Assessing the utility of umbrella species using co-occurrence, habitat, and management perspectives: An example with the Florida Scrub-Jay

Umbrella species have been championed as an efficient means to monitor habitat conditions needed to support a community of co-occurring species in shrub and forest ecosystems. Yet management goals for target species are often multifaceted and non-target species may respond to each facet differently. We evaluated the Florida Scrub-Jay ( Aphelocoma coerulescens ) as an umbrella species for bird species in early successional sand pine ( Pinus clausa ) scrub in Ocala National Forest, Florida, where management maintains a patchy mosaic for forest products, wildlife habitat, and recreation. We used species richness, co-occurrence, and overlap of habitat associations, estimated from multi-species occupancy models, to assess the Florida Scrub-Jay and non-target bird community. We found richness of species of conservation concern was higher where Florida-Scrub Jays were present, but Florida Scrub-Jays were more common than, and often occurred without, these species. We found non-target species had similar habitat associations as Florida Scrub-Jays, excluding two ground-nesting species that tended to occur briefly post-disturbance and three cavity-nesting species limited by snag density. Therefore, although management for Florida Scrub-Jays can provide broad umbrella-like benefits regarding scrub habitat, it does not necessarily maintain the comparatively narrow conditions needed by other species of conservation concern. Our results highlight that Florida Scrub-Jays do not act as an umbrella for all species of concern and illustrate how umbrella species assessments can vary with the information used. Including co-occurrence and habitat overlap provide critical context for how targeted management affects non-target species, context that is absent in assessments limited to species richness.