دانلود رایگان مقاله مطلوبیت زیستگاه برای جایگیری حفظ منابع طبیعى

Abstract

Habitat suitability is a critical aspect for the successful establishment of a translocated population. Past studies have identified multiple factors that contribute to habitat suitability, including resource availability, presence of invasive species, landscape connectivity and climate. However, visual camouflage – coloration that conceals individuals from predators or prey – is another important ecological requirement that has been largely overlooked. We provide a case study to illustrate how color patterns of a prey species can change from that of the source site following translocation. Shore skinks (Oligosoma smithi) were moved from a coastal sand dune ecosystem to an offshore island beach that differed in substrate and color. Within one year following release, the translocated population's color pattern variation had reduced to mostly one pattern type. The high match in color patterns between the skinks and release site (including a new substrate type) may have contributed to the observed color pattern shift. This reduced variation in color pattern implies that not all founders survived, potentially decreasing the genetic diversity in the population. Our study highlights the importance of considering a species' camouflage requirements when selecting habitat for release, not only to maximize founder survival and establishment success, but also to maintain phenotypic and genotypic diversity in the long-term.

4. Discussion

Our study provides evidence that when habitat differs from the source location, color patterns of cryptic prey can alter within a short period of time following translocation. Overall, we saw a marked effect on the color patterns of shore skinks translocated to Tiri, where there was reduced variation in body patterns favoring almost exclusively one type. This shift in color patterns did not seem to have an apparent negative effect on habitat use of the Tiri population because within one year, individuals were able to adapt and utilize a new substrate (rock) that was not present at the source coastal sand dunes of Tāwharanui. The high match (in terms of brightness and saturation) between the surviving skinks to rock (with low vegetation cover) may have contributed to the successful transition to the new substrate. But we suspect a reduced number of founder individuals survived, and discuss the consequences (i.e., reduced genetic diversity) of this strong selection for inconspicuous color patterns.