Our Work

By: Emily Blumentritt, Dr. Justin T. French, Dr. Dan P. Collins, and Dr. Maureen G. Frank

What species of birds use dirt livestock tanks, and how can we best study them?

The arid grasslands of the Chihuahuan Desert provide essential wintering grounds for many of North America’s grassland birds. Surface water is likely to be an important resource for grassland birds, especially in an arid region that receives only 9 inches of rainfall a year on average. However, scientists lack information on how much freestanding water is used by birds in desert grasslands, and use of supplemental water by birds and other wildlife is largely understudied. Because livestock grazing is one of the primary land uses of Chihuahuan Desert grasslands, dirt or earthen livestock tanks are a common feature on the landscape. Data on bird use of dirt tanks could provide guidance to land managers with dirt tanks on their property who want to support bird populations, not only in the Chihuahuan Desert but in all regions where dirt livestock tanks are common features.

While point counts are traditionally used to measure bird diversity at a specific resource, passive acoustic monitoring is an alternative method that can continually monitor bird activity. Most bird studies utilizing passive acoustic monitoring are conducted in the breeding season, when birds sing highly distinctive songs. This study is evaluating whether passive acoustic monitoring is effective during the migratory and nonbreeding seasons. We are comparing traditional point count surveys to passive acoustic monitoring to determine which method works best.

The goals of this study are to (1) determine which bird species are using dirt livestock tanks in the Chihuahuan Desert grasslands during winter and migration; (2) determine how birds are using dirt tanks as a resource; and (3) compare acoustic monitoring with in-person point count surveys for detecting species richness.