摘要:

Five Cape grey mongooses (Galerella pulverulenta(Wagner, 1839)) were radio‐tracked from November 1988 to February 1989 in the West Coast National Park, Cape Province, South Africa. Animal locations numbering 2253 were recorded. Radio‐tagged mongooses were diurnally active and frequented thick mediterranean‐type scrub; sightings of untagged mongooses followed the same pattern. Home range size (95% harmonic mean) of resident animals in the study period ranged from 21 to 63 ha. One female had the smallest range; the other, a juvenile, ranged more widely, possibly dispersing, and utilized a more varied habitat. Home ranges overlapped widely, both within and between sexes, although territoriality among adult females cannot be ruled out. Males showed some degree of sociality. Possible reasons for this spatial system are disc

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04037.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The diet of great black‐backed gulls (Larus marinus) on Cape Clear Island, Ireland consists largely offish and auks. Other foods, including mammals, crabs and goose barnacles (Lepas), represent less than 10% of the diet by weight. Most fish consumed are obtained as waste from fishing boats. The use of otoliths to determine fish dimensions and problems with the technique are discusse

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04038.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Although the bones of rapidly growing animals are composed of weak tissue, they often must function in locomotor activity. We address the conflict between development and skeletal function by analysing the ontogeny of skeletal strength in the California gull,Larus californicus.Changes in shape and mechanical properties of the femur, tibia, tarsometatarsus, humerus, ulna and carpometacarpus were analysed in a complete post‐hatching growth series. During post‐hatching growth, strength and stiffness of the skeletal tissue increases six‐ to ten‐fold. At hatching, long bones of the wing are relatively weak and they remain so throughout the major portion of the growth period. However, in the hind limb, relatively thick bones in juveniles compensate for the weak tissue such that the force required to break the bones remains constant relative to body mass. This difference between hind limb and wing parallels the development of locomotor function; young gulls begin to walk within a day or two of hatching, but they do not fly until they are fully grown. Thus, in the bones of the hind limb, the conflict between rapid growth and skeletal function is solved by negative allometry of bone thickness.After young gulls reach adult size, the breaking strength of the wing bones increases three‐ to four‐fold, the mass of the pectoralis muscle triples and the surface area of the wing doubles. The one aspect of wing development that is not delayed until shortly before fledging is linear growth of the bones. Bones of the wing increase in length at a rapid and relatively constant rate from the time of hatching to the attainment of adult size. Relatively early initiation of linear growth of the wing bones suggests that the rate at which bones grow in length may be the rate limiting factor in wing

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04039.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

In 1988, there was a marked increase in the mortality rate of the common seal (Phoca vitulina) in European waters which was shown to be associated with a canine distemper‐like virus (CDV), recently named Phocid Distemper Virus (Cosbyet al., 1988). Investigations were carried out to determine the ability of common seals to respond immunologically and to determine the levels of antibody produced. Common seal immunoglobulins were purified, analysed and shown to be similar to those of other mammals. A simple immunoassay to measure seal antibodies to CDV was developed and showed striking differences between the susceptible seals (low levels of antibodies) and the surviving common seals (high amounts of anti‐distemper antibodies). Similar results were obtained with a neutralization test currently used to measure antibody titres to canine distemper virus in the dog. The adult common seals had high antibody titres and may be protected for future years, whereas the younger seals did not develop high levels of antibodies. This may be because either the younger seals had not encountered the virus or had not developed effective immun

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04040.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

This paper presents a study of patterns of cranial variation within and between extant hominoids. Particular attention is paid to the relationship between sexual dimorphisms and size differences between sexes. It emerges that shape contrasts between sexes are closely linked to size differences whilst variance dimorphism appears to be relatively independent of size effects. This study demonstrates that there are differences between the hominoids in their magnitudes and patterns of sexual shape contrasts. These types of differences are also found to exist between subgroups of modern humans. It is suggested that the differences which occur between hominoid groups in their patterns of sexual dimorphism are probably the result of a mixture of time and rate hypermorphoses (in males relative to females) acting upon different ontogenetic trajectories. The findings of this study suggest the need for caution in extrapolating from the sexual dimorphisms found in living hominoids to hypothesized dimorphisms in fossils.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04041.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Fourteen species of reptiles have been recorded from the island of Dominica, Lesser Antilles. As part of a larger study of the ecology of Dominica's forests, the distribution, density and biomass of three widespread lizard species (Anolis oculatus, Ameiva fuscataandMabuya mabouya) were estimated in all major vegetation types. No consistent differences between seasons occurred for any of the three species, and at no site was a definite breeding season detected. Densities, estimated mainly by plot counts, were highest in coastal woodlands where mean densities reached 2148Anolisper hectare, 379Ameivaper hectare, and 751Mabuyaper hectare. Densities in rain forest sites were often very low. Combined biomass for the three species also reached a maximum in coastal woodlands of 44.7 kg/ha. This value is amongst the highest recorded for terrestrial reptile assemblages, and suggests that Dominica's coastal woodlands are unusually favourable habitats for reptiles.Previous studies of Caribbean lizards have suggested that either competition or predation from birds may influence lizard densities. The present study, however, found no such relationships, and it was concluded that lizard density was independent of bird density.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04042.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Marthasterias glacialissecretes a watery mucous liquid consisting of 14% carbohydrate and 86% protein. The mucous secretion possesses different biological active molecules responsible for lysozyme‐like, protease and haemolytic activities. These substances could constitute a molecular barrier playing a protective role against the penetration by bacteria, fungi and parasites. The secretory apparatus consists of two unicellular glands, a large goblet cell and a granular cell, which open directly into the epidermi

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04043.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The degree and direction of sexual dimorphism across different species is commonly attributed to differences in the selection pressures acting on males and females. The extent of these differences is especially apparent in species that practise sexual cannibalism, where the female attempts to capture and eat a courting male. Here, we investigate the relationship between sexual dimorphism in size and leg length, sexual cannibalism and courtship behaviour in three taxonomic groups of orb‐weaving spiders, using morphological data from 249 species in 36 genera. Females are larger than males in all three taxonomic groups, and males have relatively longer legs than females in both the Araneinae and Tetragnathidae. Across genera within each taxonomic group, male body size is positively correlated with both female body size and male leg length, and female body size is positively correlated with female leg length. Sexual size dimorphism is negatively correlated with relative male leg length within the Araneinae, but not within either the Tetragnathidae or the Gasteracanthinae. There was no negative correlation between sexual size dimorphism and relative female leg length in any taxonomic group. We argue that the relationship between sexual size dimorphism and relative male leg length within the Araneinae may be the result of selection imposed by sexual cannibalism by female

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04044.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A limb bone will be lighter if it is made thinner. However, thinner bones are more flexible (for given length and shape of cross‐section) so their muscles must shorten more to move the distal end of the bone against a resisting force. To shorten more, a muscle needs longer muscle fibres and so must be heavier. Thus a particular thickness for the bone will enable the combined mass of bone plus muscle to be minimized. Peak stresses due to bending moments, in bones that were optimized according to this criterion, would be about ±70 MPa. Stresses of about this magnitude have been found in leg bones of various mammals, in strenuous activities such as running and jumping. However, similar stresses might be predicted on grounds of strength requirements, to give adequate factors of safe

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04045.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The Scientific Meeting of the Zoological Society of London held on 13 March 1990 consisted of three reports on different aspects of the biology of schistosomes, with particular emphasis on the interactions of schistosomes with their hosts and schistosomes with other schistosomes.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1990.tb04046.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY