International tracker evaluation system helps biologists improve otter monitoring.
By Ciel Wharton
It is a warm fall day, and a group of TPWD biologists is staring intently at a clue left on the muddy banks of the Neches River. A white note card pointing to a nearby animal track reads, “Who made this track?” Ideas race through the minds of the group members as they attempt to solve the mystery. The track is way too small to be an alligator, but too big to be a mink. There are five toes — with webbing — and nail marks showing. Could it really be? Yes, this track was left by one of Texas’ most inconspicuous inhabitants — the Northern River Otter.
River otters are one of the Houston Zoo’s most popular attractions because of their playful nature, yet the zoo may be one of the few places wildlife watchers are likely to see them. Historically, river otters were common throughout the eastern half of Texas, but today they are only known to be in the major watersheds of the eastern quarter of the state. Does this mean that the state’s otter population is in decline? TPWD has been trying to answer this question for the last 30 years. Since 1977, they have conducted otter track surveys under bridges in East Texas to monitor the distribution and status of river otters in Texas in addition to the effects of otter trapping (which is legal with appropriate permits).
Identifying river otter tracks can be challenging because soil type, animal movement and weather all affect a track’s appearance. For example, a raccoon track in dry sand can easily be misidentified and reported as an otter track. Because of the inherent difficulty of tracking, skill levels among otter surveyors vary greatly. Therefore, intensive training and assessment of each tracker’s abilities is necessary in order to ensure monitoring accuracy.
To address these concerns and work toward improving otter monitoring, Texas A&M organized a two-day tracker evaluation workshop for 20 TPWD biologists. This evaluation system was originally designed by South African Louis Liebenberg and CyberTracker Conservation to validate the tracking skill of the Kalahari Bushmen. To date, this is the only internationally recognized evaluation system being used to measure tracking skill.
The tracker evaluation is a test of tracking skill and knowledge, but it also serves as in-depth training. During the workshop, participants were asked to identify and interpret tracks and other animal signs that ranged from turtle and crayfish trails to nutria scat and otter tracks.
Since the workshop, TPWD participants have indicated that it was a resounding success and hopes are high that river otters can now be more accurately monitored. Wildlife biologist Gary Calkins says, “This is one of the best training opportunities that we have had the privilege to attend. I would love to attend this workshop again, at least once a year; there is that much benefit.” Armed with their expanded tracking knowledge, the wildlife detectives are ready to take away some of the mystery of Texas’ elusive river otters.
Future workshops will be offered to the public. For more information, visit <www.wildlifetrackers.com>.