bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maximum diving depths for feeding attained by Bulwer's petrels (Bulweria bulwerii) during the incubation period
Authors: Mougin J.‐L. , Mougin M.‐C. 
Published: February 2006

AbstractAll 20 of the Bulwer's petrels Bulweria bulwerii of Selvagem Grande (30°09′N, 15°52′W) equipped with maximum depth gauges had dived during the feeding trips performed during the incubation period, the mean maximum depth being 2.4 ± 1.0 m (range: 1.0–5.3 m). The depth reached showed no correlation with the breeding experience of the birds, with the length of their trip or with their body size and there were no differences between males and females. Thus, the Bulwer's petrel are among the numerous Procellariiformes which perform regular but comparatively shallow dives, unlike shearwaters (Puffinus) and diving petrels (Pelecanoides) which can reach depths of several tens of metres.
Comparative analysis of dental fluorosis in roe deer (Capreolus capreolus) and red deer (Cervus elaphus): interdental variation and species differences
Authors: Kierdorf Uwe , Kierdorf Horst 
Published: February 2006

AbstractThe interdental and interspecific variation in the prevalence and severity of macroscopic fluorotic alterations of the permanent mandibular cheek teeth (P2–4, M1–3) was studied in 331 roe deer and 62 red deer exhibiting severe dental fluorosis. The material originated from the fluoride‐polluted region of the Ore mountains and their southern foreland (Czech–German border region). Scoring of dental fluorosis was based on an ordinal measurement scale with six scores (score 0: unfluorosed, scores 1–5: increasing severity of fluorotic alterations). The observed variation in dental fluorosis both within the cheek tooth row of a species and between certain homologous teeth of roe and red deer could be related to the development of the dentition in the two species, especially the timing of tooth crown formation in relation to weaning and the subsequent period, where the animals feed upon (fluoride‐contaminated) plant material. The lower prevalence (roe deer: 3%, red deer: 42%) and severity (fluorosis scores ð 2) of dental fluorosis in the M1compared to the other permanent cheek teeth were attributed to the fact that the crown formation of this tooth takes place largely (roe deer) or to a considerable extent (red deer) prenatally and during the period of milk feeding. It is assumed that during these ontogenetic stages several mechanisms (partial placental diffusion barrier to fluoride, low fluoride content of milk, rapid clearance of fluoride from the blood resulting from a high skeletal growth rate) to some extent protect the developing teeth from increased fluoride exposure. Therefore, in both species apparently only the (late) maturation stage of M1amelogenesis can be affected by fluoride in a way to induce visible enamel changes. The higher prevalence and severity of fluorotic lesions in the M2of red than roe deer was related to the fact that in the former species crown formation of this tooth, like in the P2–4and M3of both species, takes place completely post‐weaning.
Jaw anatomy of the blood‐sucking leeches, Hirudinea Limnatis nilotica and Hirudo medicinalis, and its relationship to their feeding habits
Authors: Orevi Miriam , Eldor Amiram , Giguzin Ida , Rigbi Meir 
Published: February 2006

AbstractThe triple jaws of the leeches Limnatis nilotica and Hirudo medicinalis (both Hirudinidae, Hirudininae) are compared, using the stereomicroscope and scanning electron microscopy (SEM). The jaws of Limnatis are relatively small, rounded and soft, bearing about 30 flat‐topped, rough‐surfaced teeth, and papillae which presumably secrete saliva. Limnatis sucks blood in stages from internal soft vascular tissue, often in the pharynx, and may stay inside the host for several weeks. Evidence is strong that it is unable to pierce external skin. Hirudo jaws are rigid, have no papillae and bear about 60 sharp teeth, each tooth possessing a secretory aperture on its side, close to the tip. In contrast to Limnatis, Hirudo is an external feeder. It pierces the skin and usually gorges itself with blood in one meal, after which it detaches itself from the host. It gains from six to nine times its weight in a meal, and remains satiated for 3–18 months. The ingested blood of Limnatis, unlike that ingested by Hirudo, is particulate and resembles a liver homogenate. This is probably a result of some scraping by its teeth as the jaws thrust towards a blood vessel. The relationship between jaw anatomy and feeding habits of L. nilotica and H. medicinalis is shown. Clearly, each species has adapted to the particular environment supplying its food (soft internal tissues, external skin).
Dining on diplopods: remarkable feeding behaviour in chlamydephorid slugs (Mollusca: Gastropoda)
Authors: Herbert D. G. 
Published: February 2006

AbstractThe diet of southern African carnivorous slugs of the endemic family Chlamydephoridae is discussed. At least three species,Chlamydephorus bruggeni,C. burnupiandC. sexangulus, are predators of pill‐millipedesSphaerotheriumsp. The feeding behaviour ofC. sexangulusis described in detail and illustrated. It is suggested that the prey, once captured, is killed or immobilized by the introduction of a toxin through the intersegmental membrane joining the millipede's skeletal plates. The source for such a toxin may be the anterior pedal mucous gland. Predation on sphaerotheriid millipedes may be a behavioural apomorphy associated with a clade within the Chlamydephoridae, including taxa with longitudinal body keels and distinctive radula morphology, but it is evidently not confined to this clade. Whether the diet of such millipede‐eating slugs is limited to millipedes is unknown, but it is probable that at least some chlamydephorids feed on more conventional prey such as snails and earthworms.
Cub adoption by polar bears (Ursus maritimus): determining relatedness with microsatellite markers
Authors: Lunn N. J. , Paetkau D. , Calvert W. , Atkinson S. , Taylor M. , Strobeck C. 
Published: February 2006

AbstractSixteen microsatellite markers were used to determine the genetic relatedness between adult female polar bears and their accompanying cubs for three recent occurrences of natural adoption recorded in the Canadian Arctic. The estimation of the degree of relatedness was powerful and provided a high degree of separation between first order relatives and unrelated individuals with the loci used. The analysis showed that the cubs were unrelated to their adoptive mothers and that the mothers were unrelated to one another. Although the circumstances and mechanisms whereby these adoptive events occurred are unknown, the data do not support kinship theory as an explanation for the exchange of cubs. We suggest that these adoptive events probably represent instances of the misidentification of cubs by adult polar bears.
The biology and functional morphology of Fragum erugatum (Bivalvia: Cardiidae) from Shark Bay, Western Australia: the significance of its relationship with entrained zooxanthellae
Authors: Morton Brian 
Published: February 2006

AbstractThe shallow, offshore, hypersaline (∼ 60‰), benthic marine environment of Shark Bay, Western Australia, is dominated by the cockle Fragum erugatum. This small (< ∼ 11 mm long) bivalve occurs in large numbers (4000/m2) and probably completes its life cycle in 1 year. Cyclones with a periodicity of ∼ 50 years have, over the last 5000 years, deposited huge numbers of the shells of F. erugatum onto the shore as windrows, creating the unique Shell Beach, or Hamelin Coquina. In most anatomical respects, F. erugatum is a typical cockle, with a powerful digging foot, siphons formed by fusion of the inner mantle folds only, plicate ctenidia with a ciliation of type C(1) and powerful rejectory currents on the visceral mass and mantle. It is thus able to collect filterable material and digest it. The labial palps are, however, reduced, allowing the ingestion of only the finest particles of food via the acceptance tracts in the ctenidial axes and distal oral grooves. The waters of Shark Bay are hypersaline and oligotrophic, so what is the food source that supports such large numbers of filter‐feeding bivalves?Fragum erugatum possesses symbiotic zooxanthellae, as do its close relatives the giant clams (Tridacnidae), and probably obtains the same nutritional benefits from the association, which may facilitate survival in the hyperosmotic environment of Shark Bay. The association between giant clams and their zooxanthellae enhances shell growth and results in a long life expectancy and gigantism. Conversely, in F. erugatum the association facilitates a large population size (but short life expectancy), allowing it to dominate a unique, hypersaline, oligotrophic environment. Like giant clams, F. erugatum possesses a zooxanthella tube system linking the digestive diverticula of the stomach with the kidneys. Either accidentally or periodically, ingested zooxanthellae are transferred from the gut, via this tube, along with senescent zooxanthellae from the blood haemocoel, to the kidney tubules for lysosomal hydrolysis and eventual expulsion. In the light of this discovery, the functioning of the recently confirmed zooxanthella tube system in the Tridacnidae needs re‐examination and re‐evaluation.
Glycogen distribution in the larval salivary gland cells during the development ofDrosophila melanogasterandDrosophila auraria: an ultrastructural cytochemical study
Authors: Kosta Artemis , Dimopoulou Katerina , Drosou Victoria , Thomopoulos George N. 
Published: February 2006

AbstractIn this study, glycogen distribution during the development of larval salivary glands in twoDrosophilaspecies (D. melanogasterandD. auraria) was examined using the osmium tetroxide–potassium ferrocyanide technique at the ultrastructural level. Glycogen particles are found in big clumps in the salivary gland cells ofD. melanogasterduring the early third instar, mainly at the basal part of the cells; they are also found as scattered particles in the cytoplasm and very close to the apical plasma membrane during the secretory activity at this developmental stage. During the middle third instar, where the production of ‘glue’ secretory granules begins, glycogen particles are mainly scattered and they are seen near the Golgi complexes and secretory granules. No glycogen particles are seen during the late third instar and secretion of ‘glue’ secretory granules. Re‐formation of glycogen begins after spiracle eversion. In the larval salivary gland cells ofD. auraria, glycogen particles (scattered and in clumps) are seen in every developmental stage. In the larval fat body cells of both species, many huge clumps of glycogen particles are seen, independent of the developmental stage. These results indicate that glycogen provides an important source of energy during development ofDrosophilasalivary glands, but different species use glycogen at different metabolic pathways, according to their needs.
Postcranial adaptations for leaping in primates
Authors: Connour Jacqueline Runestad , Glander Kenneth , Vincent François 
Published: February 2006

AbstractLeaping primates are specialized for hindlimb‐propelled locomotion within arboreal habitats. As a group, they include members of Galagonidae, Lemuriformes and Tarsiidae. Postcranial characters analysed here include humeral and femoral diaphyseal rigidity, articular surface areas and lengths. Data for leaper taxa are compared with corresponding data for less specialized small primates. The more generalized comparative primates include both closely related prosimians and distantly related platyrrhines (New World monkeys). In addition, the leapers are subdivided for further analysis according to body size and taxonomic association. Questions addressed concern the identification of functionally and/or phylogenetically linked traits in leaper postcrania. Results indicate that leapers as a group have relatively higher femoral diaphyseal rigidity and longer femora than do more generalized primates. These traits are also present in Pithecia pithecia, a platyrrhine leaper included for comparison. These enhanced properties probably function in resisting large hindlimb forces incurred during leaping, and in producing longer, more efficient leaps. Most of the large‐bodied lemuriform leapers are further distinguished in having relatively bigger femoral heads and reduced humeral rigidity. The small‐bodied leapers, galagonids and tarsiids, do not differ in either femoral head surface area or in any of the humeral properties from more generalized primates. Pithecia has a large femoral head like lemuriforms, but it is not reduced in humeral rigidity. Aspects of hip joint structure and mobility may be related to femoral head size in lemuriforms and Pithecia. Explanations regarding reduced lemuriform humeral rigidity are also explored. Differences between lemuriform primates are also present, most notably in aspects of the distal humerus. Indrids are characterized by relatively reduced trochleae, while many lemurids have relatively small capitula. These features are interpreted with regard to frequencies of suspensory behaviour and quadrupedalism.
Variation in abundance of foxes (Vulpes vulpes) between three regions of rural Britain, in relation to landscape and other variables
Authors: Heydon Matthew J. , Reynolds Jonathan C. , Short Michael J. 
Published: February 2006

AbstractSpotlight transect surveys with distance sampling were used to estimate spring (pre‐breeding) and autumn (post‐production) fox Vulpes vulpes densities in three contrasting rural areas of Britain during 1995–97. This was the first attempt in Britain to measure and compare fox densities over large geographical areas (630–1460 km2). Mean post‐production fox abundance was estimated to be 0.90/km2, 2.62/km2, and 0.59/km2 in mid‐Wales, the east Midlands and East Anglia, falling to pre‐breeding levels of 0.41/km2, 1.17/km2, and 0.16//km2 in spring. As relative measures of regional density, these estimates are strongly supported by independent indices of fox abundance, and by the simultaneous survey of two sympatric species, the badger Meles meles and brown hare Lepus europaeus, which demonstrate the absence of any terrain‐related bias. Absolute abundance is less easy to verify, but estimates of spring density based on breeding earth censuses support the transect surveys. For two of the three regions, fox density was close to levels predicted by extrapolation on the basis of landscape, but in the third region (East Anglia), fox density was substantially below prediction. Thus, results failed to support a hypothesis that fox abundance can be predicted solely on the basis of landscape and its close correlates. Rather, they favoured a competing hypothesis that an independent factor determines fox abundance in some regions. A likely factor is culling by man.
Demography of rural foxes (Vulpes vulpes) in relation to cull intensity in three contrasting regions of Britain
Authors: Heydon Matthew J. , Reynolds Jonathan C. 
Published: February 2006

AbstractThe impact of deliberate culling of fox populations has been much debated. Although a local (< 10 km2) impact has been accepted, previous authors have denied that culling has any impact on a larger scale because local losses are compensated through immigration. Rather, it has been claimed that at this scale fox density is determined by resources, mediated through social behaviour and breeding suppression. We determined the impact of culling on a regional scale (> 1000 km2), using data on culling (Heydon & Reynolds, 2000), fox density (Heydon, Reynolds & Short, 2000) and productivity. The three U.K. study regions (size 1238–2322 km2) were in mid‐Wales (A), the east Midlands (B) and East Anglia (C). High productivity in regions A and C was associated with low density, high culling mortality and high overall mortality (all relative to region B), indicating that density was suppressed by culling. In region B (moderate) breeding suppression was associated with a higher density and lower cull than in regions A and C, implying that fox density was closer to the maximum sustainable by resources. We conclude that the impact of culling in different regions of Britain is variable, dependent on the regional prevalence, methods, and history of culling. However, it is clear that in a range of circumstances culling can substantially depress fox numbers, and that current fox densities reflect a history of culling. This conclusion is fundamental in considering the management of fox predation in farming and conservation contexts.
Osteological differences between two sympatric forms of bottlenose dolphins (genus Tursiops) in Chinese waters
Authors: Wang J. Y. , Chou L.‐S. , White B. N. 
Published: February 2006

AbstractAlthough there has been extensive research on bottlenose dolphins (genus Tursiops), much controversy over the classification within this genus still exists. Even though many morphological variants occur, the prevailing view is for a single species, Tursiops truncatus (Montagu, 1821). To evaluate this view, two sympatric forms of bottlenose dolphins inhabiting Chinese waters were examined using multivariate statistical analyses of osteological data for two meristic and 18 cranial morphometric characters from 71 specimens. Cluster and principal components analyses revealed clear osteological separation of the two forms. Furthermore, the distributions of the total number of vertebrae and several proportions of cranial characters were non‐overlapping between the two forms. These results provided strong evidence that the two sympatric forms of Tursiops in Chinese waters are isolated reproductively and do not support the current view of a monotypic genus. Classification functions of a discriminant analysis and a key of several characters were developed to help researchers identify unassigned specimens. Provisional names (T. truncatus and T. aduncus) were suggested, but a formal taxonomic revision of this genus is still required. However, regardless of the nomenclature, immediate amendments to all present wildlife conservation legislation are strongly urged.
Energetics and burrowing behaviour in the semifossorial degu Octodon degus (Rodentia: Octodontidae)
Authors: Ebensperger Luis A. , Bozinovic Francisco 
Published: February 2006

AbstractThe energetics and burrowing behaviour of the semifossorial Octodon degus (Rodentia: Octodontidae) were investigated and compared with that of more specialized fossorial rodents. An open‐flow respirometry system was used to record energy expenditure of single degus inside respirometers partially filled with soft (moist) or hard (dry) soil. In addition, digging behaviour was recorded in groups of three animals inside a large terrarium under controlled conditions of food, photoperiod and temperature. In the field, the digging activity of degus was monitored, along with seasonal variations in rainfall, content of soil moisture and soil hardness. Mass‐specific metabolic rate during digging was found to be higher in animals burrowing in soft soils compared to hard soil. However, animals burrowing in soft soil removed more soil per min than animals in hard soil. Thus, gram per gram, excavating in hard soil was energetically more expensive. The digging cost of semifossorial degus tends to be either similar to or above those of similarly sized, but more fossorial, rodents. In the field, heightened digging activity coincided with the occurrence of rainfall, greater content of soil moisture and relatively soft soil conditions. Degus generally use their front feet and teeth to shear the soil; disposal of accumulated debris being carried out by moving their front and hind feet backwards. We also observed the establishment of digging chains when two or three individuals burrowed at the same site. As far as digging is concerned, the behaviour of degus is similar to that of other fossorial rodents, such as African bathyergids and the more closely related South American ctenomyids.
Mediterranean species of Eudendrium Ehrenberg, 1834 (Hydrozoa, Anthomedusae, Eudendriidae) with the description of a new species
Authors: Marques A. C. , Peña Cantero A. L. , Vervoort W. 
Published: February 2006

AbstractA new species of Eudendrium from the Chafarinas Islands (south‐western Mediterranean) is described. The distinctive character of this species is its association with symbiotic zooxanthellae, a feature in common with Myrionema, the only other genus of the family Eudendriidae. The evolutionary implications of this similarity are discussed. A review of the Mediterranean species of Eudendriidae is presented, including data on the cnidome when available, biological data from the material studied, and a key to identify the Mediterranean species.
Habitat selection and coexistence of the Alpine chamois (Rupicapra rupicapra) and Himalayan tahr (Hemitragus jemlahicus) in the eastern Southern Alps, New Zealand
Authors: Forsyth David M. 
Published: February 2006

AbstractNumerous field studies have attempted to assess competition between ungulates through the analysis of resource overlap. However, interpreting the results of these studies has been problematic because low overlap may be the outcome of historical competition and high overlap will result in competition only when that resource becomes limiting. In New Zealand, increasing densities of introduced Himalayan tahr Hemitragus jemlahicus have competitively excluded introduced Alpine chamois Rupicapra rupicapra, but where densities of tahr have been reduced the two species can coexist. This study evaluated the role of habitat selection in the coexistence of these two recently sympatric ungulates in Carneys Creek, eastern Southern Alps, New Zealand. Seasonal habitat selection was estimated by observing unmarked male tahr, female tahr and chamois monthly for 25 months. The proportional availability of six habitats (grassland, grass bluff, rock bluff, shrubland, scree and snow) was measured from aerial photographs taken in each of the four seasons. Although the null hypothesis that tahr and chamois select habitats similarly was rejected in three of four seasons, there was high overlap in preference for grassland and shrubland, and avoidance of scree and snow. Tahr were more often observed in grass bluff and rock bluff than were chamois. Overlap in habitat selection was greatest during winter when snow dominated the landscape, reducing the availability of vegetated habitats. Using Hurlbert's statistic, the niche breadth of chamois was significantly smaller than that of tahr in all seasons except autumn, in which they were similar. These results, together with anecdotal evidence from Carneys Creek, suggest that chamois increase their habitat specialization in the presence of tahr. Although differences in habitat selection are likely to have contributed to the coexistence of chamois with tahr, even relatively small increases in tahr density in some seasons could be expected to exclude chamois from some habitats in Carneys Creek.