 45–55°N and became narrow at both lower and higher latitudes. Moreover, in the temperate zone of Europe, the degree of habitat transformation by humans significantly affected badger feeding habits. In forests, badgers relied predominantly on earthworms (on average, 62% in diets). In farmlands and pastures, earthworms and plant material (usually garden fruit and cereals) played equally important roles (34% each). This biogeographical pattern of feeding habits can be explained by variation in abundance and availability of earthworms.
Energetics of gestation relative to lactation in a precocial rodent, the guinea pig (Cavia porcellus)
Authors: Künkele Joachim
Published: February 2006

Caviomorph rodents stand out by showing long gestation periods and by producing few, extremely precocial young. This study compares the energy cost of gestation vs lactation in the guinea pig Cavia porcellus. It tests whether the long gestation period (68 days) relative to the total period of maternal care (88 days) of this species results in a high overall energetic efficiency of reproduction. Although maternal net production during gestation was as high as during lactation, the net energy cost of gestation was much lower than the energy cost of lactation. Mothers' average increase in energy intake (above the non‐reproductive level) was only 16% during gestation, but 92% during lactation. Similarly, the peak in maternal energy intake was low during gestation (2.4 times basal metabolic rate) compared to the peak during lactation (3.7 times basal metabolic rate). Consequently, the efficiency of energy conversion into offspring tissue during gestation (62%) was almost twice as high as the efficiency during lactation (35%). The results agree with the hypothesis that a prolonged gestation period increases the overall energetic efficiency of reproduction.
Use of a seaweed habitat by red deer (Cervus elaphus L.)
Authors: Conradt L.
Published: February 2006

The use of a seaweed habitat by red deer Cervus elaphus L. on the Isle of Rum, Scotland, was examined in detail. New information is provided on diet selection, timing of seaweed use relative to tides, inter‐individual differences in seaweed use, and sex differences in site use within the seaweed habitat (‘site segregation’). Interestingly, seaweed use by adult males and females was closely correlated to that of their mothers. This implies that deer ‘learn’ early in life to include seaweed into their diet. Formerly, it has been suggested that male inferiority in indirect competitive ability relative to females causes site segregation in dimorphic ungulates (‘indirect competition hypothesis’). The observed pattern of site segregation within the seaweed habitat was used to test the hypothesis, which predicts that males should be found at sites where they can achieve higher intake rates, but where forage quality is lower than at female sites. With respect to seaweed use, the hypothesis further predicts that segregation should be lower within the seaweed habitat than within terrestrial vegetation communities, and that males should time seaweed use earlier (relative to the tide) than females. This is because seaweed availability is more subject to tidal rhythm than to indirect competition in comparison to terrestrial habitats. Males and females used different bays, and within bays they used different fractions of seaweed. However, male‐preferred sites did not yield higher intake rates and were not of lower forage quality than sites preferred by females. Moreover, segregation was not lower within the seaweed habitat than within terrestrial vegetation communities, and males did not time their seaweed use earlier relative to the tide than did females. The indirect competition hypothesis could not explain the observed pattern of site segregation. Other factors, such as sex differences in sheltering or anti‐predator behaviour, or social harassment, could be responsible instead.
Testes size, body size and male–male competition in acanthocephalan parasites
Authors: Poulin Robert , Morand Serge
Published: February 2006

In most invertebrate taxa, males are smaller than females and large male sizes are only favoured when male–male competition for access to females is intense. In addition, in species where sperm competition is important, relatively large investments in testis growth and ejaculate size will also be selected. The use of copulatory plugs by males of some taxa, however, can prevent sperm competition. We hypothesized that, across related species in which males use plugs, relative testis size would decrease with increases in the severity of male–male competition. We tested this prediction across 112 species of acanthocephalan parasites, worms that use copulatory plugs and in which male–male competition occurs. As a measure of the intensity of male–male competition in a given species, we used sexual size dimorphism. Male and female body volume covaried allometrically, suggesting that sexual size dimorphism in acanthocephalans is the product of sexual selection. Our main finding is that relative testis volume, corrected for male body volume, decreases significantly as male body volume relative to female volume increases, i.e. as the sexual size dimorphism becomes less female‐biased. All our results remained unchanged after we controlled for potential phylogenetic effects. The relationship indicates that investment in testis growth beyond the minimum size required for efficient fertilization becomes increasingly less important in species where males appear to compete intensely for mating opportunities.
Mother–pup vocal recognition in the grey seal (Halichoerus grypus) of Sable Island, Nova Scotia, Canada
Authors: McCulloch S. , Boness D. J.
Published: February 2006

Parental recognition of offspring would be expected to evolve among densely populated species in which parental investment is large, and separations of the mother–pup pair are frequent. Although otariids present a well‐developed system of mutual vocal recognition, evidence in phocids is weak. Furthermore, allo‐suckling is prevalent in some species and may reflect confusion over the identity of pups. The vocalizations of grey seal Halichoerus grypus pups have been found to be stereotyped and individually distinctive on the Isle of May, Scotland. However, playback experiments showed that mothers fail to discriminate between the vocalizations of their pup and a non‐filial pup. Moreover, widespread allo‐suckling was observed. In contrast, grey seals on Sable Island, Nova Scotia, a population reproductively isolated from that of the Isle of May, show very little allo‐suckling. This may reflect the presence of a recognition system that does not seem to be present on the Isle of May. During the 1999 breeding season on Sable Island, vocalizations of grey seal pups were recorded and playback experiments carried out to determine whether female grey seals respond differently to the playback of vocalizations of their own pup, a familiar pup and an unfamiliar pup. Grey seal mothers were found to make significantly more head turns and body movements towards the loudspeaker during the playback of their own pup call than during the playback of a familiar or unfamiliar pup call. In addition, there was no evidence of an effect of pup age. This suggests that female grey seals can discriminate between pup calls using the stereotyped and individually distinctive vocalizations of their pup, and that different selective pressures may be in operation between the Sable Island and Isle of May colonies.
Nesting phenology of magpie geese (Anseranas semipalmata) in monsoonal northern Australia: responses to antecedent rainfall
Authors: Whitehead Peter J. , Saalfeld Keith
Published: February 2006

The density of nests of the magpie goose Anseranas semipalmata on the Mary River floodplain fluctuated markedly during 1988–93, failing almost completely in unfavourable (El Niño) years. Nest density and timing of nesting were strongly correlated with variations in the time of onset of the wet season, but were much less sensitive to rainfall quanta in the mid‐ to late wet season. Nest densities were higher and nesting was initiated earlier in breeding seasons preceded by sustained rainfalls during the transition from dry to wet seasons. Clutch sizes were slightly larger in years of early wet‐season onset. Within seasons, later clutches contained fewer eggs and the eggs were smaller, probably as a consequence of later nesting by younger birds. Second clutches from a small sample of marked re‐nesting birds and a pulse of nesting after flooding losses, contained similar numbers of eggs to first clutches, but the eggs were larger. Dependence of nesting on events occurring months before clutch initiation, when birds are using habitats distant from nesting colonies, illustrates the importance of integrated management of floodplain systems to meet year‐round habitat needs, and the risks posed by homogenization of wetlands by improvement of pasture for grazing.
Pristina silvicola and Pristina terrena spp. nov., two new soil‐dwelling species of Naididae (Oligochaeta, Annelida) from the tropical rain forest near Manaus, Brazil, with comments on the genus Pristinella
Authors: Collado Rut , Schmelz Rüdiger M.
Published: February 2006

Pristina silvicola and P. terrena spp. nov. are described from soil samples of the primary rain forest at the Brazilian Agroforestry Research Facility near Manaus, Brazil. Living and preserved specimens were studied. The species are among the smallest oligochaetes known (1–1.5 mm long) but they are conspicuous by their brilliant, highly refractile coelomocytes. Pristina silvicola is also described from sexually mature specimens. Its character combination invalidates Pristinella as a genus separate from Pristina. Both genera are reunited as Pristina. Pristina silvicola and P. terrena, species which lack a proboscis, share a character combination that is unique in the genus: stomach absent, first nephridia in segment VII, ventral chaetae uniform with upper tooth not longer than lower. They differ from one another in the shape of the brain and in other details of the chaetae.
Geographic and temporal variation in the condition of pups of the New Zealand fur seal (Arctocephalus forsteri): evidence for density dependence and differences in the marine environment
Authors: Bradshaw Corey J. A. , Davis Lloyd S. , Lalas Chris , Harcourt Robert G.
Published: February 2006

We report on the geographic and temporal variation in pup condition in 20 colonies of New Zealand fur seals Arctocephalus forsteri around South Island, New Zealand during three consecutive breeding seasons, 1996–98 (n= 6856 pups) and provide hypotheses to explain the observed patterns. Three alternative data combinations are presented to calculate pup condition from body measurements and identify which combination seems to be best suited for analysing geographic patterns. A morphometric index of pup condition was best estimated by comparing all pups in all years using least‐squares linear regression of the loge‐transformed measurements of length vs mass. Condition varied significantly among years and colonies, but not between sexes. We also estimated seasonal changes in pup densities at colonies and investigated the relationship between pup density and condition. Mean pup densities among colonies ranged from 4.94 to 7.46 pups/100 m2 (summer) and from 4.99 to 7.04 pups/100 m2 (winter) from 1996–98, and differences between summer and winter densities varied with year. Pup density explained a significant proportion of the variation in pup condition in 1996 and 1998, suggesting that condition is partly density‐dependent. After accounting for the effect of density, we found geographic differences in pup condition, and we offer alternative hypotheses to explain these differences. We also show that the 1998 El Niño coincided with a reduction in pup condition. A morphometric index of pup condition seems to be useful as an indicator of spatial and temporal variation in the marine environment.
The influence of risk and vulnerability on predator mobbing by terns (Sterna spp.) and gulls (Larus spp.)
Authors: Clode Danielle , Birks Johnny D. S. , Macdonald David W.
Published: February 2006

The extent to which anti‐predator mobbing can be modified in response to new predators was investigated by examining the response of terns (Sterna hirundo and S. paradisaea) and gulls (Larus fuscus, L. argentatus and L. canus) to introduced mink Mustela vison, native otter Lutra lutra and rabbit Oryctolagus cuniculus models in areas inhabited by mink and areas uninhabited by mink. Gulls and terns typically flock over predators of adult birds (a fleeing response), whilst diving at predators of chicks and eggs (an attacking response). Terns in mink‐inhabited areas flocked over a model of a mink, but did not dive at it as much as they dived at otter and rabbit models. A stronger fleeing rather than attacking response suggests that adult terns perceive mink as a threat to themselves as well as to their chicks and eggs. Gulls, in comparison, dived at the mink model, indicating that mink are not perceived as a threat to the adults of these considerably larger species. Both gulls and terns showed a much lower level of response to mink in mink‐free areas, suggesting that the type and extent of mobbing is altered through experience with predators and the level of risk associated with mobbing the predator.
The mechanics and muscular control of constriction in gopher snakes (Pituophis melanoleucus) and a king snake (Lampropeltis getula)
Authors: Moon Brad R.
Published: February 2006

Constriction of prey by gopher snakes Pituophis melanoleucus and king snakes Lampropeltis getula is highly variable in posture, muscular activity and force exertion. These snakes typically use lateral bends of the anterior trunk to wind the body into a vertical coil around the prey. Three common constriction postures are fully encircling loops that form a coil, partially encircling loops, and non‐encircling loops that pinion the prey. Initial tightening of a coil occurs by winding or pressing the loops tighter to reduce the diameter of the coil. The epaxial muscles are highly active during striking and coil formation and intermittently active during sustained constriction. These results refute the hypothesis of a mechanical constraint on constriction in snakes with elongate epaxial muscles. Constricting gopher and king snakes can detect muscular, ventilatory and circulatory movements in rodent prey. In response to simulated heartbeats or ventilation in mice, the snakes twitch visibly, recruit epaxial muscle activity, and increase constriction pressure temporarily, but then quickly relax. Muscular activity and constriction pressure are increased most and sustained longest in response to muscular struggling in prey. Although muscle activity and pressure exertion are intermittent, the constriction posture is maintained until the prey has been completely still for several seconds; thus, a snake can reapply pressure in response to any circulatory, ventilatory or muscular movement by the prey. The pressures of 6.1–30.9 kPa (46–232 mm Hg) exerted on small mammal prey by constricting snakes range from about half to over twice a mouse's systolic blood pressure, and are probably 10 times larger than the venous pressure. These high pressures probably kill mammalian prey by inducing immediate circulatory and cardiac arrest, rather than by suffocation alone.
Sympatry and hybridization between the clawed frogs Xenopus laevis laevis and Xenopus muelleri (Pipidae)
Authors: Fischer W. J. , Koch W. A. , Elepfandt A.
Published: February 2006

Though most Xenopus species are polyploid and can be hybridized in the laboratory, natural hybridization seems to be restricted to hybrids of X. laevis laevis×X. gilli. A parapatric distribution pattern between X. l. laevis and X. muelleri seems to prevent interbreeding. We found X. l. laevis and X. muelleri living sympatrically in water bodies in the Republic of South Africa west of Kruger Park and report a natural hybrid of X. l. laevis×X. muelleri. Natural occurrence of such a hybrid has not been reported previously. The hybrid character was confirmed by analysis of its advertisement calls, which were intermediate between those of the parental species, by analysis of its serum albumin pattern, and by determination of the nuclear DNA content of its erythrocytes. The results indicate that this specimen is an F1 hybrid between X. l. laevis and X. muelleri. Backcrossing with both parental species indicated that the hybrid is sterile. It is discussed why sympatry between X. l. laevis and X. muelleri though possible might be rare.
Habitat selection, ranging behaviour and diet of the stone curlew (Burhinus oedicnemus) in southern England
Authors: Green R. E. , Tyler G. A. , Bowden C. G. R.
Published: February 2006

Distribution, habitat use and selection, ranging behaviour, diet and food supply of the stone curlew Burhinus oedicnemus were studied in a small, fragmented population at the north‐western edge of its world range. Stone curlews bred on short semi‐natural grassland and spring‐sown arable farmland in areas with sandy soils with stones or rubble. They were most active at night and travelled up to about 3 km from the nest to forage. Individuals used a fragmented home range comprising an average of 30 ha of short semi‐natural grassland, short improved pasture and spring‐sown crops for foraging. Earthworms, soil‐surface arthropods and molluscs were the main prey; the proportion of earthworms being lowest when the soil was dry. Breeding densities were highest on short semi‐natural grassland. Stone curlews were most likely to breed on a spring‐sown arable field if the crop was of a type that became tall and dense relatively late in the summer and if the field was close to short semi‐natural grassland or sheep pasture and distant (> 3 km) from the nearest major road. Sparse vegetation and bare ground were the most obvious characteristics of habitats preferred for nesting and foraging.
The effects of forest fragmentation and isolation on insectivorous small mammals (Lipotyphla) on the Central High Plateau of Madagascar
Authors: Goodman Steven M. , Rakotondravony Daniel
Published: February 2006

A small mammal survey of the Lipotyphla (Tenrecidae and Soricidae) was conducted in the montane forest of the Réserve Spéciale d'Ambohitantely, Central High Plateau, Madagascar. Species richness of this group was assessed using standardized pit‐fall trap techniques in a control site of 1250 ha and four smaller forest fragments (136, 30, 12 and 0.64 ha). The forests of this reserve are highly fragmented, isolated for many decades and about 90 km from the nearest large forest block. On the basis of pit‐fall captures, lipotyphlan diversity was highest in the control site with nine species, including eight endemic taxa. The number of species declined progressively with diminishing forest size. The species richness found in the control site, the largest remaining block within the reserve, is comparable to other much more extensive forest blocks at parallel elevations and with similar botanical communities. Thus, it seems that the lipotyphlan community within the control site has not experienced notable local extinctions. The introduced Soricidae, Suncus murinus, has colonized the Ambohitantely forests. However, there is no evidence of competition between this species and members of the family Tenrecidae, particularly Microgale, as has been postulated in the literature.
Does Nathusius' pipistrelle Pipistrellus nathusii (Keyserling & Blasius, 1839) breed in northern Italy?
Authors: Martinoli Adriano , Preatoni Damiano G. , Tosi Guido
Published: February 2006

This paper reports the capture of seven adult Pipistrellus nathusii including a lactating female mist‐netted in July 1997 in Varese province (northern Italy). This record represents the first identification of a breeding female Nathusius' pipistrelle in the south part of the Alps. Other data on the reproduction of this species in Europe are discussed in order to reconsider its distribution and breeding sites.
Intra‐ and inter‐litter variation in life‐history traits in a population of fire salamanders (Salamandra salamandra terrestris)
Authors: Kopp Maja , Baur Bruno
Published: February 2006

We examined intra‐ and inter‐litter variation in larval life‐history traits in relation to maternal weight and date of larval deposition in a population of fire salamanders Salamandra salamandra terrestris in north‐western Switzerland. We also examined whether the timing of larval deposition by female fire salamanders is an adaptive strategy to the changing conditions of a temporary brook. Litters differed in mean weight at birth, weight at metamorphosis, and duration of the larval period. Mean weight at birth tended to be larger in litters deposited later in the season than in those deposited earlier. Large neonates reached metamorphosis more rapidly than small ones. A short larval period resulted in a small size at metamorphosis, indicating a fitness trade‐off between duration of the larval period and size at metamorphosis. Within litters, successively‐born larvae tend to decrease in body size, especially in litters with a relatively large variation in weight at birth. The results suggest that environmental factors such as floods or drying out of the brook may influence the timing of larval deposition.
Variation of male‐biased maternal investment in fallow deer (Dama dama)
Authors: Braza F. , San José C. , Aragón S.
Published: February 2006

In this study 529 fallow deer fawns were captured and weighed at Doñana National Park, Spain. An annual index of male‐biased maternal investment (MBMI) was calculated, and this index was found to vary in relation to environmental factors. Thus, the level of MBMI was sensitive to fluctuations of autumn rainfall and the male‐biased maternal investment carried out by mothers in the previous year (MBMIP). Our results reveal that those factors related to the female's body condition at the beginning of gestation have a high contribution to the variation of differential pre‐natal maternal investment. It has been hypothesized by other authors that male‐biased maternal investment is limited by the level of total maternal expenditure and these authors classified the fallow deer as a species near to its maximum reproductive effort, in which no sex‐biased maternal investment exists. Our study reveals that male‐biased maternal investment in fallow deer does exist and supports the hypothesis that sensitivity of maternal investment to environmental conditions could be expected to occur in species with high reproductive effort and sex‐biased maternal investment.
Behavioural correlates of predation by tiger (Panthera tigris), leopard (Panthera pardus) and dhole (Cuon alpinus) in Nagarahole, India
Authors: Karanth K. Ullas , Sunquist Melvin E.
Published: February 2006

Behavioural factors that are likely to contribute to the coexistence of tigerPanthera tigris, leopardP. pardusand dholeCuon alpinus, were investigated in the tropical forests of Nagarahole, southern India, during 1986–1992. Examination of predator scats and kills were combined with radiotracking of four tigers, three leopards, and visual observations of a pack of dhole. The three predators selectively killed different prey types in terms of species, size and age‐sex classes, facilitating their coexistence through ecological separation. There was no temporal separation of predatory activities between tigers and leopards. Hunting activities of dholes were temporally separated from those of the two felids to some extent. Rate of movement per unit time was higher for leopards compared to tigers during day and night. In general, the activity patterns of predators appeared to be largely related to the activities of their principal prey, rather than to mutual avoidance. The three predator species used the same areas and hunted in similar habitats, although tigers attacked their prey in slightly denser cover than leopards. Both cats attacked their prey close to habitat features that attracted ungulates. There was no evidence for inter‐specific spatial exclusion among predators, resulting either from habitat specificity or social dominance behaviours. Our results suggest that ecological factors, such as adequate availability of appropriate‐sized prey, dense cover and high tree densities may be the primary factors in structuring the predator communities of tropical forests. Behavioural factors such as differential habitat selection or inter‐specific social dominance, which are of crucial importance in savanna habitats, might play a relatively minor role in shaping the predator communities of tropical forests.
Early mortality and perinatal growth in the subantarctic fur seal (Arctocephalus tropicalis) on Amsterdam Island
Authors: Georges Jean‐Yves , Guinet Christophe
Published: February 2006

Early mortality and pup growth during the perinatal period were investigated in pups of the subantarctic fur seal Arctocephalus tropicalis on Amsterdam Island. Mothers that were shorter in body length and expected to be younger, gave birth earlier in the pupping season, compared with longer/older mothers. Pups born early were often still‐born, suggesting that shorter/younger mothers that gave birth early in the season were not able to carry their foetuses to term. Pregnant females arrived ashore 1.4 days before giving birth, regardless of the date and their body condition. There was a positive relationship between maternal body length and pup birth mass. Consistently, birth mass increased throughout the pupping period. After parturition, mothers suckled their pups during an average 8.7‐day postnatal period that was significantly shorter in mothers giving birth late in the season. However, the absolute gain in pup mass was 1.5 kg regardless of the birth date, suggesting that mothers did not leave their pups before they had transferred a given amount of body reserves to them. We propose that pups born late grew faster because they were bigger at birth and because their mothers were likely to be more experienced. Mothers in good condition, nursing male pups transferred more milk and therefore greater mass to their pup, whereas mothers in poor condition were unable to do so. Such differences did not occur in smaller female pups, suggesting that pup growth was limited by maternal resources in male pups but not in female pups. The lack of a relationship between birth mass and absolute gain during the perinatal period suggests that mass at birth determined pup body mass after the perinatal period. Body mass is an important factor in growth rate and survival during the period of pup dependence.