Sunday, March 29, 2015

Spotted skunk tussle

Spotted skunk camera trap extraordinaire Chuck Waggy sent us a couple of videos he captured recently of spotted skunks approaching a box trap in West Virginia.  In the coming days we will start trapping and placing radio collars on these animals.  In the mean time, it is fun to see these normally cryptic animals move and interact.

Chuck also shared with us this amazing video of two spotted skunks tussling near the trap.

Wednesday, March 25, 2015

The Camera Trapping Process

Guest post by Clemson wildlife student Sarah Wilson:

Our spotted skunk camera trap team consists of seven undergraduate students from Clemson University and our professor, Dr. David Jachowski. We are hoping to confirm the presence of the elusive eastern spotted skunk in South Carolina through an extensive camera trap survey in the southern Appalachians, along with figuring out what kind of habitats they use in South Carolina. We have twenty-six cameras traps that will be moved to different sites every two weeks. Once we have confirmation of skunks at our cameras, we will attempt to find a similarities in the habitat that each skunk is found in. We hope to add to the little knowledge known about preferred habitat characteristics of this species and confirm that they do, in fact, still reside in this state.

Step 1: Choosing the camera site.

One of the few things we know about this animal is that it prefers areas with a closed canopy and thick undergrowth. This is likely because a common predator of spotted skunks is the great horned owl, which is not able to efficiently hunt in younger, thicker forests. They also utilize logs and burrows dug by other species as dens. These are the different things that we look for when choosing an appropriate site for setting up a camera. Two trees about twelve feet apart are selected, one for the camera and one to hold the bait. The two trees should be a size appropriate for wrapping a cord around to attach the camera or large enough to nail on the sardine can.

The two larger trees were used to hold the bait and camera.

Step 2: Setting up the bait.

Canned fish and commercially made fruit paste are both common baits used to lure in mesocarnivores such as spotted skunks. We chose to use canned sardines in oil because they are readily available and the oil contributes to the distinct smell that will lure in wildlife. A hammer and nail are used to punch about twelve holes through the backside of the sardine can and then it is nailed to the base of the tree designated as the bait tree. The holes in the can allow the oil to run down the tree and scent tendrils from the fish inside pull spotted skunks to the bait.

Rob C. hammers a can of sardines to the selected tree.

Lesson Learned: The first weekend we set out our cameras, we only used two nails to hold each sardine can to its tree. When we went out the next weekend to check on the cameras to make sure they still had bait, the third site we checked was completely missing its sardine can! Guesses for potential culprits included raccoon and opossum. When we checked the pictures from that camera, this is what we found:

This coyote had no problem ripping our bait off the tree! Now, we use four nails in each can in hopes of keeping it more secure.

Step 3: Setting up the camera.

The camera is pretty easy to setup. First we take note of the memory card and camera number and mark that down on the data sheet for the site. The camera must be armed and placed in its protective case. A lockable cable is strung through the case and around the tree. This step involves two people. One person to hold the camera in place against the tree while the second person is tightening the cable. Now, finer adjustments can be made to make sure it is aligned properly with the bait. One person gets eye level with the bait and instructs the others on what adjustments need to be made. Once it is facing the right direction, block wedges are placed between the camera and the tree, if needed, to tilt it downwards towards the bait. Finally, a straight stick is used to get a better idea of how well we positioned the camera.

Amy K. and Dr. Jachowski adjusting the camera.

Step 4: Habitat data collection

Since the major predators of spotted skunks are large birds, such as great horned owls, they prefer to live in areas that make it difficult for these birds to hunt, such as those with a dense understory and closed canopy. Throughout their geographic range they are found in young shortleaf pine stands with an abundance of vines, slopes, and denning sites. These denning sites, along with resting sites, are selected based on the amount of surrounding undergrowth and the ability to protect from predation, weather, and light.

After setting the camera, we record observations about the surrounding habitat that take into account the habitat characteristics that we know about spotted skunks in other states. These include canopy cover, understory cover, dominant canopy and understory species present, presence and number of rocky outcrops, and presence and number of woody debris. This information is just as important as the pictures the camera trap will give us. Without knowing the characteristics of the camera site, if it were to capture an image of a spotted skunk we wouldn’t have any way to know what habitats they are attracted to and what new sites might also have skunky habitat.

The Final Product of Our Efforts:

Sarah R. and Rob C. are proud of their camera trap.

Further Reading:

Lesmeister, D. B., J. J. Millspaugh, M. E. Gompper, T. W. Mong. 2010. Eastern Spotted Skunk (Spilogale putorius) Survival and Cause-specific Mortality in Ouachita Mountains, Arkansas. The American Midland Naturalist 164: 52-60.

Lesmeister, D. B., M. E. Gompper, J. J. Millspaugh. 2009. Habitat Selection and Home Range Dynamics of Eastern Spotted Skunks in the Ouachita Mountains, Arkansas, USA. The Journal of Wildlife Management 73: 18-25.

Lesmeister, D. B., M. E. Gompper, J. J. Millspaugh. 2008. Summer Resting and Den Site Selection by Eastern Spotted Skunks (Spilogale putorius) in Arkansas. Journal of Mammology 86: 1512-1520.

Thursday, March 19, 2015

A Surfeit of Spotted Skunks in West Virginia

Eastern spotted skunk expert and camera trap extraordinaire Chuck Waggy sent us this series of images he recently collected in West Virginia.  Never before have I seen more than one spotted skunk in a camera trap image, let alone 3.  Given that (1) spotted skunks are generally thought to be solitary animals, (2) this is just before breeding season, and (3) families are not thought to remain together this long, it is unclear what this surfeit (what a group of skunks are termed) of skunks were doing together at this deer carcass.

Then, a couple of days later, Chuck set the bar even higher by detecting 4 different spotted skunks at the site.  

The new record has been set and further shows that the more we see and learn, the more the mysteries of the eastern spotted skunk continue to grow.