Abundance Estimates and Habitat Management for Karner Blue Butterflies on Necedah National Wildlife Refuge (Internal Report 2015)

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Anna Jocham
Bio 499
Dr. Jones
Spring 2016
Abundance Estimates and Habitat Management for Karner Blue Butterflies on Necedah National
Wildlife Refuge (Internal Report 2015)
Abstract
Karner Blue Butterflies (Lycaeides melissa samuelis), federally endangered butterflies native to
the Midwest United States, are occupants of oak savannah and barrens communities common to
restoration practices at refuges such as the Necedah National Wildlife Refuge in central
Wisconsin. These sparsely vegetated biomes provide a domain for the obligate host to Karner
blue butterfly larvae—Wild lupine (Lupinus perennis). Since Karner abundance consequently
relies on presence of wild lupine, management of savannah/barrens habitat for the lupine—and
by association the butterflies themselves—is necessary. Since no previous studies have attempted
to incorporate habitat informational statistics into abundance estimates, this study provides data
from the 2014 and 2015 summer seasons along with both conventional and hierarchical distance
sampling information for assistance in future decisions for habitat and restoration, and concludes
a federal abundance estimate of 12,390 butterflies for the 2015 season.
Introduction
The Karner Blue Butterfly (abbreviated as KBB) (Lycaeides melissa samuelis), is a small—less
than one-inch wingspan—vibrant blue butterfly, shown in Figure 1. These butterflies are a
federally endangered species, marked so in the 1990s after discovery that the species, which once
covered a wide range across the Midwest, upper East Coast, and extended into Canada, had
dwindled to only a few remnant populations across specific habitats in the Midwest (USFWS,
1992). In hopes of ascertaining the reason for such a population decrease, areas in which the
remnant populations could be found underwent habitat restoration and population study
(USFWS, 2003). These studies included habitat management techniques, such as prescribed
burns, vegetation removal, mowing, and chemical application.
a. b. c.
Figure 1: Lycaeides melissa samuelis, a) closed-wing adult, both genders identical. b)
open-winged male, note lack of orange. c) open-winged female, notice orange-colored