Effects of Supplemental Feeding
on Bobwhite Quail Populations

Few studies have assessed the long-term influence of supplemental feeding on bobwhite populations. Demographically, supplemental feeding may affect seasonal survival, nesting, nest success, and chick survival. Because the influence of weather, natural food supplies, and predators interact and vary over time, the likelihood that supplemental feeding influences a bobwhite population similarly each year is low. Therefore, short-term studies assessing only a subset of these variables may fail to provide reliable information about the long-term effect of supplemental feeding on bobwhite populations. We began conducting feeding studies in 1999 and below are some of our main findings.

Feeding Practices on Bobwhite Plantations

Typically, bobwhite plantations operate a year-round feeding program. Grain, normally sorghum or corn is spread along dedicated feed trails or along woods roads year round. By mapping existing feeding trials, we found that on average there is 1.8 miles of feed trail per 100 acres of uplands. Approximately 6 bushels of grain is spread per mile of feed trail every 2-3 weeks. This level of feeding provides bobwhites quick access to high energy foods at many locations within the home range of a covey.

Effects on Covey Movements

Our research finds that coveys move over substantially less area when supplemental feed is provided to them. We expect that lower daily movements of bobwhites during periods of environmental stress (such as drought, severe cold, and predation) may decrease their susceptibility to predation. Research by the Albany Quail Project has found that coveys are less likely to be found during hunting when they have supplemental feed available. This result makes sense as our covey movement data indicates they cover a lot less ground and therefore likely leave less scent for bird dogs to find.

Typical Demographic Response

Survival of Bobwhites

We have measured higher survival of bobwhites on areas with supplemental feed versus control areas without feed. The greatest differences in survival between bobwhites on fed and control sites has repeatedly occurred during periods of environmental stress such as low natural food abundance, heavy avian predation, or drought related stress.

Effects of feeding on nesting and survival may interact with weather and hard mast available during fall and winter. The winter of 2001-2002 and summer of 2002 were nearly ideal for bobwhite. In addition to mild weather, there was a large mast supply and bobwhite utilized them (based on crop analyses). Survival over the winter and nest production during the summer was good on all sites in 2002. In the winter of 2002-2003, we had record number of frosts and an almost complete mast failure. The summer of 2003 has had greater than normal rainfall. In 2003, bobwhite survival remained higher on fed sites through the breeding season. Similarly in 2007 we had a record drought during the breeding season. Bobwhites on fed areas had higher survival than on control sites. By increasing survival during the breeding season, more hens are available to nest and therefore production increases.

In 2007 we had the worst recorded drought during the breeding season. Bobwhites survived at a higher rate where supplemental feed was provided (42 versus 25%).

Nesting

Nesting has begun earlier in the spring on fed sites each year since 1999 and often the last nests of the season are on the fed sites. First nests were found as little as 7 days and as many as 54 days earlier on fed sites compared with unfed controls.

Based on the breeding population of hens (4/15), hens incubated an average of up to 2 times the number of nests control hens. In each year, the number of nests per hen was greater on the fed sites; however, we noted the greatest difference in the number of nests incubated during periods of summer drought.

Discussion

Few studies have documented significant effects of supplemental feeding on bobwhite populations, as pointed out by Guthery (1997; JWM 61:291-301.). However, our results suggest that supplemental feeding improves nest and chick production most years and survival in some years. By reducing annual variation in these parameters, supplemental feeding may have long-term effects on population size because it helps populations avoid “crashes” during periods of environmental stress.