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81.
Amy J. Dickman Amy E. Hinks Ewan A. Macdonald Dawn Burnham David W. Macdonald 《Conservation biology》2015,29(3):854-864
Conservation resources are limited, necessitating prioritization of species and locations for action. Most prioritization approaches are based solely on biologically relevant characteristics of taxa or areas and ignore geopolitical realities. Doing so risks a poor return on conservation investment due to nonbiological factors, such as economic or political instability. We considered felids, a taxon which attracts intense conservation attention, to demonstrate a new approach that incorporates both intrinsic species traits and geopolitical characteristics of countries. We developed conservation priority scores for wild felids based on their International Union for Conservation of Nature status, body mass, habitat, range within protected area, evolutionary distinctiveness, and conservation umbrella potential. We used published data on governance, economics and welfare, human population pressures, and conservation policy to assign conservation‐likelihood scores to 142 felid‐hosting countries. We identified 71 countries as high priorities (above median) for felid conservation. These countries collectively encompassed all 36 felid species and supported an average of 96% of each species’ range. Of these countries, 60.6% had below‐average conservation‐likelihood scores, which indicated these countries are relatively risky conservation investments. Governance was the most common factor limiting conservation likelihood. It was the major contributor to below‐median likelihood scores for 62.5% of the 32 felid species occurring in lower‐likelihood countries. Governance was followed by economics for which scores were below median for 25% of these species. An average of 58% of species’ ranges occurred in 43 higher‐priority lower‐likelihood countries. Human population pressure was second to governance as a limiting factor when accounting for percentage of species’ ranges in each country. As conservation likelihood decreases, it will be increasingly important to identify relevant geopolitical limitations and tailor conservation strategies accordingly. Our analysis provides an objective framework for biodiversity conservation action planning. Our results highlight not only which species most urgently require conservation action and which countries should be prioritized for such action, but also the diverse constraints which must be overcome to maximize long‐term success. 相似文献
82.
83.
Kitchen Dawn M. Seyfarth Robert M. Fischer Julia Cheney Dorothy L. 《Behavioral ecology and sociobiology》2003,53(6):374-384
Adult male baboons (Papio cynocephalus) give loud two-syllable 'wahoo' calls during dawn choruses, interactions between groups, when chasing females, and in aggressive interactions with other males. These 'contest' wahoos are acoustically different from 'alarm' wahoos given to predators. In a study of free-ranging baboons in the Okavango Delta, Botswana, we found no significant correlations between the acoustic features of wahoos and adult male size; however, acoustic features were correlated with male dominance rank, age, and calling bout length. Here we show that other measures of calling behavior also appear to function as honest indicators of stamina and competitive ability. High-ranking males were more likely than middle- or low-ranking males to participate in wahoo bouts. They called at significantly higher rates, and their bouts were longer and contained more calls. All males were significantly more likely to participate in wahoo bouts with another male if their opponent's rank was similar to their own. Bouts involving males of similar ranks were longer, contained more wahoos, and involved calling at higher rates, than other bouts. In contests between males of similar ranks, the subordinate and dominant were equally likely to end the bout, whereas in contests involving males of disparate ranks, subordinates were significantly more likely to end the bout. Bouts involving males of similar rank were significantly more likely than others to escalate and result in physical fighting. 相似文献
84.
Embryos of the large infaunal clam Laternula elliptica and the scallop Adamussium colbecki, from Antarctica, were cultured over an 18-month period. Their development rates were extremely slow, taking 240 and 177 h,
respectively, to reach the trochophore stage. This is ×4 to ×18 slower than related clams and scallops from temperate latitudes.
The relationship between temperature and development rate for bivalve molluscs shows the expected slowing with reduced temperature
(Q
10 in the range 2–4) for temperate and tropical species. However, the slowing at polar latitudes is much stronger than at warmer
waters, and all of the limited data for Antarctic species are well above the Arrhenius plot for the overall bivalve data,
and the Q
10 value for Antarctic to cool temperate species is 11.8, well outside the expected range for biological systems. Either the
relationships describing the effects of temperature on the kinetics of biological systems do not apply to Antarctic bivalve
molluscs, or some other factor that cannot be compensated for becomes important at low temperature. In the laboratory, L. elliptica embryos stayed viable in very sticky egg capsules for up to 18 months without hatching. However, even the disturbance of
removing eggs using a pipette ruptured some egg capsules allowing embryo release. Gametogenesis in Antarctic marine invertebrates
is almost universally slowed compared to temperate species, with nearly all cases documented requiring more than 1 year to
complete oogenesis. The only exception so far appears to be A. colbecki, which has a 1-year gametogenic cycle. The data here indicate that it has been unable to adapt embryonic development in a
similar way, and we are not aware of any exceptions to the markedly slowed development at low temperature rule. 相似文献
85.
Steffen Stubenrauch Reinhold Hempfling Peter Doetsch und Dirk Grünhoff 《Umweltwissenschaften und Schadstoff-Forschung》1999,11(4):219-226
Zusammenfassung Um zu einer sachgerechten und nachvollziehbar quantifizierbaren Beurteilung der m?glichen Gesundheitsbelastungen des Menschen
durch Schadstoffe zu gelangen, ist es von grundlegender Bedeutung dessen ?u?ere Schadstoffexposition absch?tzen zu k?nnen.
Um die Durchführung derartiger Absch?tzungen zu erm?glichen, werden nutzergruppen- und expositionsszenariospezifisch orale,
inhalative und dermale Aufnahmeraten für die Kontaktmedien Boden, Pflanzen aus Haus- und Schreberg?rten, Trinkwasser, Staub,
Hausstaub und Innenraumluft vorgeschlagen. Diese Aufnahmeraten dienen, gemeinsam mit gemessenen oder berechneten Schadstoffkonzentrationen
in den entsprechenden Kontaktmedien, zur Absch?tzung der von Menschen aufgenommenen Schadstoffdosen und erm?glichen durch
einen Vergleich mit tolerierbaren Schadstoffdosen eine stoff-, nutzungs- und standortbezogene Beurteilung von Schadstoffexpositionen,
auch für komplexe Nutzungen.
相似文献
86.
87.
88.
Why run and hide when you can divide? Evidence for larval cloning and reduced larval size as an adaptive inducible defense 总被引:1,自引:1,他引:0
Dawn Vaughn 《Marine Biology》2010,157(6):1301-1312
Predator-induced cloning (asexual reproduction), with reduced size as consequence of cloning, suggests a novel adaptation
to the threat of predation. Although cloning is a common reproductive strategy of many plants and animals, cloning in response
to stimuli from predators has, at present, been documented only in the larvae (plutei) of the sand dollar, Dendraster excentricus. Other studies report larval cloning in echinoderms under optimal conditions of food and temperature. A burst of asexuality
should be favored when environmental conditions are conducive to growth, but it is less clear that cloning is advantageous
when conditions indicate risk from predators. This study tested the hypothesis that the small size of predator-induced clones
reduces vulnerability during encounters with planktivorous fish. Successful cloning was inferred from an increase in larval
density, a reduction in larval size and stage, and some direct observations of budding. All clones were smaller than uncloned
sibling larvae, suggesting an advantage against visual predators. Pair-wise predation trials demonstrated that planktivorous
fish ate more uncloned sibling plutei than small clones. These results offer a new ecological context for asexual reproduction:
rapid size reduction as a defense. If the identifiable cues for cloning in echinoderm larvae (food and predators) are linked
in nature, then larval cloning may be a response to a single ecological scenario rather than two separate and unrelated conditions. 相似文献
89.
Shiny Mathews Dawn Reinhold 《Environmental science and pollution research international》2013,20(7):4327-4338
Tetracyclines and sulfonamides used in human and animal medicine are released to terrestrial ecosystems from wastewater treatment plants or by direct manure application. The interactions between plants and these antibiotics are numerous and complex, including uptake and accumulation, phytometabolism, toxicity responses, and degradation in the rhizosphere. Uptake and accumulation of antibiotics have been studied in plants such as wheat, maize, potato, vegetables, and ornamentals. Once accumulated in plant tissue, organic contaminants can be metabolized through a sequential process of transformation, conjugation through glycosylation and glutathione pathways, and ultimately sequestration into plant tissue. While studies have yet to fully elucidate the phytometabolism of tetracyclines and sulfonamides, an in-depth review of plant and mammalian studies suggest multiple potential transformation and conjugation pathways for tetracyclines and sulfonamides. The presence of contaminants in the vicinity or within the plants can elicit stress responses and defense mechanisms that can help tolerate the negative effects of contaminants. Antibiotics can change microbial communities and enzyme activity in the rhizosphere, potentially inducing microbial antibiotic resistance. On the other hand, the interaction of microbes and root exudates on pharmaceuticals in the rhizosphere can result in degradation of the parent molecule to less toxic compounds. To fully characterize the environmental impacts of increased antibiotic use in human medicine and animal production, further research is essential to understand the effects of different antibiotics on plant physiology and productivity, uptake, translocation, and phytometabolism of antibiotics, and the role of antibiotics in the rhizosphere. 相似文献
90.
Oliver R. Price Dawn K. Munday Martin S. Holt Gerard Morris 《Environmental pollution (Barking, Essex : 1987)》2009,157(10):2610-2616
Higher-tier environmental risk assessments on “down-the-drain” chemicals in river networks can be conducted using models such as GREAT-ER (Geography-referenced Regional Exposure Assessment Tool for European Rivers). It is important these models are evaluated and their sensitivities to input variables understood. This study had two primary objectives: evaluate GREAT-ER model performance, comparing simulated modelled predictions for LAS (linear alkylbenzene sulphonate) with measured concentrations, for four rivers in the UK, and investigate model sensitivity to input variables. We demonstrate that the GREAT-ER model is very sensitive to variability in river discharges. However it is insensitive to the form of distributions used to describe chemical usage and removal rate in sewage treatment plants (STPs). It is concluded that more effort should be directed towards improving empirical estimates of effluent load and reducing uncertainty associated with usage and removal rates in STPs. Simulations could be improved by incorporating the effect of river depth on dissipation rates. 相似文献