bluuebunny/crossref_metadata_2025 huggingface dataset:
Inter‐ and intraspecific variation in the post‐natal skull of some lacertid lizards
Authors: Barahona Fabiola , Barbadillo Luis Javier
Published: February 2006

Intra‐ and interspecific variation are analysed for the post‐natal skull of the lacertid lizards Gallotia galloti, Acanthodactylus erythrurus, Algyroides marchi, Lacerta monticola, Lacerta vivipara, Podarcis bocagei, Podarcis hispanica, Podarcis muralis, Psammodromus algirus and Psammodromus hispanicus. Individual variations identified include: the presence/absence, number and morphology of some structures, mainly in the lacrimal, sclerotic ossicles and maxilla; the number and location of foramina and the degree of ossification of some processes in chondrocranial bones. No differences have been found between the sexes with respect to presence and morphology of the bones but some species show sexual dimorphism in the size and robustness of the head and this may be reflected in the individual. The most substantial variations seen are ontogenetic: the appearance of new traits; development of articulations; differences between species in the timing of the stages of development of a given structure; changes in the relative position of some cranial elements; and the degree of calcification or ossification of processes. A total of 63 characters showing interspecific variations are identified. Some have not previously been described while others used in previous studies are redefined here on the basis of new morphological information obtained.
Eye morphology reflects habitat demands in three closely related ground beetle species (Coleoptera: Carabidae)
Authors: Bauer Thomas , Desender Konjev , Morwinsky Thomas , Betz Oliver
Published: February 2006

Asaphidion flavipes, A. curtum, and A. stierlini, which are similar in shape and size, were compared for morphological measurements of the head and eyes. The species not only differ in body size but also in the relative length of their antenna, the surface area of their compound eyes, the number and density of their ommatidia, and the structure of their visual space. These differences can be interpreted functionally and correlate well with features of the various habitats in which the species are found.
Applicability of external measurements to sexing of the Cape petrel Daption capense at within‐pair, within‐population and between‐population scales
Authors: Weidinger Karel , van Franeker Jan Andries
Published: February 2006

Sexual size dimorphism in the Cape petrel Daption capense was analysed to improve methods for sexing live birds in field studies. Samples originated from two geographically distant study populations in the Antarctic: Nelson Island, South Shetland Islands (sample N: 83 M, 89 F), and Ardery and O'Connor Islands, Windmill Islands (sample A: 36 M, 27 F). Using single characters with cut points calculated from sexed individuals, about 59–76% (N; best separator tarsus length) and 61–86% (A; best separator tube length) of birds could be assigned to the correct sex. Combination of characters improved performance of sample‐specific discriminant functions to a maximum of 84% in the N‐sample (five characters) and 95% in the A‐sample (four characters). The most useful character sets as well as ranking of individual characters (their weights) differed between samples. At the same time, cross‐testing revealed asymmetry in the applicability of sample‐specific functions to the other sample. Hence, the method of a generalized discriminant (Auk110: 492–502, 1993) was implemented and tested to develop a species‐specific discriminant for the Cape petrel. For all examined character sets, results of their cross‐application to the other sample were improved by using character weights estimated from combined samples instead of weights derived only from the original sample. The generalized function (tube length + 1.05*bill depth at tube + 0.72*culmen length + 0.07*wing length) combined with a cut point calculated from a distribution of discriminant scores (assumed mixture of two normal distributions with possibly unequal variances) is suggested as currently the best compromise for sexing Cape petrels in populations for which specific functions are not yet available: comparison with our best sample‐specific functions shows a decrease in accuracy by only 1% to 3%. However, examination of other promising characters (head length, bill depth at gonys, mid‐toe length) is recommended to improve further a generalized discriminant. In all cases a larger percentage (N: 87–89%, 38 pairs; A: 100%, 27 pairs) of individuals was correctly sexed by within‐pair comparison of discriminant scores than according to the sample‐specific cut point. No clear evidence for assortative mating with respect to body size has been found in this study. Available biometric data show little evidence for geographical variation in the Cape petrel, which suggests good applicability of generalized sex‐discriminants in other populations.
Respiratory stratagems, mechanisms, and morphology of the ‘lung’ of a tropical swamp worm, Alma emini Mich. (Oligochaeta: Glossoscolecidae): a transmission and scanning electron microscope study, with field and laboratory observations
Authors: Maina J. N. , Maloiy G. M. O. , Wood C. M.
Published: February 2006

The swamp worm Alma emini subsists in the highly productive waterlogged swamps around the East African Lake Victoria. The soil consists of putrefying plant matter from which gases like methane, carbon dioxide, and hydrogen sulphide are formed and profusely discharged. The interstitial spaces in the soil are generally anoxic and the soil is highly reducing. To survive in such an inimical habitat, Alma has evolved a remarkably unique respiratory strategy. The posterodorsal part of the body, which is well supplied with blood, is regularly converted into a ‘lung’ across which gases are exchanged at the surface or under water. Air and/or water may be entrapped in the ‘lung’ and carried for use (as a source of oxygen and/or a depository of carbon dioxide) during the ensuing underground sojourn. By evolving a unique respiratory potential, Alma emini has been able to flourish in a highly dynamic and virtually anoxic habitat while essentially having a capacity for aerobic biochemistry. Putative indications of cellular adaptations against hydrogen sulphide toxicity were observed, especially in the cells that line the ‘lung’. A. emini presents a good example of nature's tenacious and innovative designs for surviving in severe environments.
Activity budgets and ranging patterns of the Atlantic forest maned sloth Bradypus torquatus (Xenarthra: Bradypodidae)
Authors: Chiarello Adriano G.
Published: February 2006

Three maned sloths were observed for a total of 680 h throughout 14 months in an Atlantic forest reserve of south‐eastern Brazil. The study animals were located in the forest, monthly by radio‐telemetry, and data on daily activity budgets were collected recording the actual time they spent in major activities. Individual home ranges were very small (0.5–6 ha, depending on the method used) and the sloths travelled an average of only 24 m during the 24 h period. A comparison between day‐ and night‐range lengths suggests that maned sloths ranged more during daytime (17 m) than at night (5 m), indicating a predominantly diurnal period of activity. They rested, on average, for 74% of daytime, but a substantial variation was found between individuals (range 60–80%). Although a lack of synchrony was observed in activity pattern between study animals monitored simultaneously, all three sloths tended to start feeding and moving at the same time of the day (07:00–08:00), and the time that elapsed between the start of these activities on consecutive days was about 24 h, indicating a circadian rhythm of activity for the species. This finding contradicts previous studies on congeneric sloths, in which suggestions that Bradypus does not show cyclic patterns of activity were based on qualitative rather than quantitative data. Given the species' highly folivorous diet and the characteristic low basal rate of metabolism in this genus, the rather high levels of activity and the predominantly diurnal period of activity observed for maned sloths are probably related to the lower ambient temperatures found in the Atlantic forest when compared to other more equatorial localities of the Neotropics. Further studies with additional sloths are necessary, however, to ascertain the validity of this conclusion.
Stabilimentum variation and foraging success in Argiope aurantia and Argiope trifasciata (Araneae: Araneidae)
Authors: Blackledge Todd A.
Published: February 2006

Many spiders include conspicuous designs of white silk called stabilimenta in the centre of their orb webs. Stabilimenta are highly variable in their form and frequency and are hypothesized to function in either defence against predators or attraction of prey. These hypotheses generate different predictions about the effect of foraging success on variation in the form and frequency of stabilimenta. If stabilimenta serve as prey attractants, then starved spiders should invest more in them than well‐fed spiders, while the opposite pattern is expected if stabilimenta function as a predator defence mechanism. This study examines the effect of variation in foraging success of the yellow garden argiope Argiope aurantia and the banded argiope Argiope trifasciata on variation of their stabilimenta and orb webs. Both species built smaller stabilimenta when fed less, even though a stabilimentum accounts for only 10% of the dry weight of an orb web. Poorly fed A. trifasciata also included stabilimenta in their webs less often than did well‐fed A. trifasciata. Differences in stabilimenta were independent of differences between treatments in the orb webs themselves. These results argue against the prey attraction hypothesis, but not the predator defence hypothesis, since well‐fed spiders invested more in stabilimenta.
Estimating numbers of the water vole Arvicola terrestris: a correction to the published method
Authors: Morris P. A. , Morris M. J. , MacPherson D. , Jefferies D. J. , Strachan R. , Woodroffe G. L.
Published: February 2006

In Britain, the water vole (Arvicola terrestris) has declined in numbers and distribution (Jefferies, Morris & Mulleneux, 1989; Strachan & Jefferies, 1993). This species now enjoys a higher profile than hitherto and many local surveys have been initiated, following published methods. To monitor the status of the population or the effectiveness of habitat restoration projects, a method for estimating numbers of water voles is often needed, preferably based on latrines (a characteristic field sign of this species). Unfortunately, the published literature includes two potentially misleading components. In view of the significance of population size in a declining species, and the heightened interest in this animal, we felt it would be helpful to publish clarification and corrections in the hope of forestalling erroneous reports and conclusions in future investigations.
Foraging behaviour and diet of lactating female southern sea lions (Otaria flavescens) in the Falkland Islands
Authors: Thompson D. , Duck C. D. , McConnell B. J. , Garrett J.
Published: February 2006

This study investigated the foraging behaviour, diving behaviour, movements and diet of lactating southern sea lions in the Falkland Islands. They appeared to be primarily nocturnal, benthic foragers hunting at depths ranging from the surf line down to 250 m, and from just off their breeding sites out to 45 km offshore. Occasional longer trips may extend foraging ranges to over 150 km from breeding sites. Attendance patterns suggest that Falklands' sea lions do not haulout simply to feed their pups. Other factors such as predation and thermoregulation may cause them to come ashore. When at sea they travelled at approximately 1 m s−1, slower than previous studies of otariids indicated. Absence from the breeding site did not imply continuous foraging; all study animals used remote haulout sites away from their pups. Repeated use of the same areas and the short duration of foraging trips suggest that they were able to catch enough food within a fairly small foraging range. Data on diet support the suggestion that lactating sea lions are mainly benthic foragers. They take a wide range of prey species. The most common cephalopods were Loligo gahi, similar in size to those taken by the fishery. There is therefore potential for competition between the sea lion population and the Loligo trawl fishery. There was considerable overlap between the diet of sea lions and those of Gentoo and Magellanic penguins, which suggests that sea lions may compete with both species.
Use of European hare (Lepus europaeus) carcasses by an avian scavenging assemblage in Patagonia
Authors: Travaini Alejandro , Donázar José Antonio , Rodríguez Alejandro , Ceballos Olga , Funes Martín , Delibes Miguel , Hiraldo Fernando
Published: February 2006

We studied the use of European hare (Lepus europaeus) carcasses by avian scavengers in Argentinean Patagonia. A total of 16 hare carcasses were placed in locations that could be observed without disturbing birds feeding on them. Six avian species fed on these carcasses: chimango caracara (Milvago chimango), crested caracara (Polyborus plancus), black vulture (Coragyps atratus), grey eagle‐buzzard (Geranoaetus melanoleucus), red‐backed hawk (Buteo polyosoma) and cinereous harrier (Circus cinereus). Turkey vultures (Cathartes aura), although abundant, never fed on the hare carcasses. The Andean condor also did not feed on the carcasses. Mammals visited hare carcasses on only two occasions. Of the hare carcasses, 69% were fully consumed during the first day of exposure and 25% in two days. There was no difference in the time elapsed from the placement of the carcass and its detection by crested and chimango caracaras. There were similar time periods from detection to first arrival, and time elapsed from first arrival to the start of feeding at the carcass by crested and chimango caracaras. Hare body parts were consumed in different proportions by crested and chimango caracaras whereas black vultures consumed the whole carcass. Interspecific hierarchies at the carcass in a decreasing sequence of dominance were crested caracara > black vulture > chimango caracara, coinciding with that expected from a body mass perspective. The scavenging species that consume hare carcasses did not show a clear pattern denoting they were a highly interdependent assemblage in the way described for scavengers in Africa.
How high ambient temperature affects the daily activity and foraging time of a subtropical ungulate, the greater kudu (Tragelaphus strepsiceros)
Authors: Owen‐Smith Norman
Published: February 2006

The influence of ambient temperature on daily activity level was assessed for greater kudus observed in two study areas in South Africa. Active time proportion for adult females and subadults of both sexes was significantly negatively correlated with maximum daily temperature, but uninfluenced directly by cloud cover. However, maximum temperature differences between days accounted for only a quarter of the variability in active time. On most days the overall activity level and hence daily foraging time allocation were somewhat lower than the maximum levels observed for the prevailing temperature conditions. The upper limit to the distribution of active time was lower during the mild dry season than over the hot wet season, probably due to a seasonal change in pelage by kudus. Temperature influences were strongest during the early growing season, when food availability was low and conditions frequently hot. The active and foraging times of kudus during daylight hours appeared to be restricted below the target level only when maximum daily temperature exceeded 36 °C in the wet season, and 30 °C in the dry season. Only 15% of days exceeded these levels during the respective mid‐seasonal periods, suggesting that foraging activity was effectively constrained by thermal tolerance on only about one day in seven. Optimal foraging models that assume thermal stress to be a consistent daily constraint on foraging time may be misleading.
The behaviour and captive maintenance of the terrestrial nemertine (Geonemertes pelaensis)
Authors: Gerlach J.
Published: February 2006

The first successful captive maintenance of living terrestrial Geonemertes nemertines is reported. Behavioural observations are described, including the first data on diet in this genus. The species G. pelaensis is found to be a predator of small molluscs. In 1907 the Seychelles population was described as a distinct species, G. arboricola, largely on the basis of its arboreal habit. Recent field data from the Seychelles islands of Mahé and Silhouette confirm the tendency towards arboreal behaviour.
Diet of feralXenopus laevis(Daudin) in South Wales, U.K.
Authors: Measey G. J.
Published: February 2006

African clawed frogs (Xenopus laevis) in a South Wales pond ate a wide variety and size range of prey. Zoobenthos and zooplankton made the greatest contribution to diets, both numerically and by weight. Terrestrial invertebrates made up a small proportion of the diet numerically but a large proportion of the diet mass during the spring and summer. Nektonic prey were present throughout the year but made up a very small proportion of diet. Cannibalism was important when eggs and larvae were present in the pond. Electivity values were consistently positive for chironomids (larvae and pupae) and daphnids but were consistently negative for tubificids. In addition, electivity increased for larger sizes and pupae ofChironomus plumosus, but was low for the largest size class (> 12 mm). Electivity of other taxa showed an increase when densities of chironomids and daphnids were reduced. Mean sizes of daphnids and cyclopods were consistently larger in frog stomach contents than in the water column, indicating that predation on zooplankton byXenopus laevisis size‐selective.
Microhabitat and spatial dispersion of the grassland mouse (Mus spretus Lataste)
Authors: Gray Samantha J. , Hurst Jane L. , Stidworthy Richard , Smith John , Preston Rowan , MacDougall Robert
Published: February 2006

Many small mammals inhabiting vegetation habitats where food resources are scattered have large home ranges with limited overlap. One way that they may effectively defend large territories is to establish dominance over the limited number of sites that provide good protection from predators, since displacement from these sites could have a very high cost to intruders. To examine this hypothesis we studied the fine‐scale use of habitat and spatial dispersion of all adult male Mus spretus inhabiting a 1.1 ha grassland study site near Lisbon, Portugal, by radio telemetry, at the start of the breeding season. The location of each of the 10 males was mapped every hour, 24 h/day for up to seven days. Microhabitat characteristics were compared between a random sample of points in the study site and those where mice were found. Individual ranges did not overlap, despite the close proximity of their borders and the occupation of almost all suitable habitat, suggesting that individual dispersion was strongly influenced by the presence of neighbours; mean range size was 343 ± 95 m2. Residents covered less than one‐third of their total range over 24 h, though neighbours did not intrude despite the apparent opportunities. Each male territory overlapped the territory of at least two females. Mice were neither nocturnal nor crepuscular, moving around mostly during the morning and evening. They avoided open woodland or pathways, preferring grassland sites with tall vegetation and sites where shrubs, bramble, or dead wood provided additional cover. Most fixes per male (70%) were located in one to four core areas, which represented only a tiny proportion of each range (6.9 ± 0.9%). Although exclusive defence of large complex ranges is likely to be impracticable, defence of core areas seems much more feasible. Our results thus support our hypothesis that mice may be able to maintain large exclusive ranges due to a combination of high predation pressure and a limited number of sites with sufficient ground and overhead cover. This will result in a very high risk to mice entering areas where competitors have priority of access to protected sites.
Neotricula aperta (Gastropoda: Pomatiopsidae), the intermediate host of Schistosoma mekongi: allozyme variation and relationships between Khmer, Lao, and Thai populations
Authors: Attwood S. W. , Kitikoon V. , Southgate V. R.
Published: February 2006

Variation was studied at 13 electrophoretically detected allozyme loci for samples of six populations of the polytypic snail Neotricula aperta; this was the first time that topotypic material from southern Laos and material from Kampuchea had been so examined. In addition, samples of all three strains of N. aperta from North East Thailand were examined and the findings compared with those of Staub et al. (1990). The samples were taken from the Mekong and Mul rivers of the Lower Mekong Basin. A small sample was also included from a γ‐strain population in the Xé‐Bang‐Fai (XBF) river of central Laos. The γ‐strain population of southern Laos and of Kampuchea has been shown to act as an intermediate host for Schistosoma mekongi.

In contrast to the work of Staub et al. (1990) significant multilocus genetic differences (Nei's D, DN= 0.6–1.2) were detected between the three strains from Thailand and no cryptic taxon, that included both α‐ and γ‐strains could be demonstrated. However, there was agreement with the 1990 report in that the β‐strain was divisible into two new taxa, with a reduction in heterozygote deficiency, although the genetic distance was not marked (DN= 0.12). Significant genetic distances were found between γ‐strain snails from the type locality and β‐ and γ‐strain samples from North East Thailand (DN= 2.0 and 1.5, respectively). On the basis of genetic distance measures, the Β‐strain is probably a sibling species of N. aperta and the γ‐strain of North East Thailand may also be a separate species. The population at XBF appears to be N. aperta s.s. The public health implications of the findings are discussed, particularly in the context of Mekong river water resource development.
Long‐term study of litter size in relation to population density in rabbits (Oryctolagus cuniculus) in Lincolnshire, England
Authors: Trout R. C. , Smith G. C.
Published: February 2006

After the introduction of myxomatosis to the U.K. in 1953, the rabbit Oryctolagus cuniculus population crashed to less than 1% of its original size (Lloyd, 1970). Since that time the population has been slowly recovering, and reached about 20% of pre‐myxomatosis levels by 1980 (Lloyd, 1981; Trout, Tapper & Harradine, 1986). Between 1980 and 1986 an index of rabbit abundance was produced from field surveys, which resulted in an estimated population growth rate of just under 1% per year but there has been no objective assessment of the changes nationally since 1986.
The influence of female size on the extent and intensity of mate guarding by males in Chamaeleo chamaeleon
Authors: Cuadrado Mariano
Published: February 2006

In ectotherms, the size of the female correlates with fecundity and thus, males prefer large more fecund females as potential mates in some species. The idea that the extent and intensity of mate guarding are also size‐related was tested in the common chameleon Chamaeleo chamaeleon. Mate guarding was studied in 43 radio‐tagged females during 3 years in a population in southern Spain. The extent and intensity of male guarding of their mates varied greatly. On average, the guarding started on 20 August and ended on 2 September (mean duration = 12.6 days, range 2–44 days, n= 35; six females were not guarded). Guarding continued for some days after mating (range = 0‐13 days, n= 16). Guarding intensity (mean = 65.8% of net observation time with a guarding mate, range = 23–90, n= 27) and number of guarding males (mean = 1.8, range = 1–7) also varied greatly. The extent and intensity of mate guarding was strongly influenced by female size and the guarding period after mating: large females were guarded early in the season, for longer periods, and more intensively than small ones. Large females were also guarded for longer periods after mating. The overall variation in the guarding period was due to the duration of guarding before mating which was longer for large females. To my knowledge, this is the first time that prolonged mate guarding of larger females has been reported.
The influence of rainfall on range in a female desert ungulate: the Arabian oryx (Oryx leucoryx) in the Sultanate of Oman
Authors: Corp N. , Spalton A. , Gorman M. L.
Published: February 2006

In this study we investigated the effect of rainfall on the home range (calculated over 90 days) of adult female Arabian oryx (Oryx leucoryx) in a reintroduced population in central Oman. We looked at response to rainfall for six rain events in the period June 1986 to January 1992; rainfall was localized on five occasions and on one occasion covered the study area. Response, in terms of range and core area, showed considerable variation between rainfall events, perhaps as a result of variation in ranging behaviour between individual oryx. However, in the first 90 days after localized rainfall the home range and core area of oryx outside rain areas increased before decreasing significantly 91–180 days after rain. In comparison, range and core area of oryx inside areas of localized rainfall either did not change or decreased after rainfall as animals took advantage of improved conditions locally rather than investigating grazing elsewhere. When rain fell over the whole study area, range size did not change, but there was an immediate increase in core area and a reduction in range overlap indicating movement to new areas. During extended drought very localized rainfall caused oryx to move quickly to areas of new rain and by 28 days 70% of all adult females had found fresh grazing. Thereafter numbers declined to around 30% by 225 days, before oryx again moved back into the new rain areas. We attributed this pattern of movement to changes in the nutritional quality, measured as crude protein, of available forage. Data for single animals revealed considerable individual variation in response to rainfall; some animals moved quickly to rain whilst others failed to reach it. This variation had consequences for reproductive success and survival and illustrated that, for the oryx, response to rainfall is a key to desert success.
Presence of acid phosphatase in the epidermis of the regenerating tail of the lizard (Podarcis muralis) and its possible role in the process of shedding and keratinization
Authors: Alibardi L.
Published: February 2006

The activity and distribution of the lysosomal marker enzyme acid phosphatase have been studied in the epidermis during tail regeneration in the lizard Podarcis muralis. This study gives information both on the mechanism of separation of the old from the new epidermal generation and on the involvement of lysosomes in β‐ and α‐keratinization in lepidosaurians. The biochemical analysis shows that the activity of acid phosphatase was higher in the regenerating tail than in the normal tail until the stage of skin shedding at around 25–30 days post‐amputation. The enzyme was present in keratinizing layers of epidermis, and particularly in the shedding layer. The shedding layer followed the outline of the regenerating scales beneath the wound in the epidermis showing that lysosomal enzymes are involved in epidermal shedding. The ultrastructural study showed that acid phosphatase was initially localized within the lysosomes but, with the progress of differentiation, it also appeared free within the cytoplasm of the cornifying cells of the shedding complex and of the β‐keratinizing cells, and in the intercellular space among them. The role of lysosomal enzymes in the shedding process and their involvement in the mechanism of β‐keratinization is discussed. While the process of β‐keratinization has an intracellular and extracellular localization of acid phosphatase, the process of α‐keratinization shows that most acid phosphatase is localized within the cell. Lysosomes and mesos granules containing acid phosphatase were concentrated in the cytoplasm of differentiating mesos cells. Some mesos granules later discharged their contents into the extracellular space. The α‐layer was partially formed in proximal regenerated scales around 30 days post‐amputation. Lysosomes appeared to concentrate within pre‐keratinizing cells of the α‐keratin layer and little reactivity was seen extracellularly.
Phylogenetic relationships of otters (Carnivora: Mustelidae) based on mitochondrial cytochrome b sequences
Authors: Koepfli K.‐P. , Wayne R. K.
Published: February 2006

Otters are classified in the Lutrinae and are united by a suite of semi‐aquatic adaptations that distinguish them from the rest of the Mustelidae. Past systematic studies have been based primarily on overall similarity of morphological characters but have not been concordant, with regard either to relationships within the subfamily or to the relationships of the Lutrinae to other taxa in the Mustelidae. We evaluate the relationships among nine of the 13 species of otters and their position in the Mustelidae through phylogenetic analysis of the complete nucleotide sequence of the mitochondrial cytochrome b gene. Based on the sequence data presented here, our results suggest that otters are divided into three primary clades that include: (1) the North American river, neotropical and marine otters; (2) the sea, Eurasian, spotted‐necked, cape clawless and small‐clawed otters; and (3) the giant otter. Furthermore, our results indicate that among sampled mustelid taxa, members of the genus Mustela are most closely related to otters. The hierarchical relationships among clades are not well resolved, particularly the monophyly of otters, largely because a pattern of short internal branches combined with long terminal branches suggests a rapid evolutionary radiation. Estimates of divergence time calibrated by the fossil record suggest that the lineages leading to the North American river, neotropical and marine otters, and the giant otter diverged before the end of the Miocene, much earlier than predicted from the fossil record.
DNA fingerprinting reveals high levels of genetic diversity within British populations of the introduced non‐native grey squirrel (Sciurus carolinensis)
Authors: David‐Gray Z. K. , Gurnell J. , Hunt D. M.
Published: February 2006

In general, if populations are founded by very small numbers of individuals, low levels of genetic diversity amongst subsequent generations known as founder effects, can be predicted to occur as a result of genetic drift (Franklin, 1980; Lacy, 1997). A loss of genetic variation has been reported in several species that have experienced genetic bottlenecks because of habitat fragmentation, geographic isolation or inbreeding depression (Gilbert et al., 1990; Hoelzel & Dover, 1991; Ellegren et al., 1993; Timms et al., 1993; Wauters, Casale & Dhondt, 1994; Wauters, 1997). This loss of genetic diversity can have deleterious effects on reproductive output. For example, laboratory and captive breeding programmes provide extensive evidence of both decreased fecundity and reduced juvenile survival (Ralls & Ballon, 1982, 1986; Du Bois, Dhondt & Van Puijenbroek, 1990; Brock & White, 1992), and research conducted on natural populations of common shrews Sorex araneus has reported similar findings (Stockley et al., 1994). However, genetic evidence from some wild populations shows that highly inbred populations can survive and thrive despite low levels of genetic variability (Gilbert et al., 1990; Wayne et al., 1991; Ellegren et al., 1993). Grey squirrels Sciurus carolinensis, were introduced into Britain from eastern North America on several occasions between 1876 and 1910. Furthermore, between 1906 and 1937 grey squirrels were translocated to a variety of different locations within Britain (Middleton, 1931; Shorten, 1954). From the 1930s it rapidly expanded its range and is now ubiquitous to almost all of central and southern England, Wales and some lowland areas of Scotland (Lloyd, 1962, 1983; Gurnell &; Pepper, 1993). In view of this highly successful colonization by an invading species the grey squirrel appears to have been unaffected by any loss of genetic diversity as a result of recent population bottlenecks. We have used DNA fingerprinting (Jeffreys, Wilson & Thein, 1985a), a technique which provides a good indication of genome variability (Jeffreys et al., 1985b; Kuhnlein et al., 1990; Kunieda et al., 1993) to assess overall levels of genetic diversity in two British grey squirrel populations; Alice Holt Forest on the borders of Hampshire and Surrey in southern England and Thetford Forest in East Anglia.
Use of artificial water supplies by captive‐born mountain gazelles (Gazella gazella) released in central Arabia
Authors: Dunham K. M.
Published: February 2006

Tagged, captive‐bred mountain gazelles were released into Hawtah Reserve, Saudi Arabia. More than 1 year after they were freed, their drinking behaviour at two water troughs was recorded for 2.5 months during late summer/autumn, using automatic cameras and monitors triggered when an infra‐red beam was broken. Only 30% of gazelles (n= 40) were recorded drinking and only individuals which lived close to troughs drank. No gazelles visited the one natural water point. Among gazelles which lived close to the troughs, older individuals were more likely to drink than younger animals. The noise of the cameras as they took a photograph frightened some gazelles and may have influenced their frequency of drinking after they were photographed for the first time.
Estimating the population density of Galemys pyrenaicus in four Spanish rivers
Authors: Nores C. , Ojeda F. , Ruano A. , Villate I. , González J. , Cano J. M. , García E.
Published: February 2006

In spite of the studies carried out for several decades on Galemys pyrenaicus, no paper has specifically estimated desman densities, although indirect information can be inferred from the studies in the French Pyrenees on the use of space by Stone & Gorman (1985) and Stone (1987a).
Wing shape in New Zealand lesser short‐tailed bats (Mystacina tuberculata)
Authors: Webb P. I. , Sedgeley J. A. , O'Donnell C. F. J.
Published: February 2006

The theoretically optimal shape of a bat's wing changes with flight mode (Norberg, 1987; Norberg & Rayner, 1987) and several studies have shown this theory to be largely born out in practise (Aldridge & Rautenbach, 1987; Norberg & Rayner, 1987; Crome & Richards, 1988). For instance, bats with wings of relatively low surface area (high wing loading) that are also relatively long and thin (high aspect ratio) tend to be fast, straight fliers spending most of their flying time foraging or commuting in open areas such as pasture or above the forest canopy (Norberg & Rayner, 1987). In such bats manoeuvrability is improved by the possession of small, pointed wing tips to reduce drag. In contrast bats with wings of relatively high surface area that are also relatively short and wide with large, rounded wing tips tend to be slow, highly manoeuvrable fliers foraging in cluttered habitats such as woodland (Norberg & Rayner, 1987).
The influence of public access and sett visibility on badger (Meles meles) sett disturbance and persistence
Authors: Jenkinson S. , Wheater C. P.
Published: February 2006

The impact of public rights of way on badger setts was examined in the Bradford area of West Yorkshire using comparisons of 38 setts surveyed in 1985–1996 and again in 1992–1993. Badger setts were compared on the basis of whether they were still in use or not, and on the number of illegal disturbance events recorded over the study period. The number of, and distance from, public accesses did not influence sett persistence, and the least frequently disturbed setts (i.e. those with an average of one or less disturbance incidents every 2 years) were closer to a larger number of accesses. Frequency of poaching was high near to heavily disturbed setts and those no longer occupied at the later survey. Less frequently disturbed setts were associated with landowners who were unsupportive of badger conservation: it is possible that such landowners are highly protective of their land and thus incidentally reduce the frequency of poaching and other forms of disturbance. Setts in areas with formal authorized shooting were less disturbed. Setts still in use tended to be in open habitats and visible from roads and nearby dwellings. Setts in open areas were less often disturbed than those in wooded sites. Since public access may not reduce sett persistence and may even be beneficial in an area of high wilful persecution, there are implications for the management of public access.
Morphological diversity of ground beetles (Coleoptera: Carabidae) in Scottish agricultural land
Authors: Ribera I. , McCracken D. I. , Foster G. N. , Downie I. S. , Abernethy V. J.
Published: February 2006

The morphospace defined by 87 species of ground beetle (Coleoptera: Carabidae) of Scottish non‐forested habitats is described with multivariate methods, using 13 linear quantitative measurements of the body, hind legs, eyes and antennae, plus five qualitative characters concerned with body shape, colour, wing development, and pubescence. Relationships between pairs of variables are studied with phylogenetic independent contrasts, using two different taxonomic classifications as an approximation to the phylogeny of the group. The first ordination axis of the morphospace was found mainly to reflect the positive correlation between length of the antennae and length of the hind legs, the second to reflect the width of the head, diameter of the eye and pronotum height, and the third the width of the pronotum and elytra, length of the metatrochanter and width of the metafemur. The principal relationships involving qualitative characters were between colour of the body and legs and shape of the pronotum with ordination axes, wing development with width of the elytra, and pubescence with colour of the legs. Most correlations between quantitative variables, in particular those most influencing the ordination axes of the morphospace, remained significant when measured with phylogenetic independent contrasts using both classifications. Independent contrasts comparing qualitative with quantitative variables or ordination axes were only significant for the colour of the body with the second axis for both classifications used, and length of the antennae with colour of the body and shape of the pronotum for only one of the classifications. The main morphological trends within the morphospace defined are related with published information on their performance, in particular running speed and pushing abilities, following previous work on the functional morphology of the group. The morphospace defined by the species studied is a fundamental tool that will allow further investigations on the relationships between their morphology and life traits, as well as on the relationships of the functional diversity thus characterized with environmental correlates.
Foraging strategies and food partitioning in the neotropical frugivorous mammals Caluromys philander and Potos flavus
Authors: Julien‐Laferrière D.
Published: February 2006

The bare‐tailed woolly opossum, Caluromys philander, and the kinkajou, Potos flavus, are two syntopic neotropical nocturnal, arboreal and frugivorous mammals. Because of close ecology but great difference in size (weight 300 vs 3000 g), they represent pertinent models to examine the influence of size on foraging strategy. These species were studied by radio‐tracking and direct observation during 22 months in a tropical forest in French Guiana. Both mammals’ foraging strategies with regard to flowers and fruits are characterized as follows: (1) numerous plant families and species are exploited; (2) most plant species are selected according to their abundance; (3) diet selectivity and diversity are similar in both mammals; (4) relative parts of flowers and fruits in the diet vary according to their year‐long availability; (5) the choice of fruiting species is not related to the morphological type, size, or nutritious quality of fruits but instead depends on easy access to the edible part; (6) the length of foraging bouts is correlated with production for the most frequently exploited tree species; (7) feeding bouts are shorter in P. flavus than in C. philander; (8) P. flavus exploits large, highly productive canopy trees, while C. philander also visits canopy trees with low production and understorey trees. In conclusion, both mammals are opportunistic flower‐ and fruit‐eaters, but the larger species (P. flavus) exploits larger, more scattered food patches, while the smaller one (C. philander) also exploits smaller, more numerous and more evenly distributed food patches.
Study of the spatial organization of the gas exchange components of a snake lung – the sandboa Eryx colubrinus (Reptilia: Ophidia: Colubridae) – by latex casting
Authors: Maina J. N. , Veltcamp C. J. , Henry J.
Published: February 2006

The vasculature and the air ways of the lung of the sandboa Eryx colubrinus were cast using latex rubber, corroded, and studied with a scanning electron microscope to determine the shape, topographic configurations, and relative sizes of the gas exchange components. The sandboa had a right lung and a vestigeal left one. The lung, which terminated close to the anus, consisted of two distinctive anatomical regions. The exchange tissue was located in the cranial half of the lung while the caudal one consisted of a transparent avascular ‘air sac’. The right pulmonary artery, which was found on the laterodorsal aspect of the lung, gave rise to branches which supplied blood to the pleura and the faveolar septal walls. The geometric relationship between the flow of the venous blood (from the pulmonary artery) into the parenchymal zone of the lung and the convective/diffusive outwards air flow from the central air duct into the parenchyma is essentially counter‐current: the air moves centrifugally and the blood centripetally. However, the arrangement between the air flow in central air duct and that of the venous blood is cross‐current (i.e. the two media run in directions perpendicular to each other). These architectural schemes are similar to those that have developed in the avian lung. In fact, in its simplest form, the parenchymal region of the snake's lung corresponds with a single tertiary bronchus (parabronchus) of a bird lung. Further investigations are necessary to identify the factors that enforced this morphological convergence and to verify whether these congruent features are analogous, as they would seem to be, or from a phylogenetic perspective possibly homologous.
Geophagy in the golden‐faced saki monkey (Pithecia pithecia chrysocephala) in the Central Amazon
Authors: Setz E. Z. F. , Enzweiler J. , Solferini V. N. , Amêndola M. P. , Berton R. S.
Published: February 2006

The golden‐faced saki monkeyPithecia pithecia chrysocephala(Cebidae, Primates) was observed eating soil from termite nests during a long‐term study of a family group in a Central Amazonian forest fragment. In this paper we describe the behaviour involved in the geophagy in these monkeys, and the results of geochemical and physical analyses of the termite nest material, as well as root mat and topsoil samples below the trees, in order to clarify the possible reasons for it. The sakis ate soil from nine arboreal termite nests on 26 soil feeding‐bouts (in 853 observation hours); 25 soil feeding‐bouts occurred in March 1987 (rainy season), during 19 days or 132 observation hours, and occupied 0.7% of the feeding time. Geophagy frequencies did not differ between sexes (17 feeding‐bouts of four females and 8 for two males). Mineral composition was higher in arboreal termitaria than in the topsoil. Kaolinite was the major clay component. Tannin adsorptive capacity, tested through a modified radial diffusion method of Hagerman, was around 10–20%, similar to a control with kaolin (10–20%), but lower than bentonite or celite (30–45%). The observations reported here, although inconclusive as to the function of geophagy in this species, indicate that it is not a mineral supplement during times of scarcity or high consumption of leaves, as has been reported for other primates, nor that it is related to fruit consumption (redressing possible mineral imbalance), as has been suggested for some other frugivorous mammals. Our results do not rule out tannin adsorptive hypothesis for the ingestion of clays, but, being an irregular habit, we argue that it is most likely related to rare and occasional dietary components.
Use of space and social organization of female mountain gazelles (Gazella gazella gazella) in Ramat HaNadiv, Israel
Authors: Geffen H. , Perevolotsky A. , Geffen E. , Yom‐Tov Y.
Published: February 2006

The social organization of female mountain gazelles was studied on Mount Carmel, Israel. The behaviour of distinctly recognized individuals was studied by year‐round observations. Female gazelles lived in groups whose composition remained constant throughout the year, and new females did not freely enter the established groups. Group home ranges overlapped, but various groups replaced each other in the same area at different times of the day. Different groups tended to use different parts of the overlapping home range. In general, but especially in summer, the different groups largely avoided being synchronously together in the same area. The occurrence of two groups in the same area at the same time was a rare event and when it occurred, a high rate of agonistic interaction was observed between the groups. Hence, groups of female mountain gazelles hold and defend temporal territories against other female groups. Mean seasonal group size ranged between 3.4 and 6.4 and was largest during winter, when groups of females joined together occasionally and little agonistic interaction was observed between the groups. It is suggested that group size is affected by food availability and predation pressure.
Do acid rain and calcium supply limit eggshell formation for blue tits (Parus caeruleus) in the U.K.?
Authors: Ramsay S. L. , Houston D. C.
Published: February 2006

The normal diet of most small passerines contains insufficient calcium for effective eggshell formation and birds must often forage specifically for calcium‐rich items in the environment. It has been demonstrated that anthropogenic acid precipitation can significantly reduce levels of available calcium in soil and the abundance of calcareous items such as snail shells. Recent research in areas adversely affected by acid precipitation on Continental Europe has suggested that reduced calcium availability has resulted in an increased incidence of eggshell defects in small birds. In this paper we present data from one of the areas of the U.K. most severely affected by acid precipitation and where snail abundance (0.36 snails per m2) and exchangeable soil calcium levels (0.02 mg g−2) were very low: lower than values at sites in the Netherlands where severe eggshell defects occurred. The provision of supplementary calcium and the examination of eggshells, however, provided no evidence that blue tits Parus caeruleus were constrained in their ability to form effective eggshells as a result of calcium deficiency. We suggest that other factors, besides low calcium availability, may be contributory to the high incidence of eggshell defects seen in other areas.