title: Twenty Years of Elfin Enumeration: Abundance Patterns of Five Species of Callophrys (Lycaenidae) in Central Wisconsin, USA.
abstract: We recorded five species of elfins (Callophrys) during annual spring surveys targeting frosted elfin C. irus (state-listed as threatened) in 19 pine-oak barrens in central Wisconsin USA during 1994-2013. At the northwest end of its range here, C. irus co-varied with spring temperature, but declined significantly over time (eight sites verified extant of originally 17). Two other specialists increased significantly. The northern specialist, hoary elfin C. polios (nine sites), correlated positively with the previous year's growing season precipitation. The southern specialist, Henry's elfin C. henrici (11 sites), co-varied with winter precipitation and spring temperature and dryness. The two resident generalists had stable trends. For all species, the first observed date per year became earlier over time and varied more than the last observed date. Thus, flight period span increased with earlier first observed dates. Elfin abundance increased significantly with earlier first observed dates in the current and/or prior year. Three species (C. irus, C. henrici, a generalist) had more positive population trends in reserves than non-reserves. This suggests that C. irus declines correspond to habitat conditions. Thus, monitoring programs and habitat management specifically for C. irus appear necessary to obtain a long-term stable trend for this species in Wisconsin.
authors.affiliation: 909 Birch Street, Baraboo, WI 53913, USA. swengel@naba.org.
authors.forename: Ann B
authors.initials: AB
authors.lastname: Swengel
authors.affiliation: 909 Birch Street, Baraboo, WI 53913, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Swengel
keywords: Callophrys; Callophrys irus; Theclinae; climate effects; elfin; frosted elfin; long-term monitoring; pine barrens; population trends; reserves and non-reserves