bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histoircal changes in the ecology and behaviour of semaphore geckos (Pristurus, Gekkonidae) and their relatives
Authors: Arnold E. N. 
Published: March 2009

Semaphore geckos (Pristurus) and thier relatives have a very robust and explicit morphological phylogeny, consisting of a long pectinate tree in which the number of derived morphological states increases steadily through time. This clade consequently provides a firm base for investingating changes in ecology and behaviour. Data on these topics including diet, pattern of tail shedding and clutch size were integrated with the phylogeny and substantial regularity demonstrated in the way they have changed over time. Ancestral forms were apparently climbers on rocky surfaces and active in subdued light. There was subsequent shift into more open, sunny situations with two or three transfers into arboreal habitats which were accompanied by reversion to more shaded conditions. A change to ground‐dwelling occurred perhaps twice within Pristurus, including the ancestor of the Spatalura clade, a group which has reverted to typical gecko nocturnality while still retaining diurnal activity. Overall, there has been a progression into hotter, drier and more open habitats.Other shifts within the clade are adoption of passive foraging techniques, development and elaboration of intraspecific tail signalling and change in the kinds of refuges used. Clutch size fell from two eggs to one early in the clade history with subseqauent partial reversion to two. Ants and sometimes termites became an importnt item of diet in some taxa and frequent trombiculid mite infestation appeared in the terminal group within which caudal autotomy became confined to the tail base.Overall, the habitats occupied by morphologically advanced Pristurus, appear more demanding, and perhaps less rewarding, than those in which their more primitive relatives live. This may result from species that did less well in competition, following each of the speciation events on the main stem of the phylogeny, being dispolaced into increasingly severe niches. The substantial morphological changes taking place in the evolution of the clade may be related to the problems of survival in these.
New methods of tooth microwear analysis and application to dietary determination of two extinct antelopes
Authors: Solounias N. , Hayek Lee‐Ann C. 
Published: March 2009

A separation exists between the tooth microwear of extant ruminant browsers and grazers when examined with new statistical techniques such as the dichotomous, polychotomous and continuous methods. Extant mixed feeders, however, could not be discerned as a distinct group. Many variables were used in the analysis, including two new variables; the area and perimeter of scars.A standard definition of a pit is deduced and a recommendation is made for a method and a model which best charactrizes the enamel scars for determination of browsing and grazing dietary categories. The best diagnostic method of tooth microwear analysis utilizes the number of pits smaller than or equal to the ratio four (lenth over width), the number of scratches between four and 100 micrometres in length to width ratio, and the number of gouges greater than 100 micrometres in length to width ratio. Browsers have many pits and few scratches, with the exception of the giraffe. Grazers have many scratches and few pits, with the exception of the common waterbuck.The tooth microwear analysis suggests that Tragoportax amalthea (Boselaphini, Bovidae) was a mixed feeder at Pikermi and a grazer at Samos. Using the dietary adaptations and the time differences (Pikermi is slightly older than Samos), it is assumed that we ahve recorded evolutionary change from a mixed feeder to a grazer. Tragoportax rugosifrons from Samos was a grazer. Pikermi and Samos are Miocene (Turolian) localities in Greece.
Social organization and mating system of the plains viscacha (Lagostomus maximus)1
Authors: Branch Lyn C. 
Published: March 2009

Plains viscachas live in communal burrow systems in groups containing one or more males, several females and immatures. Viscachas forage in groups at night and aggregate underground during the day. All members of a group use burrows throughout the communual burrow system and participate in digging at the burrows. Alarm calls are given primarily by adult males. Allogrooming occurs among all sex‐age classes within a social group but not between members of different social groups. Agonistic interactions occur more often between members of different social groups than within a group.The long‐term social unit of the plains viscacha is the female group. Resident males disappear each year and new males join groups of females. Dominance is absent among females. Agonistic interactions are rare among adult males within a social group and dominance is not clearly evident.
Sympatric populations of muntjac (Muntiacus reevesi) and roe deer (Capreolus capreolus): a comparative analysis of their ranging behaviour, social organization and activity
Authors: Chapman Norma G. , Claydon Kathie , Claydon M. , Forde P. G. , Harris S. 
Published: March 2009

The ranging behaviour, activity and social organization of sympatric populations of Reeves' muntjac (Muntiacus reevesi) and roe deer (Capreolus capreolus) in a mainly commercial coniferous forest in eastern England were studied by means of radio‐tracking techniques. Muntjac showed no seasonal changes in range size; muntjac bucks had significantly larger ranges than does at all times of the year. For roe deer there were significant seasonal changes in home‐range size; bucks had largest ranges in the winter months and smallest ranges in September‐October, whereas does had largest ranges during January‐February and minimum ranges during May‐June. There was no seasonal change in the number or size of muntjac core areas; bucks always had larger and more numerous core areas than does. Neither was there a seasonal change in the number or size of roe deer core areas; whilst there was no difference in the number of core areas for roe bucks and does, those of bucks were significantly smaller. There was no seasonal change in daily distance travelled by muntjac bucks or does, or roe bucks, but there was a significant seasonal trend for roe does, whose daily distances travelled were longest during January‐February and shortest during May‐June.Spatial organization of muntjac consisted of groups of overlapping doe ranges but exclusive back ranges; these overlapped with one or more groups of doe ranges. During the summer, roe deer buck and doe ranges overlapped, and some doe ranges were shared with other adult does, but buck ranges were exclusive. During the winter, roe deer were more wide‐ranging and mixed more freely. There was no evidence for spatial separation of muntjac and roe deer; minimum convex polygon ranges overlapped and core areas often coincided. Mean annual activity was 69.3 ± 1.5% for muntjac and 56.4 ± 1.8% for roe deer. Mean length of active periods was significantly greater for muntjac than roe deer, and roe deer had significantly longer inactive periods. For muntjac there were peaks of activity at dusk and dawn, with lower levels of activity during the day and night. For roe deer the dawn and dusk peaks were more clearly defined, and at most times of the year nocturnal activity was higher than diurnal activity.These results are discussed in relation to the physiology of the two species and their patterns of space and food utilization, and the evidence for resource partitioning between the two species is evaluated. It was shown that neither muntjac nor roe deer had an effect on the ranging behaviour, activity and social organization of the other species, but that at very high densities muntjac can have an impact on established roe deer populations by changing their pattern of habitat utilization and by locally reducing their numbers.
Foraging ecology in the lizard Anolis oculatus (Iguanidae) from Dominica, West Indies
Authors: Bullock D. J. , Jury H. M. , Evans P. G. H. 
Published: March 2009

In general, populations of Anolis lizards on West Indian islands face few predators, are at high density and are thought to be limited by food. This paper describes how the foraging ecology of Anolis oculatus, a solitary species confined to the island of Dominica, Lesser Antilles, varies with habitat and season in relation to the quantity and quality of available food.Availability of invertebrate food (determined using pitfall traps and sticky traps) was greater in a dry scrub woodland site, Cabrits National Park (CNP), compared with a montane rainforest site, Palmiste Ridge. In the former, there were general increases in abundance, volumes of softbodied prey and sizes of invertebrates from dry season to wet season. Concomitant dietary changes, as determined principally by stomach flushing, included an increase (by volume) in the proportion of soft‐bodied prey. Dietary analyses confirmed the importance of ants (Formicidae) in the diet of A. oculatus, although for large individuals (mainly adult males) at the rainforest site, soft‐bodied prey such as Oligochaeta and Orthoptera were, in volumetric terms, more important. Prey capture observations showed that large A. oculatus fed mainly above ground. Anolis oculatus at the montane rainforest site used higher perch heights than those in dry scrub woodland, although in both habitats, small individuals (mainly juveniles) fed mainly at ground level on ants. In the dry season in CNP, the diet (in volumetric terms) of smaller Anolis was dominated by hardbodied prey such as ants, springtails (Collembola), barklice (Psocoptera) and beetles (Coleoptera). large Anolis used springtails and barklice to a lesser extent, resulting in relatively low food niche overlap values between size classes and a reduced potential for intraspecific competition compared with the wet season.
The functional morphology of the alimentary canal of larval stages of the parasitic copepod Lepeophtheirus salmonis
Authors: Bron J. E. , Sommerville C. , Rae G. H. 
Published: March 2009

The functional morphology of the alimentary canal of copepodite and chalimus stages of Lepeophtheirus salmonis (Krøyer, 1837) is described and compared with that found in other copepods studied to date.The buccal cavity passes into a gut comprising three major regions: foregut (oesophagus), midgut and hindgut. The foregut and hindgut both posscss a cuticular lining whereas the midgut is lined with specialized epithelial cells. The midgut is divided into three recognizable zones, namely anterior midgut caecum, anterior midgut and posterior midgut. Three main types of epithelial cell are recognizable in the midgut: vesicular cells, microvillous cells and basal cells which correspond to the cell types normally described in other parasitic and free‐living copepod species.Digestion is thought to occur in the midgut and be mediated by the epithelial cells that line it. Although several glands appear to discharge into the area of the buccal cavity, none was seen to interface to any other area of the gut. There was no evidence for the involvement of commensal gut bacteria in food digestion.
An ecomorphological review of the dodo(Raphus cucullatus)and solitaire(Pezophaps solitaria),flightless Columbiformes of the Mascarene Islands
Authors: Livezey Bradley C. 
Published: March 2009

This paper describes a morphological study of the dodoRaphus cucullatusand solitairePezophaps solitariaextinct, flightless Columbiformes of the Mascarene Islands, Indian Ocean—based on mensural data from 387 skeletal elements, comparative data from four flighted species of Columbidae, ancillary mensural data from other Columbiformes, and the literature.Raphus cucullatus and P. solitaria are characterized by great body size and substantially reduced pectoral limbs. Sexual size dimorphism is unusually great in bothR. cucullatusandP. solitaria,and sexual dimorphism ofP. solitariamay be the greatest of any carinate bird. Estimates of body mass (kg), based on femur lengths of flighted columbids and adjusted for flightlessness and seasonal deposition of fat, were: 21 and 17 for male and femaleR. cucullatus,and 28 and 17 for male and femaleP. solitaria,respectively. Pectoral reduction is greater in R. cucullatus than in P. solitaria, but both species are characterized by differential shortening of wing elements, changes in the sternum and scapulocoracoidal angle. R. cucullatus has disproportionately long femora, short tarsometatarsi and long digits, whereas P. solitaria has disproportionately long tibiotarsi, short tarsometatarsi and short digits; relative shaft widths of leg elements are substantially greater in bothR. cucullatusandP. solitariathan in flighted columbids.As is typical of other birds, giantism ofR. cucullatusandP. solitariaprobably was associated with physiological changes, increased longevity, enhanced thermodynamic efficiency and improved capacity for fasting. Evidently bothR. cucullatusandP. solitariawere primarily frugivorous, and foraging‐related morphological peculiarities include an enlarged crop and the retention of ‘gizzard stones’. Both species had clutch sizes of one, and egg masses of the flightless species approximated that predicted for a flighted columbid of equal size. Extreme sexual dimorphism and territoriality ofP. solitariasuggest that the species may have been polygynous and perhaps lek‐breeding. The description of ‘gigantic immaturity’ inR. cucullatusby Strickland & Melville (1848) probably represents the first recognition of paedomorphosis in any species of bird. Pectoral underdevelopment and (in at leastR. cucullutus) comparatively ‘juvenile’ plumage in adults substantiate the role of paedomorphosis in the ontogeny of flightlessness inR. cucullatusandP. solitaria;both species also were characterized by peramorphic skulls, trunks and pelvic appendages. The common assumption of monophyly of the fligHtless species (it. Raphidae) lacks rigorous analytical support. In spite of the anthropogenous extinction of both species, bothR. cucullarusandP. solitariawere evolutionarily innovative in ontogeny, morphological characters and life‐history strategies.
Intraspecific variation in nemerteans (Nemertea): synonymization of genera Paroerstedia and Oerstediella with Oerstedia
Authors: Envall M. , Sundberg P. 
Published: March 2009

AbstractsIntraspecific variation in internal morphological charactcrs is substantial in many nemertean species, mainly due to the tendency for specimens to contract during fixation. It is shown that variation within the type species for the genus Oerstedia, O. dorsalis (Abildgaard, 1806), encompasses all the character states that have been used to erect the two related genera Oerstediella and Paroerstedia. These genera are synonymized with Oerstedia, and the validity of species previously assigned to these genera is discussed.
Conception rates following intrauterine insemination of European (Dama dama dama) fallow deer does with fresh or frozen‐thawed Mesopotamian (Dama dama mesopotamica) fallow deer spermatoza
Authors: Jabbour H. N. , McG. Argo C. , Brinklow B. R. , Loudon A. S. I. , Hooton J. 
Published: March 2009

A total of 121 European fallow deer does, being either parous (n= 15) or nulliparous (n= 106), were treated with intravaginal progesterone impregnated controlled internal drug release (CIDR) devices for 14 days. The does were divided into three treatment groups and inseminated in utero by laparoscopy, at approximately 65 hours after CIDR device removal, with 25 × 106fresh Mesopotamian (n= 40), 25–35 × 106frozen‐thawed Mesopotamian (n= 41) or 30–32.5 × 106frozen‐thawed European (n= 40) fallow deer spermatozoa. The semen used had been collected, from two Mesopotamian and two European fallow deer bucks, by electroejaculation under general anaesthesia. Pregnancy was diagnosed by rectal ultrasonogrdphy on Day 50 after insemination.There were no apparent differences in the quality of ejaculates between the two subspecies of fallow deer. The volume of semen and the total number of spermatozoa ranged between 0.6–1.2 ml and 2.11–4.95 × 109per ml of semen, respectively. Evaluation of frozen‐thawed spermatozoa revealed post‐thaw motility rates between 50–70%. The overall conception rate was 65.3%. A higher conception rate was observed following insemination with European than Mesopotamian frozen‐thawed spermatozoa (75% vs. 53.7%, respectively,P< 0.05). Insemination with fresh Mesopotamian spermatozoa increased the conception rate to a level not significantly different from that observed following insemination with European frozen‐thawed spermatozoa (67.5% vs. 75%, for fresh Mesopotamian and frozen‐thawed European semen, respectively).
The influence of birth date on the development of seasonal cycles in red deer hinds (Cervus elaphus)
Authors: Sibbald A. M. , Fenn P. D. , Kerr W. G. , Loudon A. S. I. 
Published: March 2009

The relative importance of age and photoperiod in the timing of seasonal cycles was studied in red deer during the first 18 months of life. Seasonal cycles of appetite, live‐weight change, coat growth, oestrus and metabolic rate were examined in two groups of seven hind calves born in early May (group E) or nine weeks later in July (group L).There was no difference between groups in the timing or amplitude of the seasonal voluntary food intake (VFI) cycle, or in the timing of seasonal changes in rate of live‐weight gain, although mean live‐weight gain was significantly greater for group L than group E during the first winter of life.Four animals in group L retained their calf coats throughout the first winter. In group L, the first summer coat fibres appeared approximately four weeks earlier, and mean fibre length for the subsequent winter coat was longer in group L than in group E. There was no difference between groups in the timing or amplitude of the seasonal cycle of plasma prolactin concentration, or in the incidence and mean time of onset of puberty.There was no difference between groups in mean energy expenditure per unit of live weight at any time of the year. Mean daily energy expenditure was significantly higher in summer than in winter, but values measured when the animals were resting and corrected for differences in VFI were similar throughout the year.It is concluded that the seasonal cycles of appetite, live‐weight change and oestrus in young red deer hinds are not modified by age, although the normal cycle of coat replacement can be disturbed in animals born towards the end of the calving season.
Factors influencing population dynamics of the plains viscacha (Lagostomus maximus, Mammalia, Chinchillidae) in scrub habitat of central Argentina1
Authors: Branch Lyn C. , Villarreal D. , Fowler G. S. 
Published: March 2009

Population dynamics of the plains viscacha (Lagostomus maximus), a highly social burrowing rodent, were studied in desert scrub habitat of central Argentina from 1984 to 1991. The viscacha population declined between 1984 and 1987 from 96 to three individuals, and all but one of eight social groups went extinct. Our data provide support for both food shortage and predation as important factors in the population crash.During this study, rainfall was above average for the first three years and then fell below average. Vegetative cover, especially plant species consumed by viscachas, declined concurrently with the drop in rainfall. A decrease in body weights of adult viscachas and growth rates of young indicated that food was limited. Predation by mountain lions (Felis concolor) was high throughout the study. However, observations of mountain lions foraging in viscacha colonies increased during the decline of the viscacha population. Predation rates may have increased because viscachas spent more time searching for food, and they were in poor body condition.Following the decline in the viscacha population and after a slight increase in rainfall, vegetation cover increased. However, the viscacha population did not recover except in areas that were burned subsequent to the population crash. Fire, a natural part of the ecosystem, may be necessary to reverse changes in vegetation that occur when viscachas are removed from the landscape, and to allow viscacha populations to recover.
Reproductive suppression in social Cryptomys damarensis colonies—a lifetime of socially‐induced sterility in males and females (Rodentia: Bathyergidae)
Authors: Bennett N. C. 
Published: March 2009

The Damaraland mole‐rat, Cryptomys damarensis, is a highly social subterranean rodent that exhibits reproductive suppression. Inhibition of reproduction occurs in colonies of the Damaraland mole‐rat such that only one female and one or two males are reproductively active. A strict breeding system is set up in which the sole reproductive female initiates courtship and selects her mate who is paired with her throughout the year.The present study has shown that in C. damarensis colonies, both adult and juvenile non‐reproductive females are anovulatory and have low concentrations of oestrogen, 2.2 ± 4.6 nmols/mmol creatinine (n = 133) throughout the year. In contrast, the reproductively active female has elevated concentrations of oestrogen during pregnancy, 95.0 ± 151.O nmols/ mmol creatinine (n = 17). The non‐reproductive females are rendered at least temporarily infertile in that, instead of the secondary follicles maturing and ovulating, they develop into luteinizing follicles. This suppression of ovulation is maintained for as long as there is a reproductive female in the colony. These data support the behavioural findings that non‐reproductive females are never involved in courtship or copulatory behaviour nor do they solicit male colony members. Thus a socially induced suppression of reproductive physiology is apparent in females.In the male Damaraland mole‐rat, suppression of reproduction is due entirely to an inhibition of reproductive behaviour. The mean urinary concentration of testosterone of the reproductive male was 3.8 ± 3.7 nmols/mmol creatinine (n = 25) and that of the five non‐reproductive males 4.4 ± 5.3 nmols/mmol creatinine (n = 114). All male mole‐rats are capable of undergoing spermatogenesis and thus are physiologically capable of fertilizing the reproductive female.It appears, therefore, that reproductive suppression amongst non‐reproductive female mole‐rats is more profound than that which occurs in non‐reproductive males. The latter are apparently restrained from sexual activity by being subordinate to the reproductive male(s), excluded from the pair bond and by being the progeny of the reproductive animals. Thus a predominantly behavioural control mechanism would be in force on male colony members.