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991.
Z. G. Prishutova 《Russian Journal of Ecology》2010,41(1):55-59
Vegetation was considerably trampled throughout Vodnyi Island in the Rostovskii Nature Reserve in 2007 because of a high pasture
load due to feral horses (0.15 horses/ha). Calculation of the food resources on the island, with its protection as part of
a nature reserve taken into account, has shown that the herd size is 3.5 times larger than the maximum allowable value. 相似文献
992.
V. N. Orlov Yu. M. Borisov S. Yu. Irkhin A. A. Kovaleva 《Russian Journal of Ecology》2010,41(6):519-523
The distribution of three chromosome races (Moscow, Western Dvina, and Seliger) of the common shrew Sorex araneus L. in the zone of contact between their ranges in the Valdai Heights (32°00′ E, 57°00′ N) is discussed. The area co-inhabited
by all the three races is extremely small. Representatives of all the three races have been captured on only one trap line,
although there are no obstacles to the expansion of shrews. The extremely small area co-inhabited by the three races, as well
as the strictly parapatric distribution of the Moscow and Western Dvina races, may be related with competition forms such
as avoidance of contacts and separation of ecological niches. 相似文献
993.
Using the long-tailed tit (Aegithalos c. caudatus) as an example of the so-called irruptive species, the ecophysiological characteristics (body mass, fat reserves) and migration
speed during autumn period were analyzed. The mean body mass and the median fat score did not depend on the number of migrating
individuals. There was no evidence of the so-called stress in birds, participating in migration: migrants had even higher
fat reserves than residents, while no significant difference in the body mass was recorded. The increase in fat reserves in
the long-tailed tit during migration period was similar to the seasonal changes in energy reserves known for typical migrants.
This makes it possible for late-migrating individuals to maintain higher total speed of migration compared to early-migrating
ones. Basing on the obtained data, we conclude that the ecophysiological characteristics of the long-tailed tits migrating
in autumn are similar to those of regular migrants. 相似文献
994.
995.
Sex-biased predation is thought to have important implications for sexual selection, sex allocation, and population dynamics (Magnhagen, 1991; Le-Galliard et al., 2005 for an example in lizards). Most studies found that males are subjected to higher predation pressure than females during the reproductive season (Korpimäki, 1985; Lodé et al., 2004; Christe et al., 2006; Costantini et al., 2007). In that period, males are very mobile, emit acoustic signals and exhibit brilliant colourations, which are needed to attract females but may make them more visible to predators. With regard to lizards, a recent study provided the first evidence that males of a lizard species may be preyed on more than females (Costantini et al., 2007). In the present study, we investigated whether there is sex-biased predation on two small lacertid species, the common wall lizard Podarcis muralis (Laurenti, 1768) and the Italian wall lizard Podarcis sicula (Rafinesque-Schmaltz, 1810), by Eurasian kestrels (Falco tinnunculus) during the reproductive season. We also examined whether (1) the rate of predation differed between species and (2) the rate of predation differed across years or among hunting habitats for each species. 相似文献
996.
A. V. Artem’ev 《Russian Journal of Ecology》2010,41(5):418-421
On the basis of long-term studies on the ecology of pied flycatcher in Karelia, it has been shown that male nonparticipation
in nestling feeding is due to the course of postnuptial molt rather than to the mode of mating relationships, as it was considered
previously. This is confirmed by the results of selective capture of birds that have stopped to feed their brood. It is suggested
that reduction of parental care is associated with changes in the hormonal balance of molting birds. 相似文献
997.
998.
A set of criteria allowing demarcation between algocenoses is proposed. These criteria characterize the species composition,
group of dominants, and taxonomic and ecological structure of algocenoses. 相似文献
999.
The abundance of terrestrial arthropods in the Orenburgskii Nature Reserve has decreased since its establishment in 1989.
At present, this parameter fluctuates considerably, and the species composition of arthropods is changing in favor of xerobiontic
and eurybiontic species. These changes result from the absence of grazing load as well as from periodic fires. Therefore,
it is necessary to organize controlled livestock grazing and reliable fire protection in reserved areas. 相似文献
1000.