Texas Quail Index 2014 Summary: Part I

One year is in the books (or spreadsheet, as it were) for the revival of the Texas Quail Index (TQI).  If you were paying attention back in 2002, you might remember the first run of the Texas Quail Index. This past year we instituted basically the same program with a few minor tweaks and changes as part of the extension "wing" of the Reversing the Quail Decline Initiative. At it's most basic, it is designed to teach landowners and county Extension agents about the value of collecting data on quail populations and habitat (you can read about it more in depth in a previous blog article here: http://wild-wonderings.blogspot.com/2014/03/the-texas-quail-index-hands-on.html). 

Thirty-six counties participated in 2014 across the state, representing the Rolling Plains, Gulf Coast, Edwards Plateau, High Plains, Cross Timbers, and Blackland Prairie Ecoregions.  During April and May, we held 5 different 2-day training sessions attended by 71 people including landowners, county agents, Texas Parks and Wildlife biologists, and Texas Master Naturalists volunteers. The properties in each county varied in size, ownership, and management. The properties ranged in size from just over 1,000 acres to over 500,000 acres. They included private lands, Wildlife Management Areas, and even a National Wildlife Refuge. They do have one thing in common, however: each landowner or manager has an interest in increasing the abundance of quail on their property, whether for additional hunting income or just sheer enjoyment of the resource.  

Burnet County Texas Master Naturalist volunteers
conducting spring call counts. Photo by Wade Hibler. 

The first task in the TQI was spring call counts. Participants were required to start immediately following their training April. Spring call counts are a measure of the population's breeding capital (to learn about how to conduct a spring call count, click here: http://youtu.be/-fB3gRRvn8I). Three factors contribute to the variation in the number of birds that you count: population size, how actively the quail are calling, and your ability to detect those quail.  The detection of calling quail is in turn influenced by another whole host of other factors including the wind speed at the time of the count, ambient noise (e.g. oil field traffic or other species of birds), and the listener’s hearing ability. When we conduct these counts we try to control for detection as much as possible so that we are just measuring the combined influence of the population size and calling activity. The percentage of males calling in a population of quail is thought to be influenced by their willingness to breed for the year and the environmental conditions present. This measure of breeding capital is then comparable (in a rough sense) to other sites across in the TQI and (most applicable) on the same site year after year.  When judging the response of spring call counts, an approximate rule-of-thumb is as follows: counts from 0-3 are considered poor, 3-6 are considered fair, and 6-9 are considered good. Counts above 9 are excellent, but it is difficult to distinguish individual quail above 9 roosters per stop. The map and graph below illustrates the average number of quail heard calling per mile marker across the participating sites.

 Yellow represents the lowest averages per mile marker and red represents the highest averages. We felt we could identify two hotspots based on these results: the rolling plains ecoregion and the gulf coast ecoregion. Sites in the gulf coast had some of the highest counts in the participating counties, recording 8-9 birds per stop in some cases. The only site to rival those numbers outside of the Gulf Coast Ecoregion was a site in Stonewall county.

Colloquial wisdom in quail country is that the best time to hear birds calling is immediately following a rain. We were able to test that wisdom using the data from the TQI last spring during the spring call counts. Prior to the Memorial Day weekend in 2014 most of Texas remained dry and in severe drought conditions. Then a large storm system moved across the state delivering up to 5 inches of rain on some of our TQI sites. Just by chance, 7 counties conducted counts immediately before the rain and immediately after. We compared the average number of bobwhites calling at each mile marker on each site before and after the rain event. We found that the number of individual bobwhite roosters calling doubled following the rain event across the 7 sites. Furthermore, the average number of calls per bird did not increase contrary to what you might expect. They were still calling at the rate of roughly one call per 20 seconds; there were just more birds calling at each site. All of those quail had been present before the rain, but something about the rain we received prompted more birds to call.