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Kirsten?Kreuter Elfi?Bunk Anna?Lückemeyer Robert?Twele Wittko?Francke Manfred?AyasseEmail author 《Behavioral ecology and sociobiology》2012,66(3):475-486
Social parasitism is widespread in many groups of social living hymenopteran species and has also evolved in the genus Bombus. Cuckoo bumblebees (subgenus Psithyrus) are obligate brood parasites in nests of other bumblebee species. After nest usurpation and the killing of the host queen,
the parasite female has to control worker reproduction in order to accomplish and maintain reproductive dominance and to ensure
her reproductive success. The aim of our study was to examine whether the generalist parasitic bumblebee Bombus bohemicus monopolizes and prevents worker reproduction by physical or chemical means and to identify possible odor compounds involved
therein. We performed bioassays with callow workers of the host Bombus terrestris and have shown that B. bohemicus females are able to suppress host worker ovarian development, when these host workers are under the direct influence of the
parasite female. Furthermore, by chemical analyses, we have demonstrated that the parasite females adjust to the odor profiles
of their host queens in order to maintain the level of fertility signaling inside the host colony although the host queen
is absent. We also found that host workers change their odor profile after nest usurpation by the parasite female and consequently,
we suggest that the host and parasite are caught up in a chemical arms race. 相似文献
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Matthew Wagner Ronald Kaiser Urs Kreuter Neal Wilkins 《Journal of the American Water Resources Association》2007,43(3):698-711
Abstract: As nearly all of Texas’ rural lands are privately owned, landowner associations for the management of white‐tailed deer and ground‐water have become increasingly popular. Deer are a common‐pool resource with transboundary characteristics, requiring landowner cooperation for effective management. Ground‐water reserves are economically important to landowners, but are governed by the “rule of capture” whereby property rights are not defined. One ground‐water association and four wildlife management associations (WMAs) were surveyed to characterize their member demographics, land use priorities, attitudes, and social capital. Members of the ground‐water cooperative were part of a much larger, more heterogeneous, and more recently formed group than members of WMAs. They also placed greater importance on utilitarian aspects of their properties, as opposed to land stewardship for conservation as practiced by members of WMAs. If ground‐water association members could be more locally organized with more frequent meetings, social capital and information sharing may be enhanced and lead to land stewardship practices for improved hydrologic functions and sustained ground‐water supply. This, coupled with pumping rules assigned by the local ground‐water district, could yield an effective strategy that is ecologically and hydrologicaly sound, and that allows rural provision of water supply to urban consumers. 相似文献
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Kjelland ME Kreuter UP Clendenin GA Wilkins RN Wu XB Afanador EG Grant WE 《Environmental management》2007,40(2):231-244
Fragmentation of family-owned farms and ranches has been identified as the greatest single threat to wildlife habitat, water
supply, and the long-term viability of agriculture in Texas. However, an integrative framework for insights into the pathways
of land use change has been lacking. The specific objectives of the study are to test the hypotheses that the nonagricultural
value (NAV) of rural land is a reliable indicator of trends in land fragmentation and that NAV in Texas is spatially correlated
with population density, and to explore the idea that recent changes in property size patterns are better represented by a
categorical model than by one that reflects incremental changes. We propose that the State-and-Transition model, developed
to describe the dynamics of semi-arid ecosystems, provides an appropriate conceptual framework for characterizing categorical
shifts in rural property patterns. Results suggest that changes in population density are spatially correlated with NAV and
farm size, and that rural property size is spatially correlated with changes in NAV. With increasing NAV, the proportion of
large properties tends to decrease while the area represented by small properties tends to increase. Although a correlation
exists between NAV and population density, it is the trend in NAV that appears to be a stronger predictor of land fragmentation.
The empirical relationships established herein, viewed within the conceptual framework of the State-and-Transition model,
can provide a useful tool for evaluating land use policies for maintaining critical ecosystem services delivered from privately
owned land in private land states, such as Texas. 相似文献
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