Plants Far from Home Isle Royale CANADA l Common loon ll Some plant species that thrive along Isle Other species, like Isle Royale’s iconic l l © DAVE OSTROM l G R l l GREAT E A Royale’s cooler shores are not typically thimbleberry shrub, are western dis­ LAKES T found this far south. Northern paintbrush juncts. Thimbleberry is typically found and three-toothed saxifrage, both arctic west of the Rocky Mountains. L disjuncts, were probably stranded when A K the last continental ice sheet retreated. E S l Range of devil’s club Thimbleberry © TONY ERNST Disjunct plant species are This shard of a continent FROM THE NORTHWEST CORNER OF closely related but widely becalmed in the green LAKE SUPERIOR A ROCKY ARCHIPELAGO separated from each other UNITED geographically. STATES RISES HE COLD DEEP WATERS OF ONE National Park Service Park National U.S. Department of the Interior fresh-water sea is indeed . T , Northern paintbrush OF THE WORLD’S LARGEST LAKES BOTH © MARK EGGER royal, isolate, and Devil’s club Three-toothed © MARTHA DE JONG LANTINK saxifrage ISOLATE AND PROTECT THIS PLACE. ITS supreme. NPS T. Morris Longstreth DISTANCE FROM THE MAINLAND HAS The Lake Superior Country, 1924 LIMITED THE DIVERSITY OF SPECIES— From Isolation, Novelty Island Laboratory ONLY THOSE ABLE TO MAKE THE CROSS­ Kayaker on Lake You will see the red squirrel more often than any other mammal Scientist Durward Allen, who founded on other species. Monitoring of bird Superior ING CAN CALL THE ISLAND HOME. on Isle Royale. How did it make the crossing from the mainland? the Isle Royale Wolf-Moose Study in and fish populations, water levels, © THOMAS AND DIANNE JONES No one knows—but because of its long isolation from its relatives 1958, expressed one value of islands as and water quality sheds light on the HUMANS TOO MUST MAKE THE CROSS­ the Isle Royale red squirrel is now considered a subspecies. Smaller laboratories when he described them as consequences of global changes. Re­ ING, AND HAVE BEEN DOING SO FOR AT and less red than its mainland counterparts, it makes different places “where the animals you are search revealing a rainbow of colors sounds. Its subspecies name, regalis (regal) suits its self-important counting and studying do not wander in the island’s garter snake popula­ LEAST 4,500 YEARS. ISLE ROYALE’S behavior. Other mammals on Isle Royale, like the American mar­ away.” tion rekindles our wonder for the ten, are also genetically distinct from mainland species. vibrancy of the natural world. Isle Park National Royale Michigan GEOGRAPHIC SEPARATION PROTECTS IT Isle Royale’s isolation shapes its ecosys­ FROM OUTSIDE INFLUENCES, BUT IT IS tem. It excludes some species. Others Nothing stays the same for very long NOT IMPENETRABLE. HIGH CONTAMI­ arrive by chance. Some that could make on an island. A little over a hundred Evolving Wilderness the trip rarely do so. As a result, less years ago, a survey of Isle Royale’s NANT LEVELS IN INLAND LAKES AND than half of the over forty mammal spe­ mammals would have resulted in a list REDUCED WINTER ICE COVER REMIND Early human crossings of Lake Superior to Isle Royale pre­ cies on the surrounding mainland have quite different from the present one. sented both risks and rewards. Pre-contact cultures, and populations on Isle Royale today. Fewer Moose would be noticeably absent. US THAT ACTIONS ELSEWHERE CONNECT later the Ojibwe, harvested copper deposits, an abundant species result in fewer relationships Caribou would represent the large prey fishery, and other resources. Commercial fishermen and cop­ among species—creating opportunities species, while coyote and lynx would ISLE ROYALE WITH THE REST OF THE per miners, lumberjacks, and lighthouse keepers depended for research and long-term monitoring serve as the predators. WORLD. HOWEVER ISOLATED, ISLE upon the island for their livelihood. Cool summer temperatures in a relatively simple ecosystem. and wilderness pursuits enticed vacationers in the early 1900s. This ecosystem may not be as simple as ROYALE IS NOT IMMUNE TO HUMAN- Today Isle Royale National Park is a designated wilderness and Studies on the island have increased it first appears. On Isle Royale, a world DRIVEN CHANGE. biosphere reserve, attracting hiking, paddling, and backpacking Isle Royale red squirrel our understanding of predator-prey within our world, all life exists in a dy­ Moose enthusiasts as well as boaters, divers, and others. © JOHN AND ANN MAHAN interactions and their cascading effects namic web. © CARL LINDBLOOM Chippewa Harbor © JOHN AND ANN MAHAN Isle Royale Isle Royale.