Friday, June 9, 2017

7 mile dispersal by a spotted skunk in West Virginia

Spotted skunk researcher Chuck Waggy recently passed along the story below about a record long-distance dispersal by one of his collared skunks:

"On March 8 we (Emily Thorne and I) trapped and transmitted a male spotted (Joe) on my study area.  On March 22 we trapped and transmitted a female (Mary) at this same location.  Both skunks remained in the vicinity of the trap site until late April.  The female left this area on April 23, moved a short distance south and has been tracked daily to date. 

The male left the area on April 20 and went completely off the transmitter radar.  I tried night tracking and daytime tracking from all access points I could get to that I considered a reasonable distance from the trap site (2-3 miles radius ) but no signals from April 21-May 31. 

Today I was going to survey a timber rattlesnake site and checked on the female spotted enroute (good signal--same place now for nine days).  After locating the female, on a whim I connected my receiver to an omni antenna, switched to the male's frequency and decided to leave the receiver on for the entire trip as my rattlesnake site was very near a golden eagle cam site where I had gotten spotteds on cam in the past.  After driving about eleven miles (road miles) from the last know location of the male on April 20 I got a good signal on normal pulse mode from the male's transmitter.  Stopped and got a good bearing location via telemetry.  Had two co-workers with me who verified signals and location.  Completely accidental that I located him.

The male is now 7.2 air miles from the trap site, although it would be almost impossible for him to go in a straight line as this would have required him to cross a major river twice.  He traversed some of the most rugged terrain in eastern WV and had to be on at least four different mountains.  As of today the telemetered male and female are 8.3 miles apart.

In April of 2015 we had two males to suddenly go off the radar within a few weeks of transmitting.  Today's experience with the male just about verifies my suspicion that we didn't have transmitter failure or immediate mortality.  I am now about positive those two males simply went way farther in distance than I ever expected."

Chuck is not alone in observing this type of long-distance movement, as Damon Lesmeister, during his thesis work in the Arkansas Ouachitas, observed the following long distance dispersal:  "We observed the dispersal of one male in the spring after his capture as a subadult. The animal was captured and fitted with a radio transmitter in October, 2005. The following April, the animal dispersed 6.5 km in less than 48 hours and during the following summer established a territory 9.8 km from it’s winter range. The animal was not observed to return during the course of the study, thus we considered it a dispersing juvenile."

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