bluuebunny/crossref_metadata_2025 huggingface dataset:
Communally breeding skuas: breeding success of pairs, trios and groups of Catharacta lonnbergi on the Chatham Islands, New Zealand
Authors: HEMMINGS ALAN D.
Published: March 2009

One‐third of territories on South East Island are occupied by trios or groups of communally breeding skuas. Comparisons were made of the reproductive performance of pairs, trios and groups over three (and ten) seasons to assess whether any ‘advantage’–in terms of offspring production–could be demonstrated for communal breeding. Egg size was not significantly different between pairs and trios, or between years. There were no significant differences between the chicks of pairs, trios or groups in growth characteristics and chick condition appeared similarly good. Overall breeding success was generally lower for trios than for pairs. Although chick production per territory was not significantly different between pairs and trios, it was substantially lower on a per‐adult basis. The breeding success of this population is generally high compared to others studied, however, there is no evidence to suggest that skua communal breeding has advantages in terms of offspring production.
Maternal behaviour and neonatal development in three species of Namib Desert rodents
Authors: DEMPSTER EDITH R. , PERRIN M. R.
Published: March 2009

Gerhillurus paeba paeba, G. tytonis and Pelromyscus collinus inhabit arid areas of southern Africa. Several litters of each species were bred in the laboratory; aspects of maternal behaviour and development of neonates are reported. Pelromyscus collinus has a smaller litter size and the young are less altricial at birth than young of G. paeba or G. tytonis. Gerhillurus tytonis young have the slowest rate of physical and behavioural development, while P. collinus young develop most rapidly. Young of P. collinus nipple‐cling from birth, but those of G. paeba and G. tytonis do not. This dichotomy may be related to phylogeny, mode of locomotion, and/or nesting habits.
Grooming and resting of otters Lutra lutra in a marine habitat
Authors: NOLET B. A. , KRUUK H.
Published: March 2009

Daily activity of Eurasian otters (Lutra lutra) was recorded along the coast of Shetland, UK, in the summer of 1984. Data of three otters fitted with radio‐transmitters were analysed in detail. Compared to sea otters (Enhydra lutris), these otters spent up to 4.5 times less time per day hunting (12%), but devoted the same time per day to grooming (6%). Hunting bouts (mean 13.7 min) were interrupted by resting bouts (17.0 min) during which the otters groomed (9.1 min) and slept (6.6 min). The duration of the resting bout was significantly correlated (P < 0.05) with that of the preceding hunting bout. Also, the time spent grooming was correlated with the encountered underwjter pressure (P < 0.05). The functions of resting and grooming probably include reestablishing air in the fur and rapid recovery after diving; also avoiding encrustation of salt on the fur might be important.
Pre‐ and post‐natal development of pouched mice, Saccostomus campestris
Authors: AARDE LILIAN M. WESTLIN‐VAN
Published: March 2009

Pre‐ and post‐natal growth of the pouched mouse (Saccostomus campestris) were investigated and growth curves were calculated as described by Stevens (1951). Measured values of foetal weights put into Huggett & Widdas' equation (1951) revealed that the actual correction factor for species with a gestation period of 50 days or shorter was different from the one given by Huggett & Widdas. Therefore, the calculated value of specific growth velocity for pouched mice was lower than when using the correction factor given by Huggett & Widdas (1951).

Ninety percent of the asymptotic body weight was attained at an average age of 135.2 and 143.1 days for males and females, respectively, while 90% of the asymptotic body length was achieved when males and females were 71.9 and 69.3 days old, respectively. Post‐natal growth rates of females and males were not significantly different from each other, and the average rate of weight increase for male and female pouched mice was lower than for other rodents studied (see Case, 1978).

Ages at which tooth eruption, eye‐opening and eye usage occurred were also recorded.
Ecological structure of tropical fish assemblages in wet‐zone streams of Sri Lanka
Authors: WlKRAMANAYAKE E. D. , MOYLE P. B.
Published: March 2009

The introduction of four fish species into a depauperate stream system in central Sri Lanka provided a ‘natural experiment’ that enabled us to determine the ecological structure of wet‐zone stream fish assemblages. All the species indigenous to this ‘introduction’ stream system also co‐occur naturally with the introduced species in nearby streams. Analyses of habitat use and dietary requirements revealed that most species in the assemblages were segregated on the basis of macrohabitat, microhabitat and food, regardless of origin of the fishes. Macrohabitat and microhabitat utilizations by species were similar in each stream of the ‘introduction’ system despite differences in stream conditions. Thus species distributions, relative to each other in ecological space, were consistent among streams, and with the combined data. High overlaps along the resource axes of velocity, depth, substratum and food were few. A major proportion of the high overlaps was due to associations with introduced species; especially Barbus nigrofasciatus and Barbus cumingii. The other two introduced species, Barbus titteya and Rasbora vaterifloris, were more specialized, and interacted relatively less with indigenous species. The indigenous species, however, exhibited pronounced complementarity along three resource axes representing depth, velocity and food. Rasbora vaterifloris and B. nigrofasciatus grew to larger sizes in one stream which had fewer indigenous species, suggesting competitive release. In this stream, the most common indigenous species was a dietary specialist that fed on diatoms, and B. nigrofasciatus, which fed heavily on diatoms in other streams, switched to feeding more on macrophytes. Overall, the data suggest that these assemblages are predictable, co‐evolved systems with competition serving as an important structuring force that reinforces species segregation.
Spatial distribution and movements of elephants (Loxodonta africana) in the northern Namib Desert region of the Kaokoveld, South West Africa/Namibia
Authors: Viljoen P. J.
Published: March 2009

The home ranges, space‐use patterns, seasonal distribution, long‐distance movements, water‐related movements and movement patterns of elephants (Loxodonta africana) residing in the northern Namib Desert region of the Kaokoveld, South West Africa/Namibia, are discussed. All movements of the desert‐dwelling elephants, including occasional wanderings up to 195 km, were confined to the northern Namib Desert and no evidence could be found of any movements including migrations to and from the Etosha National Park. Home range size varied from 1763 to 2944 km2 and the main feature of the spatial distribution of these elephants is the marked fidelity to individual home ranges. Seasonal distribution and space‐use patterns within individual home ranges coincide with seasonal climatic changes and the corresponding changes in food and water availability. The elephant's normal movements and migrations were confined to individual home ranges and no mass population migrations took place. Their mobility and their ability to go up to four days without drinking water enabled them to utilize food sources up to 70 km away from waterholes and, together with their intimate knowledge about resource distribution within their home ranges, are regarded as key factors in their survival in the desert. The elephants' spatial distribution and movement patterns indicate a natural population segregation from other elephant populations in the Kaokoveld, clearly demarcating the desert‐dwelling elephants as a distinct population with their own movement patterns and geographic range.
Nutritional ecology of a browsing ruminant, the kudu (Tragelaphus strepsiceros), through the seasonal cycle
Authors: Owen‐Smith Norman , Cooper Susan M.
Published: March 2009

The activities and food selection of four hand‐reared kudus were recorded in a large fenced enclosure containing natural savanna vegetation in the Nylsvley Nature Reserve, South Africa. Leaves of selected species were analysed chemically for crude protein, fibre constituents, phosphorus, condensed tannin and total polyphenols. Available protein and metabolizable energy were estimated allowing for potential antinutritional effects of tannins.

Leaves of palatable deciduous woody plants and herbaceous forbs formed the main dietary constituents during the late wet season. Foliage from palatable evergreens and robust forbs were added to the diet during the dry season. Towards the end of the dry season unpalatable species of evergreens were eaten. At the start of the growing season new leaves of otherwise unpalatable woody species formed the staple food source, together with fruits of Strychnos spp. Correspondingly, protein and digestible dry matter concentrations in the diet declined to reach a low at the end of the dry season.

Total daily food intake increased to compensate for reduced dietary quality during the dry season, until little edible foliage remained. While the estimated daily intake of protein remained well above maintenance requirements, the estimated metabolizable energy intake fell below requirements during the late dry season. Phosphorus intake may have been submaintenance in the dry season. Nutritional balance was dependent on the availability of particular vegetation components to serve as nutritional stepping stones during crucial times of the year. These included forbs during the late wet season, palatable evergreens in the dry season, and Strychnos fruits plus early‐flushing woody plants during the dry season‐wet season transition.
The seasonal pattern and distribution of green turtle (Chelonia mydas) nesting activity on Aldabra Atoll, Indian Ocean
Authors: Seabrook Wendy
Published: March 2009

Green turtles nest all year round on Aldabra, but nesting activity was found to be concentrated during the monsoon season (late November‐April) rather than the dry season as previously reported. More trial nests and emergences were made during the dry season. This was considered to be the result of difficulties in nesting during this time of the year rather than to more females attempting to nest, because fewer nests were dug during this season. The number of beaches being used by the turtles has apparently increased but no clear reason could be provided for the varying levels of use of different beaches.
Feral cats (Felis catus) as predators of hatchling green turtles (Chelonia mydas)
Authors: Seabrook Wendy
Published: March 2009

In many parts of the world feral animals have been reported to have severe effects on marine turtle hatchling production. In this study, green turtle (Chelonia mydas) hatchlings were shown to be an important component of the diet of the feral cat (Felis catus) on Aldabra Atoll, Seychelles, and feral cat activity in the coastal areas was found to be concentrated on the beaches used most intensively by turtles for nesting. The impact of the feral cat's predation on green turtle recruitment could not be determined. However, despite cat predation, the size of the Aldabran green turtle nesting population has increased considerably since human exploitation ceased.
High incidence of malocclusion in an isolated population of the red fox (Vulpes vulpes) in the Netherlands
Authors: Bouwmeester J. , Mulder J. L. , Bree P. J. H. van
Published: March 2009

Out of 72 fox skulls (Vulpes vulpes L.) collected in the North Holland Dune Reserve (NHD) between 1979 and 1985, 12 (16.7%) skulls showed a pronounced protrusion of the maxillary incisors over the mandibular incisors. Comparison of dimensions of affected and normal skulls revealed that this protrusion was the effect of a shortening of the front part of the mandibles. The mode of inheritance of this aberration is thought to be under recessive monogenetic control. This was deduced from the family relations between individual foxes radio‐collared or earmarked during five years of ecological research, and from the clear bimodal distribution in mandible length. The high incidence of the aberration can be explained by the history of the fox population in the NHD. Before 1968 the NHD was not inhabited by foxes as a result of its ecological isolation. It is rumoured that in that year four cubs, probably from one litter, were set free. It is believed, therefore, that the present population has originated from a small and isolated gene pool. Compared to normal foxes, affected animals are likely to be at an ecological disadvantage. Hence it is expected that the incidence of the aberration will decline in the future, since the population density reached a stable maximum around 1982 and the selective forces against the aberration will presumably be stronger now than during the phase of rapid population growth.
Covariation between clutch size, egg weight and egg shape: comparative evidence for chelonians
Authors: Elgar M. A. , Heaphy L. J.
Published: March 2009

The variation in reproductive variables is documented both within and across species of chelonians. At both the generic and family levels, egg weight and clutch size show positive, significant correlations with adult carapace length. There is a negative correlation across both genera and families between clutch size and egg weight after removing the effects of body size, suggesting an evolutionary trade‐off between these two life‐history characteristics. However, the trade‐off is not complete, since clutch size is positively correlated with clutch weight after removing the effects of body size. Terrestrial species lay fewer and larger eggs for their size than freshwater or marine species, but this association is statistically confounded by the fact that chelonian families form ecological groups. There is no significant association between habitat and clutch weight after removing the effects of body size, nor between latitude and either egg weight or clutch size, but temperate species have a heavier clutch weight after removing the effects of body size. Larger species lay eggs that are more spherical, but after controlling for body size, egg shape is not associated with clutch size. The patterns of covariation between adult weight, egg weight and clutch size contrast with those reported for birds and mammals, and some reasons for these differences are discussed.
Seasonal and diel behaviour of radio‐tagged Clarias gariepinus in Lake Ngezi, Zimbabwe (Pisces: Clariidae)
Authors: Hocutt Charles H.
Published: March 2009

Seasonal and diel behaviour of six sharptooth catfish, Clarius gariepinus (Burchell), was monitored in Lake Ngezi, Zimbabwe, from May 1986 to February 1987. All specimens were equipped with surgically‐implanted radiotransmi tters, 48–49 mHz, after they were anaesthetized in 6 mg l‐1 quinaldine. This represented the first known use of this methodology in subSaharan Africa.

It was determined that C. gariepinus exhibited three movement patterns on a day‐to‐day basis: long‐distance movements ( 2200 m), moderate movements (c. 40–200 m) and local movements (<40 m). Major movements were not restricted to night‐time conditions, nor were inshore/offshore movements related to time of day. Seasonal activity peaks occurred in July/August 1986 and again in January 1987, with rate of swimming exceeding 470 m/h on some occasions. Home range of some individuals encompassed the entire lake (> 5 km2).
Ecology of Chondromorpha kelaarti (Diplopoda, Polydesmida)
Authors: Bhakat Somnath
Published: March 2009

Stadia 11‐VII and adults of Chondromorpha kelaarti (Humbert) can be separated by segment number, length, breadth and paired legs. Sexes are distinguished from stadium IV and the sex ratio vaned around SO%, though females were prevalent in May and June.

In females, a positive and significant correlation was found between number ofeggs present and body width at the 17th Segment.

Population density and biomass of C. kelaarti varied from 0.06 to 12.94 and 1.75 mg to 811.24 mg per 0.1 mz, respectively. From May to November, populations of C. kelaartiare aggregated in distribution.

Chondronrorphu keluurti passed the dry season in late stadia (VI, VII and adult) and may complete the life cycle in one or two years.
A possible energy‐saving role for the major fascia of the thigh in running quadrupedal mammals
Authors: Bennett M. B.
Published: March 2009

Experiments were performed to determine the mechanical importance of the fascia lata in stopping the hind limb during its rearward extension and reversing the direction of leg swing. Samples of fascia lata from a number of different mammals were subjected to tensile tests. Tangent Young's moduli reached about 0.5 GPa and stresses at failure about 50 MPa for fascia from each of the species examined. Energy losses incurred in a loading‐unloading cycle were generally about 20%. The moment arms of the fascia lata, in combination with its muscle, about the hip and knee joints were determined and the extension of the fascia lata while its muscle is active was estimated. Calculations suggest that the fascia lata could help to reverse the backward swing of the hind limb by recoiling elastically shortly after the foot leaves the ground. Substantial savings of internal kilnetic energy could be made.
Food utilization and niche overlap in three species of lake‐dwelling leeches (Hirudinea)
Authors: Young J. O. , Splelling S. M.
Published: March 2009

The diets of Erpobdella octoculata, Glosiphonia complanata and Helobdella stagnalis on the stony littoral zone of eutrophic Crose Mere were examined over two years using the precipitin test. The abundances of food organisms were measured. For all leech species, juvenile mortality was greatest in locations where a low ratio of prey abundance to recruited leech abundance occurred, and the intensity of feeding by Erpobdella and Helobdella fell slightly in late summer when large numbers of juveniles of these species were present; these suggest the involvement of food in juvenile mortality, Seasonal changes in feeding intensity were similar for all leech species, with the exceptions outlined above and for Glossiphonia in April when feeding by brooding adults ceased, at which time the severity of any interspecific competition would have been reduced. Within a leech species, there was little change in the food spectrum as the leeches grew. Niche breadth was lowest for Erpobdella and highest for Helobdella. Niche overlap was greatest between Glossiphonia and Helobdella, and there was a trend for overlap values to be lower between Glossiphonia and Erpobdellu than between Helohdellu and Erpohdellu. Erpobdella fed mainly on chironomids and oligochaetes, Glossiphonia on molluscs, oligochaetes and chironomids, and Helobdella on oligochaetes, chironomids, Asellus, molluses and amphipods, all in decreasing order of importance. It is suggested that coexistence in the leech species may be due in part to Erpobdella and Glossiphonia having ‘food refuges’ in chironomids and molluscs, respectively, with Helobdellu being more of a general predator.
Growth dynamics in the American alligator (Alligator mississippiensis)
Authors: Jacobsen T. , Kushlan J. A.
Published: March 2009

The growth dynamics of the American alligator (Alligator mississippiensis) were studied in the subtropical Florida Everglades using extensive mark‐recapture data from over 2000 recaptures of known‐aged and unknown‐aged animals. A model based on the power curve best describes growth of Everglades alligators. The nonasymptotic character of this curve leads to rejection of the hypothesis that alligator growth is determinate. A model consisting of piece‐wise linear equations better described growth in the first year, and suggested a period of arrested growth occurred in the first winter. A comparison of predictions from growth models derived from several populations indicated that Everglades alligators grew more slowly than did those in more temperate areas, leading to the rejection of the hypothesis that growth rates in subtropical Florida would be elevated because of the long growing season. We attribute this result to a combination of increased maintenance costs and a limited resource base in the Everglades.

Analyses considered the extent to which growth model evaluation and use can be affected by data selection. Mathematical constraints posed by negative growth data can be alleviated by including growth records over combined recapture intervals to achieve a positive growth increment. However, periods of no to negative growth may be real, and such deviations are obscured by fitting growth data to monotonically increasing models.
The effects of acid water and aluminium on the embryonic development of the common frog, Rana temporaria
Authors: Tyler‐Jones R. , Beattie R. C. , Aston R. J.
Published: March 2009

A decline in recent decades in the status of Rana temporaria in the British Isles has been attributed to a number of factors, mostly relating to increased urbanization. Acidification has recently been suggested as a factor which could affect R. temporaria populations in certain areas.

The effects of acid water and aluminium on the embryonic development of R. temporaria were investigated using eggs obtained by artificial fertilization from frogs caught in two widely separated areas; an upland area (acidic ponds) and a lowland area (circumneutral ponds). The eggs were kept in artificial soft water at either pH 4.5 or pH 6.0 and with aluminium concentrations covering the range measured in water from the acidic ponds.

The survival of embryos to normal free‐swimming larvae was not affected by water pH in the absence of aluminium. Increasing aluminium concentrations reduced the survival of lowland embryos in circumneutral water, but upland embryos were unaffected. However, in acidic water the survival of embryos from both areas decreased with increasing aluminium concentrations. Embryos which did not survive either died early in development, or developed gross abnormalities, or were constricted in the perivitelline membrane and failed to hatch. The body length of surviving larvae was decreased by both increasing aluminium concentrations and low pH, probably owing to a reduction in growth rate rather than development rate. The body length of larvae from upland ponds was decreased less than that of lowland larvae in acidic water, suggesting a greater acid tolerance in embryos from acidic ponds.

Reduced embryo survival, sublethal effects, such as reductions in embryonic growth rate, and indirect ecological effects may affect recruitment to the adult population in acid ponds. It is not possible to predict from the present data what effects these results of acidification may have on regional population because the acid tolerance of embryos varies widely within regions.
Spatial organization of a riparian population of the carnivorous marsupial Dasyurus geoffroii
Authors: Serena M. , Soderquist T. R.
Published: March 2009

Radiotracking and live‐trapping were used to describe spacing patterns of Dasyurus geoffroii along the Murray River in Western Australia. Both sexes are essentially solitary, and occupy numerous dens which define stable core areas. Female core areas typically showed little or no mutual overlap, suggesting that females are intrasexually territorial. As an exception to this, a non‐dispersing daughter may share her mother's core area and successfully rear young there. Transient females were rarely encountered, and vacant female core areas were eventually occupied by juveniles known to have been born on the study area. Male core areas were much larger than those of females, and overlapped broadly with those of other males as well as females. In captivity, females deposit scent by cloacal dragging in response to odours left by foreign conspecifics, and both sexes tend to defecate at sites already containing faeces. In the wild, faecal aggregations occurred throughout the areas used by Dasyurus, but were especially well developed in places where animal movements were likely to be concentrated, such as paths and river crossing points.
Lactation in the tammar wallaby (Macropus eugenii). I. Milk consumption and the algebraic description of the lactation curve
Authors: Dove H. , Cork S. J.
Published: March 2009

The milk intake of suckling tammar wallabies (Macropus eugenii) was estimated between 213 and 339 days of age using a double‐isotope procedure in which tritiated water (TOH) was injected into the dams and deuterium oxide (D2O) injected into the offspring. Recycling of isotopes between mothers and offspring was shown not to be a significant source of error. Estimates of body water (isotope dilution space) in the mothers or offspring, as a proportion of their body weight, were similar to values obtained with other macropodids and with placental mammals (0.73–0.75). Total water inflow in the offspring increased throughout the period, but the proportion of this contributed by milk fell in sigmoid fashion from 95.6% at 213 d to 3.7% at 340 d. Milk intakes reached a peak of about 86 ml/d, which was low compared with placental species. Before the peak, intakes were more closely related to body weight than age. Peak milk intake corresponded with the period of emergence from the pouch. Milk intakes were also in excellent agreement with published data obtained earlier in lactation, in animals drawn from the same population. These data were therefore combined to provide estimates of intake for the whole of lactation in the tammar wallaby, and algebraic models fitted to describe the pattern of milk intake in relation to body weight or age. With body weight, the pattern of milk intake was well described by a rising linear phase to a peak intake of about 86 ml/d near 1110 g body weight, followed by a gradual exponential decline. When related to age, the pattern was well described by a rising logistic phase (peak at 251 d) followed by a sharp exponential decline. It is shown that this latter pattern is markedly similar to the shape of the functions describing the energy requirements for the sum of pregnancy and lactation in a placental species, the sheep.
Lactation in the tammar wallaby (Macropus eugenii). II. Intake of milk components and maternal allocation of energy
Authors: Cork S. J. , Dove H.
Published: March 2009

The intake of milk components (total solids, carbohydrate, protein, lipid, energy) by suckling tammar wallabies (Macropus eugenii), from peak lactation to independence, was measured using a double‐isotope dilution technique and chemical analysis of milk samples. The time of peak intake of milk solids (day 256 of lactation or 1126 g of offspring weight) was similar to that for whole milk. Peak intake of carbohydrate occurred earlier than this (235 days) and peak intakes of protein and lipid occurred later (262 days and 266 days, respectively). Intake of gross energy peaked at 262 days and represented a maternal yield of about 207 KJ.Kg‐0.75.d‐1. This is much lower than peak lactational energy yields in most other mammals, but the duration of lactation is longer in tammars than in other mammals. Total output of energy in milk by tammar mothers was 63 MJ, and this would require an intake of about 98 MJ of metabolizable energy in food. This requirement, which is equivalent to 21 MJ/kg of maternal weight, is similar to those calculated for sheep and cattle, suggesting that there are not large differences between marsupial and placental herbivores in terms of weight‐related allocation of energy to reproduction. We suggest that a strategy of minimizing the peak energetic demand of lactation may be an important adaptation for a small, primarily grazing mammal due to size‐related physiological constraints on elevating herbage intake and the increasing risk from predators when grazing time is increased.
Development and maturation of plumage in the wandering albatross Diomedea exulans
Authors: Weimerskirch H. , Lequette B. , Jouventin P.
Published: March 2009

Changes in the plumage of the wandering albatross Diomedea exulans were studied on the Crozet Islands, using a population of birds of known sex and age and including some birds more than 32 years old. Plumage phases of a cross‐section of the male and female populations are presented. Males and females fledge with a dark brown plumage. Between the first and fourth year the male's plumage becomes much whiter than the female's. Between five and 15–18 years old the whitening of plumage in either sex develops in parallel though still separated by the extent of the initial divergence. Male plumage probably attains a definitive snowy stage after 30 years while the plumage of the female does not mature beyond an intermediate stage, which is reached after 20 to 25 years. Maturation of the plumage of head, back and wing are compared. In birds of similar age, breeding birds tend to have a whiter plumage than non‐breeders. In the oceanic range of the species, white birds, i.e. mostly adult males, favour cold antarctic waters while dark birds, i.e. mostly adult females and juveniles, are observed in warmer subtropical and subantarctic waters. We discuss the possible adaptive significance of the slow maturation in the plumage of the wandering albatross and of the differences in plumage between sexes and between populations.
Morphology, histology and histochemistry of the ventral buccal salivary glands of the Arabian camel (Camelus dromedarius)
Authors: Taib N. T. , Jarrar B. M.
Published: March 2009

Morphometric, histological and histochemical investigations were carried out on the ventral buccal salivary glands of the Arabian camel (Camelus dromedarius). The ventral part (inferior molar gland) is composed of serous acini with abundant myoepithelial cells and the dorsal part of the gland comprises mucoserous acini. The serous acini are devoid of any type of mucosubstances while the mucoserous cells of the dorsal part show neutral glycoproteins and sialomucins but neither glycogen nor sulfomucins. The histoenzymological tests employed have detected alkaline phosphatase, adenosine triphosphatase, succinic dehydrogenase, non‐specific esterases and α‐amylase but no activities for aminopeptidase, lipase, cholinesterases and β‐glucuronidase.
Growth in harbour seals (Phoca vitulina) on the Norwegian coast
Authors: Markussen N. H. , Bjørge A. , ØRitsland N. A.
Published: March 2009

The weight gain in lactating harbour seal pups and sex‐specific growth curves are described. The relationship between body length, body weight and age were derived by regression analysis based on length and age data from 365 seals, and weight values from 136 seals. The asymptotic values of the curves describing body length were 148.0 cm and 147.2 cm in females and 153.9 cm and 155.5 cm in males using Gompertz and von Bertalanffy, respectively. The corresponding body weight values were 72.8 kg and 76.7 kg in females and 90.7 kg and 88.4 kg in males.
Frugivory in Amazonian Artiodactyla: evidence for the evolution of the ruminant stomach
Authors: Bodmer Richard E.
Published: March 2009

Red and grey brocket deer and collared and white‐lipped peccary of the Peruvian Amazon are frugivores and consume many types of seeds. The ruminant stomach of brocket deer functions as a mechanism to digest the abundant hard palm seeds of Iriartea sp., Euterpe sp. and Mauritia flexuosa. The sympatric peccaries also consume hard palm seeds; however, peccaries crack these palms by using their strong jaws, thick skull bones and interlocking canines. The ruminant stomach might have evolved as a means to digest structural components of seeds, similar to that employed by extant brocket deer, since ancestral ruminants appear to have evolved as smallbodied, forest‐dwelling frugivores.
Functional morphology of the Conus proboscis (Mollusca: Gastropoda)
Authors: Greene Janet L. , Kohn A. J.
Published: March 2009

The extended proboscis of the toxoglossan gastropod Conus may exceed four times its contracted length and 1.5 times the shell length. The proboscis wall consists of cuboidal epidermis and circular, crossed helical and longitudinal muscle layers. Between the proboscis wall and its lumen, free longitudinal muscles and nerves course through haemocoel. A thick layer of connective tissue and columnar epithelium surround the proboscis lumen. In C. Catus, muscle comprises about 70% of the volume of the proboscis (exclusive of its lumen) and haemocoel about 20%, in both moderately extended and contracted states. Differentiation along the length of the proboscis includes gradual replacement of muscle by connective tissue distally in the proboscis wall, and a subapical sphincter muscle that probably prevents back‐slippage of the detached radular tooth prior to its use in feeding and aids injection of the tooth into the prey during capture.
Population dynamics of an outbreak of house mice (Mus domesticus) in the mallee wheatlands of Australia—hypothesis of plague formation
Authors: Singleton Grant R.
Published: March 2009

A plague of mice (Mus domesticus) in the Victorian mallee wheatlands of south‐eastern Australia in autumn 1984 appeared to be generated by a sequence of rainfall events: high autumn (March), mid winter and late winter rainfall in 1983, and high summer rainfall in 1983/84. The March rainfall in 1983 ended a drought; mice began to breed and bred until the end of May. Relatively high survival of mice for 12 months after March 1983, together with early onset of breeding and high reproductive performance throughout the 1983/84 breeding season, including summer, were key demographic processes during the formation of the plague. Temporal differences in mouse abundance and breeding performance between habitats highlighted the relevance of specific habitats to the dynamics of mouse populations in the wheatlands. Fencelines were the most important habitat of mice because they were foci for breeding at the start of the breeding season, good nesting sites which were rarely disturbed, and widespread and in close proximity to crops. Cereal crops were colonized in spring 1983 and in autumn 1984; they became important habitats in 1983 when mice dispersed and bred there in early spring. Redhead's (1988) model was sufficient to explain the 1984 plague, but not the magnitude of the decline of mouse numbers in 1984, nor the absence of a further outbreak in 1985. A new model is proposed based on a sequence of rainfall events beginning at least 10 months prior to a plague.
A scanning electron microscope study of the odontoids and teeth in Hemiphractus proboscideus (Anura: Hylidae)
Authors: Shaw J. P. , Ellis S. A.
Published: March 2009

In Hemiphractus proboscideus odontoids are found on the dentary, angular and palatine bones. The morphology of all odontoids is similar, although there are minor variations. They grow by appositional growth, probably quite slowly and possibly seasonally. The odontoids are produced as a result of increase in width of the lamellae near the surface of their supporting bone, and seem to be capable of repair after damage in vivo. The teeth on the premaxilla, maxilla and prevomer are strongly recurved and are composed of dentine covered over their apical one‐fifth by a thin layer of aprismatic enamel. The teeth are monocuspid but each possesses two small tubercles which are situated on the mesial and distal margins near the apex. The surface dentine is composed of longitudinal bundles of calcified fibres connected by horizontal interlocking fibres. During tooth replacement resorption bays are visible on the external and pulpal surfaces of the dentine.
Two new species of the genus Tyrophagus (Acari: Acaridae)
Authors: Lynch Corinne A.
Published: March 2009

Two new species of Tyrophagus Oudemans, 1924, are described. One species, T. Savasi, has been discovered in several habitats of economic importance. It closely resembles T putrescentiae (Schrank) and T. neiswander Johnston & Bruce. The second, T. rebertsonae, has so far been discovered in only two, soil and tree bark. It differs from other species of Tyrophagus by a number of character. Both new species have pigmented ‘eyespots’ on the prodorsal shield. A new character used to differentiate these species is the shape of the sclerotized neck of receptaculum semins.

The position of the new species in three commonly used keys to adults of the genus Tyrophagus is indicated
An experimental examination of the colour component in visually mediated sexual arousal of the male chacma baboon (Papio ursinus)
Authors: Bielert C. , Girolami L. , Jowell S.
Published: March 2009

Male chacma baboon (Papio ursinus) sexual arousal response as gauged by the coagulated seminal emissions resultant from masturbatory activity was experimentally assessed. Males were initially exposed to an ovariectomized female prior to and during daily oestradiol benzoate treatment. Males were then re‐exposed to the same female prior to and during the wearing of a thermoplastic model of a swollen female perineum. A total of eight different colours were sequentially applied to the model. It was only the red model that elicited a response similar to that shown to the oestradiol‐treated female. The behavioural data collected from the stimulus female supported the view that it was model colour that determined the differential male response.
Demography and habitat selection of small mammals on Zomba Plateau, Malawi
Authors: Happold D. C. D. , Happold M.
Published: March 2009

Small mammals were studied in tow montane grassland‐forest areas on Zomba Plateau (1900m), Malawi, in 1984–85. Seasonal changes in numbers, age‐structure and reproduction are given for the three commonest species. Mus triton (36%), Praomys delectorum (29%), and Lophuromys flavopunctatus (19%). Total population numbers for L. flavopunctatus and P. delectorum were lowest at the end of the dry season, and highest at the end of the wet season; reproduction is seasonal, and most young are born in the wet season. Mus triton did not exhibit such large fluctuations in numbers, and reproduced in both wet and early dry seasons. Each species was found in several habitats, but L. flavopunctatus showed a strong preference for unburnt grasslands, M. triton for burnt grasslands, and P. delectorum for forest and tangle habitats. Each species had a different population survival rate, and few individuals survived for more than 5–6 months. Trapped‐revealed home ranges were about 3100 m2 for L. flavopunctatus, and 2700 m2 for M. triton. Monthly changes in grass biomass, cover and height were recorded and related to the numbers of small mammals. General features of the small mammals of African mountains, based on data from the Drakensberg, Ethiopia and this study. are presented.
A new species of a phyllophorid holothurian from southern Africa
Authors: Thander Ahmed S.
Published: March 2009

A new species of a phyllophorid holothurian, Neothyonidium arthroprocessum, is described from the shallow waters of False Bay, South Africa. The new species is distinct from other phyllophorids in possessing peculiar narrow transverse slits in the body wall, a calcareous ring with joined posterior processes to the radial plates, and short thick perforated rods as body wall deposits. The diagnosis of the genus Neothyonidium is amended to accommodate the new species.
Social contraception in naked mole‐rats and marmoset monkeys
Authors: Abbott D. H. , Barrett J. , Faulkes C. G. , George L. M.
Published: March 2009

This review summarizes some of the recent advances in our understanding of the social suppression of reproduction. The subject is considered mainly at the physiological level in two mammalian species which display social suppression of reproduction to an extreme degree: the eusocial naked mole‐rat, Heterocephalus glaber, and the common marmoset monkey, Callithrix jacchus. Such complete social control of reproduction provides useful models to study basic neuroendocrine and physiological mechanisms involved in mammalian reproduction.
Tent selection, roosting ecology and social organization of the tent‐making bat, Ectophylla alba, in Costa Rica
Authors: Brooke Anne P.
Published: March 2009

Small groups of the tent‐making bat, Ectophylla alba, were found roosting in Heliconia (Musaceae) tents in old secondary‐growth forest in north‐eastern Costa Rica. The choice of specific Heliconia leaves for tents was predicted on the basis of leaf size and age. Additionally, tents in shrubs, saplings and epiphytic plants were found scattered throughout both primary‐ and secondary‐growth forest. Tents were used either as night feeding roosts or as day‐roosts for as long as 45 days. Groups of bats remained together when they moved to newly cut tents. After parturition, tent groups divided into all‐male colonies and maternity colonies with females, non‐volant young and a single adult male.
Skeletal biology and individual life history of Gombe chimpanzees
Authors: Zihlman Adrienne L. , Morbeck Mary Ellen , Goodall Jane
Published: March 2009

Skeletons of Gombe chimpanzees representing both sexes and ages from infancy to old age are examined in detail by a variety of techniques. The combination of biological and lifetime behavioural data presents an integrated view of individuals which make up a local population. These skeletons reflect species‐patterned growth, development and ageing. Furthermore, individual variation is related to lifetime experiences: for example, the impact of nutrition, injury and disease on survival and reproduction in the physical and psychosocial environments. Size, shape and internal structure of bones and teeth record life‐history features associated with both primary and secondary life‐history characters. These case studies emphasize the role of the individual in the evolutionary process.
Resistance to desiccation and distribution patterns in bush‐dwelling land snails
Authors: Arad Zeev
Published: March 2009

Bush‐dwelling land snails are exposed to desiccating conditions that are more severe than those of snails that seek the shelter of rock crevices, litter or the upper layers of the soil. We studied the resistance to desiccation in four bush‐dwelling species of Israeli snails to evaluate a possible relation between their water economy and their distribution pattern. The resistance to desiccation decreased in the following order: Xeropicta vestalis (a widely distributed Mediterranean species), Trochoidea simulata (a desert species), Theba pisana (a Mediterranean species from the sand dunes of the coastal plain), and Monacha haifaensis (a Mediterranean species). Xeropicta vestalis also had the quickest response to the desiccating conditions. It is probably prevented from establishing itself in the desert, in spite of its superior water economy, because it is an annual, semelparous species, and the desert is a highly unpredictable environment. An immediate response to desiccating conditions may be a key factor in the success of desert‐inhabiting land snails. Snails from more humid regions take several days to recruit their water preserving mechanisms, a delay which may be crucial to their water balance. The conchiometrics of X. vestalis and T. simulata suggest that the main water preserving mechanisms of these species are located in the mantle, rather than in the shell and epiphragm.
Female mate choice in the carpenter bee Xylocopa varipuncta (Hymenoptera: Anthophoridae)
Authors: Alcock J. , Johnson M. D.
Published: March 2009

Females of the carpenter bee Xylocopa (Neoxylocopa) varipuncta Patton exhibit highly active mate choice. During the spring in central Arizona, males of this species hover at shrubs and trees on or near ridgelines in late afternoons. Occasionally, females fly to and closely approach pheromone‐releasing males on their territories, but in 65 of 85 approaches the female left without copulating. Some females visited several males in a few minutes. Copulation only occurred when the female landed on a spot that the resident male rubbed with his body upon the female's arrival. Males did not attempt to disrupt courtship or copulation by other males. In 1988 one creosote bush proved especially attractive to males, as measured by the frequency with which the site was occupied simultaneously by more than one male. The majority of close approaches by females occurred in this one bush. Simultaneous occupation of hovering sites was very rare in 1989. In this year, there was a weak but significant correlation between the frequency with which different sites were visited by intruder males and by females. These results support the hypothesis that males are able to identify locations most likely to attract potential mates.
Hypertrophied phalangeal chondroepiphyses in the gekkonid lizard genus Phelsuma: their structure and relation to the adhesive mechanism
Authors: Russell A. P. , Bauer A. M.
Published: March 2009

The gekkonid genus Phelsuma is unique in possessing hypertrophied distal chondroepiphyses on the antepenultimate and penultimate phalanges of digits two to five of both manus and pes. These epiphyses have relationships with the adhesive systems of the digits which suggest that they play a role in enhancing the effectiveness of adhesion. It is suggested that the hypertrophied chondroepiphyses result from alterations in developmental timing and the suppression of the elaboration of secondary centres of ossification. They may be at least partially analogous to the intercalary elements of hylid and other frogs. The presence of hypertrophied chondroepiphyses in Phelsuma ocellata further strengthens the case that this species belongs to the genus Phelsuma and not to the southern African genus Rhoptropus.
Secretion rates and composition of parotid saliva in the koala (Phascolarctos cinereus)
Authors: Beal A. M.
Published: March 2009

Parotid salivation was stimulated in anaesthetized koalas by intravenous infusion of carbamylcholine chloride to ascertain flow rates, composition and possible adaptations of salivary function to a diet of eucalypt leaves. Maximum fluid secretion rates per gram tissue (62.0 ± 4.89 μl/g gland/min) were very low but, because the gland is relatively large, maximum flow rates (1.14 ± 0.105 ml min−1) were comparable with other herbivores when scaled for animal size. Salivary concentrations of protein (1.34 ± 0.165 to 3.35 ± 0.298 g 1−1), Na (42.0 ± 4.19 to 142.9 ± 1.78 mmol 1−1), Ca (0.97 ± 0.152 to 2.21 ± 0.300 mmol 1−1), HCO3 (14.3 ± 2.18 to 78.4 ± 2.48 mmol 1−1), Cl (10.6 ± 1.29 to 58.6 ± 1.16 mmol 1−1) and the osmolality (107.0 ± 7.67 to 273.9 ± 1.31 mosmol kg−1) were positively correlated with salivary flow rate. The concentrations of urea (4.22 ± 0.345 to 1.71 ± 0.386 mmol 1−1), K. (25.1 ± 3.04 to 8.92 ± 0.71 mmol 1−1), Mg (206.1 ± 42.78 to 18.3 ± 0.64 μmol 1−1), H+ (273.6±51.23 to 17.5 ± 1.16 μmol 1−1) and PO4(29.6 ± 2.78 to 4.3 ± 0.39mmol 1−1) were negatively correlated with flow rate. The functional significance of the high buffer capacity of the saliva is unclear as koalas do not foregut ferment. The saliva lacked amylase activity entirely and plasma amylase activity was very low indicating low production rates by other tissues, both of which are probable adaptations to the low starch levels of the eucalypt diet. Salivary Na/K ratios were unaltered by aldosterone infusion (3 h at 5 and 50 μg h−1) which was interpreted as an indication that the koala gland, like the macropod parotid, requires long exposure to high mineralocorticoids to sensitize the gland.