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31.
Reports of the damage from wolf attacks have increased considerably over the last decade in Georgia (in the Caucasus). We interviewed locals about this problem in two focal regions: the Lanchkhuti area (in western Georgia) and Kazbegi District (in eastern Georgia) where livestock numbers had increased by an order of magnitude owing to dramatic shifts in the local economies over the last decade. This coincided with expanding habitats for wolves (abandoned plantations, for example). We found that the perceived damage from wolves was positively correlated with a poor knowledge of wolf habits and inappropriate livestock husbandry practices. Our results suggest a loss of traditional knowledge contributes strongly to the wolf–human conflicts in Georgia. Restoring traditional, simple but good practices—such as protecting herds using shepherd dogs and introducing bulls into the herds—can help one solve this problem.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-014-0580-1) contains supplementary material, which is available to authorized users. 相似文献32.
经四年研究,本文提出了适宜丘陵地区的作物-猪-鱼复合生态系统模型。在该系统中,淡水鱼的养殖以半精养方式最佳。本文还讨论了半精养方式的混养结构、水质管理和饵料组合等配套技术。 相似文献
33.
2004年11月~2005年4月,进行了王锦蛇的冬眠期饲养试验.结果表明:在王锦蛇的冬眠期内,人工保持其环境温度为25~30℃,相对湿度为60%~85%,并提供其所需要的食物条件,就能够使王锦蛇在冬眠期内正常地生长发育,不仅能缩短其饲养时间,而且能提高其成活率,从而达到高效饲养王锦蛇的目的. 相似文献
34.
Is helping a beneficial learning experience for red-cockaded woodpecker (Picoides borealis) helpers?
Several hypotheses have been suggested to explain the evolution and maintenance of helping behavior in cooperatively breeding
birds, one of which we investigated in the red-cockaded woodpecker (Picoides borealis). Helping may provide a learning experience that improves reproductive success once the helper becomes a breeder. We used
data collected from a population of red-cockaded woodpeckers in the Sandhills of North Carolina to compare the reproductive
success of 2-year-old breeders that were helpers at age 1 (helping experience) to those that were floaters or solitary males
at age 1 (no helping experience). Reproductive success of the two groups was similar, indicating that helping provides no
experience useful in reproduction. We reject the learning experience hypothesis as an explanation for the maintenance of helping
behavior in red-cockaded woodpeckers.
Received: 29 July 1996 / Accepted after revision: 27 April 1997 相似文献
35.
Plasma concentration of androgens and gonad development were studied in wild cooperatively breeding bell miners (Manorina melanophrys) of different age, sex and social status. Plasma levels of androgens increased with age of birds. For sexually mature (SM) bell miners, androgen levels were higher in breeders than in nonbreeding (NB) helpers (P < 0.005), and they were marginally higher in females than in males (P < 0.10). Thus female breeders showed the highest plasma levels of androgens. This pattern may be explained by an asymmetry between the sexes in the levels of competition needed to reach and defend breeding status; the degree of intra-sexual competition seems to be higher among female bell miners than among males. In general, male breeders had larger gonads than male SMNB helpers; male breeder gonads produced spermatozoa whereas most helpers' gonads did not. However, old (i.e. 34 months) SMNB male helpers had large gonads producing spermatozoa in spite of having low plasma levels of androgens. We suggest that young male bell miners may be under a voluntary mechanism of reproductive suppression perhaps favoured by inbreeding avoidance; although some aggressive interactions observed between very young helpers (about 2 months) and adult members of the breeding unit suggests that a certain degree of imposition also occurs at young ages. Older male helpers may avoid aggression with the male breeder and imposed reproductive suppression, hence the low circulating levels of androgens, but they have the potential to sneak extra-pair copulations. Gonad size decreased during the non-breeding season in both sexes. 相似文献
36.
Effects of Climate and Land-Use Change on Species Abundance in a Central European Bird Community 总被引:2,自引:0,他引:2
NICOLE LEMOINE† HANS-GÜNTHER BAUER‡§ MARKUS PEINTINGER KATRIN BÖHNING-GAESE†‡‡ 《Conservation biology》2007,21(2):495-503
Abstract: Although it is known that changes in land use and climate have an impact on ecological communities, it is unclear which of these factors is currently most important. We sought to determine the influence of land-use and climate alteration on changes in the abundance of Central European birds. We examined the impact of these factors by contrasting abundance changes of birds of different breeding habitat, latitudinal distribution, and migratory behavior. We examined data from the semiquantitative Breeding Bird Atlas of Lake Constance, which borders Germany, Switzerland, and Austria. Changes in the regional abundance of the 159 coexisting bird species from 1980–1981 to 2000–2002 were influenced by all three factors. Farmland birds, species with northerly ranges, and long-distance migrants declined, and wetland birds and species with southerly ranges increased in abundance. A separate analysis of the two decades between 1980–1981 and 1990–1992 and between 1990–1992 and 2000–2002 showed that the impact of climate change increased significantly over time. Latitudinal distribution was not significant in the first decade and became the most significant predictor of abundance changes in the second decade. Although the spatial scale and temporal resolution of our study is limited, this is the first study that suggests that climate change has overtaken land-use modification in determining population trends of Central European birds. 相似文献
37.
38.
Regina?H.?F.?MacedoEmail author Mariana?O.?Cariello Jeff?Graves Hubert?Schwabl 《Behavioral ecology and sociobiology》2004,55(3):213-222
Guira cuckoos, Guira guira, exhibit a rare polygynandrous reproductive system with groups containing several male and female breeders, allowing for important tests of reproductive skew models. Female reproductive strategies involve leaving the group, varying clutch size, egg ejection and infanticide, among others. Here we examined the predictions of reproductive skew models relative to reproductive partitioning among females in groups. We used yolk protein electrophoresis to identify individual females eggs in joint nests. We found that reproductive partitioning favors early-laying females, which lay and incubate more eggs than females that begin laying later. Because the female that lays first tends to switch between repeated nesting bouts, and females do not always contribute eggs to each bout, female reproductive success tends to equalize within groups over time. The pattern of reproductive partitioning differs from that described for anis, another crotophagine joint-nester. We calculated reproductive skew indices for groups in 2 years, for both laying and incubation, as well as an overall population value. These were compared to random skew generated by simulations. Varying degrees of skew were found for different groups, and also across sequential nesting bouts of the same groups. Overall, however, skew did not deviate from random within the population. Nests that reached incubation tended to have lower skew values during the laying phase than nests terminated due to ejection of all eggs followed by desertion. Groups had higher reproductive skew indices in their first nesting bout of the season, and these nests frequently failed. These results illustrate the importance of social organization in determining not only individual, but group success in reproduction, and highlight the flexibility of vertebrate social behavior.Communicated by J. Dickinson 相似文献
39.
Aneil?F.?AgrawalEmail author Jeremy?M.?Brown Edmund?D.?BrodieIII 《Behavioral ecology and sociobiology》2004,57(2):139-148
Maternal-offspring interactions are important in a variety of animals. Understanding the evolution of these interactions requires that we also study the broader social context in which they occur. To date, behavioral studies on burrower bugs, Sehirus cinctus, have focused exclusively on interactions between mothers and offspring. Here we ask whether these interactions occur in a social context that extends beyond the family unit of a mother and her own genetic offspring. Such social structure can arise from behaviors that occur before eggs are laid, or from actions of individuals that occur post-hatching. We present field data showing that lay sites of mothers are spatially aggregated on a scale that would lead to behavioral interactions among families. Microsatellite markers suggest neighboring mothers are unrelated. Laboratory experiments do not support the hypothesis that spatial aggregation results from a direct attraction of females to one another. Other laboratory studies reported here indicate that, after hatching, unrelated clutches sometimes join together to form multifamily groups. Experiments reveal that mothers are not necessary for these joining events to occur. In sum, these data suggest that both mothers and offspring play active, but different, roles in generating the social environment in which offspring rearing occurs.Communicated by N. Wedell 相似文献
40.
本文立足于辽东山区微型小流域的地域空间,以经营开发“特色农业”为主线,着眼于山区小流域的特产资源的培育与开发。通过资源培育和对初级产品的深加工,将山区小流域的资源优势转化为产品优势和商品优势,从而实现山区流域经济运行的良性循环。 相似文献