Male common chameleons Chamaeleo chamaeleon actively followed the female closely as a typical mate guarding behaviour during the mating season. Guarding behaviour and spatial organization were studied in 34 radio-tagged males in a population in southern Spain during three summers. Timing and extent of guarding were highly variable among males. Overall, guarding started on 16 August (range 28 July–5 September, n=34) and ended on 4 September (range 21 August–15 September, n=24) lasting 13.4 days (range 0–46 days, n=30). Males showed a polygynous serial-type mating system where males sequentially guarded (and mated) several females during the breeding season but only one at a time. The number of guarded females (mean 2.8, range 0–8, n=34) and number of mates per male (mean 0.7, range 0–3, n=34) were also highly variable among males. In general, guarding males abandoned the females soon after mating in association with clear signs that females were no longer receptive. Males showed a remarkably complex spatial organization in close association with the home range of guarded females. Guarding behaviour resulted in territorial behaviour, and ‘stable’ as well as ‘mobile’ territories were recorded. In ‘stable’ territories, males defended non-overlapping areas where the home range of one female or more was included. Although monogamy was the predominant mating system recorded in this population, social polygyny occurred in all study years. Polygynous groups were only feasible because females aggregated in small-sized areas without apparent symptoms of intrasexual competition. Breeding asynchrony of females seems to influence this complex mating system as more competitive (large) males mated with large (early reproducing) females and small (late reproducing) ones (cf. Cuadrado, 1999). Most aggressive interactions were male–male chasing of a solitary intruder by a guarding male. A removal experiment of guarding males revealed that newcomers were small-sized males, suggesting that an important fraction of males were acting as floaters searching for mating opportunities. Male characteristics (especially size and body weight) were the main factors influencing the spatial organization and the reproductive success of males in this population.

There is no consensus on the question of whether or not free-living protist species have biogeographies, with the strongest disagreement coming from advocates of the hypothesis that the extraordinary abundance of protists drives their ubiquitous dispersal. If the probability of a species being ubiquitous is a function of its absolute global abundance, then the species that are least likely to be ubiquitous are those with relatively small global populations, i.e. the largest species. Among the free-living ciliated protozoa, a prime candidate for such an organism must be the large (~1200 μm long), unmistakable, fragile, non-encysting karyorelictid Loxodes rex. This ciliate was known only from fresh waters in tropical Africa and it was long considered to be a rare example of an endemic ciliate. Here it is reported that Loxodes rex is thriving in a pond in Thailand. The status of other alleged endemic ciliate species is discussed.

Few have served the Zoological Society of London longer or more faithfully than Alexander Cave who died on 17 May at the great age of 100.

As a Fellow, his record is outstanding: Member of Council, Vice President, Silver Medallist of the Society, Honorary Research Associate; and withal, an unending stream of original papers on various aspects of comparative anatomy. Unending? Well, almost, for he was still being published in his 95th year. Nor should be forgotten the great volume of work that he did in refereeing papers for the Journal of Zoology – an onerous and time-consuming task that he dealt with meticulously.

This paper presents basic demographic parameters of African elephants (Loxodonta africana) living in and around Amboseli National Park, Kenya. The study was conducted from 1972 to the present and results are based on the histories of 1778 individually known elephants. From 1972 to 1978, the Amboseli elephant population declined and then increased steadily from 1979 to the present. Births occurred throughout the year but over 80% occurred between November and May. Birth rate varied from year to year with a pattern of peaks and troughs at 4- to 5-year intervals. The birth sex ratio did not differ significantly from 1:1. Mean age at first birth was 14.1 years, determined from a sample of 546 known-age females. Mean birth interval (n = 732) was 4.5 years for 255 females. Fecundity and calf survival varied by age of the females. Mortality fluctuated from year to year. Sex-specific mortality rates were consistently higher for males than females at all ages.

In Mediterranean environments browse is expected to be a major component of the diet of red deer Cervus elaphus during the summer when most grasses senesce. In this study the hypothesis is tested that, if browse is an essential food resource at this time, the sex with the larger body size may have a greater physical ability to reach the tree canopy and include a higher proportion of browse in its diet. The organic matter digestibility (OMD) and composition of the diet of a population of red deer males and females were measured between July and September, in 1996 and 1997, in an area of Portugal with a Mediterranean type of climate, using the n-alkane technique. Direct observations of animals browsing on tree canopies and shrubs were made also during the same period. The OMD of the diet was significantly different between sexes and between years and was higher in males than females both in 1996 (means ± sem for males and females, 0.65 and 0.58 ± 0.026, respectively) and 1997 (means for males and females, 0.59 and 0.48 ± 0.045, respectively). The proportion of cork oak Quercus suber in the diet was also significantly different between sexes and between years, with males having a higher proportion of cork oak in their diets in 1996 (males and females, 0.30 and 0.16 ± 0.037, respectively) and 1997 (males and females, 0.41 and 0.23 ± 0.064, respectively). A significantly lower proportion of the herbage layer was found in the diet of males in 1996 (males and females, 0.46 and 0.64 ± 0.048) but not in 1997. The number of observations of males browsing on tree canopies was significantly higher than females. It is concluded that there are differences between sexes in the composition and quality of the diet and that a larger body size may confer advantages in situations where browse is an essential food resource.

Insular populations typically occur at higher densities, have higher survivorship, reduced fecundity, decreased dispersal, and reduced aggression compared to their mainland counterparts. Insularity may also affect mating system and genetic population structure. However, these factors have not been examined simultaneously in any island vertebrate. Here we report on the ecological, behavioural and genetic characteristics of a small carnivore, the island fox Urocyon littoralis, from Fraser Point, Santa Cruz Island, California. Dispersal distances in island foxes are very low (mean 1.39 km, SD 1.26, range 0.16–3.58 km, n=8). Home-range size is one of the smallest (mean annual home range=0.55 km2, sd 0.2, n =14) and density is nearly the highest recorded for any canid species (2.4–15.9 foxes/km2). Similar to other fox species, island foxes are distributed as mated pairs that maintain discrete territories. Overlap among mated pairs was always high (mean 0.85, sd 0.05), while overlap among neighbours (mean 0.11, sd 0.13), regardless of sex, was low. Despite this high degree of territoriality, island foxes are not strictly monogamous. Four of 16 offspring whose parents were identified by paternity analysis were a result of extra-pair fertilizations. Mated pairs were unrelated, however, suggesting inbreeding avoidance. Substantial population differentiation was found between the Fraser Point subpopulation and one only 13 km away (Fst=0.11). We suggest that the primary effect of finite island area is to limit dispersal, which then influences the demography, behaviour and genetic structure of island fox populations.

In the February 2001 issue of the Journal of Zoology a paper was published by Robert Timm and John Brandt (2001) that provided a new identification for two bovid frontlets held in the Kansas Natural History Museum. The frontlets had been collected in 1929 from Suoi Kiet, Binh Tuy Province in Vietnam and had been previously identified as kouprey Bos sauveli. Timm and Brandt re-identified the two frontlets as adult male and female representatives of the recently described spiral-horned ox Pseudonovibos spiralis Peter & Feiler, 1994.

Two orb-web spider species, one diurnal and one nocturnal, were studied and shown to be highly flexible in their behaviour. Flexibility is discussed in relation to improving capture success and avoiding predation. Although earlier studies have revealed that spiders modify web design and web orientation according to light and wind direction, here we show that orb-web spiders can further respond to light and wind direction by choosing a side of the web to reside on. The diurnal species, Argiope keyserlingi, tended to orient its dorsal side into vegetation gaps and towards light, whereas the nocturnal species, Larinioides sclopetarius, tended to expose its dorsal side into the oncoming wind. While orientation on the web had little affect on prey capture success, in A. keyserlingi, orientation into vegetation gaps may reduce attacks by praying mantids which approach the spiders by walking along the vegetation surrounding the web. In contrast, exposing the dorsal side into the wind may increase stability on the web for L. sclopetarius, preventing the spiders from being dislodged from the webs by strong gusty wind.

The hypothesis that Brants' whistling rat Parotomys brantsii is a central place forager, whose foraging decisions are modified by (a) predation risk, (b) time of day, and (c) food choice, was tested. Field observations showed that whistling rats followed central place foraging rules for a single-prey loader and much of their food material was brought back to burrow entrances to feed on, with larger food items being carried back greater distances than small ones. Small food items were consumed in situ more often than large ones, suggesting that predation risk may also play a role in their foraging behaviour. Larger food items were preferentially stored at burrow entrances or carried underground, whilst smaller items tended to be consumed immediately. Individuals foraged more actively in the afternoon than in the morning and, although there was no tendency for individuals to eat more food at this time, far more food was stored or taken underground during the afternoon. Different foraging strategies were used for different plant species with some species preferentially eaten, and others stored or taken below ground more frequently. This study shows that the foraging behaviour of Brants' whistling rats is complex, and whilst they may follow simple central place foraging strategies, other factors such as the time of day and food plant species also influence their foraging behaviour.

We describe diurnal resting dens (setts) used by Eurasian badgers Meles meles L. in Coto del Rey, Doñana National Park, south-western Spain, and analyse the factors that determine sett location and selection in relation to territory outlines, soil type and vegetation structure. Setts were located by tracking radio-tagged badgers daily. Badger setts were mainly underground burrow systems with, on average, 2.6 badger entrances. Frequently, badgers constructed setts by enlarging existing rabbit warrens. Setts were located almost everywhere, but badgers preferred easily dug, well-drained soils with good vegetation cover within foraging habitats. A logistic regression model showed that badgers select sites with high surrounding shrub density, large shrubs covering the burrow and close to the centre of the territory (in Mediterranean scrubland habitat). The small size of badger setts in Coto del Rey is common to other low density areas, and probably relates to the extent of use (i.e. age of the burrows and number of badgers using them) of the burrow system. The number of setts per badger territory is related positively to territory size. The similarity of sett densities between this low density population and high density populations, points to a minimum number of setts being required to maximize territory use, and to offer easily-available protection. The preservation and improvement of Mediterranean scrubland vegetation, as well as of large and old shrubs, are important for the future conservation of the badger in Mediterranean landscapes. In these areas, and given the impossibility of distinguishing main setts, the estimation of absolute densities in population surveys using main sett numbers should be avoided in favour of relative indices of abundance.

Portia fimbriata from Queensland, Australia, is an araneophagic jumping spider (Salticidae) that includes in its predatory strategy a tactic (cryptic stalking) enabling it to prey effectively on common sympatric salticids from other genera. Using standardized tests in which only optical cues were available (prey enclosed in small glass vial within large cage), the reactions of P. fimbriata to 114 salticid species were investigated. Except for Myrmarachne spp. (ant mimics), all salticids tested triggered cryptic stalking by P. fimbriata. This included not only sympatric, but also allopatric, salticids. The salticid on which P. fimbriata most commonly preys in nature is Jacksonoides queenslandicus, but cryptic stalking was triggered by salticid species with considerably different appearances, including beetle mimics, species with unusual body shapes and species with a wide variety of camouflaging markings. Portia fimbriata was also tested with lycosid, clubionid, theridiid and desid spiders and with flies and ants, but none of these arthropods triggered cryptic stalking. Optical cues used by P. fimbriata for discrimination between salticid and non-salticid prey are discussed.

The reproductive tracts of 152 female Atlantic walruses Odobenus rosmarus rosmarus were analysed. The material was collected between 19 January and 19 November in 1977–78 (n = 44) and 1988–91 (n = 108) from the subsistence hunt by Inuit in north-west Greenland (i.e. in the eastern parts of the North Water polynya in northern Baffin Bay). Seventy-six per cent of the walruses were sexually mature. Oestrus females (n = 23) were found between 19 January and 25 June. Based upon ovarian anatomy, females may ovulate several times during oestrus but ovarian anatomy could not be used to determine if an individual was pregnant. The youngest female that had given birth was 5 years old, indicating that some female Atlantic walruses become sexually mature at 4 years of age. The oldest immature female was 8 years old, and the oldest animal that ovulated for the first time was 11 years. Age-related growth in the reproductive tract indicated that sexual maturity was reached between 6 and 8 years of age. Based on reproductive history of 93 individuals (0–12 years old) the average age of attainment of sexual maturity (i.e. first ovulation) was 6.1 years (95% CI: 5.2–7.1 years). Of 81 mature females collected during May–November, 34.6% were pregnant, 43.2% postpartum and 22.2% inactive. These proportions did not differ from a model assuming a triennial reproductive cycle. Growth in foetal length and mass with time indicated that implantation occurred between 29 June and 11 July or between 26 June and 5 July, respectively. Mean birth date based on observations of 28 newborns was 20 June (range 4 February–11 November).

Nectivory was studied in 90 species from the spider family Salticidae. Observations of 31 of these species feeding on nectar from flowers in nature was the impetus for laboratory tests in which all 90 species fed from flowers. That sugar, not just water, is relevant to salticids was implied by choice tests where salticids spent more time drinking from a simulated nectar source (30% sucrose solution) than from distilled water. Our findings suggest that nectar feeding may be widespread, if not routine, in salticid spiders.

Naked mole-rats Heterocephalus glaber are highly social hystricomorph rodents endemic to the arid regions of East Africa. Living entirely underground, they excavate an extensive system of tunnels with their continuously growing extra-buccal incisors. The majority of the burrow is composed of foraging tunnels, constructed in search of the underground roots and tubers that form their staple diet. Subterranean foraging imposes risks associated with not finding food, and a high energetic cost, and in addition could be limited by the rate of wear of the incisor teeth. The aim of this study was to determine eruption rates for mandibular incisors in naked mole-rats to investigate whether they showed evidence of faster eruption as an adaptation to their subterranean niche and mode of digging. Impeded eruption rates (when the teeth were left in normal occlusion) were initially determined over a period of 1 week in a group of 12 naked mole-rats kept in laboratory conditions. Unimpeded eruption rates were then monitored in the same animals by cutting one mandibular incisor free of occlusion thrice weekly, and measuring growth over a 2-week period. Mean daily impeded eruption rates were c. 228.7±17.5 μm, while mean daily unimpeded rates were higher at c. 624.7±10.4 μm. While impeded eruption rates under laboratory conditions may be an underestimate of the rates occurring in the wild, unimpeded rates (usually about twice the impeded rate) indicate the maximum potential eruption rates of the teeth and are independent of functional activity. These data are not dissimilar from those determined for laboratory rodents and lagomorphs suggesting that the naked mole-rat does not display unusual patterns of eruptive behaviour. Tooth wear resulting from their subterranean lifestyle may be offset as a limiting factor by the social behaviour of the naked mole-rat, where digging activity is distributed among a large workforce during favourable burrowing conditions.

Discontinuous individual variation among members of the same sex, in the same life stage, within a population, is an important phenomenon for our understanding of more fundamental issues in evolutionary biology. One set of morphological characters is conspicuously rare in the literature on intrasexual polymorphisms: genitalia. In this paper we report the first case of female genital polymorphism, the first not only for spiders but apparently for animals in general. We argue that the overwhelming use of genitalia in species identification practiced by many invertebrate taxonomists presents a strong bias against discovering polymorphisms in genitalia. Further methodological and practical aspects of invertebrate taxonomy are discussed that, taken together, make the discovery of genital polymorphisms unlikely, no matter whether or not the phenomenon is rare.

Karyotypic and allozyme analyses were carried out on 55 individuals of Microtus subterraneus and M. majori from 19 populations in Europe and Anatolia. The occurrence of M. subterraneus in Asia Minor was proven. Standard karyotypes were found in M. majori (2n=54), M. subterraneus from Poland (2n=54), and central and south-eastern Europe (2n=52). Although the karyotype of M. subterraneus populations from Anatolia (2n=54), resembled that from Poland, there were apparent differences in the X chromosomes: it was larger and submetacentric (instead of metacentric) in the Anatolian populations owing to the presence of a large block of heterochromatin. The heterochromatic segment was also found to cause the size and shape differences in the X chromosomes between M. majori and European M. subterraneus (both in the 2n=52 and 2n=54 karyotypes). However, the location of this segment differed between the latter species and M. subterraneus from Anatolia. The distribution of the 2n=52 and both the 2n=54 karyotypes of M. subterraneus suggests that the Robertsonian fusion, distinguishing these different karyotypes, originated within the range of the species (i.e. within the 54-chromosome karyotype) and has spread subsequently towards its periphery. It is also suggested that both the fusion in European populations and amplification of heterochromatin in Anatolian populations are quite recent phenomena. The allozyme data indicate that gene flow is limited between populations of M. subterraneus and they are concordant with the isolation-by-distance model. There seems to be little correspondence between patterns of chromosomal and allozyme variation in M. subterraneus. Nei's genetic distance between M. subterraneus and M. majori was low (D=0.169), suggesting their recent divergence.

A large data set, comprising certain measurements of middle ear structures in mammals, was compiled both from measurements made by the author and from the literature. Parameters of the middle ear apparatus believed to be important to audition were compared between fossorial and non-fossorial species, in an attempt to identify general trends among fossorial groups. Although their tympanic membranes are not of unusual size, many fossorial mammals possess enlarged stapes footplate areas, resulting in low anatomical area ratios. Low anatomical lever ratios are also common, and the reduction or loss of middle ear muscles seems to be a consistent trend. These characteristics might be associated with poor sensitivity to airborne sound. Other features of the middle ear apparatus are more variable both between and within fossorial families. The middle ear ossicles of fossorial rodents, talpid moles and some golden moles were not found to differ in mass from those of non-fossorial mammals of similar body size. The similar ossicular morphologies of these animals suggest convergent adaptation towards a subterranean environment, but the middle ear structure alone does not seem to explain the restricted hearing range observed in certain of these species. Some genera of golden moles possess extraordinarily hypertrophied auditory ossicles, which, relative to body mass, are the largest of all mammals for which data are available. These ossicles seem to be adaptations towards a form of inertial bone conduction, used for the detection of substrate vibrations. In stark contrast, the marsupial mole Notoryctes has particularly small ossicles. The unusual middle ear structures of this animal may well be degenerate.

Group pattern and social segregation of the sexually size dimorphic Przewalski's gazelle Procapra przewalskii were studied for 7 years in the Qinghai Province, China. The main social units were: female groups; male groups; mixed groups. Mixed groups were the largest and most visible, whereas adult male groups were small and of similar size. The group size of the gazelle varied during different seasons (P < 0.002) and the type of social groups (P < 0.001). Mixed-sex groups were larger than female groups or male groups across all the seasons (P < 0.008). Adult males and females were mainly in separate groups except during the rut. Groups of adult females were the most common social unit in Przewalski's gazelle, followed in frequency by adult male groups and mixed groups. From late June to late August, social separation was most pronounced. From late October to mid-September, social segregation was not pronounced. Social segregation showed significant seasonal differences in Przewalski's gazelle (P < 0.004), especially between the rut and other seasons (P < 0.008). The pattern of social segregation of groups and behaviours observed imply that social factors play important roles in social segregation and group formation.

Piscivorous birds consume diets which are rich in highly-polyunsaturated n-3 fatty acids; these play vital roles in embryonic development but are very susceptible to oxidative damage. The effects of such diets on the fatty acid composition and antioxidant content of the yolk were investigated in the northern gannet Morus bassanus, the great skua Catharacta skua, the American white pelican Pelecanus erythrorhynchos and the double-crested cormorant Phalacrocorax auritus. The phospholipid fraction of the eggs of these four species contained high proportions of the n-3 fatty acid, docosahexaenoic acid, which formed 7.5–11.3% (w/w) of the fatty acids of this fraction. The presence of eicosapentaenoic and docosapentaenoic acids also contributed to the total n-3 content of the phospholipid. The n-6 polyunsaturate, arachidonic acid, formed between 8% and 19% (w/w) of the phospholipid fatty acids. For the pelican and cormorant, this is consistent with the consumption of freshwater fishes in which arachidonic acid may be a significant acyl constituent. This finding is, however, more difficult to explain for the gannet and skua which largely consume marine fish with a low arachidonic acid content. The yolks of all four species contained relatively high concentrations of vitamin E (90.2–302.3 μg g−1 wet yolk) which was mainly present as α-tocopherol. The eggs of the pelican and cormorant were especially enriched in carotenoids (150.9 and 115.7 μg g−1 wet yolk, respectively).