How Quail Handle the Heat: A Look at Thermal Ecology

By Abigail Holmes, Texas A&M University WFSC ‘19

Edited by Amanda Gobeli, Extension Associate and Dr. John Tomecek, Extension Wildlife Specialist

Texas is a massive state with many diverse ecosystems but all of them have at least one thing in common: the weather can be sweltering. The hottest temperature ever recorded in Texas is 120°F in Monahans, located in west Texas (Brown 2016). The four species of quail that are native to Texas - northern bobwhites (Colinus virginianus), Gambel’s quail (Callipepla gambelii), scaled quail (Callipepla squamata), and Montezuma quail (Cyrtonyx montezumae) – can all be found in various areas of west and central Texas where temperatures can exceed 100°F. As small, ground-dwelling birds, quail may seem ill-suited to dealing with high temperatures, but they have ways of beating the heat.

A male Gambel’s quail – a common inhabitant of the hot, arid regions of far west Texas. 

Photo from Katja Schulz.

Gambel’s quail can be found in Trans-Pecos areas of west Texas that are generally dry and desert-like, but they also inhabit similarly xeric climates as far west as California. One study conducted at the Philip L. Boyd Desert Research Station in Palm Desert, CA sought to answer the question of how these birds manage to survive the scorching heat. They found that Gambel’s quail have a bimodal activity pattern: they forage for food during the morning and late afternoon hours, but stop for a long midday break when the temperatures are highest. Researchers found that throughout most of the day, the quail were operating at the highest limits of thermoneutrality possible. In other words, their body temperatures were as high as they could possibly be without becoming lethal to the birds – around 46°C, or an average of 114.8°F. Because of this limit, their goal throughout the hottest parts of the day is to minimize thermal stress by staying out of the sun and relaxing under plant cover. Some individuals also scratched depressions into the ground before laying down to further cool themselves with dirt that had not been warmed in direct sunlight. (Goldstein 1984).

Another way quail and some other species of birds regulate their temperature is by initiating a behavior called gular fluttering. This involves the bird contracting its upper neck muscles to rapidly move air across the membranes in its mouth and throat – similar to panting in mammals – helping it cool down (Griffin 2012). Studies found that some Gambel’s quail did not begin gular fluttering until temperatures reached above 45°C (113°F), while northern bobwhites began gular fluttering at an average temperature of around 30.4°C (around 86.5°F; Goldstein 1984 and Guthery et al. 2005). This is not surprising, considering Gambel’s quail are generally found in hotter, more desert-like environments than bobwhites and are more accustomed to such extreme temperatures (TPWD). A study of scaled quail found that they did not exhibit the gular fluttering behavior at any temperature, likely because they are so efficient at using evaporative water loss and increasing their metabolism to lower their body temperature. However, this becomes less effective when temperatures reach 40°C (104°F) and scaled quail begin experiencing hyperthermia. Temperatures above 40°C exceed their ability to regulate their body temperatures effectively because they cannot increase their metabolism any further. It is difficult for scaled quail to survive in such environments, and this may explain why scaled quail prefer slightly more mesic habitats that provide a bit more moisture and less extreme temperatures than the Gambel's deserts (Henderson 1971).

Northern bobwhites depend on shade from woody plants like this mesquite tree to stay out of the heat. 

Photo from Mark Tyson.

Northern bobwhites naturally prefer lower temperatures than the desert quail species. A study at the Rolling Plains Quail Research Ranch found that northern bobwhites began experiencing thermal stress at temperatures above 35°C (95°F). Hyperthermia, or overheating, is a major concern for bobwhites, especially during nesting season when they must protect and provide for their young chicks during the hottest months of the year. Generally, bobwhite nests are found at temperatures around 30°C (86°F). This is actually lower than the body temperature of an adult bobwhite, which is possible because the nests are typically shaded by plant cover and are lower to the ground. Landowners who are managing for northern bobwhites must consider the critical need for suitable plant cover to provide shelter from the midday sun and keep bobwhite nests cool (Guthery 2005). The most severe hyperthermia situations are lethal for quail, but extreme temperatures can also create heat stress that causes many other problems. In adult quail, this may mean less hens participate in reproduction or they aren’t able to successfully nest more than once. Chicks may face early incubation or irregular hatchability as well as extremely limited foraging time if they manage to hatch successfully (Guthery et al. 2001). Two of the best ways to remedy the negative effects of extreme heat on quail are sufficient precipitation and plant cover. Any bare ground not protected by plant cover can reach temperatures exceeding 160°F during the summer, making it impossible for quail to survive during the day without shade (Tomecek 2016). Bunchgrasses are one of the best examples of plant cover that protect quail from this heat and maximizing the availability of these thermal refuges is one way to ensure bobwhite survival through the summer (Tomecek 2017). Quail may be well adapted to survive the scorching heat, but they need proper habitat to keep them cool.

Literature Cited

1. Brown, Angela K. 2011. Record heat scorches Texas. ABC news.
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4. Griffin, Catherine. 2012. How birds keep their cool. Audobon. Web.
5. Guthery, Fred S. et al. 2005. Aspects of the thermal ecology of bobwhites in north Texas. Wildlife Monographs 159: 1-36.
6. Guthery, Fred S. et al. 2001. Heat loads on reproducing bobwhites in the semiarid subtropics. The Journal of Wildlife Management 65(1): 111-117.
7. Henderson, Carl W. 1971. Comparative temperature and moisture responses in Gambel and scaled quail. The Condor 73(4): 430-436.
8. Russell, Morgan and John M. Tomecek. 2016. Managing heat for wildlife on Texas rangelands. Texas A&M AgriLife Extension EWF-034.
9. Texas Parks and Wildlife. 2017. Bobwhite quail management. Tpwd.texas.gov. Web.
10. Tomecek, John M. et al. 2017. Inadequate thermal refuge constrains landscape habitability for a grassland bird species. PeerJ 5:e3709.
11. Tomecek, John M. and Morgan Russell. 2016. Managing heat for wildlife on Texas rangelands. Texas A&M AgriLife Extension EWF-034.