"Isle Royale National Park is a remote island, 15 miles from Lake Superior’s northwest shoreline"..........."The Isle Royale wolf population typically varied from 18 to 27 animals, organized into three packs"............"The moose population usually numbered between 700 and 1,200"..........."The wolf-moose project of Isle Royale, now in its 61st year, is the longest continuous study of any predator-prey system in the world"..............."Moose first arrived on Isle Royale in the early 1900s, then increased rapidly in a predator-free environment"..........."For 50 years, moose abundance fluctuated dramatically, limited by bottom-up factors (i.e., forage availability, winter ticks, and various weather influences)"............"Wolves established themselves on Isle Royale in the late 1940s by crossing an ice bridge between the island and mainland Ontario"..............."Researchers began annual observations of wolves and moose on Isle Royale in 1958–1959".........."Isle Royale provides an outstanding venue for ecosystem science because wolves and moose are isolated from mainland populations most of the time, and the population fluctuations we observe are due primarily to births and deaths, not the movements of animals to and from the island"....................."Also, the small number of mammal species provides a simpler system for study as the wolves are the only predator of moose here".............."Therefore, their effect on the moose population is relatively easy to monitor and understand".............."Moose are essentially the only food for wolves, although beaver are a significant food source at times".............."Finally and importantly, human impact is limited in the sense that people do not hunt wolves or moose, or harvest the forest"............."Between 2009 and 2016 the wolf population dwindled from 24 to two wolves(inbreeding) and remained at two until this past year"............."In October 18, 4 Minnesota wolves were transported to the island, with 2 of them surviving(one died and one crossed this past winter created ice bridge) as of March of this year(2019)"..........."Additionally, 7 male and and 4 female wolves were translocated to Royale from Ontario, Canada"............"The remaining two island born wolves have thus far survived the winter of 2018, bringing the wolf population to 15, as of March 2019" ............"Reintroducing a thriving wolf population to Isle Royale will also have an effect on the island's other residents, which include beavers and foxes"............"Wolves eat beavers as well as moose, and so the beaver population, which has been booming since 2012, may eventually decline to levels of a decade ago, about 20% of current numbers".............."Foxes, which are scavengers, will likely benefit from the return of the island's apex predator"............."Also of interest to the scientists is evidence of yet additional wolves who may have crossed the ice bridge and visited Isle Royale during the winter"............."Each winter, the Isle Royale wolf-moose project embeds a husband-wife team, Ky Koitzsch and Lisa Osborn, to observe the moose and wolves by skis, and they found evidence of the tracks of an unknown wolf on the island"................."Aerial survey suggested that perhaps three wolves crossed the ice and circumnavigated the island, but this may have been just a quick visit followed by a return home to the mainland"

From: Leah Vucetich lmvuceti@mtu.edu
Date: April 30, 2019 at 6:16:57 AM PDT
To: Rick Meril
Subject: 2018-2019 Ecological Study of Wolves on Isle Royale

The 2018-2019 Ecological Study of Wolves on Isle Royale is now available for download here.

Thank you for your continued interest and support!

Rolf & John

Summary
Between 2009 and 2016 the wolf population dwindled from 24 to two wolves and remained at two until this past year. In June 2018 the US National Park Service (NPS) decided to restore wolf predation in Isle Royale National Park. In early October 2018 the NPS and the Grand Portage Band of Lake Superior Chippewa led an effort that moved one male and three female wolves from Minnesota to Isle Royale. The male died about a month later. The NPS reported the proximate cause of death as pneumonia. One of the females left the island in late January 2019 by crossing an ice bridge to the mainland. In March 2019 the NPS and Ontario Ministry of Natural Resources and Forestry led an effort that moved seven male and four female wolves from Ontario, Canada. The last two island-born wolves of Isle Royale also survived the past year, bringing the total number of wolves on Isle Royale to 15 by the end of March 2019 (eight males and seven females).

Two of the newly introduced gray wolves pick their way through deep snow on Isle Royale. Credit: Rolf Peterson/Michigan Tech

Aerial observations suggested that the new wolves had not yet formed solid or stable social bonds by the end of winter study 2019, which is not surprising given how little time has passed since their arrival. The moose population increased to an estimated 2,060. The average annual growth rate of the moose population for the past eight years has been 19 percent.

The newly arrived wolves have been on Isle Royale for too brief a time for them to have significantly influenced the demography of the moose population. The impact of the moose population on vegetation is increasingly apparent. In February 2019, 20 female moose were outfitted with GPS radio-collars as part of a project to better understand how the arrival of new wolves will impact moose demography and behavior.

 BACKGROUND Isle Royale National Park is a remote island, 15 miles from Lake Superior’s northwest shoreline. The Isle Royale wolf population typically varied from 18 to 27 animals, organized into three packs. The moose population usually numbered between 700 and 1,200 moose. The wolf-moose project of Isle Royale, now in its 61st year, is the longest continuous study of any predator-prey system in the world. Moose first arrived on Isle Royale in the early 1900s, then increased rapidly in a predator-free environment.

For 50 years, moose abundance fluctuated dramatically, limited by bottom-up factors (i.e., forage availability, winter ticks, and various weather influences). Wolves established themselves on Isle Royale in the late 1940s by crossing an ice bridge between the island and mainland Ontario. Researchers began annual observations of wolves and moose on Isle Royale in 1958–1959. Isle Royale provides an outstanding venue for ecosystem science. That is, Isle Royale’s wolves and moose are isolated from mainland populations most of the time, and the population fluctuations we observe are due primarily to births and deaths, not the movements of animals to and from the island.

One of the newly translocated wolves on royale out on a nightime hunt

Also, the small number of mammal species provides a simpler system for study. The wolves are the only predator of moose on Isle Royale, and their effect on the moose population is relatively easy to monitor and understand. Moose are essentially the only food for wolves, although beaver are a significant food source at times. Finally and importantly, human impact is limited in the sense that people do not hunt wolves or moose, or harvest the forest.

The original purpose of the project was to better understand how wolves affect moose populations. The project began during the darkest hours for wolves in North America—humans had driven wolves to extinction in large portions of their former range. The hope was that knowledge about wolves would replace hateful myths and form the basis for a wiser relationship with wolves. After six decades, the Isle Royale wolf-moose project continues.

Many of the project’s discoveries are documented at www.isleroyalewolf.org.