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An existing spatial population model, developed to assess the reintroduction of the European beaver Castor fiber to Scotland, was applied to predict the likely result of reintroducing beavers to Norfolk, England. A habitat analysis was conducted using the Land Cover Map (classified satellite imagery developed by the Institute of Terrestrial Ecology) to predict the location of areas suitable for beavers. The model was used to simulate population processes within these areas and dispersal between them following a range of reintroduction scenarios. To represent uncertainty regarding the probable behaviour of beavers in Norfolk, the habitat analysis and model were applied using three sets of parameter values (high, medium and low) derived from the literature. It was predicted that Norfolk could support between 18 and 40 beaver families. Using high or medium parameter values, beaver populations were predicted to expand following reintroduction and spread to new areas. Using low parameter values populations were predicted to decrease, risk extinction and not colonize new areas. This analysis is a preliminary investigation into the likely fate of beavers in Norfolk. Checking the estimates of habitat availability in the field would enable greater confidence to be placed in these predictions.

In Zimbabwe the incidence of reported jackal rabies varies predictably over the year with peaks during June to August (cold dry season) and December to May (wet season), and may be explained by the social behaviour of jackals. June to August is the mating season, at which time home ranges increase in size, and overlap between species and neighbouring conspecifics is greater. Intra-group concordance in range use decreases in association with the social stress caused by mating and mate guarding, and young adults use peripheral areas, perhaps increasing contact with neighbouring jackals. Dispersal is most likely to occur in the mating season. These factors increase the contact rate between neighbours and, therefore, rabies incidence. In the hot dry season (the whelping season), home ranges decrease in size, and the overlap of interspecific and neighbouring conspecific ranges decreases. Concordance in range use of intra-group conspecifics increases and activity focuses on the den; inter-group contact rate therefore decreases, as does rabies incidence. The addition of juveniles to the population in the wet season increases jackal density and thus contact rate and also coincides with a high rabies incidence. Taking these factors into account, we suggest that the control of jackal rabies by oral vaccination should focus on the period before the mating season and after the whelping season.

We tested the hypothesis that the parasite Toxoplasma gondiimanipulates the behaviour of its intermediate rat host in order to increase its chance of being predated by cats, its feline definitive host, thereby ensuring the completion of its life cycle. Here we report that, although rats have evolved anti–predator avoidance of areas with signs of cat presence, T. gondii's manipulation appears to alter the rat's perception of cat predation risk, in some cases turning their innate aversion into an imprudent attraction. The selectivity of such behavioural changes suggests that this ubiquitous parasite subtly alters the brain of its intermediate host to enhance predation rate whilst leaving other behavioural categories and general health intact. This is in contrast to the gross impediments frequently characteristic of many other host–parasite systems. We discuss our results in terms of their potential implications both for the epidemiology of toxoplasmosis and the neurological basis of anxiety and cognitive processes in humans and other mammals.

In total 445 faecal samples were collected from 259 European badgers (Meles meles) in Wytham Woods, Oxfordshire, UK (462080). Microscopical examination revealed infection with 2 species of coccidia Eimeria melis and Isospora melis. From the initial examination of each animal, point prevalence rates of 0·44 and 0·35 were calculated for Eimeria and Isospora respectively. The intensity of infection was significantly greater for Eimeria than Isopora and the distribution of intensities was highly skewed for both species, with a few individuals shedding the majority of oocysts. Incidence and recovery rates for both coccidia species were calculated from longitudinal data collected at 3-monthly intervals from a subset of the adult badger population, and the predicted prevalence rates based on these were similar to the point prevalence rates. This suggests little, if any, parasite-induced mortality in the adult population. In contrast, there was a marked and significant reduction in the point prevalence and intensity of infection with Eimeria from cub to adult badger suggesting a degree of acquired immunity to Eimeria melis on initial exposure and/or that there is significant Eimeria-associated mortality in the cub population. No such relationship was found for Isospora infection. In those adult badgers with co-infections there was a direct relationship between the intensity of Eimeria and Isospora. The taxonomic status of these parasites suggests a heteroxenous life-cycle for I. melis, and direct transmission of E. melis. However, the greater than expected prevalence of co-infection is consistent with a common source of infection, such as communal latrines.

Adaptations to extreme environmental conditions were investigated in a detailed study of red foxes Vulpes vulpes inhabiting a desert region of Saudi Arabia. Forty-two adult foxes were live-trapped during 3 years of field work. In contrast to red foxes studied in other areas, no strict territoriality was observed in this population. Although close interaction (separation < 1 m) was more common between members of the same, rather than different, social groups, medium distance interactions were similar. Further, intra-group encounters were much less common than for foxes in the U.K., and foxes did not avoid each other at territory boundaries. All foxes used food-rich sites associated with human activity, and aggregations of up to four foxes were regularly seen in these areas. It is suggested that the combination of an extremely harsh environment, with spatially and temporally variable food supplies, leads to the formation of loosely knit social groups. Saudi Arabian red foxes followed Bergmann's rule in being considerably smaller than those found in cooler areas. They also had a lighter coloured pelage than red foxes typical of Europe and North America. These morphological differences may represent adaptations to the low availability of food and rest sites in the desert.

Body sizes of European mink (Mustela lutreola L.), polecat (M. putorius L.) and American mink (M. vison Schreber) were studied over a 10-year period in an area of north-eastern Belarus, before and after the invasion by American mink, and data are presented on interspecific interactions. On arrival in the study area American mink males were larger than males of European mink and polecat, and American mink females were larger than females of the other species. After arrival of the American mink its mean body size decreased, whilst the resident male and female European mink and female polecat increased as measured in absolute mass, length and relative mass. The observations suggest a strong character convergence most plausibly explained as a response to the invading exotic by the residents as well as in the invading species itself, whilst a divergence had been expected. There was no evidence to show whether these differences were genetically based. The body size data are consistent with the hypothesis that European mink, and to a lesser extent polecat, are responding to direct aggression from American mink (rather than merely competing for resources), with the smaller individual European mink being more likely to disappear first. We provide direct evidence for the aggressive nature of inter-specific relations from observations using radio-tracking: all observed inter-specific interactions were aggressive, significantly more so than intraspecific encounters, causing the European mink to flee, and several left the study area altogether. Implications for niche theory and for conservation management are discussed.

The set-aside scheme, whereby land is removed from arable production, is primarily aimed at manipulating agricultural surplus within the European Community, but has potentially great consequences for biodiversity and wildlife management (Feber et al., 1995; Macdonald et al., 1998; Sotherton 1998). Managed inappropriately, set-aside could prove environmentally damaging by reducing biodiversity and directly harming certain species, such as ground-nesting birds (Thompson, 1993). Conversely, appropriately managed set-aside could foster desirable ecological communities, with enhanced populations and biodiversity.

Whistle vocalizations of five odontocete cetaceans, the false killer whale P. crassidens, short-finned pilot whale G. macrorhynchus, long-finned pilot whale G. melas, white-beaked dolphin L. albirostris and Risso's dolphin G. griseus, were analysed and summarized quantitatively. Recordings were acquired from a number of locations and encounters. Significant differences were found between species and, to a lesser extent, between locations. The calls of the two pilot whale species are distinct despite their close relatedness, and similar size and morphology. This may be due to selection pressures to maintain distinctiveness. The variance was partitioned into between-species, between-location (within species) and within-location factors. For the frequency variables, variation between-species is high relative to variation between locations. Thus geographic variation is a relatively minor effect, compared to the many processes which cause interspecific differences. The within-location component includes such factors as social context, behaviour and group composition. This component is of a similar magnitude to the between-species component, indicating that whistles vary considerably with these factors. Significant between-location differences may be attributable to these confounding factors. For whistle duration, most of the variation occurred within location. There is less significant variation in duration across species compared with the frequency measures. This study highlights the need to collect samples across all potential strata whenever possible, and provides a framework for future, more comprehensive work.

Popularity as a fur-bearing species led to the American mink Mustela vison being transported far beyond its native range in North America (Dunstone, 1993). In many places the species was bred in fur farms, from which there were inevitably escapes, and in some areas it was deliberately released in large numbers with the intention of establishing harvestable populations. Both routes led to the widespread establishment of feral populations of this versatile semi-aquatic mustelid. Invariably, close scrutiny of the impact of feral American mink on native fauna has led at least to concern, and increasingly to proof, that they are inimical to the conservation of native species. Evidence of the impact of the American mink on native species falls into two categories. First, American mink may reduce significantly, and locally exterminate, certain vertebrate prey (Macdonald et al., in press). Second, as versatile and seemingly aggressive competitors they may alter the competitive balance within the local guild of semi-aquatic predators, even ousting native mustelids.

Abstract:  Using ratio-tracking data obtained at three sites, we assessed the effects of season and of neighbour avoidance on the activity and patterns of home range use by European moles (Talpa europaea). The home ranges of non-breeding male and female moles did not differ significantly in size, and averaged 2324 m2 (minimum convex polygon). Although overlap between ranges was small (an average of 12.8% of each range being shared with neighbours and an average of only 3.3% of 22 m grid cells were shared with an individual neighbour, ranges were not oriented to avoid neighbours. Non-breeding male/female neighbours tended to share more of their grid cells (3.95.7%) mean SD than did neighbours of the same sex (male:male 1.20.95%; female:female 1.11.3%), but there was no significant difference in overlap between any combination of sex pairings. On average, each mole spent only 0.9% of its time within 6 m of another mole, and only 3 out of 46 dyads showed evidence of being attracted to each other; there was no evidence from the simultaneous movement patterns of neighbouring moles that they avoided each other. Although moles tended to return to the same part of their range at the same time on successive days, there was also some indication of gradual changes in the spatial pattern of daily home range use. Moles had a triphasic pattern of activity, but this became tetraphasic under drought conditions. There were significant differences between sites, but not between sexes, in sleeping behaviour and activity patterns. These differences could be related to seasonal differences in soil moisture and thus probably to prey renewal rates. We conclude that in our sites, the activity patterns and movements of moles depend on the temporal and spatial dispersion of food, rather than on short-term interactions between the movements of neighbours.

During a period in the 1980s when both European mink Mustela lutreola and American mink M. vison were present in Estonia, their food was significantly different. European mink ate a greater proportion of fish and crustaceans, whereas American mink took relatively more mammals and frogs. This was probably related to a difference in habitat selection. After the disappearance of the European mink, the diet of the American mink in our main study area was similar to that of the European in the same area previously. Two alternative hypotheses are presented for the mechanisms which led to the replacement of European mink by the American species: (i) the two species have a different niche, and the American mink could replace the European mink after the latter had disappeared for unrelated reasons, or (ii) the American mink aggressively ousted the European mink, a process starting in the American mink's preferred habitat (slow flowing rivers). At present there are insufficient data to reject either of these scenarios.

1. In addition to calcitonin and katacalcin, it is now known that the human calcitonin gene encodes a novel peptide called calcitonin gene related peptide (CGRP). In experimental animals, CGRP produces vasodilatation and complex changes in plasma calcium. 2. We have now assessed its biological activity in man by infusing human CGRP (hCGRP) into six normal volunteers. hCGRP (545 pmol/min) caused the diastolic pressure to fall from 64 ± 5 to 55 ± 7mmHg (P < 0.05), the heart rate to increase from 61 ± 7 to 87 ± 5 beats/min (P < 0.05) and the skin temperature to increase from 33.7 ± 0.9 to 34.9 ± 0.5°C. Plasma noradrenaline increased from 481 ± 126 to 835 ± 65 pg/ml (P < 0.05) and plasma adrenaline from 57 ± 17 to 82 ± 12 pg/ml (P < 0.05). There were no significant changes in the albumin-corrected plasma calcium. 3. hCGRP is thus a potent endogenous vasodilator in man and is in fact more potent than any other known vasodilator. Together with the observations that CGRP circulates in normal subjects at relatively high concentration (approximately 25 pmol/l) and that CGRP is present in perivascular nerves, this study suggests a possible role for CGRP in controlling peripheral vascular tone in man.

Feline immunodeficiency virus (FIV) has a worldwide distribution among feral and domesticated cats and in many cases induces immunodeficiency disease analogous to that of human acquired immune deficiency syndrome. FIV is genetically homologous to human immunodeficiency virus (HIV) in both genome organization and gene sequence and, like HIV, exhibits enormous sequence variation throughout the range of host species. We sampled 91 feral cats from six disparate locales and studied the phylogenetic relationships of viral DNA from infected cats using bothpolandenvgenes (520 and 684 bp, respectively). The patterns from the two genes recapitulated previously described major FIV clades and showed concordance between phylogenetic patterns of thepolandenvgenes. Evidence for recombination between thepolandenvgenes was not found among a sampling of nine isolates, although evidence for intragenic exchange within theenvgene was observed in two isolates. A small local population of cats from a rural farm in the United Kingdom had a remarkably high FIV antibody prevalence (47%), but displayed 8-fold less overall diversity of FIV genomic variation compared with FIV from different parts of the world. We interpret this low variation as a consequence of a recent monophyletic introduction of FIV into the population.

The sedimentation coefficients of the NADPH: cytochrome-c oxidoreductase enzymes from wild-type and mutant strains of Aspergillus nidulans have been estimated by sucrose density gradient centrifugation. In the wild-type, two species of cytochrome-c reductase were found, with sedimentation coefficients of 13.7s and 7.6s respectively. The 13.7s species did not appear to be associated with the enzymes of nitrate reduction, whereas the 7.6s species was closely associated with NADPH: nitrate oxidoreductase. In mutant strains lacking nitrate reductase, a thir species of cytochrome-c reductase with a sedimentation coefficient of 4.5s was found. There is some evidence that this 4.5s cytochrome-c reductase is a subunit or breakdown product of nitrate reductase and a model is presented for the role of this 4.5s cytocnorome-c reductase in the assembly of the intact nitrate reductase molecule.

A pyrG-Aspergillus strain was transformed with plasmid pDJB-1, derived from pBR325 by insertion of the Neurospora crassa pyr4 gene (orotidine 5'-phosphate carboxylase), giving mitotically unstable transformants. Aspergillus DNA which acted as an “autonomously replicating sequence” (ARS) in yeast was inserted into pDJB-1 and the resulting construct, pDJB12.1, gave mitotically stable transformants when introduced into Aspergillus. Transformants obtained with pDJB-1 and pDJB12.1 gave few pyr- progeny in crosses to a pyrG+ strain. Southern hybridisation analysis of pyr+ transformants obtained with pDJB-1 revealed restriction fragments expected for integrated plasmid but transformants obtained with pDJB12-1 showed only bands derived from free plasmid. pDJB-1 and derivatives of pDJB12.1 could be recovered from transformants. These derivatives could not be explained by straightforward excision of integrated pDJB12.1 sequences but could result from recombination between plasmid molecules. Hybridisation of undigested transformant DNAs showed that the transforming DNA was present in a high molecular weight form. These results suggest: (1) pDJB12.1 derivatives and possibly pDJB-1 can replicate autonomously in Aspergillus; (2) A. nidulans DNA acting as an ARS in yeast enhances replication and/or segregation of transforming plasmids in Aspergillus; and (3) recombinant plasmids may undergo rearrangements when introduced into Aspergillus.

Five allelic glutamine auxotrophs of Aspergillus have been assayed for glutamine synthetase activity. The amounts of glutamine synthetase activity present in these strains were proportional to their ability to grow in the absence of L-glutamine, whereas the amount of ?-glutamyl transferase did not correlate with the amount of synthetase or with the growth properties. Two out of this sample of mutants have been shown to have a glutamine synthetase with a Km for L-glutamate which differs from the wild type.

Differences in the prevalence and abundance of helminth parasites amongst host populations may result from variations in resistance to infection, differences in habitat preferences, diet or social behaviour. The use of helminth parasites as ‘ecological markers’ for determining differences between morphological groups of wild-living cats in Scotland was investigated, in light of the debate over the definition of a wildcat. The prevalence and abundance of the tapeworm Taenia taeniaeformis did not differ significantly between cats designated as ‘wild’ and ‘feral’ types. The prevalence of both helminths was high (94% and 69%, respectively) and there was significant variation in worm abundance related to season and geographical area. Also, prevalence of infection with Toxocara cati was significantly higher in female cats. Cats which harboured large numbers of one worm species were also likely to harbour large numbers of the other. However, a possible relationship with cat condition was only found for T. taeniaeformis for which there was a significant negative correlation between an index of cat condition and worm abundance amongst ‘wild type’ cats, but not amongst ‘feral type’ cats. Variations in worm burdens could not be attributed to differences in the diet of the cats as there was no significant relationship between the presence of any individual prey type and either the presence or abundance of T. cati or T. taeniaeformis. There was a significant negative correlation between density and biomass of individual worms in infections of T. taeniaeformis, suggestive of a density-dependent constraint on tapeworm growth.

A total of 263 individual badgers Meles meles provided 718 blood samples which were screened for parasites. This revealed that 77.2% of individuals tested positive for Babesia missirolii at least once over 3 years, whereas 7.7% did so for Trypanosoma pestanai. However, the prevalence was highest in younger age classes, except in 1990 when it was high in most categories. There was some evidence that following a positive test for Babesia badgers were more likely to be caught again in subsequent years when compared to individuals testing negative. For Trypanosoma, although prevalence decreased from a peak of 29.2% from June onwards in 1990, we found no significant corollaries of infection. These results are discussed in the light of inter-annual variation in weather and other factors.

1. Gluconeogenesis from pyruvate was measured in renal-cortical-tubules fragments prepared from fed male rats 6-8 days after adrenalectomy or sham adrenalectomy. The response of this process to 3′:5′-cyclic AMP and adrenaline was compared in these two states at two Ca2+ concentrations. 2. Adrenalectomy decreased the percentage stimulation of gluconeogenesis by 3′:5′-cyclic AMP, but increased percentage stimulation by adrenaline. Cortisol treatment of adrenalectomized rats (50 mg/kg, twice daily for 2 days) did not reverse the change in responsiveness to 3′:5′-cyclic AMP and adrenaline. 3. Stimulation of gluconeogenesis by 1 micron-adrenaline was unaffected by 10 micron-propranolol (beta-blocker) in either state. Phentolamine (alpha-blocker; 10 micron) totally blocked stimulation of gluconeogenesis by 1 micron-adrenaline in the sham-operated condition, but was only partially effective in this respect after adrenalectomy.

Glutamine synthetase activity in the ascomycete fungus Aspergillus nidulans is regulated by nitrogen source. The lowest activities are obtained when the fungus is grown on L-glutamine, and the highest activities when grown on L-glutamate + arabinose. Glutamine auxotrophs of the fungus have been isolated, and one of these mutant strains, glnA-1, has been shown to lack the enzyme glutamine synthetase. The mutation is recessive, and is located on the right arm of chromosome II. In addition to abolishing glutamine synthetase activity, the mutation results in the relief of repression for several enzyme activities normally subject to repression by ammonium. These include nitrate reductase, asparaginase, proline uptake and urea uptake.

A letter is presented which discusses European moles, Talpa europea, and the not-so-humane mole tube traps. The mole traps are marketed as Fito humane mole trap, Katcha humane mole trap, and Eco-talp. The letter also informs that mole tube traps are entirely unregulated and mentions that the welfare threats related to live-trapping and relocation are not restricted to the time a mole spends in a trap.