With a lot of recent interest in bringing back the northern bobwhite quail, conversations with landowners often turn to reflections on bygone days. They recall working fields with bird dogs alongside their fathers and/or grandfathers and flushing numerous coveys within a few hours. Others reflect on simply hearing the whistling of cocks in the spring and the covey calls in fall. This leads to speculation on the reason for the rapid and dramatic decline of the species, especially in the past fifty years. Two of the most likely culprits frequently put forth as suspects are the coyote and red imported fire ants. Several diet studies of coyotes looking at stomach contents reveal that quail, either in the form of adults or eggs, make up only a very minor component of their diets. In fact, many quail biologists believe that coyotes may actually benefit quail by controlling populations of mesopredators, such as raccoons, armadillos, skunks, and opossums, which are much more efficient nest predators than coyotes. The verdict on fire ants is less clear. They can negatively impact quail in several ways. First, they may overwhelm and kill newly hatched or pipping chicks that have not yet become mobile and able to escape. The risk of this is dependent on the proximity of the nest to an ant mound. The second negative impact of fire ants is more indirect. In areas with large concentrations of fire ant mounds, insects and other invertebrates may be significantly reduced in numbers. These invertebrates are essential to quail hens for egg development due to their high protein content. They are also extremely important to rapidly growing chicks for the same reason. So while fire ants appear to have a negative effect on bobwhite quail, the impact varies with site and weather conditions and cannot alone account for the drastic decline of bobwhite quail numbers across its range. We must look elsewhere for an explanation.
Most people are familiar with the saying, “A chain is only as strong as its weakest link.” Wildlife biologists take a similar approach when evaluating the factors that may affect a species’s population. All wildlife species have various habitat requirements. In the most basic form, these are food, water, shelter, and space. Suppose an area has the water, shelter, and space required by a species but lacks sufficient food resources. In that case, wildlife biologists recognize food as the weakest link, also referred to as the “limiting factor.” If we address that lack of food through habitat improvements and food increases, the wildlife population should now grow until it reaches a level where something else, maybe shelter, becomes the limiting factor, and so on.
Through years of studies and management efforts, it has become evident that the limiting factor for the northern bobwhite is the lack of nesting and brood-rearing resources. The bobwhite is a grassland/scrub species. They nest in the dried native bunch grasses from the previous year’s growth and rear their brood in areas of forbs (flowering, broad-leaved plants) where insects are abundant. These areas must be near denser cover, such as blackberry and plum thickets, where the birds can find refuge from predators, heat, torrential rains, and other negative factors.
So what do these resources look like, and where have they gone? Why are they limited? As with most things, there is no single answer. One of the drivers has been changes in agricultural practices over the past 60 years. Farms and fields used to be smaller. Fencerows, hedgerows, and ditches were more numerous. Unproductive field borders near treelines were not planted, leaving grassy buffers between fields and forests. Little odd corners or portions of fields where planting and harvesting equipment could not easily navigate were left fallow, although they may have been occasionally mowed, disked, or burned to prevent trees from encroaching. The few available herbicides were expensive, so ditch banks and their edges were allowed to grow up, again with occasional manual maintenance to prevent woody encroachment. These areas tended to be dominated by native warm-season grasses, such as little bluestem, broomsedge, and yellow Indiangrass, which quail used for nesting. Flowering forbs, such as ragweed, partridge pea, native lespedezas, and beggar lice not only attracted insects so important for hens and chicks but also served as a source of nutritious seeds later in the season.
Another force that historically created habitat beneficial to quail was the widespread use of prescribed fire in pine woodlands. Prescribed fire keeps hardwoods from encroaching and allows sunlight to reach the forest floor. This promotes the beneficial grass and forb understory.
So what changed? First and foremost would be the direct loss of habitat due to farmland and forest converting to other uses, such as residential and commercial development. In the United States, farm area declined from 449,268,645 ha in 1964 to 373,158,947 ha in 2007. Another large factor is additional habitat loss due to the intensification of agricultural activity. Over the same time period of 1964 through 2007, the amount of land on individual farms planted for crops increased from 39.1% to 44.1%. Smaller fields with more edge habitat were combined into larger fields with less edge. Fields were expanded from treeline to treeline. Though yields immediately adjacent to trees may not offset input costs due to shading, changes in soil type, and competition for water and nutrients. The surge in numbers and production of less expensive herbicides led to the use of those chemicals to maintain ditches, removing additional cover and food sources previously used by quail in these travel corridors. At the same time, the efforts of decades of public fire suppression campaigns and the concern over liability issues led many to abandon prescribed fire as a management tool. This, combined with poor timber thinning management, resulted in overstocked timber stands where sunlight cannot reach the ground. This results in ecological deserts devoid of resources to support quail and other wildlife.
The loss of grassland habitat as the limiting factor for northern bobwhites is strengthened by the corresponding decline in other birds in the grassland guild, such as eastern meadowlarks, grasshopper sparrows, field sparrows, and loggerhead shrikes. The 2019 Breeding Bird Survey found that approximately 720 million grassland birds (53%) have been lost since 1970, more than any other guild of birds. This includes a loss of 3 in 4 eastern meadowlarks.
The picture is not all bleak, though! Conservation efforts across the northern bobwhite range show that habitat creation and restoration does bear fruit in the form of increased numbers of quail and other grassland birds. If you build it, they will come. Some of the things you can do include: leaving a 30 ft buffer around agricultural fields and allowing native grasses and forbs to grow. Establish herbaceous filter strips along ditches and pond margins to filter runoff and remove sediment and chemicals before entering the water. Provide quail with travel corridors. Plant brood patches of partridge pea and ragweed in non-productive or difficult-to-work areas that may otherwise be mowed. Thin densely stocked pine stands and introduce prescribed fire to prevent hardwood encroachment. Also, implement integrated pest management to reduce the amount of pesticides that impact beneficial insects along with target species.
There are many other practices that you can employ to benefit quail and other grassland species. Many of these are eligible for cost-share and technical assistance through the Farm Bill administered by the US Department of Agriculture. Talk with your local Natural Resources Conservation Service and Farm Service Agency for more information. You can also get more information from your local Clemson Extension Forestry and Wildlife Agent.
Author(s)
TJ Savereno, Cooperative Extension, Forestry and Wildlife Agent
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