Is there anybody out there? Occupancy of the carnivore guild in a temperate archipelago

M. L. Allen, M. J. Farmer, J. D.J. Clare, E. R. Olson, J. Van Stappen, T. R. Van Deelen

Research output: Contribution to journalArticlepeer-review


Carnivores are important components of ecological communities with wide-ranging effects that vary with carnivore size, natural history, and hunting tactics. Researchers and managers should strive to understand both the presence and distribution of carnivores within their local environment. We studied the carnivore guild in the Apostle Islands, w h e r e the distribution and occupancy of carnivores was largely unknown. We monitored 19 islands with 160 functioning camera traps from 2014-2017, from which we collected 203,385 photographs across 49,280 trap nights. We documented 7,291 total wildlife events with 1,970 carnivore events, and detected 10 of the 12 terrestrial carnivores found in Wisconsin. Detection rates for species were generally higher in summer than winter, except for coyotes (Canis latrans) and red foxes (Vulpes vulpes). Finite-sample occupancy estimates for carnivores varied across islands, with mean estimated occupancy across islands varying from a high of 0.73 for black bears to a low of 0.21 for gray wolves. Of the potential island biogeography explanatory variables for carnivore occupancy we considered, island size was the most important, followed by distance to the mainland, and then inter-island distance. We estimated that terrestrial carnivore species varied in the number of islands they were detected on from 1 island for gray wolves to 13 islands for black bears. Estimated carnivore richness across islands (i.e., the number of carnivores occupying an island) also varied substantively from 1 species on Michigan Island to 10 species on Stockton Island. Island size and connectivity between islands appear important for the persistence of the carnivore community in the Apostle Islands.

Original languageEnglish (US)
Pages (from-to)272-280
Number of pages9
JournalCommunity Ecology
Issue number3
StatePublished - Dec 2018


  • Apostle Islands
  • Camera traps
  • Carnivore
  • Community
  • Distribution
  • Island biogeography
  • Occupancy
  • Species richness

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology


Dive into the research topics of 'Is there anybody out there? Occupancy of the carnivore guild in a temperate archipelago'. Together they form a unique fingerprint.

Cite this