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The split-beam hydro-acoustics surveys were conducted to learn about the diel migration and distribution characters of Toxabramis houdermeri and to assess its current abundance in Baise Reservoir of China in October 2013. The study revealed the average density of T. houdermeri was 258 individuals/1000 m3, and gradually increased from downstream, through middle to upstream (203 individuals/1000 m3, 252 individuals/1000 m3 and 318 individuals/1000 m3, respectively). The study also showed that the target species always distributed in the 2–42 m water layer during the daytime, before migrating upward around dusk which led the fish density to sit in the 2–12 m water layer, to reaching a peak value of 1740 individuals/1000 m3 during the night. Finally, the fish volume density was found to positively correlate with the concentration of chlorophyll, dissolved oxygen (DO) and pH value in their studied areas. In conclusion, the results presented that T. houdermeri preferred a relatively higher average chlorophyll concentration of 3.58 ug/L DO of 6.33 mg/L, and pH of 7.96 in the upstream and upper layers of Baise Reservoir.
The bleak, Alburnus alburnus, is an invasive fish in the Iberian Peninsula, where this species mainly disturbs the highly endemic fauna via competition and aggression. Despite this impact, information on bleak autecology is scarce in the Iberian Peninsula, with no data on growth and reproduction. The aim of the present study was to compare bleak populations across four Iberian streams: Muga, Fluvià, Cardener and Foix (northeastern Iberian Peninsula). These streams have similar environmental conditions at the regional scale (e.g. Mediterranean climate, geomorphology). In Muga and Foix streams, bleak showed lower growth rate and back-calculated length at age 2. Body condition was lower in Foix streams, whereas length at maturity was higher. In Muga stream, the proportion of females was lower. In Cardener stream, bleak showed higher back-calculated lengths at ages 1 and 2, growth rate, body condition and reproductive investment. Results showed that bleak populations are able to display wide phenotypic plasticity in small Mediterranean-type rivers. Specifically, bleak population “health” appears to be better in Cardener stream, whereas it is worse in Muga and Foix streams. Present findings suggest that inter-population plasticity allows bleak more successfully to invade Mediterranean fresh waters in the Iberian Peninsula.
Four piscivorous fishes such as pike, Esox lucius, European catfish, Silurus glanis, pikeperch, Sander lucioperca, and Eurasian perch, Perca fluviatilis, co-occur in Kaniv Reservoir (Ukraine). In total, 47 food items were identified in their diets including remains of fish and invertebrates. Sixteen prey items were identified in pike diet including 15 fish species; 33 prey items in European catfish diet, among which 20 fish species; 21 prey items in pikeperch diet, among which 18 fish species; and 28 prey items in perch diet, among which 12 fish species. The most important prey for pike were roach, Rutilus rutilus (%IRI = 25.9 %), Prussian carp, Carassius gibelio (34.7 %), and perch (18.4 %); for catfish — roach (55.5 %) and perch (20.6 %); for pikeperch — roach (52.8 %) and perch (34.1 %); and for perch — monkey goby, Neogobius fluviatilis (85.7 %). Highest diet overlap indices were observed between catfish and pikeperch (84.8 %) while the lowest between catfish and perch (33.7 %). No significant difference was observed between the average sizes of fish prey in the stomachs of pikeperch and European catfish (t-test, P > 0.05), but there were significant differences between all other pairs of piscivorous species (t-test, P < 0.001).
Two species of brush-tailed mice, genus Calomyscus, are known from eastern Iran: Calomyscus hotsoni has been reported from southwestern Pakistan and southeastern Iran, and C. elburzensis ranges through northeastern and central Iran. Based on molecular studies of two mitochondrial genes, all the specimens from eastern Iran examined herein belong to either of these two species. Furthermore, our data expand the northern distribution limits of C. hotsoni to just south of Birjand and the southern limits of C. elburzensis to east of Birjand. Morphometric analyses conducted on three geographic groups of C. hotsoni within Iran, contained specimens from Birjand (group 1), Zahedan and Khash (group 2) and Saravan (as group 3) revealed a north-to-south cline of decreasing body and cranial size, such that the most significant differences were between the northern and southern most groups. Karyological studies also showed differences in autosomal arms between the two geographical groups in Iran. Although the phylogenetic analyses separated these two groups into distinct clades, along with a third clade containing most of the C. hotsoni from Pakistan. The morphometric and molecular partitioning of geographic populations of C. hotsoni were not concordant. We consider the north and south groups of C. hotsoni as distinct Evolutionary Significant Units. There is evidence of introgression between the two forms across a broad geographic area presented by individuals of group 2 resulting in a clinal pattern of variation.
Knowledge of the activity patterns and budget provide insight into how animal adapt to the environment through behavioural modification. Time activity budget of Indian giant flying squirrel (Petaturista philippensis) was studied in the tropical deciduous forests of the Sitamata Wildlife Sanctuary, Rajasthan, India, from March 2009 to February 2010. The study revealed that the species exhibited a bimodal activity pattern with a first peak in the early-night, while a second lower peak occurred during the late-night. Annual activity budget was mostly devoted to resting (45.85 %) and feeding (27.72 %) followed by locomotion (10.84 %), grooming (6.20 %), exploring (5.71 %), inside tree cavity (2.15 %), and calling (1.24 %) activities. Except grooming (P < 0.05) and inside tree cavity (P < 0.0001), all other activities did not show significant difference (P > 0.05) among seasons. Among all seasons, the species was found more active in winter season.
White-nose Syndrome (WNS) decimates bat populations in North America but similar effects have not been recorded in Europe. WNS-affected bats exhibit abnormal hibernation behaviour that prematurely deplete fat reserves and ultimately causes death by starvation. In the deep hibernation period (December–March) of 2006/07 (pre-WNS) and 2010/11 (post-WNS), we monitored bat hibernation behaviour and flight activity to test the potential impact of WNS on European bats. We registered no abnormal changes in bat hibernation behaviour (movement to visible sites, utilization of dynamic cave sections), flight activity level, its direction or seasonal pattern remained unchanged following WNS infection. Flight activity inside the cave and at its entrance was generally low during the deep hibernation period and temperature remained the best predictor of activity level. In general, stable hibernation behaviour and activity patterns suggests that they are apparently optimized for European winter conditions and support the hypothesis that the fungus has been present in Europe for a long time and has only recently invaded North America.
According to hunting statistics in the last two decades, both the population numbers and harvesting of roe deer in Poland have been on the increase from 597000 to 876000 animals and from 158000 to 172000 harvested individuals, respectively. The number of roe deer reported by hunters are mainly based on guesswork, therefore the objective of the study was to verify the inventory of roe deer conducted by hunting clubs in the Myślibórz Forest District (north-western Poland) and to determine the sex ratio and age structure this species. The study area is including 86 small size forest complexes and covers 12990 ha. Roe deer number were determined over four years from 2002 to 2006. In sampling plots (February 2002) data from snow tracking and driving census showed significant correlation (r = 0.663, p = 0.003) between the relative population density (N/km) — independent variable and population density (N/1000 ha) - dependent variable. Roe deer snow tracks were counted during five days each year on 16 line transects (length 66.4 km) and the relative population densities (animal per km*day-1) for the whole study area were calculated. These indices were inserted into the regression formula that was obtained from sampling plots. It allowed to calculate the population density (N/1000 ha) and then roe deer numbers inhabiting the study area. Population density ranged from 300.1–319.0 individuals/1000 hectares of forest, and the differences between the four years of study were statistically insignificant. In summer, the sex ratio of the population was 1:1.4 in favour of females, and the autumn increment of young animals amounted to 70.2 fawns/100 does. The average population number of roe deer assessed for these four years was 3568 individuals and was more than two times higher than the average population size (n = 1670) given by hunters.
The aim of present studies was to examine the interrelationships between reproductive events, age, body mass and steroid hormones in roe deer females (Capreolus capreolus). For this purpose we compared seasonal changes in body mass, blood levels of progesterone and estradiol (1) in young (1 year) and adult (2–4 years old) does and (2) in pregnant and non-pregnant animals. Monthly during 12 months all animals were weighed, blood plasma was collected, and concentration of progesterone and estradiol was analysed by RIA. Pregnant animals had significantly higher body weight, than non-pregnant ones, in November (before foetus implantation), and lower body weight in comparison with non-pregnant females in August (after parturition). In non-pregnant females high level of progesterone was observed from August (mating) up to December. Thereafter progesterone level declined up to minimum in summer months (April–July). Pregnant animals had increased progesterone level from February (foetus implantation) up to June (time after labour). In non-pregnant females, three peaks of estradiol concentration were observed in October, December and May. Pregnant animals, in contrast to non-pregnant females, had spring (January–March) gravidity-associated peak of estradiol level, but absence of summer (May) peak before parturition. Comparison of annual changes in body weight and plasma steroid hormone level in pregnant yearlings and old animals, as well as the number of offspring in these animals did not show principal age-dependent differences in these indexes, although yearlings had higher absolute progesterone (in December) and estradiol (in October and November) level than old animals. Our observations suggest significant seasonal changes in plasma progesterone and estradiol level and body weight in this species. Substantial differences in these changes in pregnant and non-pregnant animals demonstrate the involvement of steroid hormones in control of pregnancy in roe deer does. The absence of age-dependent differences in body weight and fecundity rate do not confirm previous hypothesis that age-dependent differences in metabolism and body mass can reduce fertility rate in yearlings. Moreover, our observations are the first demonstration of higher rate of steroidogenesis in young animals, than in adult females during early stages of gravidity and before embryo implantation. It is not to be excluded, that age-dependent reduction in ovarian steroid hormones level could be a cause of future infertility in old animals.
Habitat degradation is a major threat to the survival of chiru (Pantholops hodgsonii). Detailed knowledge for habitat conservation in this steppe-dwelling ungulate is needed if effective conservation and management strategies are to be developed. The distribution of potential habitat and the relative value of habitat to chiru on a regional scale remains unknown, hindering landscape conservation planning. Our aim was to identify and rank chiru habitat across the Chang Tang region of the Tibetan Plateau. We assessed overall habitat suitability using geographical data, field surveys, and information contained within previous studies. We identified 10194 km2 of optimal habitat (1.71 % of the region), 256816 km2 of suitable habitat (43.17 % of the region), and 213799 km2 of marginal habitat (35.94 % of the region). Our habitat model shows that suitable habitat is located primarily in the central (Nyingma county and Shuanghu county) and western (Geze county) regions of the study area. When we looked specifically at a chiru reserve (Chang Tang Nature Reserve) located within the study area, we found that over half of the reserve could be classified as suitable habitat. This highlights the regional importance of this reserve to chiru conservation. Our findings further indicate that the protection of suitable habitat and improvement of habitat linkages will be important features of any regional chiru conservation plan.
The European badger (Meles meles) and the red fox (Vulpes vulpes) are the two most common mesocarnivores in Hungary. The populations of both species are increasing. The badger has settled in various habitats in the last two decades, while the red fox can often be seen in urban habitats. Due to their wide tolerance of environmental conditions wildlife managers and conservation experts realized that both species have an important (predatory) role in many ecosystems. During the course of our research we examined the preferred locations of the den sites of the European badger and the red fox on the basis of set locations for both species in various areas across Hungary (badger: n = 142, fox: n = 113). Our aim was to find out whether there is a connection between these species' habitat selection on a small scale (locally) and on a large scale (at countrywide level). Field data were collected in four hilly areas and four lowland areas in Hungary. Badgers preferred deciduous and coniferous forests, and rarely used open areas, whereas foxes did not seem to use either coniferous forests or open areas. In the case of both species the preferred locations of the den sites were sharply demarcated in coniferous forests.
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