Long-term Population Dynamics of Scaled Quail

Despite the decline of scaled quail populations over the last quarter century, few studies have investigated ecological concepts such as reproduction, population dynamics, home range size, and habitat selection. To amend this vacancy in research, the Borderlands Research Institute have set up several 5 year studies on different ranches across the Trans-Pecos region. Study site locations range from the Van Horn Mountains to the Santiago Mountain range.

During our course of research, a total of 3,418 scaled quail have been captured and banded since the fall of 2011. Serially numbered aluminum leg-bands were affixed to all quail captured, and several measurements were obtained (weight, tail length, wing length, culmen length, tarsus length, and head and bill length). Each individual’s sex was identified as well as age, which was determined based off of wing molt. Mortality sensitive radio-transmitters were attached to 46 female scaled quail across 3 study sites in 2012, and 107 hens in 2013.

Individuals equipped with radio-transmitters were used to estimate female survival during breeding season (March – August).  Survival estimates varied across the study sites and ranged from 56-76%. 

Even though scaled quail populations have been known to fluctuate with precipitation from year to year, they do not seem to have the dynamic “boom” and “bust” as displayed in bobwhites. Drought years are typified by low reproduction, while in a year with average rainfall, reproduction is typically high with 90% of hens attempting to nest. Sixty three nests were identified resulting in an average clutch size of 11 eggs.  Microhabitat analysis of nesting areas, nest predation occurrences, and the number hens that nest more than once per season were obtained.

By assessing temporal factors that influence demographics, we gain a better understanding of what might be influencing quail populations. Each research project is an opportunity to identify a factor that is either detrimental or favorable in influencing population trends. Ultimately, research will identify the factors that have caused quail population to decline over the past few decades, and offer innovative ways to increase current populations so that scaled quail are viable for generations to come.


Scaled quail with a newly attached leg band ready to be released. The use of leg bands allows us to estimate population size and age structure across scaled quail populations.

 

graph


Survival estimates during breeding season obtained from scaled quail equipped with radio telemetry across 3 different study sites in the Trans-Pecos.   Breeding season survival averaged 66%.