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).