TWEL Kaley Donovan Thesis

Songbird Habitat Models on the Landscape-scale in Southeast Ohio’s Public Forestland

Kaley Jean Donovan, MS
Advisor: Stephen N. Matthews

Thesis

In the Appalachian Foothills Region of Ohio, active timber management provides an opportunity for sustainable management of forest resources and conservation for the long term viability of songbirds. This region also contains the highest biodiversity of birds within the state. With continued declines in bird populations and increased conservation attention placed on songbirds, it is important to capture how forest management and wildlife responses are linked. Birds have been the focus of critical research that provides essential information of how fine scale patterns such as vegetation structure influence population processes. However, if and how these patterns transfer to the broader landscape where forest management decisions are made remains unclear. The aim of this research was to add to current knowledge of habitat relationships of songbirds by sampling across a broad extent to identify the relative influence of landscape and local features on bird species occurrence. In addition, by considering unique disturbance histories implemented at the state forest scale, I quantified how these activities influence occupancy of focal species. Birds were surveyed at 280 point count locations in 2015 and 2016 in Southeast Ohio across Tar Hollow and Zaleski State Forests, and Vinton Furnace State Experimental Forest. Comprehensive habitat models were developed for five focal species of conservation concern representative of varying forest successional stages using occurrence data, detailed vegetation data, and remotely sensed data for land cover composition and landform variables. I found the majority of focal species were affected by management and structural variables, but relationships varied in direction and magnitude. Early-successional habitat, classified as even-aged timber harvests ten years old or younger, strongly positively affected Prairie Warblers (Setophaga discolor), weakly positively affected Eastern Towhees (Pipilo erythrophthalmus), strongly negatively affected Cerulean Warblers (Setophaga cerulean), and weakly negatively affected Wood Thrushes (Hylocichla mustelina). For example, with an increase from 20% to 100% early-successional habitat within 75-m of a point count, an increase from 37% to 99% probability of occurrence was predicted for Prairie Warblers. Kentucky Warblers (Geothlypis formosa) did not show associations with any variables. I also found that occupancy of Cerulean Warblers was greater while Prairie Warbler and Eastern Towhee occupancy was less in Zaleski State forest compared to Vinton Furnace State Experimental Forest, which can be attributed to the greater amount of early-successional habitat within the landscape at Vinton (~21% compared to ~6%). To bring these two analyses together, I projected habitat suitability across the forests to illustrate how these focal species’ associations with land cover overlap in space. These results provide an informative component towards planning for conservation at the landscape level within state forestland in Southeast Ohio, and lend support to providing a mosaic of conditions to optimize habitat for a variety of forest songbirds.