DESERT BIGHORN SHEEP RESEARCH
Bighorn Use of Supplemental Water
One of the most limiting and precious resources in arid environments is water. Water is a requisite of all living things. Though water can come in many forms, it is one of the most sought after resources landowners and living organisms seek in the desert mountains of the Trans-Pecos.
With most rainfall occurring in the monsoonal season of July-September, perennial water sources are important to maximize habitat suitability. Water guzzlers have been around since the 1940s. They have a design consisting of an apron for catching rainwater, a pipe to direct the water, a cistern for water storage, and a trough for drinking. If designed properly, guzzlers can provide water year round in the harshest of environments.
In addition to desert bighorn sheep, a variety of wildlife species were documented using the guzzlers.
We conducted a study on the Black Gap WMA to document wildlife use of guzzlers. In that study we documented >12 different species utilizing guzzlers. Bighorn sheep accounted for 15% of occurrences at the guzzlers. As expected, bighorn sheep use of guzzlers peaked during the hottest times of the day and the hottest times of the year. In fact, once temperatures were consistently over 100 F, guzzler use by bighorns was more prominent. By comparing rainfall patterns, we were also able to demonstrate that guzzler use decreased after rainfall events when more surface water was present, preformed water in vegetation was higher, and temperatures were cooler.
In our study, we also documented high use of guzzlers by aoudads, an exotic known to compete with desert bighorn sheep. Unlike bighorns, aoudads used guzzlers in a more generalized fashion. Aoudads consistently used guzzlers year round and throughout the day. Also of concern was the length of time aoudads used guzzlers. Aoudad spent considerable time at guzzlers and were documented loafing around troughs, bedding at, taking mud baths, dust baths, and climbing in guzzler troughs. We also noted that as aoudad use increased on a particular guzzler, bighorn use decreased. We believe these behaviors prevented bighorn sheep from using those specific guzzlers.
When developing guzzlers, landowners and wildlife managers need to consider habitat requirements and specific watering hole attributes of the species they are managing for. If guzzlers are implemented for bighorn use, we recommend that guzzlers should be placed on the upper 1/3 of the terrain, placed in or near escape terrain (slope >60%), and dense vegetation surrounding the trough (up to 30 yards) should be cleared.