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Frogs of the genus Indirana belong to the endemic family Ranixalidae and are found exclusively in the Western Ghats biodiversity hotspot. Since taxonomy, biology and distribution of these frogs are still poorly understood, we conducted a comprehensive literature review of what is known on the taxonomy, morphology, life history characteristics and breeding biology of these species. Furthermore, we collected information on the geographical locations mentioned in the literature, and combined this with information from our own field surveys in order to generate detailed distribution maps for each species. Apart from serving as a useful resource for future research and conservation efforts, this review also highlights the areas where future research efforts should be focussed.
We examined the demographic structure and mortality rate of the Baltic grey seal (Halichoerus grypus) population from the early 2000s when the population increased rapidly to the late 2000s when the growth rate slowed down. We calculated life tables based on the age structure of hunted grey seals in the Finnish sea area. The catch was treated as a sample of the dying part of the population. The catch was male biased and the proportions of female pups and mature males in the catch increased from the early to late 2000s. Annual mortality rate of the youngest age classes was high and higher among males than females, which resulted in low sex ratio (males to females) of the population. Sex ratio was, however, higher in the latter years due to the increased mortality rate of females, especially those < 10 years of age. Accordingly, the proportion of mature females in the population decreased and relatively fewer pups were produced during the late 2000s than in the early 2000s.
Small mammals with leucism are very rarely recorded, most likely because the probability of surviving to maturity would be very low for abnormal, white individuals. Here we report a record of a bank vole (Myodes glareolus) with complete leucism delivered to a nest of the Eurasian kestrel (Falco tinnunculus) in the boreal forest in SE Norway.
Protura, an almost neglected taxon in ecological studies of soil microarthropods, were examined at highly vulnerable sites of fluvial forest stands of the Transcarpathian Lowland. To compare the effects of different hydrologic disturbance regimes on Protura assemblages, we examined part of a river floodplain subjected to periodical inundation, and a non-inundated part with limited fluvial activity, behind the river embankment. Ten sites were selected for sampling, with four sites dominated by oak and one dominated by poplar in each part. The type of hydrologic disturbance regime in the river floodplain shaped Protura assemblages and influenced their variability. Highest abundance and species richness were correlated with the non-inundated part of the floodplain under oak stands, although Protura also tolerated soil conditions of exposure to regular inundation. We present and discuss several hypotheses concerning the causes of distribution patterns of Protura in the river floodplain with different hydrologic disturbance regimes, including sensitivity to mycorrhizal associations and the role of Protura assemblages as a potential ecological bioindicator of pedogenic transformations in riverine wetlands.
Differential predation on certain classes of individuals within prey populations might make owls strong selective agents on their prey. We investigated selective predation of tawny owls (Strix aluco) on yellow-necked mice (Apodemus flavicollis, A.f.) and bank voles (Myodes glareolus, M.g.) for two years by comparing prey from owl nests with live-trapped individuals. The owls killed significantly more male M.g. (73%) than females, but not more than expected from traps (57%). For A.f., owls selected adults in favour of subadults, and for adults, individuals with longer femurs. Adult males of A.f. killed by owls had significantly heavier testes in relation their size than the trapped males. Prey selection did not correlate with size-adjusted body or spleen mass. Owl-killed A.f. had higher prevalences of the intestinal helminth Heligmosomoides sp. than trapped individuals, but hosted similar numbers of parasite species. Differential predation of tawny owls on yellow-necked mice and bank voles seems to reflect higher exposure to predator encounters of prime individuals rather than selection for substandard individuals.
Indrikis Krams, Valērija Suraka, Dina Cīrule, Markku Hukkanen, Lea Tummeleht, Pranas Mierauskas, Seppo Rytkönen, Markus J. Rantala, Jolanta Vrublevska, Markku Orell, Tatjana Krama
This study compares the sensitivity of two methods for diagnosing avian haemosporidian parasite (Plasmodium, Haemoproteus and Leucocytozoon) prevalence in Siberian tits Poecile cinctus breeding in northern Finland: a polymerase chain reaction (PCR)-based method and microscopy examination of blood smears. During molecular analysis, we used PCR screening and RFLP as a post-PCR diagnostic step. PCR screening detected haemosporidian parasites in the blood of 38 out of 40 (95%) breeding Siberian tits. Microscopy examination of blood smears and PCR diagnostics showed the same prevalences for Eeucocytozoon spp. infections. In contrast, prevalences of Haemoproteus spp. and Plasmodium spp. determined by molecular methods were significantly higher than the prevalence determined by microscopy screening. However, habitat and sex effects on the total count of parasites, Plasmodium spp., Haemoproteus spp. and Eeucocytozoon spp. counts appeared to be similar when assessed with either screening method, giving the same interpretation for the ecological hypotheses tested. Finally, this study shows that transmission of avian malaria can occur in the area of the Arctic Circle in northern Europe.
Haemoparasites prevalence in birds can vary among species, age and sex groups and ecological conditions. To comprehend the host—parasite assemblages, it is important to investigate physiological mechanisms underlying the interactions in wild bird species. Here, using blood smears we investigated how leukocyte profiles in reed warblers (Acrocephalus scirpaceus) and sedge warblers (Acrocephalus schoenobaenus) vary in relation to the heamoparasite presence with respect to the host's age and sex. We sampled the birds during their autumn migration in 2008 at a stopover site in northern Poland. We found a significant relationship between the leukocyte profiles and parasite infection. Parasite infection was associated with elevated relative number of heterophils with simultaneous lowered relative number of lymphocytes. These opposite pattern resulted in an elevated H/L ratio in infected birds. Total leukocytes, lymphocytes and heterophils counts were elevated in birds infected with blood parasites as compared with those of non-infected ones. Leukocyte profiles of parasitized birds were similar regardless of individual age. However, non-infected adults had lower total leukocyte counts and values of H/L than non-infected immatures.
Information about factors influencing catch per unit effort (CPUE) are not only interesting in commercial and sport fisheries contexts, but also for scientists fishing for research purposes. Here, the influence of trap type, baiting and attractors on CPUE in pond nine-spined sticklebacks (Pungitius pungitius) were investigated. The results show that baiting improved CPUE considerably, but trap type had a smaller effect on CPUE. Visual attractors (i.e. aluminium foil) did not improve CPUE. Apart from showing that nine-spined sticklebacks are likely to use olfactory cues for locating food, the results should provide useful information for those interested in catching nine-spined sticklebacks with the aid of minnow traps.
The phenomenon of creating a breeding association by the barred warbler (Sylvia nisoria) and the red-backed shrike (Lanius collurio) was documented relatively long ago by several researchers. Some of the authors suggest that this phenomenon is a result of similar habitat requirements rather than a product of active selection. The main goal of this study was a quantitative analysis of differences and similarities in selection of breeding habitats by both species in the area of their sympatric occurrence. Research was carried out in the years 2009–2011 in the study plot located in the Middle Vistula Valley (central Poland). The red-backed shrike preferred shrubs and open areas, however, it avoided woods and waters. The only habitat strongly preferred by the barred warbler was bushes, and this species avoided waters, woods and open areas. Neither species nested in places with a thick tree concentration. Because of differences in their feeding strategy, as opposed to barred warblers, red-backed shrikes preferred habitats with low vegetation and a low concentration of shrubs. In nest location selection, the red-backed shrike clearly preferred hawthorns, whereas the barred warbler nested also in other species of bushes. As compared with warblers, shrikes more often preferred to nest in high bushes. The knowledge of the red-backed shrike's and the barred warbler's optimal habitat requirements can provide useful guidelines for future conservation projects involving these vulnerable birds.
Crossing dispersal barriers with hostile environments is difficult for species with low environmental tolerance. Thus low environmental tolerance could result in small geographic ranges. In the case of mainland biotas, where mountain ranges are important dispersal barriers, this means species range size would decrease with the species inability to tolerate high altitude conditions. This idea predicts endemic species are more sensitive to elevational barriers than non-endemic species, other things being equal. Here, I test this prediction in the Mediterranean herpetofauna (southern Europe), using reported maximum altitude as a surrogate for tolerance to altitude. After correcting for sampling effects (influence of range size on reported altitude), phylogeny, and topographic biases (regional availability of maximum altitudes), a strong pattern is revealed: endemic amphibians and reptiles reach lower maximum altitudes than nonendemic counterparts. This suggests range size is controlled by the species ability to cross elevational barriers. Available data suggest this may be a general trend among endemics from mainland biotas.
We examined the effects of tannins on food digestion in the plateau zokor (Eospalax baileyi), a rodent that lives primarily underground. Our results indicate that (1) all experimental groups maintained their body weight; (2) food intake and food assimilation increased, while food digestibility decreased with an increasing tannin concentration in the diet; (3) protein digestibility, but not protein assimilation, decreased significantly with an increasing tannin concentration in the diet; (4) mean dry weights of the small intestine of the zokors fed with feed containing 3% and 6% tannic acid were 67% and 87%, respectively, greater than that of the control. Therefore, tannins in the diet affected negatively food and protein digestibility in zokors. The animals counteracted these effects and maintained their body weight and nutrient assimilation by increasing food intake as well as widening the lumen of their small intestine.
During human evolution, finding an intelligent mate could have resulted in more high-quality offspring via better access to resources or via “good genes”. Considering that the choice of a mate is an important issue, one would expect that intelligence could be accurately judged by human observers at the beginning of sexual maturity when women of primitive tribes generally establish pair bonds. Male facial photographs and IQs were used to study how well adolescent versus older women can judge intelligence from a picture. There was no correlation between men's IQ and the perceived intelligence rankings given by female adolescent judges, nor did these judges perceive men of higher IQ as more attractive. Interestingly, however, there was a significant correlation between the measured IQ and the intelligence ranking by older female respondents. The ability to readily judge intelligence seems to be learned, or it matures later. As surprising as the inability of adolescent women to correctly evaluate intelligence is, it in any case may partly explain why they did not find intelligent men attractive: they could not estimate whether they were intelligent or not. Evaluation of human intelligence could, indeed, represent a case where it can be worthwhile for young or inexperienced individuals to copy more experienced ones, at least in cases where only limited information exist.
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