Conserving Breeding Birds at Schlitz Audubon

Marc White – Director of Conservation

In setting the conservation priorities for Schlitz Audubon, I’ve had the opportunity to take a bird’s-eye view of the land. Based on a review of 253 species (plus three additional subspecies) of migrant and breeding birds observed here over the last 42 years, I recently completed a list of 23 priority birds (see Table 1, below) for the Center. Our treasure trove of gathered bird data is unprecedented in this region, and because of the detailed data gathered by our birders, since 1974, we are able to create a comprehensive management plan to support these species.

It is our intention, although it is not a certainty, that in creating habitat for these birds they may begin to nest at Schlitz Audubon with greater frequency. All 23 bird species are listed as endangered, threatened, or special concern in Wisconsin. 20 of them are listed as species of greatest conservation need (SGCN) in the 2015 revision of the Wisconsin Strategy for Wildlife Species of Greatest Conservation Need.

Conserving this small group of birds will benefit many others. Among scientists, a group of species that utilize the same class of environmental resources in a similar way is called a guild. Conservation biologists use the guild concept to help understand and guide the conservation of species that share common habitat needs. Birds that use the same resources should respond similarly to changes in their environment. Breeding period foraging guild (the location and type of food that a species relies on when rearing its offspring), as well as nesting location and plant community preferences, were evaluated for each of Schlitz Audubon’s 23 target bird species.

Twenty of our priority birds nest either on the ground, or in low branches of shrubs and saplings. It is clear that as we work to control Common Buckthorn and other invasive species, we will need to restore native ground-layer and shrub-layer vegetation. With effective conservation, we can support nesting and reproduction of our 23 target species, as well as other birds that share their resource requirements.

The following are three of the species of birds for whom we plan to provide better breeding habitat:

The Wood Thrush is a member of a guild of insectivorous and frugivorous (fruit eating) ground gleaning birds, which prefer to nest in low shrubs and sapling vegetation. The Swainson’s Thrush and Brown Thrasher also belong to this guild. As our volunteer land stewards work to reduce dominance by Common Buckthorn and other invasive shrubs, improvements in native ground-layer and shrub-layer dominance and diversity will provide improved breeding habitat for members of this group.

The Red-headed Woodpecker (pictured above) prefers oak opening and open woodland habitat. This bird is an insectivorous air-sallier (they leave their perch to capture food in the air, then return). During its breeding period, it excavates a cavity nest in dead trees and tree limbs. Habitat quality for the Red-headed Woodpecker and other members of this guild, such as the Purple Martin and other woodpeckers, will increase with the death of large ash trees being attacked by Emerald Ash Borer, and the demise and clearing of young ash thickets for oak savanna conversion.

American Woodcock belongs to a guild of vermivorous (worm eating) ground nesting ground foragers. Management techniques that include forest thinning, burning and mowing that promote understory development will help to rejuvenate singing grounds, roosting areas, and feeding grounds for the American Woodcock.

 

Schlitz Audubon Target Bird Species Conservation Summary