Numerous studies have documented the decline of amphibians following timber harvest. However, direct evidence concerning the mechanisms of population decline is lacking and hinders attempts to develop conservation or recovery plans and solutions for forest species. We summarized the mechanisms by which abundance of amphibians may initially decline following timber harvest into three testable hypotheses: (1) mortality, (2) retreat, and (3) evacuation. Here, we tested the evacuation hypothesis within a large-scale, replicated experiment. We used drift fences with pitfall traps to capture pond-breeding amphibians moving out of experimental clearcut quadrants and into control quadrants at four replicate arrays located within the Daniel Boone Conservation Area on the upper Ozark Plateau in Warren County, Missouri, USA. During the preharvest year of 2004, only 51.6% of the 312 individuals captured were moving out of pre-clearcut quadrants, and movement did not differ from random. In contrast, during both postharvest years of 2005 and 2006, the number of captures along the quadrant edge increased, and a higher proportion of individuals (59.9% and 56.6%, respectively, by year) were moving out of clearcut quadrants than entering. Salamanders moved out of clearcuts in large percentages (Ambystoma annulatum, 78.2% in 2005, 78.2% in 2006; A. maculatum, 64.0% in 2005, 57.1% in 2006). Frogs and toads also moved out of clearcut quadrants, but in lower percentages (Bufo americanus, 59.6% in 2005, 53.3% in 2006; Rana clamitans, 52.7% in 2006). Salamanders moved out of clearcuts with low-wood treatments more than out of clearcuts with high-wood treatments. Movement of salamanders out of clearcuts was independent of sex. Estimated movement out of clearcuts represented between 8.7% and 35.0% of the total breeding adults captured for two species of salamanders. Although we recognize that some portion of the amphibian population may retreat underground for short periods and others may not survive the effects of timber harvest, these data are the first direct evidence showing that individuals are capable of leaving clearcuts and shifting habitat use.

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Our study focuses on the spatial ecology and seasonal habitat use of two aquatic turtles in order to understand the manner in which upland habitat use by humans shapes the aquatic activity, movement, and habitat selection of these species in an urban setting. We used radiotelemetry to follow 15 female Graptemys geographica (common map turtle) and each of ten male and female Trachemys scripta (red-eared slider) living in a man-made canal within a highly urbanized region of Indianapolis, IN, USA. During the active season (between May and September) of 2002, we located 33 of the 35 individuals a total of 934 times and determined the total range of activity, mean movement, and daily movement for each individuals. We also analyzed turtle locations relative to the upland habitat types (commercial, residential, river, road, woodlot, and open) surrounding the canal and determined that the turtles spent a disproportionate amount of time in woodland and commercial habitats and avoided the road-associated portions of the canal. We also located 21 of the turtles during hibernation (February 2003), and determined that an even greater proportion of individuals hibernated in woodland-bordered portions of the canal. Our results clearly indicate that turtle habitat selection is influenced by human activities; sound conservation and management of turtle populations in urban habitats will require the incorporation of spatial ecology and habitat use data.

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Notes aiid Discussion Descriptive Ecology of a Turtle Assemblage in an Urban Landscape cr.-We studied luixle populations inhabiting a canal and a lake (both mau-tnadc) within a hoavi!y disturbed, urban setting. Six aquatic and semi-aquaiic turtle .species were collected in both liabitats: spiny softshell turtle (Afiohne apinifera). painted turtle (Chrysimys pkta), coninmn snapping tnil!e {Uielydra strfuniliua), common map turtle {Grnptpmys gungrtiphira). common musk turiJe (Sttmolhentf odimilus) and rod-caied siidcr {Trachemys srripla). VVIiik' ('-. gpograpliiai WAS the must common species in the canal habit:it, 7! sniplfi WAS most (ommon in ihe lake habitat. We describe patterns of sexual size tlinioiphism and sex rdtio.s for the three most abundant species (fi. gengmphica, T. scripta and S. udoralus). We discuss our data in light of problems facing turtle assemblages in urban settings. iNTRODlKmON Habitat conversion and degradation is generally recognized as the most pervasive and important of the six major threats to biodiversity (other tJireats being invasive species, enviionmenlal poltutioii, disease/parasitism, unsustainable use and global climate change; Gibbons ft uL. 2t)00). The major effect of habitat conversion is the outright loss of critical habitats for essential life functions, including feeding {Vickery el «/., 2001), courting and nesting (Heckert et ai. 2(>03) and hibernation (Ball, 2002). Habitat conversion as the result of increasing urbanization, in particular, affect.s a wide aiTay of organisms, from large carnivores (Reilty et al.. 2003) tn buticrflies (Collingc et al.. 2003) to plants (Frtinsisco-Ortgca et al., 20((0) in terrestrial situations and from salaniatiders (Willsoti and Dorcas, 2003) to fish (Paul and Meyer. 20111) to algae (Fore and Gmle, 2002) in aquatic environments.