Distribution, Ecology and Genomics of Montezuma Quail in Mexico and Implications for Conservation in Texas
Request for Proposals November 2021
Upland Game Bird Program Leader
Montezuma quail are the least understood of Texas’ four quail species. Persisting at the periphery of their core range in Mexico, Texas populations are restricted to the Trans-Pecos and Edwards Plateau ecoregions. Range contraction over the past century has resulted from land use changes, incompatible grazing practices and fire suppression, which have led to reductions in herbaceous cover and forage resources and facilitated the expansion of woody plant species (e.g., juniper spp.). Shifts in vegetation communities have reduced habitat connectivity and isolated populations within Texas making them vulnerable to extirpation.
TPWD lists Montezuma quail as a Species of Greatest Conservation Need, but little information exists supporting a definitive conservation status assessment. A combination of their cryptic behavior, remote geographic distribution and low population densities have made previous scientific investigations difficult with few contemporary studies addressing population abundance or declines (Brennan et al. 2017, Sanders et al. 2017, Pearson 2018). Recently, concerns regarding reduced genetic diversity in Texas populations have raised concern among conservationists (Mathur et al. 2019). Previous sampling of Montezuma quail populations in Arizona, New Mexico and Texas by Mathur et al. (2019) found that Texas birds may be genetically isolated and exhibiting signs of genetic erosion with an extremely small effective population size. In support, Mathur and DeWoody (2021) stated that Texas populations had low genomic diversity, showed high levels of inbreeding and suggested the adaptive potential of these small, isolated populations may be limited. Given evidence of genetic drift, further erosion in habitat conditions is likely to be detrimental to populations putting them at risk of slipping into a negative, genetic feedback loop.
According to Brennan et al. (2017), “Because so little research has been conducted on the Montezuma Quail in Texas, virtually any study focused on its distribution, general life history, population ecology, habitat use and censusing techniques will yield valuable information.” The difficulty of monitoring and sampling cryptic birds at low densities limits our ability to answer fundamental ecological questions about the species. Additionally, it is unknown whether low values of genetic variability and the genetic structure of Montezuma quail populations in the United States and Texas are unique or rather indicative of the species overall. For our purposes, international research on distribution, abundance, occupancy and genomic variation in Mexico, along with genetic comparisons of US populations, can inform and advance quail conservation efforts in Texas and improve our understanding of this secretive species.
Research to further our knowledge of Montezuma quail would address several strategies under goal one of TPWD’s 2015 Land and Water plan. Specifically:
- Goal 1: Practice, encourage and enable science-based stewardship of natural and cultural resources.
- Protect native plants, fish and wildlife and their habitats
- Conduct strategic research on species, habitats, and ecosystems
- TPWD will maintain the highest level of scientific validity and credibility
Pursuing this research would also directly address Goal #3 in the most recent Upland Gamebird Strategic Plan (2021) which states, “Promote upland game bird research and the restoration of native habitats for upland game birds using science-based management techniques.”
The study design should address these main objectives:
- Characterize seasonal geographic distribution and abundance/occupancy rates of Montezuma quail in northern Mexico and describe regional patterns in habitat use,
- Characterize the genomic variation and estimate genomic load for Montezuma quail populations in Mexico and compare those samples to samples collected from their ranges in Arizona, New Mexico and Texas (this can include using previously collected samples, as well as additional samples collected for this study) and
- Compare and describe how distribution, ecology and genomic data obtained in northern Mexico relates to and can inform Montezuma quail conservation (i.e., research and management) in Texas.
- Assess various seasonal capture techniques, preferably between core and presumably stable, but geographically isolated Montezuma quail populations in northern Mexico.
Research should be focused across multiple sites and habitat types (e.g., Coahuila, Chihuahua, Sonora). If possible, inclusion of a presumably stable, but geographically isolated population in northern Mexico should be considered; this step will help facilitate appropriate comparisons with Texas, especially populations in the Edwards Plateau. For abundance and occupancy rates, comparisons of multiple techniques across seasons are preferred.
The lead entity coordinating and contracting for this project must be based in the United States. In addition to the standard guidelines for submitting proposals, applicants must briefly outline their approach and ability to conduct international research in their submission.
Expected Management Implications
Montezuma quail conservation efforts in Texas are hamstrung by deficiencies in information. This lack of general knowledge strains resources and limits the effectiveness of targeting partnership programs focused on the recovery of avian communities and their associated habitats (e.g., South Texas Grassland Restoration Program – Rio Grande Joint Venture). As importantly, genetic studies suggest Montezuma quail populations in Texas are at risk and the likelihood we will observe reductions in demographic performance are high. International research has the potential to guide on-the-ground habitat delivery and reveal whether Mexican Montezuma quail populations could provide a genetic reservoir for Texas. Should the need for genetic rescue arise, a combination of habitat work and translocations may be a possible remedy.
- Brennan, L.A., D.L. Williford, B.M. Ballard, W.P. Kuvlesky, E.D. Grahmann, and S.J. DeMaso. 2017. The upland and webless migratory game bird of Texas. Texas A&M University Press, College Station.
- Mathur, S., J.M. Tomeček, A. Heniff, R. Luna, and J.A. DeWoody. 2019. Evidence of genetic erosion in a peripheral population of a North American game bird: the Montezuma quail (Cyrtonyx montezumae). Conservation Genetics 20:1369-1381.
- Mathur, S., and J.A. DeWoody. 2021. Genetic load has the potential in large populations but is realized on small inbred populations. Evolutionary Applications 14:1540-1557.
- Pearson, Z.J. 2018. Montezuma quail habitat and occupancy in the southern Edwards Plateau of Texas. Thesis. Texas A&M University, Kingsville, TX.
- Sanders, C. G., F. Hernández, L.A. Brennan, L.A. Harveson, A.N. Tri, and R.M. Perez. 2017. A presence–absence survey to monitor Montezuma quail in western Texas. National Quail Symposium Proceedings 8:375–386.