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111.
The growing gray seal population in the Baltic Sea has led to increased conflicts with fisheries. Despite limited data on gray seal ecology, management measures, such as culling, have been implemented recently. We studied movements and site fidelity of Baltic gray seals using mark-recapture analysis based on photographic identification of individuals (photo-id). Seals were photographed at the major summer haul-out sites. Profile photographs of the head and neck were matched using purpose-written software to generate a database of capture histories from 1995-2000. The haul-outs were grouped into seven areas. Darroch's method (20) for a two-sample capture-recapture census was adapted to estimate rates of movement between the areas. The majority of seals were estimated to remain within the same area, suggesting that Baltic gray seals exhibit a high degree of site fidelity during the summer, and that fidelity to a site lasts for more than one season. 相似文献
112.
Eckerman DA Abrahamson K Ammerman T Fercho H Rohlman DS Anger WK 《Journal of Safety Research》2004,35(3):317-327
INTRODUCTION: Interactive computer-based safety instruction (CBI) was given to 73 workers in the food services department of an urban hospital. RESULTS: Post-test accuracy (95%) improved significantly (p < or = 0.0001) from the pre-test (74.5 %), d = 1.09. Generalization was confirmed by increased accuracy in answering questions, posed on-the-job, that required application of knowledge to the work setting (from 46% to 79%; p < 0.0001). Problematic kitchen conditions such as puddles increased slightly after training, but adjustment for increasing production/workload revealed an overall post-training decline in problems from 0.58 to 0.32 (p = 0.0001, d = 0.89). Work practice improvement was seen in 79% of workers (p < 0.0001, d = 1.00). Effect sizes (d) of knowledge, location, and work practice improvements are large and demonstrate that the benefits of CBI extend to the workplace floor. Further, the decrease between knowledge and behavior change (d = 0.09-0.2) is less than reported following other forms of training. 相似文献
113.
Sexual selection in a monomorphic lek-breeding bird: correlates of male mating success in the great snipe Gallinago media 总被引:2,自引:0,他引:2
Summary In the lek-breeding great snipe, male morphology, behaviour, and territory features were recorded for individually marked birds on two adjacent leks. Partial correlation sshowed that male mating success, expressed as the number of female solicitations and copulations, was negatively correlated with the distance of a display territory to the lek center and positively correlated with the number of displays per unit time given by a male. No other variables were directly correlated with male matin success. Thus, central males obtain more matings than peripheral males and successful males display more per unit time than do less successful males, independently of position on the lek. Central males were found to be older than peripheral ones and were present more often on the lek. Furthermore, central males had a larger number of white tail feathers, which are usea as visual signals in the displays, but this may be explained by the fact that these males were older. It is suggested that male great snipe are subject to sexual selection mainly in behavioural and vocal cues and that this may explain the absence of size and plumage dimorphism in this species. 相似文献
114.
Spring snowmelt is an important period of mercury (Hg) export from watersheds. Limited research has investigated the potential effects of climate variability on hydrologic and Hg fluxes during spring snowmelt. The purpose of this research was to assess the potential impacts of inter-annual climate variability on Hg mobility in forested uplands, as well as spatial variability in hillslope hydrology and Hg fluxes. We compared hydrological flows, Hg and solute mobility from three adjacent hillslopes in the S7 watershed of the Marcell Experimental Forest, Minnesota during two very different spring snowmelt periods: one following a winter (2009-2010) with severely diminished snow accumulation (snow water equivalent (SWE) = 48 mm) with an early melt, and a second (2010-2011) with significantly greater winter snow accumulation (SWE = 98 mm) with average to late melt timing. Observed inter-annual differences in total Hg (THg) and dissolved organic carbon (DOC) yields were predominantly flow-driven, as the proportion by which solute yields increased was the same as the increase in runoff. Accounting for inter-annual differences in flow, there was no significant difference in THg and DOC export between the two snowmelt periods. The spring 2010 snowmelt highlighted the important contribution of melting soil frost in the timing of a considerable portion of THg exported from the hillslope, accounting for nearly 30% of the THg mobilized. Differences in slope morphology and soil depths to the confining till layer were important in controlling the large observed spatial variability in hydrological flowpaths, transmissivity feedback responses, and Hg flux trends across the adjacent hillslopes. 相似文献