Factors potentially influencing Montezuma quail populations in the Trans-Pecos region of Texas

Maya Vaughn, Justin French, Fidel Hernandez, and Ryan Luna

Montezuma quail (Cyrtonyx montezumae) are an elusive quail species inhabiting the piñon-juniper woodlands of the southwestern United States and much of Mexico. They are extremely difficult to trap and study; thus, there is little known about their ecology and population or demographic rates. Because there is such little information on this species, there are unstudied factors that could be affecting West Texas populations, such as the influence of extreme weather events and new invasive competitors, like feral pigs (Sus scrofa). To better understand how feral pigs affect Montezuma quail populations, I investigated the overlap of Montezuma quail habitat and feral pig presence. Feral pigs disturb the soil through their rooting behavior, which potentially alters vegetation communities. This could reduce forage resources, in addition to the ground cover that Montezuma quail utilize for nesting, temperature regulation, and predator avoidance. I recorded the presence of feral pigs in the Davis Mountains Preserve and extrapolated their presence across the entire Davis Mountains range. I estimated a 51% overlap of predicted feral pig presence and predicted Montezuma quail habitat in the Davis Mountains region. Feral pig presence didn’t completely overlap with predicted Montezuma quail habitat, but the overlapped areas occurred in critical habitat for Montezuma quail. These are areas that Montezuma quail need when their populations are low and resources are scarce. Extreme climatic events may also affect Montezuma quail populations. Extreme climatic events, such as droughts, extreme precipitation and temperatures, snowstorms, and extreme wildfires influence climate averages through time, affecting both flora and fauna. There are several anecdotal reports on the sudden apparent decline of Montezuma following extreme climatic events, such as high levels of overwinter precipitation or droughts. I used a 2-stage Lefkovich Matrix Population Model to simulate Montezuma quail populations under the effects of extreme climatic events. These simulations indicated that Montezuma quail populations can rapidly decline if they are subjected to several years of negative climatic conditions. I found that several years of poor climatic conditions decreased survival and recruitment of the species, leading to higher chances of local extirpation.