bluuebunny/crossref_metadata_2025 huggingface dataset:
Rate of passage of digesta through the alimentary tract of southern elephant seals (Mirounga leonina) (Carnivora: Phocidae)
Authors: Krockenberger M. B. , Bryden M. M.
Published: March 2009

The inert markers chromium‐EDTA (liquid phase marker) and ytterbium nitrate (solid phase marker) were added to the food of three southern elephant seals in Taronga Zoo, Sydney, in a series of nine trials. The enclosures were checked at 15 to 30 minute intervals for up to 60 hours after dosing, and all faeces voided on land were collected (91 samples). Marker concentrations in faecal dry matter were determined and mean retention times calculated from the concentration‐time curves.

The faeces were soft to semiliquid, with mean water content of 58% (range 24–80%). The marker concentration curves indicated a rapid rate of food transit through the gastro‐intestinal tract in elephant seals compared with other carnivores. The mean time between dosing and first recovery of marker (Initial Recovery Time) was nine hours. This was significantly longer than the figure of 4.8 hours for northern elephant seals reported previously, and possible reasons for the differences are discussed. Mean Retention Time, a better index of rate of passage of ingesta, was 13 hours for the three southern elephant seals. This compares with times of 22 hours for the dog, 15 hours for the raccoon, and 13 hours for the cat, all carnivores with much shorter gastrointestinal tracts, both absolutely and relative to body size, than the southern elephant seal.

It is suggested that the very long small intestine may be an adaptation to foraging at depth, combined with long periods of submergence and the need to ingest large amounts of food when the animal is at sea continuously for weeks or months.
Diet and foraging behaviour of huntsman spiders in the Namib dunes (Araneae: Heteropodidae)
Authors: Henschel J. R.
Published: March 2009

Diet and foraging behaviour of three species of burrowing huntsman spiders, Leucorchestris arenicola, L. steyni and Carparachne aureoflava, from the Namib dunes were investigated over a three‐year period. These nocturnal spiders are polyphagous predators that prey on more than 97 species of insects, arachnids and reptiles. Most prey were nocturnal or crepuscular tenebrionid beetles, moths and weevils. Diet varied regionally owing to faunal differences, but was relatively constant over seasons. Although spiders occasionally captured prey greater than themselves, average prey length was about two‐thirds their own length. Prey size was not strongly related to spider size. Larger spiders were both cannibals and intraguild predators. Foraging pattern of L. arenicola was variable with several nights of activity followed by one or several nights of rest. Spiders foraged within 3 m of the burrow, but occasionally pursued prey or neighbouring conspecifics further. Large prey (> 3 mm) were captured approximately every five weeks in summer and every seven weeks in winter, producing an average annual consumption of ≅ 10 prey/spider. Namib huntsmen are sit‐and‐wait predators within narrow territories waiting for the fortuitous arrival of prey and are thus unlikely to limit prey populations. They compensate for food shortages by cannibalism, thus restricting their own population.
A redescription of Aaptos aaptos with descriptions of new species of Aaptos (Hadromerida: Suberitidae) from northern New Zealand
Authors: Kelly‐Borges Michelle , Bergquist Patricia R.
Published: March 2009

The problematic genus Aaptos Gray (Hadromerida: Suberitidae) is evaluated in the light of new and re‐defined taxonomic characters. Aaptos aaptos (Schmidt) is re‐described from type material and a framework is constructed for the recognition of new species. Trachya pernucleata Carter is also re‐examined and relegated in synonymy with Aaptos. Four new species from northern New Zealand are described.
The temperature tolerances ofTetraclita squamosa(Crustacea: Cirripedia) andSeptifer virgatus(Bivalvia: Mytilidae) on a sub‐tropical rocky shore in Hong Kong
Authors: Liu J. H. , Morton Brian
Published: March 2009

Mid‐tidal levels on Hong Kong's exposed shores are dominated by sessile barnacles (Tetraclita squamosa) and mussels (Septifer virgatus).Such shores experience dramatic elevations in air and rock temperatures in mid summer that have been causally linked to mortalities of these species.Tetraclita squamosaandS. virgatushad lower body temperatures relative to their rock substratum. Mussel inhabitants of high‐ and low‐zoned pools were in temperature equilibrium with contained water. On the rocks, body temperatures ofT. squamosawere higher than those ofS. virgatus.Middle shore individuals had higher body temperatures than lower shore ones. Individuals in the sun had higher body temperatures than those in the shade. Factors possibly affecting body temperature are orientation to the incident sunlight, height on the shore and the contact area between the individual and the substratum.

Mean heat coma temperature (HCT) values for submergedSeptifer virgatuswere 45.0d̀C and 44.5d̀C for individuals of between 10‐20mm and 30‐50mm shell length, respectively. Mean median lethal temperature (LT50) values for submergedS. virgatuswere the same for both size classes (47.0d̀C). A longer exposure in air resulted in a lower LT50value; a shorter exposure in air resulted in a higher LT50value.

Water content ofSeptifer virgatuswas between 89.21–90.26%, i.e. including the water from the mantle cavity. In air temperatures of between 30–32d̀C and after long periods of exposure,Septifer virgatusshowed significant water loss, i.e. of between 13.87‐15.52% body water content. In air temperatures of between 33–36d̀C and after relatively short exposures,Septifer virgatusshowed small water losses, i.e. between 1.92‐5.74% body water content.

On Hong Kong's exposed rocky shores, sessile components of the middle shore environment are thermally stressed in summer when low tides occur in the afternoon in combination with periods of cloudless sunny days and when rock temperatures may climb to ≅ 50d̀C through solar insolation. Lower‐zoned individuals and high‐zoned pool residents are buffered from the adverse effects of such environmental extremes. Mortality occurred mainly in the sun‐exposed shore populations of bothTetraclita squamosaandSeptifer virgatusand is particularly evident when the above combination of climatic and tidal factors first occurs in July.
A new species of the holothurian genus Pkyllophorus from South Africa with a key to subgenus Phyllophorella
Authors: Thandar Ahmed S.
Published: March 2009

Fourteen specimens of a shallow‐water, sand‐inhabiting, polytentaculate holothuroid, dredged from Durban, South Africa, are new and described as Phyllophorus (Phyllophorella) rosetta sp. nov. The new species is distinct in possessing an abundance of rosettes in all parts of the body wall, often in combination with tables typical of those of the Phyllophorus subgenus Phyllophorella Heding & Panning, 1954. In the form of its tables and rosettes the new species appears to be closely related to P. (P) contractura Cherbonnier, 1988 from Madagascar but differs from it in the form of its calcareous ring, the number of polian vesicles and the presence of rosettes throughout the body wall, instead of their restriction to the anal region. The presence of rosettes makes the new species, together with P. (P) contractura, a good intermediate between Phyllophorus and Lipotrapeza. The new species increases to nine the number of species now classified in the subgenus Phyllophorella. All nine species are keyed.
Identifying the effects of history on adaptation: origins of different sand‐diving techniques in lizards
Authors: Arnold E. N.
Published: March 2009

The effects of previous history on adaptation can be studied in situations where several taxa have been independently exposed to a well‐specified problem posed by their selective regimes. This approach was applied to the ways surface‐dwelling dune lizards dive rapidly into loose sand when evading predators. Lacertids of the genus Meroles use all limbs and serpentine body and tail movements, behaviour which arose directly in the context of predator evasion in sandy habitats. The agamids, Phrynocephalus and Agama etoshae employ lateral body oscillations and descend vertically, an aberrant method resulting from previous evolution of a blunt snout. The scincid, Scincus and gerrhosaurid, Angolosaurus, both use high amplitude sinusoidal movements of the body and tail, which apparently evolved in a common ancestor of these taxa long before being co‐opted to use in sand. In contrast, the scincid, Mabuya acutilabris, holds the body straight, a method that probably originated in the context of concealment at the end of activity.

In the phrynosomatid, Uma, the head oscillates up to 60 times per second, the forelimbs are folded back and hindlimb thrust is supplemented by scales on the upper arms acting like ratchets. Some components of this method originated in the context of slow concealment in firm substrata at the end of activity periods, a basic pattern later co‐opted for rapid diving in compact sand with modification of the snout to form a drill. Finally, this elaborated mechanism was transferred to loose sand with further behavioural and morphological change. Rapid sand burial by Phrynosoma species has the same origin as that in Uma but, like Phrynocephalus, includes a strong vertical component. It too is associated with a blunt snout which, however, arose after initial burial behaviour developed, not before.

These results suggest that, once related lineages have diverged, differences may still accumulate even in similar situations. Sand diving also exhibits striking cases of convergence and provides an example of how function can be used to polarize characters, suggest the situations in which derived states arose and indicate their likely order of change.
The population dynamics and reproductive cycle of Septifer virgatus (Bivalvia: Mytilidae) on an exposed rocky shore in Hong Kong
Authors: Morton Brian
Published: March 2009

Exposed rocky shores in Hong Kong are dominated at mid‐tidal levels by a broad band of the mytilid Septifer virgatus. A 48‐month study of a population inhabiting the shores at Cape d'Aguilar has been undertaken. The species matures at a shell length of ≅ 15 mm, about one year after recruitment. Septifer virgatus is dioecious with a slight, but insignificant, female bias overall. There is, however, a significant juvenile male bias. Generally, most adult individuals remain mature year round, although spawning is limited to two periods in spring (February to March) and autumn (September to December) with subsequent recruitment into the adult population. The species lives for ≅ 4–5 years, although older individuals, possibly up to 12 years of age and with a maximum recorded shell length of 65 mm, occur as solitary individuals lower down the shore. Mortality in winter mainly affects newly recruited juveniles. A heavy mortality of adults in summer is thought to be related to high rock temperatures at midday (≅ 50°C), concurrent with low spring tides.

The life‐history tactics and sexual strategy of Septifer virgatus can be correlated with seasonal changes in hydrography. There are a number of similarities with other local mytilids, notably the dioecious condition and the bimodal pattern of spawning and recruitment. Such similarities are discussed in relation to the habitats occupied by these species.
Unusually high zinc concentrations in snake plasma, with observations on plasma zinc concentrations in lizards, turtles and alligators
Authors: Lance V. A. , Cort T. , Masuoka J. , Lawson R. , Saltman P.
Published: March 2009

We provide evidence that normal plasma zinc levels in snakes are in the same range as the elevated zinc levels associated with haemolytic anaemia and fatal zinc toxicosis in dogs, and with weight loss and anorexia in crocodiles that had ingested coins with high zinc content. Blood plasma samples from large representative groups of snakes, lizards, turtles and alligators were analysed for zinc content by atomic absorption spectrophotometry. Plasma zinc levels in all snake species were five to 50‐fold greater than levels reported in mammals. Plasma zinc levels in lizards and turtles were also higher than those of mammals, but significantly lower than those of snakes. Plasma zinc levels in alligators were in the same range as mammals and birds. After prolonged dialysis of snake plasma, 76% of the zinc remains in the retentate, suggesting the presence of a plasma protein with a strong affinity for the metal. Zinc levels vary significantly among the taxonomic groups, emphasizing the common evolutionary origin of crocodiles and birds and their divergence from the other reptiles.
Setal entanglement: an undescribed method of stridulation by a neotropical tarantula (Araneae: Theraphosidae)
Authors: Marshall S. D. , Thoms E. M. , Uetz G. W.
Published: March 2009

The theraphosid spider Theraphosa leblondi (Latreille) produces a sibilant, hissing sound during defensive displays. This sound is produced using a previously undescribed method of stridulation: setal entanglement. The opposing surfaces of the femora of the pedipalps, first, and second pair of legs are clothed in unique setae which have their distal portion bearing hooks and a shaft clothed in filaments. Experimental ablations described here showed these plumose setae to be the site of sound production. Based on examination of the fine structure of these setae, we propose that the hissing sound is produced by the entanglement and pulling apart of the hooks at the ends of the setae on one leg surface and the long, plumose filaments on the median part of the setae on the opposing leg surface. Evidence presented suggests that this is a case of an acoustic aposematic display directed at vertebrate predators.
Altered flower/fruit clusters of the kitul palm used as roosts by the short‐nosed fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae)
Authors: Bhat H. R. , Kunz T. H.
Published: March 2009

The short‐nosed fruit bat (Cynopterus sphinx) creates bell‐shaped cavities in flower/fruit clusters of the kitul palm (Caryota urens) by chewing and severing flower and fruit strings. These cavities (stem tents) in which the bats roost are usually about one metre deep and 30 cm in diameter. We observed groups of bats roosting in fully‐formed stem tents during the daytime, and the construction and subsequent occupancy of newly formed tent cavities. Stem tents are similar in principle to leaf tents except, instead of being formed when bats chew veins and the surrounding tissues of leaves, stem tents are formed in C. urens when bats completely cut several of the central flower/fruit strings. Flower/fruit strings are mostly severed when they are in an immature stage, at times when they are thin and widely spaced. Once these strings thicken and become heavily‐laden with mature fruits, bats cannot penetrate the cluster to sever them. Our observations suggest that a single male enters an immature flower or fruit cluster either from below or the sides and severs the central strings along the peduncle. In early phases of stem‐tent construction, C. sphinx severs flower/fruit strings at a rate of about one or two per day, and cluster alteration may continue upwards to two months. Only one immature flower/fruit cluster on a C. urens tree is available for alteration by bats at any given time. That this bat does not roost in the fruit/flower cluster during the day, when a tent is under construction, and the accumulation of chewed flower and fruit strings beneath such a cluster in the morning, suggests that tent construction by C. sphinx is a night‐time activity.
Embryonic development of the domestic guinea fowl (Numida meleagris)
Authors: Ancel A. , Liess S. , Girard H.
Published: March 2009

Inside the viable range 36–39°C, the development of the domestic guinea fowl embryo was studied during artificial incubation of about 5000 eggs. Equations giving internal and external pipping and hatching time as a function of incubation temperature were developed. Whatever temperature was used, internal and external pipping occurred at 89% and 95% of hatching time, respectively. The chronological development in ovo of the guinea fowl is illustrated by growth curves. Guinea fowl grew in ovo at the same rate as the chicken embryo. The embryonic mortality is significantly affected by incubation temperature. The thermal tolerance of the embryo follows a parabolic curve: temperatures below or above 37.2°C increase the rate of mortality. During the course of the incubation, the mortality frequency was mainly distributed around two peaks (each one third of the total), which occurred during the first days of incubation, that is, within the first 12% of the incubation time, and during the last days, that is, after 85% of the incubation time. At the optimal 37.2°C temperature, these two peaks occurred on days 1–3 and 23–27, respectively.
Light and electron microscope studies of the dermal capillaries in three species of hagfishes and three species of lampreys
Authors: Potter I. C. , Welsch U. , Wright G. M. , Honma Y. , Chiba A.
Published: March 2009

A dermal capillary network was found in three species of hagfishes (Myxine glutinosa, Paramyxine atami, Eptatretus stoutii) and in the adults of three species of lampreys (Geotria australis, Lampetra japonica, Petromyzon marinus). However, it was found neither in the ammocoetes of any of the species examined, nor in the adults of the lamprey Lampetra fluviatilis. The complex arrangement of dermal capillaries described for adult L. fluviatilis by Czopek & Sawa (1971) was apparently an artefact. The dermal capillaries of hagfishes and lampreys are lined by a continuous endothelium, comprising flattened cells that possess most of the usual complement of organelles found in the endothelia of higher vertebrates. The pericapillary space contains proteoglycans, glycoproteins and tubular microfibrils (diam. 11–15nm) and, in hagfishes, also irregularly arranged collagen fibrils (diam. 40–120 nm). The thickness of the endothelium varied amongst species, ranging from c. 100nm in G. australis and P. marinus to over 500 nm in L. japonica and all three species of hagfishes. In comparison with the endothelial cells of lampreys, those of hagfishes have a better developed basement membrane, possess small desmosomes in the flange‐like intercellular contact regions, and contain numerous plasmalemmal smooth tubules, rather than the smooth vesicles that are typically present in endothelial cells. In addition, the hagfish dermal capillaries have pericytes. Amongst hagfishes, the dermal capillary network is far better developed in Myxine glutinosa and Paramyxine atami, which burrow and may therefore have to rely to some degree on cutaneous respiration, than in Eptatretus stoutii which does not burrow. However, a dermal capillary network is probably important for all species of hagfishes since it would enable the precursors required for synthesizing mucus to be transported to the epidermis, where mucous cells are very abundant. The particularly well‐developed dermal capillary network in Geotria australis may facilitate the transport of oxygen through the unusually thick dermis of their migrating adults as they move around barriers on their upstream migration, and must thus presumably have to employ cutaneous respiration.
Diving behaviour and foraging location of female southern elephant seals from Patagonia
Authors: CAMPAGNA C. , BOEUF B. J. LE , BLACKWELL S. B. , CROCKER D. E. , QUINTANA F.
Published: March 2009

Our aim was to describe the free‐ranging diving pattern and to determine the location of foraging of pregnant female southern elephant seals, Mirounga leonina, from Peninsula Valdes, Argentina. This colony is unusual in two respects: it is removed from deep water by a broad shallow shelf (345–630 km wide), and colony numbers have been increasing in recent years in contrast to numbers from other southern hemisphere colonies that are stable or in decline. Microprocessor controlled, geolocation‐time‐depth recorders were deployed on four females, recording a total of 15,836 dives (270 dive days) during the period February to April, 1992. Departing seals crossed the continental shelf quickly (54–5–62–1 h) and did not show signs of foraging until reaching deep water, due east of the colony in the South Atlantic Ocean. Diving was virtually continuous (93% of the time underwater) with overall mean (±S.D.) rates of 2.5±0.2 dives/h, mean dive durations of 22.8 ± 7.1 min (maximum dive duration = 79 min) with 1.6±0.6min surface intervals between dives, and dive depths of 431±193m (maximum dive depth = 1,072 m). The diving pattern of females from Patagonia is similar to that of seals from colonies where numbers are decreasing (Macquarie stock) or are stable (South Georgia Island). Our subjects did not, however, feed in or south of the Antarctic Polar Front, or in cold waters along the Antarctic coast, where seals from declining or stable colonies forage.
Sexual differences in caudal morphology and its relation to tail autotomy in lacertid lizards
Authors: BARBADILLO L. J. , BAUWENS D. , BARAHONA F. , SANCHEZ‐HERRÁIZ M. J.
Published: March 2009

We hypothesized that the presence of the forked hemipenes, and associated musculature, at the base of the tail in male lizards should constrain the capacity to autotomize the tail. Thus, this hypothesis predicts that the non‐autotomous base of the tail should be longer in male than in female lizards. We tested this hypothesis in four species oflacertid lizards. Males have on average one to two non‐autotomous vertebrae more than females, and the sexual difference in length of the non‐autotomous tail base remains constant over the entire body size range. In addition, the first functional autotomy plane in males is usually located on, or is distal to, the vertebrae from which two hemipenial muscles take origin. These observations support the view that functional demands of the male intromittent organs impose constraints on the abilities of tail autotomy. In a natural population of Lacerta vivipara, the proportion of tail breaks that occurred at very short distances from the base was highest in females, indicating that the small sexual difference in length of the non‐autotomous tail part is of functional significance. Total length of the tail was largest in males. This can be interpreted as a compensation for the decline in autotomy capacities at the tail base, such that the length of the autotomous part remains similar in both sexes.
Functional analysis of the throat display in the sand goanna Varanus griseus (Reptilia: Squamata: Varanidae)
Authors: BELS V. L. , GASC J.‐P. , GOOSSE VÉRONIQUE , RENOUS SABINE , VERNET R.
Published: March 2009

The threat behaviour in Varanus griseus was investigated with high‐speed cinematography and X‐ray films. Lizards exhibit threat display involving throat movements and associated throat, thorax and mouth movements. The functional anatomy of the bucco‐pharyngeal region is described and threat displays are kinematically studied and functionally interpreted.
Influence of the abundance of food resources on the feeding habits of the red fox, Vulpes vulpes, in western Switzerland
Authors: FERRARI N.
Published: March 2009

J.‐M. WEBER

The influence of food abundance on red fox feeding habits was studied in the Swiss Jura Mountains between November 1990 and February 1992, during a low density period in the water vole population cycle. Six food categories–water voles, small mammals, domestic stock, earthworms, wild fruits and exploitable scraps–were censused during the present research and their seasonal abundances were estimated in fixed plots. Fox scats were collected and analysed at regular monthly intervals.

The diet of foxes was found to be correlated with seasonal food supply. A positive significant correlation between seasonal abundances and relative proportions in the diet was found for food categories showing a clear seasonality (earthworms, wild fruits and exploitable scraps), whereas no correlation was recorded for the other food resources. Diet composition observed in the present study was compared with that recorded in the same study area between 1988 and 1990 by Weber & Aubry (1993), when water voles were very common and accounted for more than 50% of the diet. A significant change was recorded in red fox feeding habits: the most important aspects of this modification of the diet was the decrease in water vole importance accompanied by the increase in the frequency of occurrence of other food categories, such as wild fruits and scavengeable items.
Ranging behaviour of feral cattle (Bos taurus) in Doñana National Park, S.W. Spain
Authors: Lazo Alfonso
Published: March 2009

The cattle of Doñana (139 individuals in four social groups in 1989) have lived under free‐ranging conditions for centuries. Their ranging behaviour was analysed during a three‐year period. A total of 17,603 locations corresponding to 247 different animals allowed both for the estimation of global and seasonal home ranges of individuals and social groups and for the comparison of movement patterns. Cattle ranging behaviour was not affected by human interference, and was shown to be regulated by a complex interaction of environment, individual and social factors. Habitat structure and seasonal fluctuations in abundance and distribution of resources determined general patterns of ranging behaviour: the greater the concentration of resources, the smaller the home ranges of individuals and social groups. These patterns were modified at an individual level by the sex of the animal and its reproductive status if male. Social influences on ranging behaviour were important because these implied the segregation of home ranges among dominant bulls and among social groups. As a result, there was a great variability in space use and home‐range behaviour.
Distribution, variation, and systematics of the Seychelles treefrog, Tachycnemis seychellensis (Amphibia: Anura: Hyperoliidae)
Authors: Nussbaum R. A. , Wu Sheng Hai
Published: March 2009

The endemic Seychelles treefrog, Tachycnemis seychellensis (Duméril & Bibron), is restricted to four of the granitic islands of the Seychelles: La Digue, Mahe, Praslin and Silhouette. Megalixalus infrarufus Gunther 1869 is a junior synonym of Eucnemis (Tachycnemis) seychellensis Dumeril Bibron, 1841. Significant variation in colour and morphometric characteristics exists within and between island populations. The patterns of geographic variation revealed support the hypothesis that the distribution of Tachycnemis seychellensis in the granitic Seychelles reflects vicariance through fragmentation of the Seychelles Microcontinent 10,000 years B. P. by marine transgression. However, the possibility of low rates of postfragmentation dispersal between islands cannot be ruled out. The close relationship of the nearby Mahe and Silhouette populations probably reflects prefragmentation gene flow over relatively short distances and postfragmentation stasis due to large population size and similar environments. The small body size and colour similarities of the Praslin and La Digue populations may result from prefragmentation gene flow between these close populations, but the relatively great differences in morphometric traits suggest rapid divergence in isolation perhaps as a result of genetic drift and strong selection. It is argued that the four island populations represent a single species and that subspecies should not be named.
Functional and systematic implications of the ear in golden moles (Chrysochloridae)
Authors: Mayer Acacia von , O'Brien G. , Sarmiento E. E.
Published: March 2009

Golden moles (Chrysochloridae) are fossorial mammals known to have unusual mallei. The aim of this study was to describe and quantify aspects of the auditory morphology of golden moles in order to determine their systematic and functional implications. Observations were made on skeletal material as well as histological sections. The results of this study do not support the separation of the genus Calcochloris from Amblysomus. It was found that the morphology shared by all the studied genera is indicative of specialization for hearing low frequency sound. The tympanic membrane to stapes footplate ratios, ossicular lever arm ratios and incudomallear joint morphology suggest low frequency specializations in genera with small mallear heads and high frequency specializations in genera with large mallear heads. However, the size and degree of trabeculation of the tympanic cavity are not consistent with this result. It is proposed that all golden moles are low frequency hearers with differences in their range of sensitivity according to how much time they spend foraging above ground.
The population dynamics of small mammals living in set‐aside and surrounding semi‐natural and crop land
Authors: Rogers L. M. , Gorman M. L.
Published: March 2009

Small mammals were found on set‐aside and surrounding farmland. Wood mice showed a different pattern of demography at two sites, with higher densities, greater survival, heavier weights and longer breeding seasons at Aldroughty than at Newburgh. These differences were thought to be due to a difference in habitat productivity at the two sites. Field voles showed less of a difference in population dynamics between the two sites, and both species of vole maintained populations at low densities.
Drinking and water expulsion in the diamondback turtle Malaclemys terrapin
Authors: Bels V. L. , Davenport J. , Renous S.
Published: March 2009

Postural and kinematic characteristics of the drinking behaviour in the diamondback turtle, Malaclemys terrapin (Latreille) were investigated by video and high‐speed filming experiments. Head, jaw and throat movements in drinking cycles are described. Postures of neck and head were compared for three water depths (2, 10 and 30 mm). Water expulsion, occurring after the turtle was disturbed, is also kinematically described. Finally, a drinking mechanism in the turtle is proposed.
Chemical and carbon isotopic composition of fatty acids in adipose tissue as indicators of dietary history in wild arctic foxes (A lopex lagopus) on Svalbard
Authors: Pond Caroline M. , Mattacks Christine A. , Gilmour I. , Johnston M. A. , Pillinger C. T. , Prestrud P.
Published: March 2009

The chemical and carbon isotope compositions of triacylglycerol fatty acids were analysed in samples from two or more adipose depots dissected from adult and subadult arctic foxes collected between November 1991 and March 1992 in four different areas of Spitsbergen in the Svalbard archipelago (latitude 78° 5′ to 79° 50′ N). Site‐specific differences were minor but there were large and consistent differences in the fatty acid composition of the storage lipids of foxes caught in the same areas, suggesting that residents of contiguous territories may have had quite different diets. The adipose tissue of adult foxes caught in Austfjordneset, an area where reindeer are rare, contained a much greater proportion of unsaturated fatty acids, suggesting that these animals were feeding mainly in the marine ecosystem, probably on seabirds and/or fish in summer and the remains of polar bear kills in winter. Measurements of the relative abundance of the carbon isotopes12C and13C in individual fatty acids show that palmitoleic acid (C16:1) in storage triacylglycerols originates from the marine food chain, probably together with most other unsaturated lipids, but that the foxes obtain oleic acid (C18:1), and probably most saturated fatty acids, from either terrestrial or marine sources.
The passage of digesta, particle size, and in vitro fermentation rate in the three‐toed sloth Bradypus tridactylus (Edentata: Bradypodidae)
Authors: Foley W. J. , Engelhardt W. V. , Charles‐Dominique P.
Published: March 2009

The digestive physiology of six three‐toed sloths (Bradypus tridactylus) fed exclusively on Cecropia palmata foliage was studied. The mass of digesta in the gut was between 17 and 37% of body mass. This was between 133 and 282% of that expected in an animal of this size, based on published allometric equations. The concentration of total short chain fatty acids in the stomach was similar to that in the fermentative regions of other foregut fermenting herbivores but the rate of fermentation measured in vitro was very slow (6–12 mmol.l‐1.h‐1) and substantially lower than that observed using similar techniques in other small foregut fermenters.

The overall (dose to excretion) mean retention time of particulate and solute digesta markers was about 150 h. Most of this (73%) occurred in the stomach but a substantial proportion (17%) could be attributed to the storage of faeces in the rectum.

The slow rate of passage of digesta through the gut together with the slow rate of fermentation in the stomach is not typical of small foregut fermenting herbivores. However, such a pattern is feasible in Bradypus tridactylus because of the large volume of digesta retained in the gut and the very low metabolic rate of these mammals.
The cannibalistic behaviour of twoGammarusspecies (Crustacea: Amphipoda)
Authors: Dick Jaimie T. A.
Published: March 2009

This study examines the cannibalistic behaviour of the freshwater amphipodsGammarus duebeni celticusStock & Pinkster, 1970 andG. pulex(L., 1758). In the first experiment, interactions were staged among all combinations of single adult males, single adult females, adults in the precopulatory mate‐guarding phase and juveniles. Cannibalism by inter‐moult individuals on newly moulted conspecifics occurred in all interaction categories in both species.Gammarus d. celticus, however, were significantly more cannibalistic thanG. pulex.Cannibalism between and within sex and size categories (males > females > juveniles) was facilitated by the vulnerability of individuals at moult. Individuals of smaller size categories, however, did not cannibalize newly moulted conspecifics of larger size categories. Males were less cannibalistic on newly moulted females than on newly moulted males and juveniles and, when in the precopulatory condition, appeared to defend females from cannibalistic attacks. In a second experiment, stream conditions were simulated in the laboratory and replicated populations monitored for nine weeks. High levels of cannibalism, and the species and sex differences in cannibalism identified in the first experiment, were confirmed under these heterogeneous conditions. Cannibalism by males on their newly moulted female mating partners, termed ‘reversed’ sexual cannibalism, was further investigated. When males were deprived of foraging opportunities, cannibalism of precopulatory partners was significantly more frequent. The occurrence of ‘reversed’ sexual cannibalism is thus interpreted as a conflict between motivation to feed and motivation to mate.
Temporal patterns of milk production in Antarctic fur seals (Arctocephalus gazella)
Authors: Arnould J. P. Y. , Boyd I. L.
Published: March 2009

The timing of milk production in Antarctic fur seals was studied at Bird Island, South Georgia. Like all lactating otariid seals (Pinnipedia: Otariidae), Antarctic fur seal females alternate between short nursing periods ashore and regular foraging trips to sea. Females do not necessarily return to the colony with full mammae, which indicates that mammary volume capacity is unlikely to limit foraging trip duration. Upon arrival at the colony, milk fat (r2= 0.33, P < 0.04) and protein (r2= 0.60, P < 0.002) content were positively correlated to the time spent at sea. A similar trend was observed in the milk produced on land. The rate of milk energy production was much lower at sea (5.02 ± 0.05 MJ day‐1) than on land (23.66 ± 4.4 MJ‐1 day‐1). The rate of milk energy production during the foraging trip was negatively correlated to the time spent at sea (r2= 0.29, P < 0.05), whereas the rate of milk energy production on land was positively correlated (r2= 0.61, P < 0.001) to the duration of the preceding foraging trip. The total amount of milk energy delivered to the pup during each twoday nursing period was positively correlated (r2= 0.60, P < 0.002) to the duration of the previous foraging trip. The overall rate of milk energy delivery, however, was independent of foraging trip duration. This accords with previous observations that the growth rates of Antarctic fur seal pups are unaffected by maternal foraging trip duration patterns.
On the ‘spitting’ behaviour in cobras (Serpentes: Elapidae)
Authors: Rasmussen Sara , Young B. , Krimm Heather
Published: March 2009

Spitting' behaviour was examined in selected taxa of Naja and Hemachatus. A description of the kinematics and variations of spitting in each species was generated from the analysis of videotape records of over 400 spits. Interspecific variation was noted in the spitting behaviour. Intraspecific variation ranged from very stereotypic spitting in N. siamensis, and H. haemachatus, to N. pallida and N. mossambica in which every aspect of the behaviour was variable. A striking lunge and exhalant burst of air may occur as part of the spitting behaviour, but are not essential agents in venom spitting.
Age determination, age structure, and longevity in the mole Scalopus aquaticus (Mammalia: Insectivora)
Authors: Hartman Gregory D.
Published: March 2009

Three hundred and eighty‐two moles, Scalopus aquaticus, were collected from 16 sampling grids located within a 23 km2 area in South Carolina, USA. Age of moles was determined using tooth wear. Both the mean and median ages of trapped moles were c. two years; the oldest mole was in its seventh year of life. More than 50% of the individuals are estimated to die during the first six months of life; adult survivorship was relatively high and age‐dependent. There was differential mortality between the sexes, and females lived longer than males. Scalopus aquaticus in South Carolina lived c. 1.2 times longer than the maximum lifespan predicted on the basis of body mass. Pooled samples of moles yielded the expected age distribution, with fewer individuals occurring in successively older age classes. However, based on bootstrap estimates of the variance in age structure, samples from some grids contained significantly more young or old individuals than expected due to sampling error. Mole populations appear not to be in demographic equilibrium at this local scale, but instead conform more closely to a metapopulation‐type of structure.
Space and resource use by brown hyenas Hyaena brunnea in the Namib Desert
Authors: Skinner J. D. , van Aarde R. J. , Goss R. A.
Published: March 2009

Two clans of brown hyenas were studied on the arid chilly Namib Desert coast where very large seal colonies are present. Carcasses from seals were abundant during summer and autumn following the seal pupping season, and scarce in winter and spring. Hyenas fed predominantly on carcasses. Members of one clan of three hyenas obtained most of their food along 3 km of coastline adjacent to the seal colonies. The other clan of nine individuals obtained food from an area along 6 km of coastline north of the seal colonies. Although carcasses were usually scavenged, seal pups were seen to be killed on occasions. Time spent foraging was not affected by carcass availability. Territories of the two clans overlapped and individual home‐range size varied from 31.9 to 220 km2. Food availability apparently had no influence on foraging activities but the dispersal of food affected territory and group sizes. Over abundance of food results in the maintenance of territories extending beyond the distribution of food. The shape and area of these territories may result from the cultural inheritance of space.
A test of Przibram's Rule
Authors: Solow A. R. , Faber D. B.
Published: March 2009

Przibram's Rule states that the ratio of the mean weights in successive instars of hemimetabolous insects is 2.09. Faber (1994) described a two‐stage approach to testing Przibram's Rule when the instars of the measured individuals are unknown. In the first stage, individuals are assigned to one of the instars on the basis of their weights. In the second stage, a test of the null hypothesis that the means of logarithmic weight in the two groups differ by the logarithm of 2.09 is performed. This approach suffers from two problems. First, errors in assigning individuals to instars will exaggerate the difference between instars. Secondly, the validity of the test in the second stage is based on the implicit assumption that the variance of logarithmic weight in the two groups is equal. This note describes a test of Przibram's Rule that avoids these problems.
Seasonal and area‐related variations in the diet of otters Lutra lutra on Mull
Authors: Watt Jon
Published: March 2009

The diet of otters Lurra lutrn living in a sea loch on the Isle of Mull was described by means of spraint analysis. Seasonal and spatial differences in the spraint composition were explored in the context of fluctuations in prey availability, as revealed by trapping. Butterfish Pholis gunnellus and the cottids Myoxocephalus scorpius and Taurulus bubalis were the most commonly occurring prey in spraints. In the winter, the proportion of rocklings (Ciliata spp. and Gaidropsarus spp.) and non‐rockling gadoids (Gadidae) in the diet increased. Their relatively large size makes these latter species an important constituent of the winter diet. Seasonal and spatial variation in fish consumption largely reflected fluctuations in availability. The mean size of principal prey fishes in spraints was similar to that observed in the traps. These observations suggest that otters were not strongly selective with regard to fish species and size. Shore crabs, in contrast, were not taken in proportion to availability. The findings are discussed in the light of other studies of the diet of coastal otters. It is suggested that the lack of selectivity demonstrated in this study, compared with previous studies, may be explained by area‐related variations in prey availability.
Sleeping habits of tamarins, Saguinus mystax and Saguinus fuscicollis (Mammalia; Primates; Callitrichidae), in north‐eastern Peru
Authors: Heymann Eckhard W.
Published: March 2009

The sleeping habits of moustached tamarins, Saguinus mystax, and saddle‐back tamarins, Saguinus fuscicollis, were studied in northeastern Peru. Five types of sleeping sites were distinguished: 1) Jessenia bataua palms; 2) tree hollows; 3) dense tangles of vegetation; 4) crotches; 5) open horizontal branches. Both tamarin species used Jesseniu‐palms most frequently. Tree hollows ranked second in the saddle‐back tamarins, but were never used by moustached tamarins. Sleeping sites of moustached tamarins were located significantly higher than those of saddle‐back tamarins. Jessenia‐palms used by moustached tamarins were significantly higher than palms from a random transect sample, but this was not the case for Jessenia‐palms used by saddle‐back tamarins. For both species, concealment seems to be more important than height above ground. The maximum number of subsequent nights spent in the same sleeping site was two in moustached tamarins and six in saddle‐back tamarins. The two tamarin species did not compete for sleeping sites. While the general pattern of sleeping site selection conforms to hypotheses predicting safety from predators as a major factor, differences between the two tamarin species reflect general niche differences between them. Most sleeping sites are located in exclusively used parts of the home range. Moustached tamarins generally use sleeping sites that are close to the last feeding site of the afternoon. The distance between simultaneously used sleeping sites of moustached and saddle‐back tamarins are generally close together, which helps to minimize time spent out of interspecific association.
Mammal life‐history evolution: a comparative test of Charnov's model
Authors: Purvis A. , Harvey P. H.
Published: March 2009

We present a comparative test of Charnov's recent theoretical model of mammalian life‐history evolution. Phylogenetic analysis of life‐table data from 64 species, ranging across nine orders. supports all of Charnov's assumptions and most of his predictions. The allometries of time from independence to maturity (a), annual fecundity, and adult and juvenile mortality rates are in agreement with previous work and with the theory, as are the signs of the relationships among these traits when body size is controlled for. As predicted, the non‐dimensional products of a and each of the other three traits are independent of adult body size, as is survivorship to maturity. However, we find that the ratio of weaning weight to adult weight (δ) is correlated with adult weight, in contradiction with the theory, and we do not find the predicted relationships between δ and the three non‐dimensional products. The discrepancies could be because we have equated independence with weaning, or because the model assumes determinate growth: they could arise if large mammals have relatively longer periods of post‐weaning care, or continue to grow after starting to reproduce. There is some evidence that δ is influenced by the nature of mortality around independence (density‐dependent or density‐independent), and we suggest this as a possible area for further work. In general, the areas of agreement between Charnov's theory and the data are more impressive than the differences, indicating that it could be a major breakthrough in understanding the evolution of life histories in placental mammals.
Advertisement calls of Bolivian Leptodactylidae (Amphibia, Anura)
Authors: Marquez R. , de la Riva I. , Bosch J.
Published: March 2009

The advertisement calls of 23 Bolivian anuran species in the family Leptodactylidae are described including information on calling behaviour. For each species, a characteristic audiospectrogram and oscillogram are presented. Numerical information about the spectral and temporal features of the calls is provided and, when available, the results are compared with any previous description of the calls. A phenogram based on holistic comparisons of the mating calls (audiospectrogram correlation) is presented for the generaEleutheroduciylus, Leptoducrylus. andPlzysalaemus. The intrageneric variability of four basic call parameters is compared. The results suggest that fundamental and dominant frequency (and possibly duration for the genus Physalaemus) are the most likely variables to play a role in isolation of congeneric species.
Spatial organization of the arboreal carnivorous marsupial Phascogale tapoatafa
Authors: Soderquist Todd R.
Published: March 2009

Phascogale tapoatafa is a squirrel‐sized carnivorous marsupial (Dasyuridae) found in dry eucalyptus forests of Australia. Radio‐tracking and live‐trapping studies at three sites in Victoria indicated that population densities were typically low, with females occupying home ranges averaging 41 ha (minimum convex polygon method) that were intrasexually exclusive. Male home ranges (mean 106 ha) overlapped extensively with females and other males, and expanded during the short breeding season to an average length of 2.7 km. When presented with the faeces of unfamiliar conspecifics, both female and male P. tapoatafa investigated the faeces of females significantly longer than those of males, suggesting that the exclusive home ranges of females are reinforced by olfactory communication, and that males are less responsive to the presence of potential rivals than to potential mates. Both sexes foraged throughout their home range, but the core area of intensive use was less than one‐third of the total area traversed. The spatial organization of P. tapoatafa differs markedly from that of the closely related species Antechinus stuartii, but is similar to that of the only other extensively studied carnivorous marsupial, Dasyurus geoffroii.