Wednesday, April 15, 2015

Spotting the Spotted Skunk: Historical and Current Ranges

Guest post by Clemson University wildlife student Rob Colquhoun

Up until the 1940’s, Spotted Skunks were an important furbearer species in the Great Plains states and were a fairly common sight, but then something happened. People started noticing that there were less and less sightings of the skunks and by the 1980’s they became a rare sight. Now, many states list the Eastern Spotted Skunk as endangered or as a species of concern. The seemingly sudden decline doesn’t appear to be linked to overharvesting rates though, instead it seems to be due to development of their preferred habitats.

Spotted Skunk are very particular when it comes to the places that they call home. They prefer habitat with lots of brush, understory cover, a closed canopy and rocky outcrops; this allows them to hide from predators like hawks and Great Horned Owls, that can’t penetrate the thick brush. Knowing this, its no surprise that populations have decreased from their historic numbers, because of habitat loss and development.

There are 4 distinct subspecies of spotted skunk within North America: the Western Spotted Skunk (Spilogale gracilis), the Eastern Spotted Skunk (Spilogale putorius), Southern Spotted Skunk (Spilogale angustifrons) and the Pygmy Spotted Skunk (Spilogale pygmaea). Our species of concern, the Eastern Spotted Skunk, is very rarely sighted.

The populations of Eastern Spotted Skunks that remain in South Carolina are mainly clustered in the upstate, where there is less development and more of the dense understory that they prefer. Recently, an extremely bright group of students have been conducting a population survey, placing camera traps in public lands near sightings from the past few decades. So far, 5 spotted skunks have been caught on camera, the first documented sightings in the state in over 16 years.

For more information on historic ranges and preferred habitat of the Eastern Spotted Skunk, you can read Lesmeister et al.’s paper “Eastern Spotted Skunk Survival and Cause-Specific Mortality in the Ouachita Mountains, Arkansas”, found in The American Midland Naturalist Journal, issue 164.

Thursday, April 2, 2015

Judgment Day

Guest Post by Clemson wildlife student Amy Klink

How do we choose what animals are more critical and require assistance over helping others? Policy makers have the difficult challenge of managing wildlife species that meets the needs of the animal, public opinion, and a strict budget. New research suggests establishment of endangered species restoration habitats can negatively affect eastern spotted skunks. One such case involves the conflict between the skunk and the infamous red-cockaded woodpecker (RCW).

Typically eastern spotted skunks prefer an early successional habitat supporting a dense understory. The dense understory is so crucial because it creates escape cover from avian predators On the other hand; RCW requires a mature, open pine forest.  The RCW habitat requires a frequent burn to open up the understory. This causes conflict for the spotted skunks. 

Damon Lesmeister, Rachel Crowhusrt, Joshua Millspaugh, and Matthew Gompper (2013) took a closer look at this conflict. They conducted their study in the Ouachita National Forest where there is a mix of pine forest types ranging from both burned and unburned areas and mature and young pine areas. Using track plates, the study surveyed the number of spotted skunks in five different forest stand types (control, burned mature, unburned mature, burned young, and unburned young). Based on their techniques, Lesmesiter et al. (2013) found more spotted skunks in large, younger pine stands, which was the opposite of the typical RCW habitat. They concluded that forest stand age was imperative when spotted skunks and RCW choose a habitat.

This causes major clash between two species that have seen a dramatic decline in populations. It brings up the questions again, how do we evaluate which species should be managed? This ethical question is a never-ending challenge most government officials have to go through every day.

Further Reading

Lesmeister, D. B., R. S. Crowhurst, J. J. Millspaugh, and M. E. Gomper. (2013). Landscape ecology of eastern spotted skunks in habitats restored for red-cockaded woodpeckers. Restoration Ecology, 21, 267-275.