Numbers of litters, litter size and survival in two species of microtines at two elevations

The number of litters, litter size and survival of Clethrionomys gapperi and Microtus pennsylvanicus were documented at two elevations (1450 m; 2240 m) in the Canadian Rocky Mountains to determine if those life history traits changed with the length of the breeding season. The high elevation was colder, had fewer frost-free days, and more precipitation than the low elevation. The length of the breeding season of C. gapperi and M. pennsylvanicus averaged 8 d and 34 d longer, respectively, at the low elevation than at the high elevation. In both species and at both elevations, most females survived only long enough to produce one or two litters. Litter size was significantly greater at the high elevation than at the low elevation in M. pennsylvanicus , but not different in C. gapperi. Overall, nestling survival was greater at the low elevation than at the high elevation in M. pennsylvanicus , but not different in C. gapperi. Summer and winter survival rates were not different between elevations in either species. Differences in litter size and nestling survival between elevations in M. pennsylvanicus may be related to differences in habitat quality.     

Historical biogeography at the crossroads of the northern continents: molecular phylogenetics of red-backed voles (Rodentia: Arvicolinae)

Evolutionary relationships of red-backed voles and their relatives were examined and used to test biogeographic hypotheses. Sequences of the mitochondrial cytochrome b gene were obtained for 25 individuals representing Alticola macrotis, Clethrionomys californicus, C. gapperi, C. glareolus, C. rutilus, and C. rufocanus. These were combined with 21 partial sequences from GenBank for C. regulus, C. rex, C. rufocanus, C. rutilus, Eothenomys imaizumii, E. melanogaster, Phaulomys andersoni, and P. smithii. Complete sequences of three species of Microtus (M. montanus, M. oeconomus, and M. pennsylvanicus), representative species of other arvicoline genera (Myopus, Synaptomys, Arvicola, Ellobius, Ondatra, Lemmus, Dicrostonyx, and Phenacomys), and a sigmodontine representative (Peromyscus) were included as outgroups. We used maximum parsimony, maximum likelihood, distance, and Bayesian based methods and conducted statistical tests on proposed hypotheses of phylogenetic relationships and biogeographic histories. A close relationship of species representing the genera Alticola, Clethrionomys, and Eothenomys was supported (Clethrionomyini); however, the genus Clethrionomys was paraphyletic with respect to both Alticola and Eothenomys. Three major clades were identified as Asian (Eothenomys andersoni, E. smithii, C. rex, C. regulus, and C. rufocanus), Trans-beringian (Alticola macrotis, C. californicus, C. gapperi, C. glarelolus, and C. rutilus), and Taiwanese (E. melanogaster). These results are consistent with the fossil record which indicates an initial diversification in Asia followed by colonization of the Nearctic on at least two occasions. The holarctic species, C. rutilus, appears to have either reinvaded Asia from North America or colonized North America more recently (late Pleistocene) than the two species of Clethrionomys (C. gapperi and C. californicus) that are endemic to North America (early to mid-Pleistocene). Finally, C. gapperi, appears to be comprised of an eastern and a western species, the former with affinities to the Asian C. glareolus and the latter more closely related to C. californicus.     

Two viruses isolated from rodents (Clethrionomys gapperi and Microtus pennsvlvanicus) trapped in St. Lawrence County, New York

Four strains of C. gapperi virus were isolated from 3 Clethrionomys gapperi and 47 strains of Microtus virus from 15 Microtus pennsylvanicus and 1 Mus musculus. One of the Microtus strains was isolated from a pool of 20 mites while the others were from rodent tissues. These agehts were insensitive to ether and sodium desoxycholate, withstood freezing at -70 C for 3 years and lyophilization without loss of titer, and were not killed when heated at 60 C for 1 hour. Their size as determined by filtration was less than 50 mg and greater than 20-35 mmicro. The strains within each group appear to be similar. The illness induced in suckling mice by the C. gapperi agents had a 5-day incubation period followed by prostration and death with a histologic picture of extensive encephalomalacia. The incubation period in mice for the Microtus agents was 9 to 11 days followed by convulsions and death. Histopathology showed meningeal infiltration and necrosis of the molecular layer. No antigenic similarity was detected between the C. gapperi and Microtus viruses by cross complement-fixation test.     

Changes in population structure and reproduction during a 3-yr population cycle of voles

Cyclic changes in population growth rate are caused by changes in survival and/or reproductive rate. To find out whether cyclic changes in reproduction are an important part of the mechanism causing cyclic fluctuations in small mammal populations, we studied changes in the population structure and reproduction of field voles ( Microtus agrestis ), sibling voles ( M. rossiaemeridionalis ), bank voles ( Clethrionomys glareolus ), and common shrews ( Sorex araneus ) in western Finland during 1984–1992, in an area with 3-yr vole cycles. We also modelled the population growth of voles using parameter values from this study. The animals studied were collected by snap trapping in April, May, June, August, September, and, during 1986–1990, also in October. We found several phase-related differences in the population structure (age structure, sex ratio, proportion of mature individuals) and reproduction (litter size, length of the breeding season) of voles. In non-cyclic common shrews, the only significant phase-related difference was a lower proportion of overwintered individuals in the increase phase. According to the analyses and the vole model, phase-related changes in litter size had only a minor impact on population growth rate. The same was true for winter breeding in the increase phase. The length and intensity of the summer breeding season had an effect on yearly population growth but this impact was relatively weak compared to the effect of cyclic changes in survival. The population increase rates of Microtus were delayed dependent on density (8–12-month time lag). Our results indicate that cyclic changes in reproduction are not an important part of the mechanism driving cyclic fluctuations in vole populations. Low survival of young individuals appeared to play an important role in the shift from the peak to the decline phase in late summer and early autumn.     

Small rodents, their habitats, and the effects of flooding at Wicken Fen, Cambridgeshire

The habitat preferences of small rodents were studied by live trapping methods at Wicken Fen, Cambridgeshire, a relict area of East Anglian fenland. The study sites were chosen to cover areas of managed fields, dominated by sedge ( Cladium mwiscus ) or by litter (grasses with sedges); the adjacent fen carr "bush growth"; and an area of unmanaged sedge. Clethrionomys glareolus is the commonest rodent species, occurring at relatively high densities, and closely associated with sedge growth. It is ubiquitous in unmanaged sedge but in managed sedge and litter field areas there is a marked preference for the field/fen carr transition where sedge growth is not cut. Thick sedge seems to afford the optimum habitat for this species probably because of the three-dimensional vegetation structure which provides dense ground cover with a natural thatch of dead leaves; this decays only slowly, even in succeeding fen carr. Sedge fields provide a less stable habitat and recolonization of a harvested field by Clethrionomys only began after eight months of sedge regrowth. Micromys minutus are caught only in sedge and litter. Apodemus sylvaticus seem to show no marked habitat preference but there are some data which suggest that high Clethrionomys densities can affect Apodemus distributions locally. Microtus agrestis prefers grassy patches within sedge fields; trap success points tending to be associated with the presence of Calamagrostis canescens. Microtus avoids fen carr and unmanaged sedge and is generally caught more often in litter fields than in sedge fields; however, this preference seems to disappear at the end of the Clethrionomys breeding season. During flooding, Clethrionomys found refuge in the dense sedge and sedge/carr transition habitats; prolonged flooding caused a decline in numbers of Clethrionomys and the elimination of Microtus , while the distribution of Apodemus was apparently unaffected.     

Carbon and nutrient mineralization and fungal spore composition of fecal pellets from voles in Minnesota

Numerous investigators have suggested that small mammals may regulate ecosystem processes because they couple producers and decomposers through deposition of fecal matenals and by dispersing spores from mycorrhizal symbiotic fungi We investigated carbon nitrogen, and phosphorus mineralization rates from feces of two arvicoline rodents, Clethrionomn gapperi and Microtus pennsylianicus common in the forests of the Lake Superior region We also examined fungal spore composition from these feces Mineralizable pools of C and N and their decay rates were higher in feces from C gapperi than from M pennsvhamcus , but there were no differences in sizes of mineralizable pools of phosphorus Feces of C gapperi contained four times more fungal spores than those of M pennsylvanicus Twenty-three fungal genera were represented in these feces, and all but one genus have predominantly ectomycorrhizal forms Fungal species composition also differed significantly between the two arvicoline species Although the amount of N and P mineralized annually from populations of these two species is small compared with nutrient budgets for the forests as a whole, these species may be important in dispersing spores and labile nutrient pools to microsites of seedling establishment     

Shrews on small islands: epigenetic variation elucidates population stability

Three large (4 to 8 ha) and 14 small islands (0.3 to 2 ha) in a lake in eastern Finland, all situated less than 0.5 km from the mainland, were surveyed for small mammals. Three species of shrew and two species of vole were resident in July 1982: Sorex araneus on 10, S. caecutiens on 2, S. minutus on 5, Microtus agrestis on 12 and Clethrionomys glareolus on 4 islands. Immigrants were trapped from tiny islets, and the data indicate that S. caecutiens and M. agrestis are better dispersers than S. minutus and C. glareolus , respectively. Microtus agrestis, S. araneus and C. glareolus occurred non-randomly, on subsets of the larger islands, while the two small Sorex species occurred more erratically, possibly because of competition with S. araneus . Juvenile sex ratio was male-biased on the mainland but female-biased on large islands, possibly because juvenile males move more and are more likely to emigrate from an island than juvenile females.
Metrical and non-metrical (epigenetic) cranial traits gave similar patterns of population differentiation in S. araneus . Two of the three large-island populations have differentiated from the mainland populations and from each other, suggesting that the populations are relatively stable. Small-island populations, which are often less than 10 individuals in size, showed little differentiation but had more epigenetic traits fixed than large-island and mainland populations (founder effect). This suggests that the small-island populations are unstable, have a high extinction rate.     

Observations of fleas of small mammals at the Gran Paradiso National Park (Italian Occidental Alps)]

The Siphonaptera of small mammals (nearly 200 rodents, insectivora and mustelids) of the Parco Nazionale del Gran Paradiso (Western Italian Alps) have been collected and studied during the years 1973-75. All the animals have been captured at altitudes ranging from 1570 to 2400 m during different seasons. Twelve genera and sixteen species have been identified, namely: Chaetopsylla (C.) homoea homoea from Mustela erminea; Hystrichopsylla (H.) talpae talpae from Clethrionomys glareolus; Rhadinopsylla (A.) integella integella from Clethrionomys glareolus and Microtus nivalis; Ctenophtalmus (C.) agyrtes verbanus from Pitymys multiplex (collected by Beaucournu); Ctenophthalmus (C.) solutus solutus from Apodemus flavicollis and Apodemus sylvaticus; Ctenophthalmus (Medioctenophthalmus) nivalis nivalis from Clethrionomys glareolus, Microtus nivalis and Pitymys multiplex; Doratopsylla dasycnema cuspis from Sorex araneus and Clethrionomys glareolus; Palaeopsylla soricis rosickyi from Sorex araneus; Leptopsylla segnis from Apodemus sylvaticus and Mus musculus; Peromyscopsylla bidentata bidentata from Clethrionomys glareolus and Microtus nivalis; peromyscopsylla fallax from clethrionomgs glareous; Amphipsylla sibirica ssp. from clethrionomys glareolus and microtus nivalis; Malaraeus (Amalaraeus), penicilliger kratachvili from Clethrionomys glareolus, Microtus nivalis and Mustela erminea; Myoxopsylla laverani from Eliomys quercinus; Callopsylla saxatilis from Apodemus flavicollis, Microtus nivalis and Mustela erminea. Species of fleas not yet described in Italy are: Chaetopsylla (C.) homoea homoea; Rhadinopsylla (Actenophthalmus) mesa; Ctenophthalmus (Medioctemophthalmus) nivalis nivalis; Callopsylla saxatilis. The genus Callopsylla is identified for the first time in Italy. New identification of hosts for the species of fleas already described in Italy are: for Rhadinopsylla (Actenophthalmus) integella integella: Clethrionomys glareolus; for Ctenophthalmus (C.) solutus solutus: Apodemus flavicollis and Apodemus sylvaticus. All the 15 male specimens of M. laverani from E. quercinus captured in the Parco Nazionale del Gran Paradiso have characters more similar to M. l. traubi than to M. l. laverani: only one long and a much shorter spine in the superior half of the movable process, a distinct tooth in the anterior margin of the movable half of the movable process, a distinct tooth in the anterior margin of the movable process, crochets of phallosome shorter and more gradually tapered, apex of fixed process very acuminated. To the contrary the shape of the movable process is similar to that of M. l. laverani. A point of particular interest is to be found also in 2 specimens of Amphypsilla of the sibirica group, respectively collected from Mustela erminea and Microtus nivalis. They have a very atypical distribution of the spine in an abnormally shaped movable process: the reasons of the abnormality are due to castration, probably of parasitic origin (absence of phallosome, tendons, etc.).     

Direct interference or indirect exploitation? An experimental study of fitness costs of interspecific competition in voles

Studies on competing mammalian species in the past have focused mainly on the competitive exclusion of one species from the preferred habitat of the other. Investigations on effects of competition and coexistence on individual fitness are rare . In this study we were able to measure effects of interspecific competition on major fitness components, using a system with two vole species in asymmetric competition. Survival, reproduction and space use of bank vole Clethrionomys glareolus females were monitored in 32 enclosed populations over four replicates of eight parallel run enclosures. Into half of the enclosures we introduced an additional number of field voles Microtus agrestis , a dominant competitor.
Survival of bank vole females was lower under competitive conditions. Total number of breeding females was lower in populations coexisting with competitors. Territory size of bank vole females decreased. Females body weight and litter size bank vole litters conceived during the experiment were not affected by interspecific competition. These characteristics should respond to differences in food resources, and territory size should increase if food was scarce, thus we found no indication of direct exploitation competition between the two species. Space use was overlapping between the species, but individuals of both species were never caught together in the same trap, indicating avoidance behaviour.
We conclude that adult bank vole females do suffer fitness consequences through interference competition with field voles, probably basing on increased number of aggressive encounters in the presence of the dominant species. Our results suggest, that direct interference rather than indirect exploitation competition may be the cause for observed fitness decrease in bank vole females.     

Dynamics of intestinal coccidia in peak density Microtus agrestis, Microtus oeconomus and Clethrionomus glareolus populations in Finland

Study of seasonal changes in the occurrence of Eimeria spp. in Microtus agrestis, Clethrionomys glareolus and Microtus oeconomus populations in Finland showed distinct seasonal variation in all three host species: the peaks occurred in both prevalence and density of infection in early autumn. The low prevalence and density of eimerian infections before and during the main crash of vole populations in late winter indicate that these organisms, although potentially pathogenic, do not significantly contribute to the drastic decline in cyclic vole populations.     

Genetic basis of the trade-off between offspring number and quality in the bank vole

One of the main tenets of modern life-history theory is the negative relationship (trade-off) between the number and quality of offspring produced. Theory predicts a negative genetic correlation between these traits since both are closely related to fitness of individuals. However, the genetic basis of the trade-off has only been tested to a limited extent in natural populations. We examined whether size and quality of offspring are negatively related to litter size in the bank vole Clethrionomys glareolus. First, we found a significant negative phenotypic correlation between the number and size of offspring at birth in both laboratory and field populations of the bank vole. Second, a larger size at birth decreased the maturation age of female offspring in the laboratory, and increased the probability of breeding and the size of the first litter in the field. Furthermore, manipulation of offspring size at weaning indicated that structural effects of birth size in mammals have a more profound effect on the expression of life-history traits than weaning size. Finally, in addition to the phenotypic negative correlation between the number and size of offspring, we found evidence for a negative genetic correlation between these two traits, which confirms the genetic basis of the trade-off. This negative genetic covariation may have considerable effects on the rate and direction of evolution of the two related life-historical traits.     

Reservoirs of Giardia spp. in southwestern Alberta

A survey of potential hosts of Giardia spp. was carried out during 1982 and 1983 in the Kananaskis Valley and Banff National Park, Alberta, Canada. Diagnosis was based mainly on fecal analysis but a few animals were examined at necropsy and scrapings from the small intestine analyzed. A total of 304 specimens was examined from humans (Homo sapiens L.) and a variety of animal species. Cysts and/or trophozoites of Giardia were found in 10.5% of the specimens examined. Positive samples were found from 20 of 21 red-backed voles (Clethrionomys gapperi Vigors), two of six meadow voles (Microtus pennsylvanicus Ord), one of three long-tailed voles (Microtus longicaudus Allen), five of 50 deer mice (Peromyscus maniculatus Mearns), and two of 58 beavers (Castor canadensis Kuhl). Cysts obtained from a beaver were successfully introduced to gerbils (Meriones unguiculatus Milne-Edwards) and the trophozoites obtained were cultured in vitro.     

Do intrinsic or extrinsic factors limit reproduction in cyclic populations of Clethrionomys glareolus and C. rufocanus?

Changes in reproduction and functional age structure of females in cyclic populations of Clethrionomys glareolus and C. rufocanus were studied by live-trapping individually marked voles during 1980 to 1984 in northern Sweden. A complete population cycle was observed in both species, with a synchronous 'summer-decline' in 1982. In both species, the length of the breeding season became successively shorter towards the peak, and it was extremely short at the decline. When the populations expanding, the density of breeding females increased in a sigmoid way, and thereafter it remained fairly constant throughout the summer. At the decline, the density of breeding females decreased successively from spring to autumn. Year-born females matured and bred in all years except at the decline. Intrinsic factors, such as spacing behaviour of breeding females, are thought to limit the density of breeders in general, but only when the populations are expanding. Other factors such as deteriorating food conditions are more likely to operate at the decline.     

Seasonal and annual variations in the prevalence of blood parasites in cyclic species of small rodents in Norway with special reference to Clethrionomys glareolus

An investigation of the blood parasites of Clethrionomys glareolus, Microtus agrestis and Apodemus sylvaticus from southern Norway revealed four genera, Trypanosoma, Babesia, Hepatozoon and Grahamella. C. glareolus and M. agrestis harbored all four genera, but Hepatozoon was not detected in A. sylvaticus. Babesia was fairly common in M. agrestis but rare in the other rodents. The peak prevalence of Grahamella and Hepatozoon in C. glareolus occurred in early summer whereas trypanosomes peaked near the end of the summer. Infections with trypanosomes and/or Grahamella in C. glareolus were associated with lowered hematocrit levels and enlarged spleens.     

Genetic and morphological heterogeneity in small rodent whipworms in southwestern Europe: characterization of Trichuris muris and description of Trichuris arvicolae n. sp. (Nematoda: Trichuridae)

Genetic and morphological variability of whipworms Trichuris Roederer, 1761 (Nematoda: Trichuridae), parasites of small rodents in southwestern Europe, was studied. Isozyme patterns of natural populations of nematodes parasitizing rodent species of the Muridae (Apodemus sylvaticus, Apodemus flavicollis, Mus musculus) and Arvicolidae (Clethrionomys glareolus, Microtus agrestis, Microtus arvalis) were analyzed at 6 putative loci. Two diagnostic loci were found in T. muris from Muridae and from Arvicolidae. Thus, the existence of 2 species of Trichuris restricted to different host families was indicated. They included Trichuris muris Schrank, 1788, originally described as being from mice, and Trichuris arvicolae n. sp., parasitizing the above species of Arvicolidae. The morphological variability of both species was compared. Although ranges of all morphological characters of the new species overlapped with those of T. muris, stepwise discriminant analysis yielded a 100% accurate classification of females when using vagina length and egg size. Males of T. muris and T. arvicolae cannot be separated entirely. A set of 6 variables yielded 95.7% discrimination; the most discriminating variables were spicule size and body width.     

Fluctuations in some small rodent populations in Norway 1971–1979

Small rodent populations were monitored by autumn snap trapping in 22 localities of Norway during the years 1971–979. A total of 105528 trap days yielded 7987 small mammals, out of which the bank vole Clethrionomys glareolus and the short-tailed vole Microtus agrestis made up 52.3 and 29.0%, respectively. Third in abundance was the wood mouse Apodemus sylvaticus .
Both M. agrestis and C. glareolus fluctuated fairly regularly, with general peak years of abundance in 1973 and 1977. Other Microtidae, such as M. oeconomus, C. rutilus and Lemmus lemmus apparently also exhibited cyclic fluctuations. In Arvicola terrestris, Apodemus , and in Sorex shrews, regular fluctuations could not be demonstrated, although the abundance varied considerably.
The body weights of sub-adult C. glareolus cycled in accordance with the fluctuations in abundance; the highest weights being recorded in peak years. In M. agrestis , this correlation was less obvious.     

阿拉斯加东南部温带雨林加氏(鼠平)和肯氏鹿鼠密度与微生境利用的相关性

为了验证对阿拉斯加东南部温带雨林中有关栖息地关系的预测,我们于1999年和2000年8-9月以及1999年和2000年4-5月研究了亚历山大群岛加氏(Clethrionomys gapperi)和肯氏鹿鼠(Peromyscus keeni)种群。我们测量了26个植被和结构特征以检验林隙老龄生长林、多时代老龄生长林、采伐前壮龄(23岁)生长林和泥炭混交针叶林的丰富度与微栖息地利用的相关性。微栖息地利用随季节和栖息地而变化,但加氏与林下落叶灌木覆盖度的正相关最显著。肯氏鹿鼠利用的微环境的林地有较少的苔藓,但是林隙与抓获加氏的概率有直接关系。两种鼠在两个季节的密度与林下腐朽的倒木直接相关。春季的肯氏鹿鼠密度说明加氏密度变化的62%,说明肯氏鹿鼠密度变化的89%。我们的结果印证了早期对阿拉斯加东南部肯氏鹿鼠在各种栖息地尤其早期的演替林中兴旺时的研究;但偏离了西部地貌中肯氏鹿鼠种群在晚期演替针叶林中达到最高密度的普遍结论。与北美西北部其它地区的种群不同,加氏能持久生活在上层被砍伐的雨林板块中。泥炭针叶混交林对两种鼠的繁殖种群几乎没有贡献,因而不可能减轻对多产的老龄生长雨林大规模皆伐所造成的影响。     

Detection of the larva of Taenia multilocularis in 2 voles (Microtus arvalis and Clethrionomys glareolus) in a focus of alveolar echinococcosis in the Massif Central (France)

Small wild rodents were collected and examined during 1983-1984 to investigate parasite-host relationships of Echinococcus multilocularis in one habitat suitable for red foxes of Auvergne (France). The natural infestation of the liver of two different voles, Microtus arvalis and Clethrionomys glareolus, by the larval stage of the cestode is recorded for the first time. In the both cases, the larvae were fully developed and numerous protoscolices were present with some calcareous corpuscules; the expansion of the larvae involved several hepatic lobes in Microtus and was restricted to a single lobe in Clethrionomys. Epidemiological consequences of the receptivity of the two hosts are not yet investigated in the field. However several species of voles inhabiting the same endemic area and which are receptive to the larval stage of alveolar echinococcosis should be a favourable factor of durability for the cestodiasis of the foxes; so the parasite is able of surviving the cyclic and considerable but not simultaneous fluctuations of the three populations of voles which are locally implicated in the zoonosis: M. arvalis, C. glareolus and Arvicola terrestris, by changing from one species to the others.     

Some population dynamics of the Bank vole, Clethrionomys glareolus and the Wood mouse, Apodemus sylvaticus in mixed woodland

The population dynamics of Clethrionomys glareolus Schr.and Apodemus sylvaticus (L.) in mixed woodland in County Durham, were studied from March 1963 to January 1965. Two areas of 0.9 ha (2.25 acres) each were trapped monthly and information was obtained on population size, reproduction, survival and growth from marked animals.
Clethrionomys populations increased from June to an autumn peak; then declined, at first rapidly, but then more slowly in winter, before reaching a spring trough. The breeding season of Clethrionomys was from May to December; juveniles were caught from mid-June to December. Survival was in general poor during the breeding season but good at other times. Survival of young born early in the summer was particularly good on one of the areas and some individuals lived long enough to breed in two successive years. On both areas young born early in the year matured rapidly and bred in the year of their birth. Young born in late summer and early autumn ceased growing at a weight of about 14.5 g, remained immature, and formed the bulk of the overwintering population. Growth was completed at the time of sexual maturation the following spring.
Trapping failed to provide adequate samples of juvenile Apodemus in summer to account for subsequent recruitment. The possibility that a substantial proportion of the adult population of this species was also either trap shy or had emigrated temporarily is discussed. Breeding occurred from April until the following January, but the numbers trapped remained very low throughout the early months of the breeding season. Large scale recruitment of young fecund animals into the trap-revealed population occurred during the autumn. Apodemus males continued to grow rapidly during the winter.     

Morphological variations in the preputial gland of wild bank voles, Clethrionomys glareolus

The size and appearance of the preputial glands of Clethrionomys glareolus showed variations which were associated with season, sex and maturation. The glands were by far largest in mature males followed by mature females, and subadult males and females, in that order. There was a positive relationship between the length, fresh weight and dry weight of the glands. The possible role of the preputial glands in relation to territorially, social status and sexual attraction is discussed.