bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of spleen congestion and decongestion on newt blood
Authors: Frangioni G. , Borgioli G.
Published: March 2009

Experiments on the newt Triturus cristatus carnifex have shown that the spleen of specimens, either anaesthetized with chlorobutanol or in a normal condition, stores red blood cells when the animal is well oxygenated and releases these into circulation under conditions of hypoxia. The extreme limits of congestion and decongestion, commonly encountered in nature, can be obtained in the laboratory by exposing the animals to the air or by immersing them in still water. During the shift from a congested to decongested state, the spleen is reduced to less than one‐fifth of its weight, while the erythrocyte concentration and correlated parameters in the blood stream increase by more than 60%. Splenic regulation of the circulating erythrocyte concentration compensates not only for variations in oxygen supply linked to environment, it may also compensate for the cyclical variations in red cell production of this amphibian, whose erythropoietic tissue activity is intermittent and subject to seasonal variations.
The external morphology of the pseudoscorpion Roncus andreinii
Authors: Gardini G. , Benelli R.
Published: March 2009

The external morphology of the four postembryonic instars of Roncus andreinii (di Caporiacco, 1925) is described and compared with one of the related R. lubricus L. Koch, 1873 (Gabbutt & Vachon, 1967), with particular emphasis on disposition of the chelal trichobothria in relation to growth.

From the evaluation of characters it is concluded that a few morphometric and chaetotaxic characters (i.e. the length, ratio and shape of pedipalpal articles, the ratio of fingers/pedipalpal hand, the chaetotaxy of sternites II and III) represent good specific discriminants, while the relative position of trichobothria along the chelal axis is nearly the same in both species.

The localization of the growing and non‐growing regions along the pedipalpal fingers may be of practical use in the search for new taxonomic characters.
Aspects of the development and functional morphology of the pericardia, heart and associated blood vessels of lampreys
Authors: Percy Lord Richard , Potter I. C.
Published: March 2009

During the early larval life of lampreys, connective tissue strands develop between the notochord and oesophagus, thereby suspending the oesophagus between the two ducts of Cuvier and above the heart, which, unlike adult lampreys, is not enclosed in a rigid pericardial capsule. Examination of histological sections from proammocoetes and young ammocoetes provides strong evidence that the growth of this suspensory tissue is responsible for the dorsal aorta moving to the right and undergoing a concomitant rotation, which shifts the origin of the anterior mesenteric artery on the dorsal aorta from a right ventro‐lateral to a right dorsolateral position. While the heart initially develops the three major layers found in craniates, i.e. epicardium, myocardium and endocardium, the innermost of these breaks down early in larval life. The myocardium thus becomes bathed in blood, a feature which would help compensate for the lack of a coronary artery. After studying the way in which they are formed early in life, it is proposed that the epicardium is best termed the visceral or splanchnic pericardium and that the thin membrane lining the cavity surrounding the heart should be referred to as the parietal or somitic pericardium. The pericardial capsule of the adult, which is made of non‐compliant walls of cartilage and connective tissue. consists of three main components. The anterior component comprises the anteriorly convex post‐branchial wall. The intermediate component is formed by the posterior part of the seventh branchial arch on each side of the body and their posteriorly‐directed processes. The latter processes expand into the cup‐shaped pericardial cartilage, which constitutes the third and most posterior component of the pericardial capsule. A pear‐shaped opening in the connective tissue formed between the two anteriorly‐directed dorsal extensions of the pericardial cartilage allows the cardinal veins to join the single (right) duct of Cuvier, which in turn enters the sinus venosus. The ventral part of the cartilaginous floor of the pericardial capsule contains a large slit of connective tissue through which the ventral hepatic vein passes upwards to enter the sinus venosus. The inner surface of the pericardial capsule contains an elaborate and very well developed network of venous sinuses and sinusoids, which are supplied by blood from the peripharyngeal sinus and are drained by the inferior jugular vein. It is suggested that this network produces fluid which helps lubricate the heart. A description is given of the way in which the adult pericardial capsule is developed during the seven stages of metamorphosis. This sequence demonstrates that much of the development of the capsule takes place during stage 3 and that by the end of stage 6 the form of the capsule has become essentially the same as that of young adults.
How cats purr
Authors: Sissom Dawn E. Frazer , Rice D. A. , Peters G.
Published: March 2009

We measured purring in unrestrained intact pumas, cheetahs and domestic cats. Domestic cats,Felis silvestrisf.catus, purr at a frequency of 26·3 ±; 1·95 (S.D.) Hz. The frequency at mid‐expiration exceeds that at mid‐inspiration by 2·4 ± 1·3 Hz. Purring frequency for individuals does not change with age. Purring can occur simultaneously with other vocalization. Two‐channel acoustic measurements confirm that the primary mechanism for sound and vibration production is a centrally driven laryngeal modulation of respiratory flow. The diaphragm and other muscles appear to be unnecessary for purring other than to drive respiration.
Morphometry, diet and habitat in the kingfishers (Aves: Alcedinidae)
Authors: Woodall P. F.
Published: March 2009

Factor analysis of the linear dimensions of 92 species of kingfisher indicated that morphological differences were associated with four diet categories (aquatic, littoral, terrestrial and fossorial animals). Analysis of covariance confirmed the significance of these differences for culmen, tarsus and tail length but not for wing length. Habitat factors resulted in some significant differences but these were less easy to interpret. One case of intraspecific variation showed similar trends for culmen length.
Behaviour of nilgai (Boselaphus tragocamelus) antelope in captivity
Authors: Oguya B. R. O. , Eltringham S. K.
Published: March 2009

The behaviour of captive nilgai (Boselaphus tragocamelus) was studied at Whipsnade Wild Animal Park, Bedfordshire, UK, by the method of focal animal sampling. There were four principal feeding periods: at dawn, in the morning, in the afternoon and during the evening. The activity pattern of the male differed significantly from that of the females but otherwise the various age/sex classes behaved similarly. There were significant associations between the classes and significant differences in the mean distances to the nearest neighbour. Play fighting, in the form of neck wrestling, occurred in the calves, mainly the males. The adult male revealed signs of territoriality and the females showed evidence of the existence of social hierarchy. Blackbuck (Antelope cervicapra) sharing the enclosure reacted with the nilgai as if they were conspecifics but other ungulates present ignored them. The area of the enclosure appeared to be adequate and it is concluded that the animals are being managed correctly.
Phylogenetic relationships of the genus Dugesia (Platyhelminthes, Tricladida, Paludicola)
Authors: de Vries Elizabeth J. , Sluys Ronald
Published: March 2009

A phylogenetic analysis was performed on the genera and subgenera within the freshwater triclad family Dugesiidae, based on 19 terminal taxa and 17 morphological characters. The phylogenetic tree proposed has length of 27 steps and consistency index of 0.66. This phylogenetic hypothesis implies that the current genus Dugesia is paraphyletic and that its subgenera Girardia, Schmidiea and Dugesia S.S. should be elevated to the rank of genus. The genera Cura, Spathula and Neppia are presumed monophyletic by default because the database was unable to provide autapomorphies for any of these genera. The genera Dugesia S.S. and Neppia share sistergroup relationship. Several characters are discussed which were previously considered to be of phylogenetic importance but were not included in the present analysis. It is emphasized that sensory organs form potentially useful set of phylogenetic characters for the Dugesiidae.
The evolution of sociality in the spitting spider, Scytodes fusca (Araneae: Scytodidae)—evidence from observations of intraspecific interactions
Authors: Bowden Karen
Published: March 2009

The intraspecific behaviour of the communal‐territorial spitting spider, Scytodes fusca, from North Queensland, Australia, is described from laboratory observations. This spider is tolerant of most conspecific intruders on the web but adults, particularly females, do display aggression to other adults by charging, chasing and spitting. During courtship, both the male and the female tap on the web. Courtship in S. fusca is similar to that of a non‐social scytodid Scytodes thoracica. Males often stay with the female for a time after mating. Adults appear to be more cannibalistic toward third than toward first and second instar juveniles, This finding is discussed in relation to the mechanisms of intraspecific recognition. The social behaviour of S. fusca is compared with that of other scytodids and the possible evolution of sociality in S. fusca from the parent offspring association is discussed.
Annual variation in breeding biology of macaroni penguins, Eudyptes chvysolophus, at Bird Island, South Georgia
Authors: Williams T. D. , Croxall J. P.
Published: March 2009

The breeding biology of the macaroni penguin, Eudyptes chrysolophus, was studied over four years, 1976 and 1986–88, at Bird Island, South Georgia. Birds were migratory, being absent during winter (May to September). Arrival at the colony was highly synchronous between years: 14–23 October, over a 7‐year period. The pre‐breeding, incubation and chick‐brooding period was characterized by long fasts ashore, for 36 and 39 days in males and 41 days in females, alternating with long periods at sea. Within years egg‐laying was highly synchronous: 95% of clutches initiated within 4–6 days. Arrival date and mean egg‐laying date were later (by 3 days), and breeding population size lower (by 20%) in 1987, compared to other years. The incubation period was 35 days and comprised three long shifts, the first shared by the male and female, the second by the female and the third by the male. In 1986 and 1988 these were of 12, 12 and 9 days' duration, but in 1987 the first shift was significantly shorter: 9 days. Chicks creched at 23–25 days of age and fledged at 60 days of age. Neither chick age nor weight at creching or fledging varied between the years 1986–88. The breeding biology of macaroni penguins at Bird Island is compared with that of other Eudyptes penguins, and with the sympatric gentoo penguin, Pygoscelispupuu. There is little variation in breeding biology within the genus Eudyptes, except in the length of time spent at sea prior to the annual moult. This is much shorter at Bird Island, probably reflecting a greater food availability compared to other localities. Inter‐annual variation in certain breeding parameters, e.g. laying date, breeding population size, is much greater in the gentoo penguin than in the macaroni penguin. The shorter breeding season, rearing of only one chick and proportionately lower chick fledging weight in macaroni penguins, may be linked to this species' migratory strategy.
Influence of flow rate and aldosterone administration on mandibular salivary composition in the koala:(Phascolarctos cinereus)
Authors: Beal A. M.
Published: March 2009

The possibility of adaptations of mandibular salivary function to a diet of eucalypt leaves and for evaporative cooling was investigated in anaesthetized koalas. Salivary composition, at a range of flow rates up to maximum and during aldosterone administration, was measured in saliva evoked by intravenous infusion of carbamylcholine chloride. Maximum fluid secretion rates per gram tissue (230 ± 18·2 μl/min/g gland) were similar to mandibular glands of other species and about four times the rates/g gland reported for the parotid gland of koalas. Salivary concentrations of Na (6·1 ± 0·91 to 67·7 ± 3·51 mmol·l−1), Cl (7·2 ± 0·71 to 53·0 ± 2·82 mmol·l−1), HCO3(8·6 ± 0·81 to 19·4 ± 2·13 mmol·l−1) and the osmolality (26·7 ± 2·34 to 132·9 ± 5·47 mosmol.kg−1) were positively correlated with salivary flow rate. The concentrations of urea (1·87 ± 0·034 to 0·71 ± 0·099 mmol·l−1), K (13·0 ± 0·90 to 6·25 ± 0·482 mmol·l1‐), Mg (33·6 ± 2·53 to 10·1 ± 4·68 pmol·l−1), H+(246·2 ± 55·78 to 62·1 ± 8·01 n̈mol·l−1) and PO4(3·46 ± 0·350 to 1·13 ± 0·044 mmol·l−1) were negatively related to flow rate. Total protein (411 ± 44·4 to 656 ± 146·4 mg·l−1) and total Ca (356 ± 45·2 to 467 ± 61·6 μmol·l−1) concentrations were not correlated with flow but were highly correlated with one another. With salivary amylase activity being absent and plasma amylase activity being very low indicating low production rates by other tissues, the koala is likely to have limited ability to digest starch. Intravenous infusion of aldosterone at 5 μg·h−1for 90 rnin followed by 50 μg·h−1for 105 min demonstrated that the gland responded rapidly to changes in endogenous mineralocorticoid levels. Mean salivary Na/K ratio before aldosterone administration was 6·9± 201, the ratio had fallen significantly (P< 0·05) after 75–90 min infusion and had fallen to 0·71 ± 0·172 by the last 30 min of infusion.

It was concluded that the mandibular gland of the koala, with its relatively high secretory capacity and its sensitivity to stimulation, would have the major influence on the composition of mixed saliva during low‐flow reflex secretion. Additionally, because the gland is responsive to acute changes in mineralocorticoids and produces a markedly hypotonic saliva, the mandibular is better adapted than the parotid gland to be the primary source of saliva for evaporative cooling.
Behaviour and movements of sympatric civet species in Huai Kha Khaeng Wildlife Sanctuary, Thailand
Authors: Rabinowitz A. R.
Published: March 2009

Five individuals of four civet species were captured and followed by radiotelemetry in a mosaic of dry tropical forest in Huai Kha Khaeng Wildlife Sanctuary, Thailand. Observations were made on a fifth, arboreal species which was never captured. Radio‐collared civets used overall areas ranging from 3.1 to 17 km2 with average monthly ranges from 0.72 to 5.4 km2. Average monthly ranges, home range centre shifts and activity radii showed a linear increase with weight and size of the individual, both within and between species. Despite individual differences, there were similar behavioural responses to extrinsic seasonal changes. Civets had activity levels of 50–55% and displayed nocturnal activity patterns. The four smallest civets used trees as resting sites extensively while the largest civet, Viuerra zibetha, was always located on the ground. Faecal analysis indicated that civets fed on at least 18 fruiting tree species as well as rodents, insects and crabs. At least one of the fruits found in civet faeces, Cassia fistula, was not eaten by other major frugivores in the area. The civets showed a preference for mixed deciduous and dry evergreen forest over dry deciduous dipterocarp forest, which had a lower abundance of known food items. The role that civets play as seed dispersal agents may help in the maintenance and structuring of tropical forest communities.
Phenotypic and genetic characteristics affecting lifetime reproductive success in female Cuvier's, dama and dorcas gazelles (Gazella cuvieri, G. dama and G. dorcas)
Authors: Alados C. L. , Escós J.
Published: March 2009

Populations of Cuvier's, dama and dorcas gazelles were removed from the western Sahara to the Estacion Experimental de Zonas Aridas, Almeria, Spain, between 1970 and 1975. The life‐history records of all the females living between 1970 and 1988 were examined.

Results show that fecundity is lower in young females than in middle‐aged females, and that juvenile mortality is higher in fawns of young females. The adult body length of Cuvier's and dorcas gazelles is affected by their early development but this does not apply to the dama gazelle. The adult body length and the birth weight are positively correlated with longevity in female Cuvier's and dama gazelles, but for the dorcas gazelle only birth weight is related to longevity. Juvenile survival and reproductive performance of the three gazelle species studied are not related to adult body length or birth weight.

A high inbreeding coefficient reduces longevity in Cuvier's and dama gazelles but not in the dorcas gazelle. The effect of a high inbreeding coefficient is pronounced in the fecundity and juvenile survival of the female dama gazelle, less pronounced but evident in dorcas gazelle. The effects of inbreeding are minimal in Cuvier's gazelle and are evident only in the twinning rate. This result is surprising in view of the high inbreeding coefficient in Cuvier's gazelle relative to the other two species.

As in many mammals, birth weights in the three species studied are closely related to the probability of survival during the first days of life. One of the causes of decreasing birth weight in male and female offspring of Cuvier's gazelles and in female offspring of dorcas gazelles is their inbreeding coefficient. The inbreeding coefficient of the mother also reduces the offspring's birth weight in both sexes of the dama gazelle, but there is no influence on offspring of Cuvier's or dorcas gazelles. On the other hand, only the birth weight of the male offspring of the dorcas gazelle is influenced by the birth weight of its mother. Mother's age and offspring birth weight are related for male offspring of Cuvier's and dama gazelles.
Jaguar spacing, activity and habitat use in a seasonally flooded environment in Brazil
Authors: Crawshaw P. G. , Quigley H. B.
Published: March 2009

Between July 1980 and February 1984, six jaguars (two males, four females) were fitted with radio‐collars and monitored for a cumulative total of 105 months, in the Pantanal region of southwestern Brazil. Mean home range size (minimum convex polygon) for five of them (one male, four females) was 142‐ 1 km2. Mean home range size during the dry season was 54·3 km2, whereas in the wet season it was significantly smaller, 12·8 km2. Mean home range overlap of the four females was 42%. Use of gallery forest and forest patches exceeded the availability of these habitat types in the animals' home ranges, whereas open forest and grassland were used less than expected on the basis of their availability. Mean distance moved between locations on consecutive days was 2·4 km (0.2‐10·4 km). The mean one‐day movement of the male jaguar was significantly (P<0·001) larger than that of the females. Mean distance travelled by all animals during one‐day intervals in the dry season was significantly greater (P<0·001) than that travelled in other months. Jaguars were more active during daytime than night‐time (P<0·001). Overall level of activity for the wet season did not differ from that of the dry season. With their larger body size, jaguars in the Pantanal may require more food than jaguars in other areas of the species' range. This, in addition to differences in prey availability and the annual availability of dry land, appear to influence the difference in home range size between jaguar populations.
Female choice of large males in the treefrog Hyla ebraccata
Authors: Morris M. R.
Published: March 2009

The mating behaviour and male mating success of Hyla ebraccata were examined over three study periods. Mated males were larger than unmated males on a significant number of nights and for one of the three study periods. In field observations of pair formation, female behaviour was consistent with choice of large males: females moved freely through the chorus, remaining within 10 cm of males larger than the nightly mean, before the male initiated amplexus. In 27% (n = 3) of these observations, males chased and fought over the female. However, the females removed two of these three males from amplexus, suggesting that females can also exercise choice after amplexus. There was a significant negative correlation between male size and dominant frequency of the primary note, indicating that the male's advertisement call contained size‐related information. Comparisons of the size of mated and unmated males suggest that two factors may have affected the degree to which female choice influenced male mating success. First, the distance between calling males may have limited the opportunity for females to express a mating preference. Secondly, an increase in mean and a decrease in the variance of male size in one of the three study periods also may have limited the ability of females to express a preference for large males.
Chilopod coxal organs: morphological considerations with reference to function
Authors: Littlewood Henk
Published: March 2009

A comparative account of the morphology of chilopod coxal organs is given with special reference to their possible function.

Allometric relationships which exist between the size of the centipede and the number of coxal pores and organs are discussed in the context of size‐dependent physiological constraints which may affect the function of the coxal organs.
Rates of water turnover and energy expenditure of free‐living male common seals (Phoca vitulina)
Authors: Reilly J. J. , Fedak M. A.
Published: March 2009

The water and energy metabolism of free‐living male common seals (Phoca vitulina) during the mating season was investigated using labelled water methods. All three seals, which were captured on two occasions, were in negative energy balance during the study. The daily energy expenditure of one animal, estimated using doubly‐labelled water was 52·5 MJ. This is equivalent to six times the basal metabolic rate predicted from Kleiber's (1975) allometric equation. Rates of water turnover were slightly lower than predicted from the allometric equation of Richmond, Langham & Trujillo (1962). The observed rates of water turnover and energy expenditure are considerably higher than those of seals which fast during the mating season, and are consistent with the observed differences in behaviour between males of the common seal and other pinniped males during mating.
Convergence in foraging strategies by two morphologically and phylogenetically distinct nocturnal aerial insectivores
Authors: Brigham R. M. , Fenton M. B.
Published: March 2009

We used measurements of morphological parameters of common nighthawks (Chordeiles minor) and big brown bats (Eptesicus fuscus)to derive predictions about foraging behaviour based on the animals foraging at the same site. We tested the predictions using data from direct observation, radio telemetry and diet analysis and found a high degree of convergence in behaviour by these two species.
The effect of temperature on the tensile stiffness of mammalian tail tendons
Authors: Wang X. T. , de Ruister M. R. , Mcn Alexander R. , Ker R. F.
Published: March 2009

Our aim is to investigate whether the stiffness of tendons, when measured at room temperature, can be safely used in considering the function of the tendons at the higher temperatures encountered in life. We have examined stress‐strain plots given by tendons subjected to longitudinal tension. Under cyclic loading the plot becomes a hysteresis loop because of energy losses. Tail tendons were chosen because they are conveniently long, thin and uniform. The results show a small, but statistically significant, variation with temperature in the energy loss of hysteresis. The slope of the stress‐strain plot (i.e. the tangent modulus) shows no significant variation. We conclude that changes with temperature, in the range 20 to 41 °C, are not functionally important.
A note on the eggs of Benthoctopus piscatorum (Cephalopoda: Octopoda)
Authors: Nixon Marion
Published: March 2009

Benthoctopus piscatorum appears to be a multiple spawner. In the ovary of one specimen about 50 eggs were found at various stages of development.
Variation in eggs and the period of rapid yolk deposition of the silver gull Larus novaehollandiae during a protracted laying season
Authors: Meathrel Catherine E.
Published: March 2009

Silver gulls Larus novaehollandiae in south‐western Australia lay eggs over an eight‐month period with peaks in April, July and September. Clutch‐sizes, egg‐sizes and laying‐intervals did not differ between these three peaks, hut second eggs were smaller than first‐laid eggs on each occasion.

Rapid yolk deposition took 7–14 days. Daily increments of yolk growth were neither constant nor maternally influenced. The yolks of first‐laid eggs were laid down faster than the yolks of subsequent eggs. Egg size, weight and composition, as well as the period of rapid yolk deposition, may be proximately linked to the age, breeding experience, and body condition of laying females.
Refuge strategies and habitat segregation in two sympatric rodents Otomys unisulcatus and Parotomys brantsii
Authors: Plessis Amanda Du , Kerley G. I. H.
Published: March 2009

The possibility of different refuge strategies resulting in habitat segregation in two sympatric rodents, the bush Karoo rat, O. unisulcatus and the whistling rat, P. brantsii was investigated. The rodents' habitats were characterized by using the multivariate analysis procedures: ordination diagrams and hierarchical classification. The most important environmental variables were identified.

Otomys unisulcatus was restricted to areas with high percentage plant cover (60.6%) and dense foliage compared to P. brantsii habitat (plant cover=34.8%). The high percentage plant cover is necessary for nest construction. Parotomys brantsii habitat was characterized by deep Soil (76.9+15cm) with larger soil particles (0.31+0.2mm) compared to 47.5+30.3 cm soil depth and 0.15+0.1 mm soil particles in O. unisulcatus habitat. A suitable substratum therefore determines distribution of P. brantsii.

The different refuge strategies result in habitat segregation and may be an important means of partitioning resources between these two sympatric rodents which have comparable body sizes, adtivitym dietary and thermoregulatory patterns.
Foraging, feeding and prey remains in middens of juvenile Octopus vulgaris (Mollusca: Cephalopoda)
Authors: M.ather Jennifer A.
Published: March 2009

Juvenile Octopus vulgaris foraged by chemotactile exploration, mainly in crevices and under rocks. They caught small crustaceans and molluscs, including Lima bivalves, and preferred crabs and Lima in a simple laboratory choice test. Octopuses consumed 30% of their prey away from home, and small remains of prey deposited in the midden were selectively removed by waves and currents resulting in an underestimate of the octopus' intake and diet.
The spatial organization of otters (Lutra lutra) in Shetland
Authors: Kruuk H. , Moorhouse A.
Published: March 2009

The dispersion of otters Lutra lutra was studied along the coasts of an area of Shetland. The population was relatively stable, with about one adult otter per kilometre of coast. They fished diurnally in a strip of water usually within 100 m of the shore. Females lived in exclusive group ranges, occupied by up to four females, with well‐defined boundaries which were respected by successive occupants. For two groups, where relatively complete information was available, range size was 4.7 and 6.4 km, occupied by two and four females, respectively; a third range was about 14 km, with possibly 4–5 females. Within the group ranges individual females moved on their own or with their cubs. Each had a core area, where they were observed > 50% of the time; these core areas were separate from each other, although each individual used the entire group range. Several or all females in each range bred in any one summer. Male ranges were larger than those of females, and overlapped with two or more female group ranges; there were several resident males along each section of coast, but the information on males was incomplete. The habitats of the sexes were different; males spent more time on exposed coasts than did females. There were frequent visits to all coasts from non‐resident otters of both sexes.

Behavioural interactions related to territoriality are described; otters showed little overt aggression, except between adult males, but there was some individual avoidance. It is argued that the survival value of this spatial organization can be understood in terms of resource dispersion, but several types of resources have to be considered (including prey and fresh water), and detailed predictions of spatial organization from resource dispersion are unwarranted.
The significance of four xeric parameters in the ecology of terrestrial Tardigrada
Authors: Wright Jonathan C.
Published: March 2009

Tardigrades were sampled from diverse biotypes and classified according to four xeric variables to assess susceptibility to desiccation: exposure to insolation, elevation, and standardized desiccation rate and hydration capacity of the habitat plant. Fifteen tardigrade species were recorded including Hypsibius cataphractus Maucci, a new addition to the British fauna.

Xeric associations with seven tardigrade species were analysed by multiple regression, using incidence and population density as independent abundance estimates. Species show considerable variation in ecotype. The hygrophilic Macrobiotus hufelandi and Hypsibius dujar dini are excluded from rapidly desiccating habitats. Xerophiles, Milnesium tardigradum and H. oberhaeuseri, do not favour high insolation or high desiccation rate but apparently shun poorly drained sites and/ or prolonged hydration. Significant interspecific associations are identified between Milnesium tardigradum and two Hypsibius species which it may exploit for food. Negative associations between three other species—M. hufelandi, M. richtersi and H. prosostomus—suggest competitive exclusion.

The interstitial meiofauna of a dehydrating moss cushion migrates vertically to the proximal C‐zone, although this behaviour is not observed in Echiniscus testudo; implications of this for the species' ecotype are discussed.
Larvae of Maculinea rebeli, a large‐blue butterfly and their Myrmica host ants: patterns of caterpillar growth and survival
Authors: Elmes G. W. , Wardlaw J. C. , Thomas J. A.
Published: March 2009

Maculinea rebeli caterpillars spend their final instar as specific parasites of colonies of the ant Myrmica schencki. This paper describes 14 experiments in which 604 caterpillars were reared with six species of Myrmica. About 40% of caterpillars died during an initial period of integration: survival was significantly greater among the larger caterpillars, in M. schencki nests, and in nests that had ant‐brood present. The growth of the survivors was extremely variable. After three weeks they had gained 2–18 times their initial body weight and appeared to belong to two distinct types: fast and slow developers. Only 11% of caterpillars died during the next 37 days of growth, before a fall in temperature to below c. 14 d̀C caused them to overwinter. By then, the caterpillars weighed from 5–90 mg (mean 22 mg).

Caterpillars of all weights lost 33% of their mass during winter, and 8% died, before rising temperatures caused growth to resume in spring. Ofthe 363 that survived winter, 44% died during a period of spring growth and 12% pupated after about seven weeks. The latter came mainly from the largest caterpillars before winter and pupal size (mean weight 81 mg) was also related to prewinter caterpillar size. The remaining 44% of post‐winter caterpillars continued to grow slowly and then entered another quiescent phase and were still alive after one year in the nest. A small number of these pupated in the second year, an average of 404 days after adoption.

It is calculated that an average‐sized Myrmica schencki colony of 350 workers can produce 4–5 adult butterflies; this laboratory result agrees well with field observations. The results are discussed in the light of a previous behavioural study.
Seasonal and developmental changes of reproductive organs of male ringed seals (Phoca hispida) in the Svalbard area
Authors: Ryg M. , Smith T. G. , ØRitsland N. A.
Published: March 2009

The weights of testes, prostate gland and baculum of ringed seal males were related to age, season and differences in body size. There was a significant seasonal variation in testes and prostate gland size of sexually mature males, with a maximum occurring in early April. There were no seasonal changes in prostate weight of immature males, but some of the older immatures had elevated testes weights in April. Testes weight was significantly correlated with lean body mass. The increase in testes size with increasing body weight was greater for seals six years of age or older than for younger males. We suggest that some testicular growth and a seasonal cycle in testes growth occur before the testes become functional endocrinologically. We also believe that the primary event leading to puberty in ringed seals is an age‐dependent shift in metabolic processes, directing a larger percentage of available energy towards the reproductive organs.
Bipedal locomotion: effects of speed, size and limb posture in birds and humans
Authors: Gatesy S. M. , Biewener A. A.
Published: March 2009

Seven species of ground‐dwelling birds (body mass range: 0.045‐90 kg) were filmed while walking and running on a treadmill. High‐speed light films were also taken of humans to compare kinematic patterns of avian with human bipedalism. Consistent patterns of stride frequency, stride length, step length, duty factor and limb excursion were observed in all species, with most of the variation among species being due to differences in body size. In general, smaller bipeds have higher stride frequencies (αM−0.18), shorter stride lengths (αM0.38) and more limited ranges of speed within each gait than large bipeds. After normalizing for size (based on Froude number, after Alexander, 1977), remaining kinematic variation is largely due to interspecific differences in posture and relative limb segment lengths. For their size, smaller bipeds have greater step lengths, limb excursion angles and duty factors than large bipeds because of their more crouched posture and greater effective limb length. The most notable differences in limb kinematics between birds and humans occur at the walk‐run transition and are maintained as running speed increases. Change of gait is smooth and difficult to discern in birds, but distinct in humans, involving abrupt decreases in step length and duty factor (time of contact) and a corresponding increase in limb swing time. These differences appear to reflect a spring‐like run that is stiff in humans (favouring elastic energy recovery) but more compliant in birds (increasing time of ground contact). Differences between birds and humans in balance of the body's centre of mass not only affect femoral orientation and motion, but also affect pattern of limb excursion with speed.
Diet of samango monkeys (Cercopithecus mitis erythrarchus) in the Cape Vidal dune forest, South Africa
Authors: Lawes M. J.
Published: March 2009

The samango monkey (Cercopithecus mitis erythrarchus Peters, 1852) is the southernmost representative of the widely‐distributed polytypic Cercopithecus mitis species‐group. At Cape Vidal (28d̀ S) climatic seasonality causes significant seasonal fluctutation in food abundance. There are, however, no congeneric competitors, and few arboreal frugivores (birds, bats). In spite of seasonality of food abundance at Cape Vidal, samango monkeys maintain a high quality diet, dominated by fruit (51.7%), throughout the year. To a large extent this is made possible by their broad dietary tolerances and the effect of competitive release on food choice. Seasonal insect abundance does, however, place serious constraints on the availability of readily‐digestible protein and the acquisition of protein‐rich foods must be seen as the critically limiting factor in the dietary behaviour of the samango monkey. Adaptation of gut morphology and symbiotic microflora permit samangos to supplement the diet with large amounts of protein‐rich foliar and floral items. Where necessary, even large quantities of less palatable items, such as unripe fruits and mature leaves, may be ingested. Although insects form a small part of the diet a larger variety, than used by equatorial C. mitis populations, are included in the diet. Given that there are no congeneric competitors, nor are the monkeys particularly food stressed, I suggest that the diet of the samango monkey at Cape Vidal most closely reflects the intrinsic food choices of the C. mitis species‐group.
Ranging and nesting behaviour of the dormouse, Muscardinus avellanarius, in diverse low‐growing woodland
Authors: Bright P. W. , Morris P. A.
Published: March 2009

Thirty‐four dormice (Muscardinus avellanarius) were radiotracked to investigate their movements and use of space. They were found to be entirely arboreal and would make considerable detours rather than cross open ground. Their activities centred upon particular feeding sites which changed as the summer progressed. The animals did not range widely and normally were not found more than 100 m from their nest. Males travelled more widely than females. Male home ranges overlapped those of females but not each other. Dormice mostly chose to use artificial nestboxes; their few natural nest sites were mostly in the high shrub canopy, not in the low shrubs where dormouse nests have previously been reported. The implications of these findings are discussed in relation to conservation management of woodlands and the vulnerability of dormouse populations.
The ecology of Hypogeomys antimena, an endemic Madagascan rodent
Authors: Cook J. M. , Trevelyan R. , Walls S. S. , Hatcher M. , Rakotondraparany F.
Published: March 2009

The subfamily Nesomyinae comprises 11 species of rodents endemic to the island of Madagascar. They show considerable ecological and anatomical diversity but little is known of their biology and they have not been studied to any extent in the wild. We present here the results of a nine‐week field study of Hypogeomys antimena, the largest of the Nesomyinae, found only in a restricted area of dry deciduous forest in western Madagascar. Radiotracking data gave a mean home range estimate of 3.5+0.71 ha for 10 animals (five males, five females). Individuals from the same burrow had highly overlapping ranges but ranges of animals from neighbouring burrows showed minimal overlap. We suggest that H. antimena lives in social units, probably consisting of a pair plus their offspring, which occupy exclusive territories. A mark/recapture study gave a minimum population estimate of 48 animals/km2 in the study site. The conservation of the species is discussed with reference to its limited distribution and current habitat degradation in the area.
The semicircular canals of the hagfish Myxine glutinosa
Authors: McVean Alistair
Published: March 2009

The internal radius (r) and radius of curvature (R) of the single semicircular canals of Myxine glutinosa have unusual dimensions. In mammals and fish the increase in dimension of r and R with respect to body weight is small; in fish r is larger than in mammals of equivalent weight in order to increase the sensitivity of the canals to angular rotation and R increases correspondingly (Jones & Spells, 1963). In Myxine r is larger than in fish or mammals yet R is smaller. It is argued that the large internal radius is the result of the need to increase the sensitivity of a single canal which has to signal rotation in three planes while the small radius of curvature follows from the absence of a cupula. In order to verify that the cristae of the canals do respond to rotational velocity, recordings were obtained from the nerves serving the canals during rotation in the horizontal plane. The frequency response of several afferents recorded simultaneously at sinusoidal rotations between 0.25 and 2.0 Hz was in the form of a sine wave 90d̀ in advance of head position, as would be expected of a velocity transducer. The gain of single afferents was an order of magnitude less than those reported for other vertebrates.
Movements, diving and foraging behaviour of grey seals (Halichoerus grypus)
Authors: Thompson D. , Hammond P. S. , Nicholas K. S. , Fedak M. A.
Published: March 2009

This study presents the first direct observations of the movements and behaviour of free‐ranging grey seals at sea. Radio and ultrasonic transmitters were attached to three sub‐adult male grey seals which were then tracked from a suitable vessel. Behaviour at sea fell into one of three categories: travelling between haul‐outs, short duration trips, and resting adjacent to haul‐out sites. Travelling was characterized by direct, relatively fast horizontal movement and by V‐shaped dive profiles. During short duration trips the seals swam slower and invariably exhibited square‐wave dive profiles, spending approximately 60% of total dive duration at the maximum depth. Resting involved shallow dives close to haul‐out sites and an absence of directed lateral movement.

The excellent navigational abilities of grey seals are illustrated by the rapid, direct swimming between distant haul‐out sites. It is proposed that short duration trips are specifically for foraging because of their association with other piscivores, and because swimming was slow and mostly on or near the sea bed (grey seals are known to feed almost exclusively on demersal and benthic fish). These trips accounted for only 14% of the nine days that seal 1 was tracked. It is also proposed that the habit of diving to the sea bed whilst travelling between distant haul‐out sites is to allow opportunistic foraging with only a small increase in total swimming distance.
Kinematics of take‐off and climbing flight in butterflies
Authors: Brackenbury J. H.
Published: March 2009

High speed flash photography (flash duration 0.1 ms) was used to analyse wing movements in over 30 species of butterfly. With few exceptions, the insects showed a clap and peel mechanism of lift production at the start of the downstroke. Early in the upstroke the wings showed pronounced ventral flexure which, combined with inertial lag in the posterior parts of both wing pairs and delayed supination in the hind wing, led to the formation of a funnel‐like space between the wings. These movements, and the resultant airflow patterns, appear to be an axi‐symmetric equivalent of the ‘near’ clap and peel (here referred to as the funnel). Hind wing movements throughout the stroke are hinged upon the claval furrow. The expanded anal lobes of the hind wing lying medially to the claval furrow help to provide an air‐tight seal around the abdomen between the upper and lower wing surfaces, which increases the efficiency of the peel and funnel mechanisms. The role of the intercalary flexion lines in controlling changes in wing surface corrugation during the cycle is also investigated.
Aspects of digestion and in vitro fermentation in the caecum of some East African herbivores
Authors: Maloiy G. M. O. , Clemens E. T.
Published: March 2009

Caecal digestive functions were compared in 22 species of East African herbivores. Comparisons were made between ruminant pseudo‐ruminant, and non‐ruminant herbivores to assess the relative in vitro fermentation rate and composition of caecal contents from these species observed in their natural habitat. Measurements were made of caecal fermentation rate, organic acid composition, osmolality, pH and dry matter content. The data were compared by foregut structure, feed preference and body weight of the herbivores.
Early locomotor behaviour and the structure of the nervous system in embryos and larvae of the Australian lungfish, Neoceratodusforsteri‡
Authors: Whiting The Late H. P. , Bannister L. H. , Barwick R. E. , Bone Q.
Published: March 2009

This paper describes the development of early locomotor responses to mechanical stimulation in the Australian lungfish Neoceralodus and compares them with structural changes in the spinal cord. Initial movements occur spontaneously prior to innervation of myotomal muscles, and are therefore myogenic. After muscle innervation, embryos only move when stimulated; the first type of response to sharp touch is a unilateral flexion away from the stimulus, then at a later stage the contralateral response is followed by a homolateral flexure which, later still, passes into bursts of swimming. The initial contralateral response occurs when decussating interneurons are detectable but before spinal sensory innervation of the trunk; however, the trigeminal sensory pathway has been established by this time and probably mediates the first mechanoreceptive signals from trunk epidermis. Later, Rohon‐Beard cells innervate the trunk skin, and then dorsal root neurons take over the major sensory role. The secondary homolateral response and bursts of swimming are paralleled by the development of several types of spinal interneurons and the ingrowth of Mauthner cell axons.
Seasonal activity patterns of female polar bears (Ursus maritimus) in the Canadian Arctic as revealed by satellite telemetry
Authors: Messier F. , Taylor M. K. , Ramsay M. A.
Published: March 2009

We examined seasonal variations in activity level and mobility of female polar bears inhabiting the Canadian Arctic archipelago. The sea‐ice habitat consisted primarily of landfast, multi‐year ice except from July through October when loose pack‐ice predominated. The proportion of the day during which bears were active, and the distance travelled, were documented for 18 bears during 20 months with the aid of satellite telemetry. A peak of activity and mobility occurred in May‐July regardless of the reproductive status of tracked bears. The period of elevated activity coincided with a period when seals were especially vulnerable to bear predation. Winter months were characterized by low activity levels and mobility, a response probably related to a reduced access to seals and to inclement weather. During the period preceding den entry (May through September), pregnant females tended to be more mobile in May‐June, and less active in August September, compared to non‐pregnant, solitary females. Early den entry by pregnant females and facultative use of dens by other members of the population are viewed as a means to conserve energy for individuals with adequate fat reserves but experiencing conditions unfavourable for hunting seals. We conclude that seasonal variations in activity and mobility of polar bears seem closely linked to the temporal dynamics of bear‐seal interactions.
Factors affecting early mortality in the South American fur seal (Arctocephalus australis) in Peru: density‐related effects and predation
Authors: Harcourt Robert
Published: March 2009

Early mortality in the South American fur seal (Arctocephatus australis) in Peru is considerably higher than that seen in any other population of fur seal; 31–49% in the first month as opposed to a maximum of 20% in other populations. In 1987 and 1988, pup mortality was found to be enhanced by density‐related effects and predation on pups by the southern sea‐lion (Olaria byronia). At a high density beach, where 60% of the fur seals bred, mortality correlated with the number of females ashore as did aggression. Female aggression was driven to high levels by a combination of high density and movement within the colony to thermoregulate. However, even at a low density, beach mortality remained high due to a high level of predation by male southern sea‐lions (low density beach 5·0–8·3% of all pups; high density beach 0·2%). Predation rates were lower at the high density beach because male fur seals expelled most attacking sea‐lions during the breeding season (low density beach 10·0% of attacking sea‐lions expelled; high density beach 58·8%).