bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative study of trophi morphology in Seisonidea (Rotifera)
Authors: Segers Hendrik , Melone Giulio 
Published: February 2006

AbstractWe report on a comparative scanning electron microscopical study of trophi morphology of the two species making up the Class Seisonidea of Phylum Rotifera. The trophi of the two are generally similar, with morphological differences being interpreted as the result of adaptations to different food sources: the trophi of Seison nebaliae are adapted to particle‐feeding, that of Seison annulatus probably functions by piercing the integument of the host using the fulcrum tip, and subsequently sucking out haemolymph. This difference in feeding ecology is believed to contribute to the co‐occurrence of both species on the same host. A new hypothesis on the evolution of rotifer trophi is proposed.
Phenology of butterflies along an altitudinal gradient in northern Spain
Authors: Gutiérrez David , Menéndez Rosa 
Published: February 2006

AbstractThe annual cycle of adult butterflies was studied at seven rocky outcrops located along an altitudinal gradient in a northern Spanish mountain area (Picos de Europa) with a Eurosiberian climate in 1993 and 1995. Both total abundance and number of species of butterflies peaked in summer at all study sites. The cumulative species number uniformly increased over the season until late summer. These results imply that butterflies concentrated their activity when temperatures were higher in the year. Regardless of their diversity and total abundance, timing of the flight period was later for assemblages at high altitude than for assemblages at low altitude. A similar trend in increasing delay in flight period was found when data were analysed separately for each species. The duration of the flight period of assemblages was correlated with abundance in 1993, but it was correlated with altitude in 1995. Most species tended to show shorter flight periods at high altitudes in both study years. These altitudinal changes in timing of adult flight are likely to be linked with effects of temperature on developmental rates of early stages of the life cycle. Changes in duration of the flight period, however, might be partly related to variability in species abundance.
Scanning electron microscopic identification of Sarcocystis gracilis from roe deer and cattle
Authors: Stolte M. , Bockhardt I. , Odening K. 
Published: February 2006

AbstractSarcocysts morphologically not distinguishable from Sarcocystis gracilis of roe deer (Capreolus capreolus, Cervidae) were found in the skeletal musculature of dwarf zebu and humpless cattle (Bos taurus, Bovidae). We contribute to the identification of this species by means of scanning electron microscopy. Special attention is paid to the species‐specific cyst wall structure. Our findings confirm previous descriptions by light and transmission electron microscopy and support the peculiarity and uniqueness of the cyst wall type ‘gracilis’.
Home‐range and movements of leopards (Panthera pardus) on a livestock ranch in Kenya
Authors: Mizutani F. , Jewell P. A. 
Published: February 2006

AbstractThe ranches of Laikipia District, Kenya, provide a very important refuge and conservation area for wildlife. Leopards (Panthera pardus) are the most numerous large predator and create problems by killing livestock. Both small and young wild ungulates, as well as small domestic stock, provide prey so that the leopards achieve unusually high densities. This study, using radio‐tagging techniques, examines the spatial relationships between resident and transient leopards on a 200 km² ranch in the Lolldaiga Hills. About 25 leopards (including estimates of subadults and cubs) live on the ranch. Typically, females occupy exclusive home‐ranges of mean extent 14.0 km² although there is some overlap with subadult females. The home‐ranges of resident males, with a mean of 32.8 km², do not overlap each other but do overlap female territories. Transient males move through the area. Analysis of home‐range and home‐range occupancy, was carried out using three methods: minimum convex polygon, grid cell, and harmonic mean. The information provided by these three different methods is compared, and the social status of the leopards is discussed.
The effects of otter (Lutra lutra) activity on spraint production and composition: implications for models which estimate prey‐size distribution
Authors: Carss D. N. , Elston D. A. , Morley H. S. 
Published: February 2006

AbstractThis study is an investigation into the influence of activity on otter (Lutra lutra) spraint production and composition, based on feeding trials involving captive, tame otters. Trials were of two types: ‘active’ where animals were encouraged to run, swim and dive for at least 33% of the time during the first six hours after each meal, and ‘inactive’ where activity varied between zero and 18% of this period. Trial types were balanced for number of fish, meal volume and fish size. Activity was found to have a large effect on spraint production and composition. For active trials, median minimum gut transit time was 67 minutes and median number of spraints per trial was 23. Corresponding figures for inactive trials were 170 minutes and 14, respectively. Of ingested salmonid (Salmo spp.) atlas vertebrae, 60% were recovered in spraints after active trials, while only 32% were recovered after inactive ones. Analyses of these effects showed that our previous models for estimating prey size distribution from bones recovered in spraints gave a better fit for inactive than for active trials. As otters in the wild are likely to spraint mostly during periods of activity, especially foraging, further feeding trials were undertaken to refine an earlier model better to mimic the field situation. Trials, involving active otters, were undertaken to: (i) produce in vivo bone to fish length equations for salmonid atlases and eel (Anguilla anguilla) thoracic vertebrae; and (ii) model the size‐related differential recovery of these bones. These refined equations are more soundly based to provide estimates of prey size distribution than the earlier ones and their use in future studies of size‐selection is recommended. The present study also highlights the potential limitations of extrapolating from the captive situation to the wild.
Survival of nests of the terecay turtle (Podocnemis unifilis) in the Nichare‐Tawadu Rivers, Venezuela
Authors: Escalona Tibisay , Fa John E. 
Published: February 2006

AbstractMortality factors and hatching success of 422 terecay turtle (Podocnemis unifilis) nests on seven beaches in the Nichare and Tawadu Rivers, Venezuela, were studied following the oviposition phase. Beaches (3.4‐28.4 km2), predominantly sandy, and bordered by riparian vegetation, were searched to record nest numbers and their distribution. Elevation and surrounding plant cover were measured for each nest. Most nests were found close to the vegetation's edge (0‐11 m), at a significant distance from the water's edge (21‐80 m), in more open ground, and along the highest points of the beach (1‐2.5 m above the water's edge). Nest density was positively correlated with beach elevation but not with beach dimensions. Most nests were concentrated in less than 10% of beach area, along the upper 20% of the beach. Average clutch size was 20.1±1.7 eggs, but larger clutches were found significantly further away from vegetation. No significant correlation between hatching success and clutch size was found.A large proportion of nests were subject to animal and human predation but environmental factors (especially flooding) affected some. The major cause of egg loss was human predation. Most clutches collected by humans were found away from vegetation, on the upper 10‐20% of beaches, in exposed unvegetated sites. Animals preyed upon those nests along the vegetation's margin (1‐2 m) in the upper 0‐9% of beaches, in sites of high plant cover (75‐100%). Nests reaching the incubation phase were mainly located in the open areas, which are more prone to human predation. About three‐quarters of nests showed high hatching rates (91‐100%). However, hatchability was highest furthest away from the vegetation. Our results indicate that humans are collecting eggs mostly from sites in which nests have the larger clutches and the higher potential hatching success. Because of this relationship between nest viability and location, sustainable yield programmes must consider where harvesting can take place and must avoid the application of standard harvests per nest.
Temporal changes in the social structure of a captive colony of the Damaraland mole‐rat, Cryptomys damarensis: the relationship of sex and age to dominance and burrow‐maintenance activity
Authors: Gaylard A. , Harrison Y. , Bennett N. C. 
Published: February 2006

Abstract Crytomys damarensis is a eusocial subterranean rodent occurring in colonies in which a sole reproductive female and one to two males are involved in procreation; the remaining colony members are non‐reproductive. Within each sex the reproductive animals are usually the largest and most dominant animals.The dominance hierarchy of a young colony consisting of a founding reproductive pair of genetically unrelated animals and the first three successive litters, comprising 12 offspring, from this pair had a non‐linear dominance hierarchy, h= 0.32. Dominance was found to be correlated positively to body mass as well as to the age of the animal. A subsequent study, which followed the incorporation of two subsequent litters and growth of the first three litters, and comprised 15 offspring, revealed that the dominance hierarchy had attained linearity, h= 0.9. Dominance was again positively correlated with the age and body mass of respective colony members. In both studies there was no clear relationship between dominance and sex within the colony.The relationship between body mass and burrow‐maintenance activity revealed that frequent workers in the colony had a greater mean body mass than infrequent workers. It is suggested that in establishing colonies, the older, stronger and hence larger animals may constitute the initial workforce. In addition the colony exhibits frequency‐related work determination into frequent and infrequent workers. Gender was found to play no role in the frequency of work associated with burrow maintenance.The social organization and temporal changes with recruitment are discussed in the light of events occurring in the field.
Dragline‐associated behaviour of the orb web spider Nephila clavipes (Araneoidea, Tetragnathidae)
Authors: Barth F. G. , Gorb S. N. , Landolfa M. A. 
Published: February 2006

AbstractDragline use by an orb web spider (Nephila clavipes) was analysed by observing both intact spiders and those prevented from producing a dragline. The behaviours observed were those associated with returning to the web hub and prey capture. Upon returning to the hub, spiders resume the resting position by rotating within the hub, producing several new dragline attachment points during the rotation. The importance of the spider's use of the dragline was made clear by preventing experimental animals from producing the dragline. During resting, the permanent dragline‐to‐web attachment enabled the spider to maintain the correct posture. Prey capture behaviour was adversely affected in spiders prevented from using the dragline: without a dragline, all relevant components of the behaviour required more time to perform, and movements within the web (e.g. toward prey and back toward the hub) were directed less accurately. The benefit of the dragline to the spider, in terms of safety, time, energy and reduced exposure to predators, is likely to be significant.
Home ranges, movements and habitat associations of red foxesVulpes vulpesin suburban Toronto, Ontario, Canada
Authors: Adkins C. A. , Stott P. 
Published: February 2006

AbstractA radio‐tracking study of two adjacent social groups of red foxes was conducted in a suburban residential district of greater Toronto from late July through December 1990. This was the first radio‐tracking study of red foxes living completely within a large metropolitan centre in North America. The groups had non‐overlapping home ranges and included both breeding and non‐breeding adult females. Mean group home range size was 52 ha, toward the small end of home ranges documented for the species, and distances travelled nightly by adults of both sexes ranged from 2‐20 km. The home ranges of both groups were primarily located in a bushy ravine containing golf courses and park land, but individual foxes readily utilized areas of low‐density housing characterized by large, well‐vegetated lots. However, the foxes avoided adjacent medium‐density housing areas, indicating that this population may not be as habituated to urban life as some populations described from Great Britain and mainland Europe. Because of their constant proximity to, and frequent use of, some residential habitat types, these foxes have ample opportunity to transmit diseases such as rabies to domestic pets and humans in the vicinity.
Coprophagy in Lepidoptera: observational and experimental evidence in the pyralid moth Aglossa pinguinalis
Authors: Sánchez Piñero F. , Pérez López F. J. 
Published: February 2006

AbstractLarvae of Lepidoptera are mainly herbivores, and only the larval stages of Bradypodicola and Cryptoses pyralid moths are known to be specialized coprophages. Here, we report coprophagy as a main feeding habit for the larvae of another pyralid moth, Aglossa pinguinalis, on the basis of observational and experimental evidence. The larvae of this moth require two years to complete development, and construct silk tubes connecting the food source with a shelter chamber. Larvae of A. pinguinalis were mostly found inside caves, where they were about 700 times more abundant than in the open field. Inside the caves, observational results indicate that 98% of the larvae fed mostly on excrement and only 2% were recorded as eating other kinds of detritus (decayed mushrooms). No larvae were recorded eating plant detritus in the censuses nor in experimental detritus patches. The larvae did not show preferences for different types of excrement in the caves. Experimental dog and sheep excrement corroborated this result, showing that the abundance of larvae did not differ between these two excrement types over the entire study. We suggest that habitat selection of A. pinguinalis is ecologically similar to the trophic specialization of Bradypodicola and Cryptoses, in spite of the differences in natural history traits among these moths. Feeding on dry excrement inside caves, or in buried sloth dung, may reflect the constraints for Lepidoptera successfully to colonize excrement: in more exposed excrement, they cannot compete with other coprophagous specialists owing to the lack of parental care (e.g. resource relocation) and slow growth rates. We hypothesize that coprophagous Lepidoptera will be restricted to competition‐ and predation‐free habitats and resources, feeding on excrement inside caves and animal burrows.
An example of segregation between age and sex classes only weakly related to habitat use in mouflon sheep (Ovis gmelini)
Authors: Cransac N. , Gerard J.‐F. , Maublanc M.‐L. , Pépin D. 
Published: February 2006

AbstractSexual segregation reported in many wild ruminants is generally assumed to result from either different habitat choices by adult males and females or ‘social factors’. In this framework, we studied group composition and habitat use of mouflon sheep (Ovis gmelini) over an annual cycle in the low‐mountain range of Caroux‐Espinouse (continental France). The analysis of group composition revealed segregation outside the rut, not only between the sexes, but also between the young (2‐3 years) and old rams ( 4 years). Moreover, ewes, young rams, and old rams exhibited some differences in patterns of habitat use in the mid‐rutting and lambing seasons, but showed similar patterns in winter and summer. These results, juxtaposed with those of studies of interactions and proximity between individuals within groups, suggest that segregation between age‐sex classes has a strong social basis in mouflon sheep.
Social structure of three sympatric bat species (Vespertilionidae)
Authors: Park K. J. , Masters E. , Altringham J. D. 
Published: February 2006

AbstractThe social structure of three sympatric bat species occupying bat boxes in woodland in southern England was studied: Pipistrellus pipistrellus (pipistrelle), Plecotus auritus (brown long‐eared bat) and Myotis nattereri (Natterer's bat). Before parturition, P. pipistrellus populations were heavily skewed towards solitary males. After parturition, the sex ratio was closer to unity. Recaptures of marked bats suggested that after parturition a resident male population of P. pipistrellus is invaded by a transient female population. The sex ratios of populations of P. auritus and M. nattereri were very close to unity, both pre‐ and post‐parturition. The numbers of recaptures of individual bats were similar for both sexes in P. auritus and slightly higher for females in M. nattereri. In the mating season (August‐October), solitary male P. pipistrellus were found with small groups (1‐9) of females. In contrast, in both P. auritus and M. nattereri, mixed sex groups were found pre‐ and post‐parturition, and roosting groups in the mating season contained up to 20 females and up to 10 males. The stability of female groups in P. auritus appeared to be higher than M. nattereri and P. pipistrellus as known females were found together more frequently. These patterns are discussed with reference to the possible differences in foraging and social behaviour.
The ecology ofEngina armillata(Gastropoda: Buccinidae) in the Cape d'Aguilar Marine Reserve, Hong Kong, with particular reference to its preferred prey (Polychaeta: Serpulidae)
Authors: Tan K. S. , Morton B. 
Published: February 2006

AbstractThe egg capsules and larvae ofEngina armillata(Reeve) (Gastropoda: Buccinidae) are described for the first time. Its general ecology in the Cape d'Aguilar Marine Reserve, Hong Kong, is also described, the species occurring under stable boulders with a community of encrusting species, notably sedentary tubicolous polychaetes. The diet ofE. armillataat Cape d'Aguilar consists of serpulid and spirobid polychaetes. Of the four commonest such species,Hydroides eleganswas preferred toPomatoleios kraussi,Simplicaria pseudomilitarisandSpirorbis foraminosus. Consumption rates byE. armillatavaried considerably amongst individuals, but generally ranged between 1.2 and 6.5% of predator dry weight day‐1during conditions wherein prey quantity was maintained. Such a figure is low when compared to other boring naticid and muricid predatory gastropods which spend much time and energy accessing their prey. The ready availability of easily accessible prey may account for the low consumption rate ofE. armillata(as also seen in other non‐boring predatory gastropods) and explain its apparent specialist feeding habits.
The allometry of life‐history traits: insights from a study of giant snakes (Python reticulatus)
Authors: Shine R. , Harlow P. S. , Keogh J. S. , Boeadi  
Published: February 2006

AbstractMany life‐history traits are allometrically tied to body size, in snakes as well as in other animals. Two problems with previous analyses on this topic for snakes are that: (i) the range of body sizes within species is generally small, so that most analyses have relied on interspecific comparisons; and (ii) available data have been heavily biased towards small, temperate‐zone colubroid species. We test the generality of results from previous work with data on a species of giant tropical snake that is phylogenetically and ecologically distinctive, and encompasses such a massive size range that we can examine intraspecific allometries. We use data from >1,000 field‐collected reticulated pythons from southern Sumatra to ask two questions: (i) do life‐history traits show intraspecific allometries similar to those revealed by interspecific comparisons?; and (ii) are mean values for life‐history traits in a giant snake consistent with allometric trends in smaller species? As predicted, strong intraspecific allometry was evident for most of the life‐history traits we measured, including reproductive output (e.g. clutch size, frequency of reproduction in females, testis volume relative to body mass) and energy stores (relative size of the abdominal fat bodies). For many traits (e.g. the means and variances of clutch sizes and maternal body sizes, relative offspring size, body size at maturation relative to size at hatching and maximum adult size), these giant pythons were near or beyond the extremes reported for smaller species of snakes, supporting the importance of allometry. None the less, reticulated pythons deviate from many of these previously‐documented allometries in significant ways, suggesting that current generalizations about life‐history allometry in snakes may be premature.
Predation on burrowing petrels by the brown skua (Catharacta skua lönnbergi) at Mayes Island, Kerguelen
Authors: Mougeot F. , Genevois F. , Bretagnolle V. 
Published: February 2006

AbstractThe diet of the brown skua (Catharacta skua lönnbergi) was studied at Mayes Island, Kerguelen archipelago, by collection of prey remains on 11 territories during the complete breeding cycle of the species there. In nine territories, collections were daily or every two days for a quantitative investigation of the diet. The blue petrel (Halobaena caerulea) and thin‐billed prion (Pachyptila belcheri) accounted for, respectively, 72.9 and 19% of the remains. Differences in diet and prey capture rate were analysed according to territory size, local abundance of prey inferred from the vegetation cover of territories, colony attendance patterns of prey, and according to the breeding timing and success of skuas. Skuas holding large territories caught more prey, and especially more blue petrels than those with small territories. Diet reflected local abundance of blue petrel and thin‐billed prion but the blue petrel was apparently preferred to other available prey. Failure to breed was not significantly related to hunting performance of the skua or to food availability, but sample size was small. Variations over time of prey capture rates reflected the colony attendance patterns of the main prey. Captures of blue petrel and thin‐billed prion were most numerous during their respective laying, incubation and hatching periods, decreasing during chick‐rearing. Prey capture rates were greatest when brown skuas were hatching, and decreased during chick‐rearing to a minimum when young skuas were fledged. Capture rate patterns differed according to laying date of skuas: early breeding skuas caught more prey and were well synchronized with the breeding cycle of the blue petrel and late breeders exhibited more dependence on the thin‐billed prion for some periods. Finally, this study has allowed us to assess the impact of the brown skuas upon the burrowing petrels on this locality.