The Wildlife Professional - Spring 2010 2009

Credit: SSaR

No Road Effect
Roads are no friends to snakes, as the rep-
tiles are commonly killed while attempting
a crossing. But a study in the Journal
of Herpetology (v. 43/4) suggests that
snakes don’t always avoid these dangerous
corridors. David Patrick and James Gibbs
of the SUNY College of Environmental
Science and Forestry set up sampling
grids at various distances from roads and
from forest edges at three sites in Cicero
Swamp Wildlife Management Area in New
York. Over the course of a summer, they
conducted 26 surveys of the grids to count
adult common garter snakes ( Thamno-
phis sirtalis) and northern brown snakes
(Storeria dekayi dekayi), noting their
locations as well as the microclimates in
which they were observed. The research-
ers found more snakes in open, unshaded
areas farther from forest edges, but saw
no evidence that snakes selected habitat
based on the distance to the nearest road.
The researchers theorize that the snakes
place more value on finding habitats that
have greater amounts of sun during the
day than on avoiding roads where they
might meet their death.

Amphibians and Timber Scientists have known relatively little about how timber harvest—a major driver of habitat modification—affects amphibians. In a report in BioScience (v. 59/10), a team of scientists led by Raymond Semlitsch of the University of Missouri, Columbia, detail the results of a set of experiments designed to better understand harvest impacts on three species of pond-breeding amphibians. The researchers established 12 experimental forest patches and divided each into quadrants—a control, a clearcut with coarse woody debris removed, a clearcut with coarse woody debris left, and a partially cut forest. They then measured 33 different responses of amphibians to the treatments. Though clearcuts offered limited benefits to species at certain stages of development, their overall effect was negative, lowering juvenile and adult survival. The authors see some hope in partial harvest treatments, however, which had weaker negative effects compared to clearcuts, and even positively influenced juvenile and adult survival in species such as wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum).

Credit: ai BS

Racing the Climate

Plant and wildlife species may need to pick up the pace to keep up with the changing climate, according to a study in Nature

(v. 462/7276). Using climate model projections, a team of scientists led by Scott Loarie of the Carnegie Institution for Science mapped out how quickly temperature conditions will move across the earth’s surface in the 21st century. They found that the global average speed of temperature change was 0.42 kilometers per year. In addition, they note that this speed will vary considerably based on topography. Thus climate velocity in mountainous tropical and subtropical conifer forests could average just 0.08 km/year, while low-lying grasslands could contend with a climate shifting at speeds of 1. 26 km/year. Loarie and colleagues grant that individual species will not necessarily have to match these speeds if they are fairly tolerant of a range of temperatures. But in a separate analysis, the authors found that climates will remain intact in only 8 percent of protected areas by the year 2100. That conclusion should give wildlife managers something to think about when designing future protected areas and putting together conservation plans for species with low tolerance for climatic swings.

Credit: nature

Credit: allen Press

Flocking to Nest Boxes Sometimes recovering a population of animals can be as simple as providing them with a home. In a four-year study of southeastern American kestrels (Falco sparverius paulus) in north-central Florida, John Smallwood and Michael Collopy organized the placement of 388 nest boxes along 20 16-kilometer-long stretches of road, installing 75 percent of the boxes at least 250 meters from the road. After conducting a complete population census each year for four years, they found that more and more kestrels attempted to breed each year. At the end of three years, kestrel densities had increased six-fold, from five birds per 100 square kilometers to 32 birds per 100 square kilometers—nearly equaling densities in a control area, they report in the Journal of Raptor Research (v. 43/4). The researchers also observed that sites with characteristics such as longleaf pine, low ground cover, and fewer broadleaf deciduous trees made kestrels more likely to nest.