Biological Characteristics of Deer Culled from Sand and York Islands, Apostle Islands National Lakeshore, 2009 - 2010

Gilbert, Jonathan

The Apostle Islands National Lakeshore (APIS) is located at the tip of the Bayfield peninsula in northwest Wisconsin and includes 21 islands. The park is at the continental limits of the hemlock-white pine-northern hardwood forest and also contains elements of the boreal forest system. Some of the islands are also home to a forest community dominated in the understory by Canada yew (Taxis canadensis) which was once common on the mainland, but is now quite rare. Land use on the islands has undergone dramatic changes in the past 150 years (APIS Wildlife Management Plan (2007). In addition to the natural disturbance processes, human activities such as farming and logging had dramatic effects on the islands. Logging continued on the islands until 1970, but was most intense between 1880 and 1920. During these early years forests were removed from the islands and fires followed this logging. Shortly after the forests began to recover from these fires, deer colonized many of the islands. Their browsing impacts have slowed the recovery of the vegetation on these islands. A few of the Islands in the Apostle archipelago have had deer eruptions in the past. Rocky Island, for example, once had extensive Canada yew dominated forests. Deer began to colonize this island early in the 20th century reaching extremely high densities. The presence of deer on the island resulted in the near decimation of the yew there. The Wisconsin Conservation Department undertook a deer culling operation on Rocky Island and that effort combined with liberal hunting seasons, harsh winters and habitat degradation eliminated deer from the island in the 1950s. Since then Canada yew has begun to recover, but 60 years later, still has not returned to the pre-deer condition (Apostle Islands, unpublished data). Hunting was included as part of the enabling legislation of the Apostle Islands National Lakeshore. As early as 1954 the Wisconsin Conservation Department has conducted deer removals from the islands. Prior to the establishment of the Lakeshore in 1970 (1950 – mid 1960), deer were present on 11 of the islands. Since the establishment of the Lakeshore deer populations have largely been limited to Basswood and Oak Islands. Others such as Rocky (as described above) had deer eruptions, but no consistent presence of deer and no long-term hunting(Apostle Islands Harvestable Species Management Plan, 2007). Beginning in 1985 muzzleloader hunting has been permitted on Oak and Basswood Islands, however, only a small number of deer were ever harvested from these islands during the muzzleloader seasons. In 2007 the Apostle Islands National Lakeshore developed and implemented a Apostle Islands Harvestable Species Management Plan for the Islands. In this plan deer population objectives were set for the islands and included keeping deer populations at levels low enough to prevent browse impacts to forest composition, and to prevent the spread of deer to islands with rare understory plant populations (i.e., yew). To meet these objectives the islands were divided into two groups or zones. Zone 1 islands were those islands that historically had few to no deer and included; Devils, Eagle, Gull, North Twin, Outer, Raspberry, Sand and York. Zone 2 islands historically had low to high deer populations and included Basswood, Bear, Cat, Hermit, Ironwood, Manitou, Michigan, Oak, Otter, Rocky, South Twin and Stockton. Deer population control was important on Zone 1 islands in order to prevent forest impacts due to deer browsing. On these islands deer would be controlled with hunting and with other ‘management’ control measures (e.g., nuisance permits or agency herd reduction) if hunting alone proved inadequate. Starting around 2000 the Apostle Islands staff started noticing increased sign of deer on Sand Island and noticed the same thing for York Island in 2005. These two islands held significant yew stands. York Island had not had any evidence of deer in the recent past.