TEXAS WILDLIFE
CAESAR KLEBERG WILDLIFE RESEARCH INSTITUTE TEXAS A&M UNIVERSITY-KINGSVILLE
The Booms and Busts of Quail Can Rainfall be the Trigger for Bobwhite Nesting?
Photo by Tim Fulbright
Article by LINDSEY HOWARD AND FIDEL HERNÁNDEZ
Bobwhite populations are strongly influenced by rainfall. Is it possible that visual cues or rainfall itself be influencing their breeding?
S
pring arrived in Texas and with it, the familiar “bob-white” whistle heard throughout the Northern Bobwhite Quail’s range as adults call for mates. As the quail breeding season got underway, many managers and landowners began speculating how well quail populations would do this year, which started off very dry. Bobwhite populations exhibit boom and bust dynamics that are characterized by drastic changes in population size from year to year. It is widely accepted that these fluctuations are related to rainfall, with years of high rainfall yielding larger quail populations than years of drought. What is not known, however, is the exact cause of this relationship. Some have speculated it’s the higher abundance of insects, or better nesting cover, or cooler temperatures. Despite decades of research on this relationship, however, no one knows what specifically links rainfall to bobwhite population fluctuations. Past research has focused on a variety of possible explanations, including heat stress and water deprivation, but a satisfactory conclusion has not yet been reached. Most hypotheses that are supported in captive or laboratory studies are disproven later during field studies. In addition, much of this research has focused on the materialized effects of rainfall; that is, the habitat features that change because of rain. For instance, during the summer months, after sufficient spring rainfall, insects are abundant. This provides a good food source for both adults and chicks, promoting reproduction and survival. Therefore, one might reason that the connection between rainfall and bobwhite populations is the increase in food. This line of reasoning, however, does not account for the time lag between when adults breed and chicks hatch. To ensure that chicks hatch when insects are most abundant, adults must have some prior indication of upcoming favorable conditions, to ensure they have time to breed, nest, and hatch chicks by the time those conditions arrive.
Sponsored by JOHN AND LAURIE SAUNDERS
30 T E X A S W I L D L I F E
JUNE 2022
