bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical power analysis: application to an investigation of dinosaur thermal physiology
Authors: Ruxton Graeme D. 
Published: February 2006

AbstractIt has been postulated that the variation in an animal's body temperature during different phases of bone deposition can be estimated from the variation in the ratio of two oxygen isotopes in phosphate recovered from its fossil. Using data from a fossil Tyrannosaurus rex skeleton, the previous researchers failed to reject the null hypothesis that the variation found in bones from the body core is significantly less than that found in the extremities; they also failed to reject the null hypothesis that the coldest and hottest parts of the body differed by less than 4 °C. This suggests that either both null hypotheses are true, or that they are false but the statistical tests used were not powerful enough to detect this. Here I use calculation of confidence intervals to differentiate between these two alternatives. In the first case, I find that the data are consistent with the variance in both the core and the extremity being up to 2.5 times that of the other. In the second case, I show that observations are consistent with temperature differences ranging from 2.6 °C to 6.4 °C. Hence, neither case provides any real support for the hypothesis that bone deposition in this specimen occurred under essentially thermostable conditions.
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

AbstractFour 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

AbstractContrary 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

AbstractThree 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

AbstractFollowing 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractWe 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

AbstractInformation 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

AbstractThe 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

AbstractAnalysis 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

AbstractPatterns 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

AbstractDiets 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

AbstractCaviomorph 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.