Assessment of Habitat Values for Indicator Species and Avian Communities in a Riparian Forest

Abstract

Habitat suitability index (HSI) models, which are meant to analyze the habitat value of an area for a particular species of interest, are commonly used to evaluate species, communities, and habitats for management or impact assessment. However, many assessments are conducted under strict time and money limitations, and this use of HSI may lead to inappropriate interpretations. The purpose of our work was to evaluate the relationships between three HSI models, the presence of their attendant species, and related avian communities at common assessment time scales. We compared the habitat values of a north Texas bottomland forest measured by HSI models for three species commonly used as indicators of this habitat type, Hairy Woodpecker, Pileated Woodpecker, and Barred Owl, with (1) the actual presence of each species, and (2) the presence of a larger forest-dependent avian community. HSI values did not correlate well with either occurrences of the indicator species or communities for any of the three models. Our results suggest that these models are not necessarily effective indicators of actual habitat use by indicator species, and may not be useful in helping managers make decisions that may affect an entire community related by habitat type. Positive assessments of habitat value through HSI values should be appraised carefully before management decisions are initiated, perhaps through outside review and/or a clear discussion of the context. The primary value of HSI use may be the ability to measure changes in the habitats themselves over time, and not exclusively as representations of species or community presence.