bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dietary adaptations of extant and Neogene African suids
Authors: Harris J. M. , Cerling T. E. 
Published: September 2010

AbstractPlio‐Pleistocene suid assemblages of sub‐Saharan Africa seem to have been derived from the immigration of Asian tetraconodontines during the late Miocene and of Asian suines in the mid Pliocene. Lineages of both subfamilies display evolutionary changes that decrease the length of the premolar row and increase the length, height and complexity of the molars. Such changes have proved useful for estimating the relative ages of the sites from which suid fossils have been retrieved. They have also been used for interpreting the probable habitat and as evidence of environmental change through time. Isotopic analyses of tooth enamel from extant suid species generally confirm field observations of their dietary preferences. Similar analyses of suid dental enamel from Neogene localities of eastern Africa provide information that partly supports previous interpretations of the diets of extinct suid species. The increase in size and complexity of nyanzachoere teeth reflects their exploitation of C4 vegetation, although the nyanzachoeres did not acquire their grazing habits until after contemporary perissodactyls and proboscideans had become dedicated C4 grazers. In contrast to earlier interpretations, kolpochoeres and metridiochoeres were already dedicated grazers by the time they became significant components of the East African biota. Like their living counterparts, the warthogs and forest hogs, metridiochoeres were less water‐dependent than kolpochoeres.
The effect of tooth wear on the feeding behaviour of free‐ranging koalas (Phascolarctos cinereus, Goldfuss)
Authors: Logan Murray , Sanson Gordon D. 
Published: September 2010

AbstractThe free‐ranging feeding behaviours of five adult koalas Phascolarctos cinereus with varying degrees of tooth wear were investigated using acoustically sensitive radio telemetry. An increase in tooth wear was found to be associated with a significant increase in the average amount of time spent feeding, average number of leaves consumed and the average number of daily chews. This suggests that koalas compensate for tooth wear by increasing food intake. Furthermore, there was a significant increase in the average number of chews per leaf and average chew rate, suggesting a greater investment in processing each leaf.
Bells reduce predation of wildlife by domestic cats (Felis catus)
Authors: Ruxton Graeme D. , Thomas Sarah , Wright Jessica W. 
Published: September 2010

AbstractTwenty‐one cat owners from a 100 km2 area, centred on Carnforth, Lancashire, England, recorded each dead prey item delivered by their cat or cats during an 8‐week period, following one of three experimental schedules, each of which required each cat to have a bell on a collar for only half of the time. The mean number of items each cat delivered to the owner was 2.9 in the 4 weeks when the cats had a bell attached, compared to 5.5 for the equivalent time when the bell was absent. The bell had no effect on the relative numbers of different prey types delivered, and there was no evidence that the cats adapted their hunting behaviour to reduce the effect of the bell over time.
Colony and social structure of the Ghana mole‐rat (Cryptomys zechi, Matchie) (Rodentia: Bathyergidae)
Authors: Yeboah S. , Dakwa K. B. 
Published: September 2010

AbstractSome aspects of the colony and social structure of the Ghana mole‐rat Cryptomys zechi were studied in a mesic Guinea savanna woodland in Ghana. Colony size ranged between one and seven (average 3.6). The mean adult body weight was 217.9 g and the colony biomass was 634 g. Responsibility for colony safety in C. zechi, as revealed from order of capture in response to damage to the burrow system, is age dependent, with sub‐adults being the most frequent repairers. There are indications that male workers are more involved in colony maintenance than females and that the reproductive individuals, especially the males, perform little work. We discuss the finding that C. zechi although a social bathyergid, is close to the bottom of the sociality ladder.
Population dynamics of badgers (Meles meles) in Oxfordshire, U.K.: numbers, density and cohort life histories, and a possible role of climate change in population growth
Authors: Macdonald D. W. , Newman C. 
Published: September 2010

AbstractBetween 1987 and 1996 the numbers of badgers Meles meles in Wytham Woods rose from 60 to 228 adults. The area occupied by the population has not changed and thus density has also risen from 10 adult badgers/km2 to 38/km2. This rise parallels an increase in badger abundance seen across Britain in recent years. The hypothesis that this increase is either the consequence of improved badger protection or of changes in habitat can be rejected for this site. Instead, a link between increasing numbers and changing weather patterns, possibly resulting from climate change, is investigated. In particular, attention is drawn to a correlation between mild winters and heavier body weights of badgers in January. Furthermore socio‐spatial restructuring within the population may be the mechanism that has permitted high density to be sustainable. The increase in badger numbers at Wytham has not affected population sex ratio, which has remained relatively constant at parity throughout the study.
Visual capabilities in a crepuscular marsupial, the honey possum (Tarsipes rostratus): a visual approach to ecology
Authors: Arrese C. , Archer M. , Beazley L. D. 
Published: September 2010

AbstractBehavioural and anatomical analyses were undertaken to determine the visual capabilities of a small nectivorous Australian marsupial, the honey possum Tarsipes rostratus. It is proposed that, despite a crepuscular lifestyle and a low visual acuity, vision contributes substantially to the honey possum's perception of its environment. Visual acuity, determined using a discrimination task, revealed a slightly higher performance in daylight (0.63 cycles/degree) than in moonlight and starlight (0.60 cycles/degree). Ultrastructural analysis of the outer retina revealed a rod to cone ratio comparable to that found in diurnal retinae (20:1 in the central retina). Two types of oil droplets were distinguished on the basis of size. The degree of neural convergence was also similar to that found in a diurnal retina, with a ratio of 12 photoreceptors:1 ganglion cell. The remarkable total field of view, approaching 240° of visual angle and including a binocular overlap of 80° in the horizontal plane, provides an efficient predator detection capacity. The visual capabilities of the honey possum are discussed in relation to its lifestyle and the associated visual requirements.
Pupillary mobility in four species of marsupials with differing lifestyles
Authors: Arrese Catherine 
Published: September 2010

AbstractThe pupillary response to the onset of bright light (10 000 lx) and darkness (4 lx) is compared in four species of Australian marsupials with different activity patterns. Maximal and minimal pupil width in relation to eye width was measured and the rate of change assessed. In the arrhythmic fat‐tailed dunnart Sminthopsis crassicaudata, there were marked changes in pupil size with the range of pupil width to eye width of 0.73–0.10; constriction was rapid (54% s−1) and dilatation slower at 10% s−1. The crepuscular honey possum Tarsipes rostratus had a small range of pupil size at 0.56–0.46, with constriction and dilatation being slow at 4% s−1 and 3% s−1, respectively. The strictly nocturnal burrowing bettong Bettongia lesueur had a small pupil with a limited size range of 0.21–0.12; constriction at 25% s−1 outstripped dilatation at 7% s−1. The greater bilby Macrotis lagotis, also strictly nocturnal, had a small and immobile pupil with a fixed pupil width to eye width ratio of 0.08. In conclusion, contrary to most previous assumptions, pupil size is not fixed in marsupials, and not all nocturnal animals possess a wide pupil. Moreover, as a regulatory process, pupillary mobility reflects more than a differentiation between diurnal or nocturnal condition, and seems to correlate with specific visual requirements. The results of this study are discussed in relation to the lifestyle of the species and the associated illumination levels, and as a method of predicting the marsupials' periods of activity in the field.
Effects of intermittent feeding on the growth of oophagous (Chirixalus eiffingeri) and herbivorous (Chirixalus idiootocus) tadpoles from Taiwan
Authors: Liang Min‐Fang , Huang Chen‐Huei , Kam Yeong‐Choy 
Published: September 2010

AbstractThe effects of intermittent feeding on the growth of oophagous Chirixalus eiffingeri and herbivorous Chirixalus idiootocus tadpoles were studied. Tadpoles were fed, once every 1, 2, 4, 8, 14, or 20 days (feeding treatments 1D, 2D, 4D, 8D, 14D, and 20D, respectively). At each feeding, C. eiffingeri were given yolk from chicken eggs, and those of C. idiootocus were given boiled spinach, ad libitum. For each species, each treatment consisted of 12 replicates of one tadpole each. For C. eiffingeri, the 1D feeding treatment was eliminated because the tadpoles were unwilling to eat daily. Chirixalus eiffingeri tadpoles in the 2D and 4D feeding treatments grew fastest, while tadpoles in the 20D treatment grew slowest. At least five tadpoles from each treatment, except 20D treatment, reached metamorphosis. Chirixalus idiootocus tadpoles in the 1D and 2D feeding treatments showed signs of growing, but tadpoles in the other four treatments did not grow at all. Only tadpoles in the 1D treatment reached metamorphosis. In another experiment, yolk digestion in the stomach of C. eiffingeri tadpoles was monitored. Yolk use was slow and egg yolk remained in the stomach for at least 8 days. Chirixalus idiootocus tadpoles could not tolerate long periods without food, probably because their digestive tract had a short clearance time and their stomach was incapable of long‐term food storage. In contrast, between feedings, C. eiffingeri tadpoles seemed to mobilize food stored in their stomach, providing a continuous supply of nutrition to facilitate normal growth and development. These results and observations provide important insights into the maternal brood care of female C. eiffingeri.
The unusual development of the sagittal crest in the Brazilian tapir (Tapirus terrestris)
Authors: Holbrook Luke T. 
Published: September 2010

AbstractTwo of the four living species of tapir (genus Tapirus) possess a distinct sagittal crest, but the development of this crest follows an unusual path in one species, T. terrestris. In T. pinchaque, T. bairdii, and T. indicus, as in other mammals, temporal ridges form on either side of the braincase, and, as postnatal ontogeny proceeds, these ridges migrate dorsad and mediad. In T. pinchaque and other mammals with a true sagittal crest, the temporal ridges eventually meet at the dorsal midline of the skull. In T. terrestris, paired temporal ridges never develop; instead, the crest simply erupts from the skull midline early in postnatal ontogeny. The sagittal crest continues to heighten, resulting in the tall crest that is characteristic of this species. Development of the sagittal crest is generally thought to be linked to the development of the temporalis muscle. Dissections of one adult and one neonate of T. terrestris indicate that the temporalis is strongly developed in this species and unusually extensive in its origin at an early age. A lack of comparative data forbids any conclusive statements about the relative development of this muscle as compared to that in other tapirs, but the unusual pattern of crest development seen in T. terrestris may be a consequence of the development of the temporalis muscle in this herbivorous ungulate. The pattern of crest development observed in T. terrestris is unique among tapirs, and perhaps among mammals. This explanation of the unusual sagittal crest morphology of T. terrestris is consistent with current interpretations of skull morphology and the taxonomy of Pleistocene Tapirus.
Factors influencing the distribution, abundance and diversity of geophilomorph and lithobiomorph centipedes
Authors: Blackburn James , Farrow Malcolm , Arthur Wallace 
Published: September 2010

AbstractGeophilomorph and lithobiomorph centipedes were collected from 45 sampling sites spread across an area ofc.4000 km2in north‐east England. Data on physical variables were also collected at these sites, including the soil variables of pH, moisture content, organic content and compaction, which have been generally neglected in previous studies of centipede ecology. Fourteen species were found overall, evenly split between the two orders. Of these 14, three were ‘rare’ (≤ three individuals), six were ‘intermediate’ (10–50 individuals), and five were ‘common’ (100+ individuals). Analysis of presence/absence data on the intermediate species showed that the geophilomorphs were markedly synanthropic whereas the lithobiomorphs were not. More extensive analysis of the data on the five common species revealed a number of patterns, including: (1) a negative association between the two largest lithobiomorphs; (2) the importance of many predictor variables, including the soil variables, but with very different patterns for different species. Overall, synanthropic sites had the highest centipede diversities, but this effect was almost entirely caused by the synanthropic tendencies of the ‘intermediate’ geophilomorphs.
Dental polymorphism in a population of the red fox (Vulpes vulpes) from Poland
Authors: Szuma Elwira 
Published: September 2010

AbstractDental polymorphism in a population of the red fox Vulpes vulpes (L.) from Poland was studied in a sample of 1453 specimens (637 males, 535 females and 281 specimens of unknown sex). Frequency distributions in 15 groups of morphotypes (A–O) were analysed and a pattern of qualitative features was constructed on the ground of frequency analysis of particular morphotypes. An increase in complication of tooth shape of the carnassial region (P4, P4, M1, M1), as well as higher morphological variation of the teeth from borders of the cheek rows (P1, P1, M2, M3) were ascertained. Almost all groups of morphotypes, excluding three, presented absence of significant sexual differences. The pattern of qualitative features was used to verify an existing model of genetic control of evolutionary changes in dental morphology of mammals. Positive, statistically significant relationships between the dental size and presence or degree of formation of the dental structures confirmed the operation of the size‐related mechanism, i.e. threshold mechanism, during ontogeny.
Patterns of growth and the effects of scale on the feeding kinematics of the nurse shark (Ginglymostoma cirratum)
Authors: Robinson Michael P. , Motta Philip J. 
Published: September 2010

AbstractSuccessful capture of prey often depends, in part, on the magnitude, duration and speed of feeding behaviours. Animal size and experience are potentially important to these aspects of behaviour, but the effects of scale on the muscular dynamics of and capture by aquatic vertebrates remain relatively unknown. This study examines scale effects on prey capture kinematics in the nurse shark Ginglymostoma cirratum, an inertial suction feeder. Morphometric analyses were performed on the heads and feeding apparati of 12 specimens between 71 and 244 cm total length (TL). These data indicated isometric growth of the feeding apparatus. The kinematics of prey capture in another 12 specimens (33 to 268 cm TL) were recorded with high speed video (200 fps). Across the size range, maximal angular excursions remained constant whereas the maxima of linear excursions increased isometrically. However, various phases of the prey capture sequence apparently did not increase in duration. Regressions of the components of prey capture timing generally had slopes between 0 and 0.5, supporting a model of muscular scaling initially proposed for largemouth bass. This model implies that increases in the duration of prey capture are the result of physiological constraints on muscular contraction. There is also a pattern of scaling across several taxa of aquatic vertebrates consistent with a second model of musculoskeletal scaling, although it does not necessarily apply within each taxon.
No lunar phobia in swarming insectivorous bats (family Vespertilionidae)
Authors: Karlsson Britt‐Louise , Eklöf Johan , Rydell Jens 
Published: September 2010

AbstractThe purpose of this study was to evaluate the impact of moonlight on the swarming activity of bats at an abandoned mine in southern Sweden. The mine serves as a hibernaculum for six species of insectivorous bats. Swarming activity at one of the mine entrances was measured on 12 nights between 1 August and 8 September 2000, by electronically counting the number of bats passing through an opening (about 30×40 cm) leading to a mine tunnel. The number of bat passes outside the mine was also counted, using a bat detector. Most bats were males, as confirmed by mist‐netting outside the mine. Low frequency vocalizations, indicating territorial interactions, were heard frequently. The number of bats entering the mine was closely correlated with the number of bats flying outside, and neither was affected by moonlight. We conclude that the insectivorous bats at high latitudes may not have been exposed to significant nocturnal predator pressure, leading to the evolution of lunar phobia, as have many tropical bats.
The hepatopancreas of Scorpio maurus fuscus; seasonal changes in mass and water content as related to gender and oogenesis
Authors: Warburg M. R. , Elias Rivka , Rosenberg Mira 
Published: September 2010

AbstractChanges in hepatopancreas mass in nymphs, male and female Scorpio maurus fuscus (Scorpiones, Scorpionidae) from northern Israel, were followed through the year, and its percentage water content calculated. The hepatopancreas mass was positively correlated with body mass in males, females and nymphs, and changed significantly with season. In nymphs it ranged between 0.1549 g and 0.5351 g, in males between 0.1631 g and 0.3431 g, and in females between 0.2240 g and 0.6669 g. The hepatopancreas mass of males differed significantly from that of females during summer and autumn, and from nymphs during summer and winter. The hepatopancreas mass of nymphs differed significantly from that of females during autumn, winter and spring. In females, the hepatopancreas mass increased from autumn to spring. During that time, the embryonic diverticula (Ed) containing the embryos increase in number and size during embryogenesis. The depletion of the hepatopancreas mass is positively correlated with the Ed during the latter part of the gestation period before parturition. The percentage water content of the hepatopancreas ranged between 47.8% and 68.4%, and varied seasonally as well as between the genders. It is suggested that these changes in both hepatopancreas mass and water content are related to physiological events such as growing and moulting in nymphs, feeding and mating activities in males and the oogenetic cycle in females.
The hair cuticle of mammals and its relationship to functions of the hair coat
Authors: Meyer W. , Schnapper A. , Hülmann G. 
Published: September 2010

AbstractBased on a computer‐assisted method and regression analysis several structural parameters of the hair cuticle pattern of primary hairs of 94 mammalian species from seven orders were evaluated and compared between the different groups studied. Relevant relationships could only be demonstrated for directly scale‐dependent parameters (scale area, scale perimeter, ratio of scale width to height). However, the species‐specific shape and size of hair cuticle scales in mammals may be of certain value for biological interpretations of hair coat structure and function. This seems to be especially true for the Canidae and the Felidae, and even more for small mammals (insectivores, chiropterans, small rodents). In the latter group relationships between scale‐dependent parameters and hair coat density indicate a homogeneity of hair coat structure which reflects effective insulation qualities.
Attendance patterns of Steller sea lions (Eumetopias jubatus) and their young during winter
Authors: Trites Andrew W. , Porter Boyd T. 
Published: September 2010

AbstractWinter attendance patterns of lactating Steller sea lions Eumetopias jubatus and their offspring were recorded during the late stages of nursing when the young were expected to move from milk to independent foraging. Trip duration and nursing visits to shore by 24 mothers with pups (7–9 months old) and six mothers with yearlings (19–21 months old) were noted during 600 h of observations (from 22 January to 1 April 1996) at a non‐breeding haulout site in south‐eastern Alaska. Pups and yearlings tended to stay on or near the haulout while their mothers were away and showed no signs of weaning during winter. Their average trips to sea were 43% shorter in duration than those of lactating females, suggesting that pups and yearlings make independent trips away from the haulout while their mothers forage. The winter attendance cycle of lactating females (consisting of one trip to sea and one visit on land) averaged about 3 days, with the mothers of pups spending an average of 15 h of this time onshore with their offspring. The winter attendance cycle of pups and yearlings averaged just over 2 days, with the immature sea lions spending an average of 22 h on shore. Foraging trips by mothers of yearlings were significantly longer than those by mothers of pups. However, there was no significant difference in the foraging times of mothers of male and female pups. Lactating females spent more time at sea during winter than during summer. The probability of sighting an individual on the winter haulout during daylight hours was 15% for lactating females and 40% for immature animals.
The photophores of the squid family Cranchiidae (Cephalopoda: Oegopsida)
Authors: Herring Peter J. , Dilly P. N. , Cope Celia 
Published: September 2010

AbstractExamples of the ocular, digestive gland and brachial end‐organ photophores of specimens from all 13 cranchiid genera are described. The cranchiine and taoniine subgroups have different ocular photophore morphologies, but very similar brachial end‐organs in adult females. Most taoniines have ocular photophores that contain large numbers of crystalloids, but these are lacking in Helicocranchia and Sandalops. There are no crystalloids in cranchiine ocular photophores, in taoniine digestive gland photophores (Megalocranchia) or in the brachial end‐organs of both groups. The cranchiine Leachia atlantica uniquely has one group of photocytes that contain aggregates with some similarities to the taoniine crystalloids. The end‐organs of mature females have a glandular structure; the deciduous photocytes are structurally different from those present in the ocular or digestive gland photophores. The reflectors of Sandalops and Megalocranchia contain unusual arrangements of iridosomal platelets. End‐organs lack any reflective structures. The comparative anatomy of the photophores supports the separation of the cranchiine and taoniine groups but the ultrastructural detail provides common links between the two.