bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanics of branchial ventilation in the valviferan isopod Idotea wosnesenskii (Crustacea)
Authors: Alexander David E.
Published: March 2009

Idotea wosnesenskii Brandt, a valviferan isopod, has five pairs of pleopods within a branchial chamber enclosed by modified uropods (operculae). The pumping mechanism of resting isopods was videotaped to observe ventilation, and particularly to determine whether or not the swimming pleopods (first three pairs) and the gas exchange pleopods (last two pairs) have ventilatory roles. Observations on intact animals (to observe water flow into and out of the branchial chamber) and on animals with operculae propped open or with parts of their abdominal wall removed (to study the actual pumping movements of the pleopods) revealed that all five pairs of pleopods function in ventilation. The ventilatory stroke has two phases: an opening phase in which the pleopods move medially and ventrally, opening spaces between pleopods (analogous to the swimming recovery stroke), and a closing phase, wherein the pleopods move laterally and dorsally, reducing the gaps between succeeding pleopods (analogous to the swimming power stroke). Ventilatory strokes may be continuous or they may be separated by resting phases. Both the frequency and amplitude are variable: the frequency changes greatly due to the wide variation in resting phase duration. By opening the operculae the amplitude can increase so that ventilatory strokes grade into swimming strokes. The ventilatory stroke pattern at rest is generally similar to the swimming stroke pattern but differs in its slower and nearly simultaneous dorsoventral movements and its lower frequencies. Dye and particle movements around intact animals and those with exposed pleopods show that water typically takes about three strokes to pass through the branchial chamber.
Effects of climate on reproduction in the European wild rabbit (Oryctolugus cuniculus)
Authors: Bell D. J. , Webb N. J.
Published: March 2009

Reproduction in a population of European wild rabbits occupying parkland habitat in East Anglia showed an annual seasonality in terms of numbers of emergent young, male testes size and an index of female oestrous status. Weather conditions showed marked variation over the four‐year study period with significantly higher minimum ground temperatures and hours of daily sunshine, and less snowfall recorded during the second two years. Parailel shifts in reproductive seasonality were found with male testes size peaking in January and February as opposed to May and April, first female oestrus recorded one month earlier (January compared to February), and young emerging over an average of 5.5 instead of 4.5 months each year and their first appearance above ground advanced by two months from April to February. Mean annual productivity increased from 7.2 and 6.1 emergent young per female, to 10.1 and 9.1 over the four years, while the number of adults present in the population at the start of the breeding season increased from 22 to 45, with females always outnumbering males. The usefulness is demonstrated of a noninvasive index of vulva appearance, and morphometric measures of testes to determine female oestrous status and estimates of male testicular weight in wild populations.

The reported changes in reproduction are probably mediated through the influence of climatic variables on the quality or quantity of food available to the rabbits. These data demonstrate the possible effects of predicted global warming on productivity in the rabbit and highlight the major influence of climate on reproductive seasonality in this important pest species.
Non‐invasive monitoring of avian reproduction by simplified faecal steroid analysis
Authors: Bishop C. M. , Hall M. R.
Published: March 2009

The measurement of urinary steroid metabolites has proved a reliable method for monitoring reproductive changes in a variety of mammalian species. Development of related techniques for assessing avian reproductive function has shown that sexing of various species is feasible and that the following of individual reproductive changes may be possible. This paper reports on the use of a simplified procedure for assay of specific excreted steroids in a 1: 60 dilution of a 0.4 g dried faecal sample from male and female Japanese quail, and the monitoring of steroid hormone changes in the plasma and faeces throughout a photoperiodically induced reproductive cycle.

Immunoreactive steroid measurements were made directly by radioimmunoassay (RIA) of ahquots of faecal homogenates in phosphate buffer and did not involve hydrolysis of steroid conjugates or organic solvent extraction. Measurements were made of immunoreactive testosterone, oestradiol‐3‐glucuronide (E‐3‐gl) and pregnanediol‐3α‐glucuronide (Pd‐3α‐gl). Plasma testosterone and progesterone concentrations, in males and females, were compared to faecal immunoreactive testosterone and Pd‐3α‐gl, respectively. Exposure to stimulatory long daylengths of 20L:4D (LD) resulted in a rise of both plasma and faecal testosterone followed by a reduction after subsequent transfer back to short daylengths of 8L:16D (SD). Male faecal immunoreactive testosterone levels were significantly correlated with the plasma testosterone concentrations (0.59, P<0.001, n= 70) and with the phase of the reproductive cycle. Faecal immunoreactive Pd‐3α‐gl levels increased following exposure to LD, and female values were well correlated with plasma progesterone concentrations (0.79, P <0,001, n= 56) and with the pattern of egg laying. Faecal immunoreactive E‐3‐gl levels were higher in LD than SD birds with higher levels in females compared to males, even under SD photoperiods.

For long‐term monitoring of the reproductive status of Japanese quail, faecal immunoreactive testosterone and Pd‐3α‐gl measurements, in a 1:60 dilution of a random 0.4 g dried faecal sample, were found to be as reliable and informative as plasma testosterone and progesterone measurements, respectively.
Fine structure of the axillary gland in the brown bullhead (Ictalurus nebulosus)
Authors: Whitear M. , Zaccone G. , Fasulo S. , Licata A.
Published: March 2009

The axillary glands of Ictalurus are lobulated invaginations of the epidermis, opening at a pore between the pectoral spine and the cleithrum. Holocrine cells lining a false lumen form a viscous secretion. The secretory cells originate in the tenuous basal layer of the gland wall. Secretion is initiated by the formation of compound vesicles in cells that become very large and have complex cytoplasm of a varied appearance. Golgi systems are well developed and the perinuclear cytoplasm may contain many mitochondria and sacs of ribosomal endoplasmic reticulum; some tracts of cytoplasm are vesicular and contain free ribosomes. Some cells contain numerous large lysosomes, and some have extensive contents of fibrillar masses imperfectly separated by membranes, that recall the appearance of the mucous secretion of goblet cells. The secretory cells break down, releasing the degenerating organelles, including the nuclei, into the false lumen. Some structures are still recognizable in the secretion even after it has been expelled, but the main part of the formed secretion consists of the mucus‐like masses. Various leucocytes are found in the gland walls and embedded in the secretion. The fine structure differentiates the holocrine cells of the axillary gland from the club cells of the epidermis, and from the venom glands associated with the fin spines of catfishes. The function of the axillary gland secretion remains unknown.
The frontal and gular dermal scent organs of the marsupial sugar glider (Petaurus breviceps)
Authors: Stoddart D. M. , Bradley A. J.
Published: March 2009

A study spanning two breeding seasons was carried out to examine the role of androgens in the control of the frontal and gular scent glands of the marsupial sugar glider Petaurus breviceps Waterhouse in a wild population. Animals were captured at monthly intervals and from these blood samples were taken and tissue biopsy samples were collected from the scent glands.

Several histological parameters underwent seasonal changes which were related to changes in the plasma concentration of free plus albumin bound (‘biologically active’) testosterone. The parameters which showed significant change did so during the July‐September breeding season coinciding with the peak in biologically active testosterone concentration.

Castration caused a significant decrease in the nuclear diameters of gular and frontal apocrine and sebaceous gland cells, and a decrease in gular apocrine cell height. These decreases were reversed with androgen replacement therapy.

The nuclear diameters of apocrine tissue cells in both scent organs are positively correlated with the plasma level of biologically active testosterone. In the gular organ, but not in the frontal organ, the depth of apocrine tissue was significantly correlated with nuclear diameter. In castration and androgen replacement studies gular apocrine tissue responded more dramatically than did frontal apocrine tissue. This suggests that the gular organ is more sensitive to testosterone than is the frontal.
Circulating levels of luteinizing hormone and steroid hormones in relation to social status in the cooperatively breeding white‐browed sparrow weaver, Plocepasser mahali
Authors: Wingfield J. C. , Hegner R. E. , Lewis D. M.
Published: March 2009

We have begun an intensive series of investigations into the environmental and endocrine mechanisms regulating cooperative breeding in a semi‐arid tropical environment. A colour‐marked population of white‐browed sparrow weavers (Plocepasser mahali) was studied at a field site near Nyamaluma Camp, Luangwa Valley, Zambia (13dG S). This species breeds from October to April, although some clutches may be found as early as August and young may be fed until May.

Non‐disruptive techniques were employed to monitor annual cycles of gonadal development, body mass and fat reserves, and small blood samples were collected to measure circulating levels of reproductive hormones and corticosterone. All individuals were released after sampling and the social and reproductive activities recorded by systematic behavioural observations. Each individual could thus be identified as: (1) a breeding adult; (2) a related helper (i.e. offspring of the breeding male and female within the group); or (3) a non‐related (=invader) helper (these birds helped defend territory but did not help feed young; they were not related to the breeding pair and usually originated from outside the group).

Breeding males had larger testes and higher levels of testosterone than either related helpers or invader helpers. In females, all status groups had follicles up to 2 mm in diameter, but only breeding females ovulated. There were no differences in plasma levels of reproductive hormones among different status females, except for higher circulating luteinizing hormone (LH) in invader female helpers during the first part of the breeding season. Although plasma levels of testosterone were highest in breeding males, the maximum titres were two orders of magnitude less than in males of passerine species from temperate regions. Furthermore, injections of a peptide hormone GnRH (gonadotropin‐releasing hormone) increased plasma LH levels in both males and females, and were followed by rises in testosterone levels only in males, but not over the normal maximum seen in February. GnRH‐induced high levels of LH did not affect testosterone concentrations in the blood of females.

Results obtained thus far indicate that the hormonal control of aggression in white‐browed sparrow weavers is different from that predicted by investigations on north temperate species. Whether these phenomena are typical of tropical species, particularly cooperative breeders, remains to be determined. Since most of the world's species of birds live in the tropics, and a substantial fraction of them breed cooperatively, more investigations are needed to establish the hormonal basis of reproductive behaviour and cooperative breeding. Given the baseline data already collected, the white‐browed sparrow weaver will be a useful model.
The development of vocalizations in Pipistrellus pipistrellus (Chiroptera: Vespertilionidae) during post‐natal growth and the maintenance of individual vocal signatures
Authors: Jones G. , Hughes P. M. , Rayner J. M. V.
Published: March 2009

The development of vocalizations during post‐natal growth in the microchiropteran bat Pipistrellus pipistrellus is described. Vocalizations served as precursors of echolocation sounds and as isolation calls used to attract mothers. Although calls judged to be echolocation precursors tended to be of short duration and possessed high rates of frequency modulation when compared with isolation calls, a wide spectrum of intermediate calls existed making classification diffuse. Changes in the frequencies and durations of calls during growth are described. Multiple discriminant analysis showed considerable inter‐individual variation in isolation calls, while the calls of any individual were remarkably consistent in their structure at both six days and 15 days of age. The relative importance of acoustic call parameters in contributing towards inter‐individual variation changed between six days and 15 days. Vocal signatures of youngsters were probably important in allowing a mother to identify her own offspring in a creche thus preventing misdirected maternal care in this species, though vocal signatures of infants changed during development. Echolocation calls of flying juveniles were compared with calls from their mothers.
Growth, weaning and maternal investment from a comparative perspective
Authors: Lee P. C. , Majluf P. , Gordon I. J.
Published: March 2009

The process of weaning is related to a critical or threshold body weight attained by offspring among large‐bodied mammals; the anthropoid primates, ungulates and pinnipeds. While weaning weight was allometrically related to maternal weight in interspecific comparisons, it was isometrically related to neonatal weight. When a neonate had grown to four times its birth weight, it was weaned. Differences between taxonomic groups were found only among the fasting phocids, where weanlings attained a lower, but proportional, weight. The duration of lactation was only weakly allometrically related to maternal or neonatal weight, and varied between individuals intraspecifically as a function of maternal condition. The time to weaning appears to be ecologically sensitive rather than to reflect interspecific life‐history variation, in that, irrespective of the time to weaning, similar proportional weights appear to be attained. Interspecific similarities in threshold weaning weights are suggested to result from constraints on maternal abilities to meet energetic requirements of offspring through lactation after infants attain a threshold weight.
Diving patterns and performance in the Antarctic blue‐eyed shag Phalacrocorax atriceps
Authors: Croxall J. P. , Naito Y. , Kato A. , Rothery P. , Briggs D. R.
Published: March 2009

The pattern and characteristics of diving of two male blue‐eyed shags Phalacrocorax atriceps were studied, using continuous‐recording time‐depth recorders, for a total of 15 consecutive days during which the depth, duration, bottom time, ascent and descent rates and surface intervals of 674 dives were recorded. Deep dives (> 35 m, averages80–90 m, max. 116 m) were twice as common (64% versus 34%) as shallow dives (< 21 m and 90% < 10 m). Deep dives were long (averages 2.7‐4.1 min, max. 5.2 min) with half the time spent near maximum depth and fast travel speeds (averages 1.0‐2.4 m s−1). Shallow dives were short (average 0.5 min, max. 1.3 min), without bottom time and with slow travel speeds (0.1–0.6 m s−1). The time spent at depth and the diet (mainly benthic fish and octopus) is consistent with benthic foraging; the function of shallow dives is uncertain. Male shags forage mainly in the afternoon in3–5 distinct bouts of diving. Within bouts (and shorter homogeneous sequences of diving) surface intervals are consistently2–3 times the preceding dive duration; in other shags the reverse is the case. Blue‐eyed shag diving depth, duration and pattern is extreme amongst shags; and the relationship between dives and surface intervals suggests that they may regularly exceed their aerobic dive limit.
Activity and weight loss in relation to solar radiation in the polymorphic land snail Cepaea nemoralis
Authors: Chang Hsueh‐Wen
Published: March 2009

Shell spectral reflectance, activity and weight loss in the land snail Cepaea nemoralis were examined to test whether solar radiation has different effects on the behavioural and physiological responses of different morphs. A uniform area from the empty shells of different morphs was cut and a spectrophotometer was used to measure the spectral reflectance at wavelengths from 220 nm to 800 nm. Snails were put into cages made of mesh hardware cloth, and their activities were observed from dawn onwards on two hot, dry days. Weight loss of snails under shade and under direct sunlight was also measured.

The results show that unbanded morphs reflect more light than five‐banded ones, but the yellow morphs reflect only a little more than pink morphs. Five‐banded morphs became inactive more quickly than unbanded ones from dawn onwards, but the differences in activity patterns were not significant between pink and yellow morphs. There are significant differences in percent weight loss between snails placed under direct sunlight and under shade. The weight loss of different morphs under shade was not statistically different. But when exposed to sunlight, five‐banded morphs lost more weight than pink and yellow unbanded morphs.

Because of their lower reflectance of solar radiation, the five‐banded morphs are, in a hot, arid climate, at a selective disadvantage compared to unbanded morphs. However, they can avoid such selective disadvantage by actively seeking a shaded area, as all other morphs do in the field. Such behavioural habitat selection could help the maintenance of genetic polymorphisms in natural populations.
Effects of tannins on digestion in the common ringtail possum (Pseudocheirus peregrinus), a specialized marsupial folivore
Authors: McArthur Clare , Sanson G. D.
Published: March 2009

Digestibility trials using common ringtail possums (Pseudocheirus peregrinus), small folivorous marsupials, were used to determine effects of tannins on a herbivore which has a specialized hind gut and which normally consumes tannin‐rich eucalypt leaves. In one group, untreated leaves were fed to possums, and in a second group polyethylene glycol (PEG) was added to the eucalypt leaves to inactivate tannins. Animals maintained weight, and intakes were not different between the two dietary groups. Digestibility was determined chemically. Digesta were examined histologically. The presence of bacterial rafts in the stomachs of possums fed either diet indicated that PEG did not alter the coprophagic behaviour of possums. Cell wall digestion did not appear to be inhibited by tannins. Tanning of cell contents was predominant, rather than tanning of cell walls. PEG increased faecal excretion of tannins, suggesting that some tannins from normal leaves were digested during gut passage. Dry matter digestibility was higher when animals were fed normal tannin‐rich leaves than when they were fed leaves in which tannins were inactivated. The difference could be explained in part by the high digestibility of tannins. The presence of tannin did not reduce nitrogen digestion. We suggest that dissociation of tannin‐protein complexes may take place in the specialized caecum. We propose that some other folivorous marsupials may have a similar capacity to overcome tannins. This capacity may allow them to consume a tannin‐rich diet.
Carnivore olfactory bulb size: allometry, phylogeny and ecology
Authors: Gittleman John L.
Published: March 2009

Olfactory bulb size was measured in 146 species of Carnivora in order to examine whether recently observed functional patterns for overall brain size were similar for component parts of the brain. Comparative measures were analysed in relation to various allometric characters (body, brain and skull size), phylogeny, behaviour and ecology. Olfactory bulbs are significantly and positively correlated with all allometric variables, but indices of skull size correlate slightly more closely than other variables. This probably relates to functional aspects of skull size, facial proportions, and anterior elements of the brain. Phylogenetic associations were examined by two comparative methods: the method of independent contrasts and phylogenetic autoregression. Both revealed similar phylogenetic correlation at generic and familial levels. Using calculated values from either method, relative olfactory bulb size only correlates with zonation among seven behavioural and ecological variables; aquatic otters have smaller bulb sizes than carnivores of other zonal types. This agrees with discussion about the diminution of olfactory communication in aquatic environments. Also, olfactory bulb size correlates with home range size, which is consistent with a recent model on the use of olfaction for foraging in designated home ranges. Generally, comparative differences in olfactory bulb size in carnivores do not associate with functional variables found in other comparative studies. Nevertheless, future analyses of specific brain components in mammals may be more useful than overall brain size for testing evolutionary hypotheses of mammalian brain size.
Mountain reedbuck Redunca fulorufula growth and age determination using dentition
Authors: Norton P. M. , Fairall N.
Published: March 2009

Lower jaws and measurements were obtained from 473 mountain reedbuck Redunca fulvorufula culled on two reserves in the north‐eastern karoo of South Africa. All mandibles were allocated to subjective age classes that were based on tooth‐eruption and tooth‐wear. In a sample of 69 jaws. the molar and premolar cementum annuli were counted by examining bisected whole teeth under reflected light. One light line appeared to have been deposited per year, and a usable relationship between tooth‐wear category and cementum line count was obtained. although indistinct and paired lines often confused the picture. Good correlations were also obtained between the number of cementum lines and the crown height of the first molar (r2= 0.68) and the second molar (r2= 0.77). Actual ages of immatures were estimated by comparing peaks in the distribution in the different age classes with the age since expected mean birth date in different culls. The age of transition to adult dentition (pL 30 months) was determined from two females that were earmarked when young and shot two years later. Von Bertalanffy (1957) growth curves were fitted to measurements of body mass, jaw length and horn length in males to aid field identification of immatures. Asymptotic body mass was reached at 30 months in females and 40 months in males, and asymptotic jaw length was reached at 30 months in both sexes. Horns in males only reached full length at about five years.
Craniometrical analysis of Bulgarian wild boar (Sus scrofa) populations
Authors: Genov P. , Nikolovg H. , Massei G. , Gerasimov S.
Published: March 2009

Skull characters of wild boars (Sus scrofa L.) from four regions of Bulgaria were compared using stepwise discriminant, cluster of cases and principal component analyses (PCA). Classification functions were derived for discriminating individuals from different areas. Specimens from the north‐eastern part of the country (Dobrudja and the Balkan Range) were found well separated from those from the south (Rila‐Rhodopes & Strandja Mountains). PCA showed the differences being mostly related to the size rather than to the shape of both the cranium and the mandible. Natural migrations, intergradation areas between different subspecies, as well as restocking and hybridization with semi‐domestic pigs are discussed as possible factors influencing the solution of the problem of the intraspecific systematics of the wild boar in Bulgaria.
Albumin evolution in West Indian frogs of the genus Eleutherodactylus (Leptodactylidae): Caribbean biogeography and a calibration of the albumin immunological clock
Authors: Hass Carla A. , Hedges S. Blair
Published: March 2009

Antisera to serum albumins from five West Indian species of the frog genus Eleutheroductylus were prepared, and the reciprocal immunological distances (IDs) obtained were used to provide a time frame for the evolution of this group in the West Indies. One‐way IDS were obtained to 25 additional species within the genus, with emphasis on those from the West Indies. These immunological data support both a recent classification of Eleutheroductylus based on an analysis of slow‐evolving allozyme loci, and the monophyly of the 17 native Jamaican species as indicated by a more comprehensive electrophoretic study. This is in contrast to the results of morphological studies supporting multiple invasions of Jamaica by Eleutherodactylus. Within the subgenus Euhyas, IDS ranged from6–27 between Jamaican species, whereas between species on different islands the range was29–67. The subgenus Syrrhophus in southern North America was found to be the sister group to the subgenus Euhyus, a western Caribbean clade. Pelorius, a subgenus restricted to Hispaniola, was found to be the sister group of the subgenus Eleutheroductylus in the West Indies. The largest IDs obtained for West Indian species were those between the two major groups, the subgenera Eleutheroductylus and Euhyas.

The albumin immunological clock for Eleutheroductylus was calibrated with three events in the geologic history of the Caribbean: the breakup of the proto‐Antilles (65‐75 million years before present [mybp]), the emergence of Jamaica (20‐30 mybp), and the uplift of the Blue Mountains in Jamaica (5‐10 mybp). Immunological distances corresponding to those events yield a calibration of 1 ID=0.60 million years (my), the same as that previously obtained for other groups of amphibians and thus supports the use of albumin immunological distance as a molecular chronometer in the genus Eleutherodactylus
Utilization of habitat by the northern hairy‐nosed wombat Lasiorhinus krefftii
Authors: Johnson C. N.
Published: March 2009

The small population of northern hairy‐nosed wombats in Epping Forest National Park is the last one known. The wombats construct their burrows in deep sandy soil, and feed through an open woodland with a grassy understorey. Individual wombats used small home ranges, with 70% core areas averaging 5.8 ha, and total range areas averaging around 25 ha. Their nightly emergences from burrows were timed to avoid extreme above‐ground temperatures. Total activity varied from 2 to 6 hours above ground per night, and was greatest during late winter and early spring, when pasture productivity had been very low for around nine months. There was no evidence of any tendency for body condition or growth to fluctuate in response to variations in seasonal conditions. The ability of this species to maintain condition during harsh seasons while adopting conservative ranging behaviour is evidence of adaptations for the minimization of energy expenditure and the utilization of poor‐quality forage. Management of the Park should attempt to see that consistent reserves of forage are maintained close to burrows throughout the year.
Social status in female bighorn sheep (Ovis canadensis): expression, development and reproductive correlates
Authors: Hass Christine C.
Published: March 2009

Female bighorn sheep were studied over a 27‐month period to quantify linearity and stability of social rank; expression of behaviour as a function of rank; development of rank relationships; and reproductive correlates of rank. Females exhibited a stable, non‐linear hierarchy that correlated strongly with age. Dominant females used proportionally more threats, whereas subordinates used more subordinance patterns. Females integrated into the hierarchy at1–2 years of age and then fought their way to high social status. Dominant and subordinate females did not differ in pre‐natal maternal investment, but dominant females nursed lambs at higher rates, and were more likely than subordinates to nurse alien lambs after their own lamb died.
Evolution and biogeography of West Indian Sphaerodactylus (Sauria: Gekkonidae): a molecular approach
Authors: Hass CarlaAnn
Published: March 2009

This study investigated the phylogenetic relationships and biogeographic history of West Indian geckos belonging to the genus Sphaerodactylus through an analysis of protein variation. Two techniques were used: sequential starch gel electrophoresis of 15 slow‐evolving loci and microcomplement fixation of albumin. The relationships obtained were used to revise the classification of this genus. Two major groups (subsections) occur in the West Indies. The sputator subsection, centred in the Greater Antilles, is composed of three series: cinereus, sputator and argus. The fantasticus subsection, restricted to the Lesser Antilles, includes only the fantasticus series.

Three antibodies (argus, asterulus and copei) were used to investigate albumin evolution and estimate times of divergence within Sphaerodactylus. Using the albumin clock calibration derived from other groups, the West Indian Sphaerodactylus had diverged from other sphaerodactylines by approximately 27 million years before present (mybp). Therefore, fragmentation of the Proto‐Antilles (60 mybp) apparently did not play a role in the group's evolution. The present distribution of West Indian Sphaerodactylus resulted from dispersal. Hispaniola probably was the centre of Sphaerodactylus diversity and the source of colonists for other islands. Certain features of Sphaerodactylus ecology and physiology make them likely candidates for dispersal. In contrast to the West Indian species of Anolis and Eleutherodactylus, few exampies of morphological convergence are found in Sphaerodactylus. Allopatric speciation, perhaps due to climatic changes in the Pliocene and Pleistocene, is suggested as the primary mechanism of species formation in West Indian Sphaerodactylus.
Meeting the energy requirements for lactation in a macropodid marsupial: current nutrition versus stored body reserves
Authors: Cork S. J.
Published: March 2009

Food intake and digestion were investigated at four stages in the first 218 days of lactation in tammar wallabies (Macropus eugenii) carrying litters of one, and in non‐lactating females as a control. This period of lactation in tammars, which includes the phase of exponential growth of the young, is comparable to gestation plus early lactation in ruminant placentals. Food and energy intakes by mothers remained at the non‐lactating level while rate of growth of young was slow (up to Day 105 of lactation) but then rose as the growth rate of young increased, keeping pace with the predicted requirements for milk synthesis and export. There was no indication of the energy deficit seen in late gestation and early lactation in many herbivorous placental mammals. The gross efficiency of utilization of ME for growth of offspring was estimated as 13–15%, which is at least as high as values for placentals during gestation. The mean intake of metabolizable energy (ME) at 218 days was 603 kJ.kg‐0.75.d‐1, which represented 136% of ME intake by nonlactating females, or an increment of 159 kJ.kg‐0.75.d‐1. It was estimated that ME intake may rise to 773 kJ.kg‐0.75.d‐1 at peak lactation, which would be 174% of the non‐lactating level or an increment of 329 kJ.kg‐0.75. d‐1. This allometrically‐scaled increment is similar to values for some ruminants that use body reserves extensively to offset peak lactational food requirements. These and previously‐reported trends suggest that ecologically comparable herbivorous marsupials and placentals utilize different physiological strategies to minimize demands on food resources during reproduction, but that both daily and overall demands can be similar.
Development of the middle ear region in Monodelphis domestica (Marsupialia, Didelphidae): marsupial solutions to an early birth
Authors: Filan Susan L.
Published: March 2009

Middle ear ontogeny in Monodelphis domestica is investigated to understand better both the immediate consequences for suckling in a neonate marsupial and the epigenetic factors that constrain morphogenesis. Neonates of Monodelphis possess neither mammalian (dentarysquamosal) nor reptilian (quadrate‐articular) jaw articulations, nor does the contact between the incus and crista parotica offer a joint surface (contra Maier, 1987). Elasticity in Meckel's cartilage allows minimal deflection of the lower jaw. Observation of the developmental rate of the individual elements reveals that mandibular arch derivatives (malleus, incus and tensor tympani) are on a slightly faster ontogenetic schedule than hyoid arch derivatives (stapes and m. stapedius).
Variability and phylogenetic significance of detachable nodes in feathers of tinamous, galliforms and turacos
Authors: Brom Tim G.
Published: March 2009

The occurrence of detachable nodal structures in the downy barbules of many birds was studied with light‐ and scanning electron microscopy. Anuli are the only type of nodal structure that may break loose and slide along the barbules to form dual or multiple nodes. Considerable variation exists in the occurrence of this feature. Multiple nodes are more frequently present in tail‐coverts than in breast feathers. This is the first report of the presence of detachable anuli in feathers of Cracidae, Numididae and Musophagidae. The suggestion by earlier workers that these structures are characteristic for all galliforms is not confirmed, since megapodes never show detached nodes. The downy barbules of Afropavo resemble those of other phasianids in all respects, while those of Opisthocomus are strikingly different from both galliforms and cuckoos. Outgroup comparison indicates that multiple nodes may be synapomorphic for Tinamidae, Cracidae, Tetraonidae, Phasianidae, Numididae, Meleagridae and Musophagidae together, but, considering the incongruence of this hypothesis with recently proposed phylogenies, alternative explanations for the structural similarities between the downy barbules of tinamous, turacos and galliforms are discussed.
Dispersal and social organization of the northern hairy‐nosed wombat Lasiorhinus krefftii
Authors: Johnson C. N. , Crossman D. G.
Published: March 2009

Burrows of the northern hairy‐nosed wombat were arranged in loose clusters, each of which was used in common by a group of up to 10 wombats. However, individual wombats rarely used the same burrows on the same days and feeding ranges tended to be separate within each sex. The incidence of breeding dispersal among females was quite high (at least 50%); dispersal distances ranged up to almost the full extent of the population's range. Dispersal by adult males was rare, and no juvenile males were observed to disperse.
Directional asymmetry in reptiles (Sauria: Gekkonidae: Ptyodactylus) and its possible evolutionary role, with implications for biometrical methodology
Authors: Werner Y. L. , Rothenstein D. , Sivan N.
Published: March 2009

In a study of morphological directional asymmetry (DA) on the population level, four characters were bilaterally examined in geckos (museum specimens, total n Ptyodactylus puiseuxi, P. guttatus and P. hasselquistii, from Israel and Sinai. Significant DA occurred in adults in five or six out of 12 character‐taxon‐combinations (CTCs): number of supralabilia in P. puiseuxi and guttatus, length of ear aperture in puiseuxi and hasselquistii; number of subdigital lamellae in guttatus; and width of the digital pad in hasselquistii. The average magnitude of DA per CTC ranged from 1.5 to 5% of organ size, without correlation to organ size. Side dominance varied, mostly witin characters between taxa. No sexual differences in DA were significant, although for two CTCs DA was significant only in one sex. Presumably neutral or pleiotropically‐adaptive DA is a potential base for the evolution of functional DA. One practical conclusion is that in comparative biometrical studies, bilateral characters should not be examined consistently on only one side.
Body composition and reproduction in mountain hares (Lepus timidus scoticus) in north‐east Scotland
Authors: Merwe M. Van der , Racey P. A.
Published: March 2009

Mountain hares in north‐east Scotland are pregnant from Mid‐February to mid‐July, although breeding is at a peak from April to June when all adult females are either pregnant or lactating or both. The onset of reproduction coincides with the highest body fat composition and the end of the breeding season coincides with the greatest depletion of body fat.
Life history and distribution of the small south‐western Atlantic octopus, Octopus tehuelchus
Authors: Iribarne O. O.
Published: March 2009

Although this species has been reported from shallow waters down to 90 m depth, knowledge is almost entirely based on intertidal samples. In this study both intertidal and subtidal samples were taken during 1982–1987, in northern San Matias Gulf (41° S, 63° 30′ W). This is a large‐egged (eggs: 9–12 mm long ×–5 mm wide, stack of 4–6 mm long) and small‐sized (up to 150 g) octopus. Egg laying occurs between autumn and winter. Embryonic development takes about four months (water temperature:–19°C). Large hatchlings (DML: 5·64 mm, TL: 14·23 mm, TW: 0·139 g) emerge over spring and early summer, and development is direct. Maximum size is reached after 17–18 months; mating takes place in summer. Females reduce their feeding activity when they reach maturity, and cease eating while brooding. Mean life‐span is two years, but some individuals (mostly females) may live up to three years. Females approaching the beginning of the brooding period move to the subtidal zone, where males outnumber females until the end of summer and females (mostly brooders) then outnumber males. In the intertidal zone sex ratio was 1:1 from December to late March, but in April males outnumber females.

These life‐history traits are compared with those of other large‐egged octopuses and are discussed in relation to environmental conditions prevailing in the San Matias Gulf.
The arrangement of the heart chambers and associated blood vessels in the Devonian osteostracan Norselaspis glacialis. A reinterpretation based on recent studies of the circulatory system in lampreys
Authors: Janvier P. , Percy Lord Richard , Potter I. C.
Published: March 2009

A brief account is given of the different arrangements of the heart and associated blood vessels of ammocoetes and adult lampreys, the significance of the oesophageal suspension in ammocoetes and the structure of the rigid cartilaginous pericardium which is developed during lamprey metamorphosis. These accounts have then been used, in conjunction with the size, shape and position of the apertures and recesses of the ossified pericardial capsule of the Devonian osteostracan Norselaspis glacialis, to reinterpret the way in which the heart chambers were arranged within this fossil agnathan and to elucidate the vessels responsible for returning blood to its heart. The dorsal aorta of osteostracans undergoes a similar right‐hand curve just behind the postbranchial wall to that exhibited by the dorsal aorta of larval lampreys. This indicates that the dorsal aorta of N. glacialis was likewise shifted to the right by vertical strands of connective tissue which suspend the oesophagus from the under surface of the notochord and between two ducts of Cuvier and the heart. The size and shape of apertures and recesses in the pericardial cavity of Norselaspis glacialis supports the view that, in this osteostracan, two ducts of Cuvier entered the pericardial cavity through a dorsal opening on the posterior part of the capsule and then joined with the sinus venosus. The marginal sinuses/veins in the anterior part of the body of N. glacialis, from which blood passed horizontally into the respective ducts of Cuvier, are now regarded as homologues of the anterior cardinal veins. While there is evidence that, as in ammocoetes, the right duct of Cuvier was larger than the left duct in N. glacialis, the relative size and position of its proposed atrium and ventricle was apparently more like that of adult lampreys. Despite differences in the mode of formation of the ossified pericardium of osteostracans and the cartilagenous pericardium of adult lampreys, these structures presumably had a similar function. This would involve generating negative pressure within the pericardial chamber during ventricular systole, thereby aiding atrial diastole and thus the influx of blood into the heart from the main venous vessels, such as the inferior jugular vein(s) and the ducts of Cuvier. The inner side of the pericardial capsule of osteostracans, like that of adult lampreys, appears to have possessed an extensive vascular network which could thus have likewise played an important role in providing fluid for lubricating the surface of the heart.
Prey‐capture techniques and prey preferences of Corythalia canosa and Pystira orbiculata, ant‐eating jumping spiders (Araneae, Salticidae)
Authors: Jackson R. R. , Olphen A. Van
Published: March 2009

Corythalia canosa from Florida is an unusual salticid because it is known to eat ants. This species' specialized behaviour for catching ants is described in detail for the first time and compared to its behaviour for catching other insects. Pystira orbiculata from Queensland is shown to be another ant‐eating salticid, although its behaviour for catching ants seems less specialized than that of C. canosa. Three different types of tests of prey preference were carried out. In each type of test C. canosa and P. orbiculata took ants in preference to other insects. Another species of salticid, Trite planiceps from New Zealand, failed to eat ants in these tests, although T. planiceps often attacked then released the ants. Corythalia canosa's and P. orbiculata's preference for ants, and their prey‐specific predatory behaviour for catching ants, are shown not to depend on prior experience with ants.
Plumage colour and feather structure of the bearded vulture (Gypaetus barbatus)
Authors: Brown C. J. , Bruton A. G.
Published: March 2009

The rufous colouring on the feathers of the under parts of adult bearded vultures Gypaetus barbatus, studied by scanning electron microscopy, energy‐dispersive X‐ray microanalysis and X‐ray diffraction analysis, is caused by an external deposit of iron oxide in the ferrihydrite state. Unstained feathers, e.g. in captive birds, are pure white. The feathers of young birds have similar coatings of iron oxide to those of adults, but because the feathers are pigmented pale to dark brown (dependent on age), the rusty colour is partly or totally obscured. The intensity of the colour in adult birds varies between individuals and within individuals with time; the more worn the feathers the more iron oxide they can hold. After heavy rainfall up to 30% of adult birds can become appreciably paler. Birds take about 6 days (range–9 days) to regain normal colouring. Iron oxide accumulates mainly in the axes of shafts and barbs, barbs and barbules and barbules and hamuli, and forms blob‐like deposits at the ends of barbs and barbules on the outer layers of feathers. Iron oxide is probably acquired passively when bearded vultures come into contact with deposits in caves and on ledges on cliffs. The colour is then spread by preening. Iron oxide imparts camouflage to adult birds, but also reduces wear on the outer layer of feathers, makes feathers more rigid and probably helps control ectoparasites.
Seasonal variation in the diet of common seals (Phoca vitulina) in the Moray Firth area of Scotland
Authors: Pierce G. J. , Thompson P. M. , Miller A. , Diack J. S. W. , Miller D. , Boyle P. R.
Published: March 2009

Seasonal variation in the diet of common seals (Phoca vitulina) in the Moray Firth, north‐east Scotland, was determined from analysis of faecal samples collected at haul‐out sites during each month of 1988. Data on diet of common seals in 1987 are also presented. Limitations of the methods available for quantification of diet are discussed. Although some of the observed variation in diet from month to month may reflect changes in the sampling regime, a clear seasonal pattern was apparent, with clupeids predominating in the winter and sandeels in the summer. The trends observed are consistent with opportunistic feeding on the most abundant Prey.
The water relations of Lithobius forficatus and the role of the coxal organs (Myriapoda: Chilopoda)
Authors: Littlewood Henk
Published: March 2009

The water relations of the common brown centipede, Lithobius forficatus (L.), are examined with regard to the possible involvement of the coxal organs in water uptake. Centipedes with blocked and open coxal pores are subjected to a variety of dehydration and rehydration regimes and weight change over time measured. Weight loss and regain is related to body surface area and is not influenced by the coxal organs.

The conclusion of the paper is that the coxal organs of L. forficatus do not contribute significantly to the ability of these animals to recover water lost through cuticular transpiration.
Diet and behaviour of a nocturnal lemur, Avahi laniger, in the wild
Authors: Harcourt Caroline
Published: March 2009

Observations were made on the diet, activity patterns, social organization, ranging and vocalizations of Avahi laniger laniger, a nocturnal prosimian, in rain forest in eastern Madagascar. A male woolly lemur was radio‐collared for a period of one month and most data were collected from follows of this individual. During this time, all observed feeding was on leaves and only leaves were found in faecal samples. Resting and grooming occupied almost 65% of each night and this inactivity is probably related to the low quality diet. Avahi were most commonly seen in pairs; the radio‐collared male almost always slept with a single female and he spent 40% of the night with her. An infant was born to the study pair in August. Range size was 1·4 ha and this appeared to be used exclusively by the male and his female. Avahi seems to be a very unusual primate; neither folivory nor monogamy is common among the nocturnal prosimians.
Home range and movements of the Namib Desert golden mole, Eremitalpa granti namibensis (Chrysochloridae)
Authors: Fielden L. J.
Published: March 2009

Eremitalpa granti namibensis is a small, blind, subterranean insectivore endemic to the Namib desert sand dunes. Unlike most other subterranean mammals, E. g. namibensis lacks a permanent burrow system and is a surface forager. Population density and home range utilization were studied by following surface trails and capture, mark and recapture. Population density was low but stable and home range size large, a reflection of the low food availability in the Namib dune environment. No permanent nests or burrows were found while the pattern of home range utilization was nomadic but circumscribed. Home ranges overlapped with those of neighbouring animals.
A comparison of the effect of captivity on the epidermis of prespawning and postspawned winter flounder, Pseudopleuronectes americanus
Authors: Burton D. , Eurtond B. A.
Published: March 2009

The effect of captivity on the epidermis of Pseudopleuronectes americanus Walbaum is influenced by the phase of the reproductive cycle. Towards the end of the prespawning period captive male flounder had a higher GSI than flounder from the wild population, and the seasonal epidermal sexual dimorphism in these captive flounder was more pronounced. Flounder maintained in the laboratory during the postspawning period manifested a thick epidermis and increased mucigenesis in late summer, when these characteristics displayed seasonally low values in the inshore population from which the flounder were sampled. Possible regulatory factors and implications for protocols involving captive fish are discussed.