Disturbing Nature's Sense of Time
By Carolyn Rumery Betz
The early bird gets the worm, and that bird is arriving earlier — not by the clock but by the calendar. The American Robin, Wisconsin's state bird, arrives earlier in the spring — 13 days earlier in 2010 than it did in 1990, according to scientists who track bird migration patterns.
Data collected by citizens involved in "Project FeederWatch" have been instrumental in tracking the presence and abundance of birds throughout the United States and Canada. Wisconsin's robin-sighting records reflect that Wisconsin is warming, particularly in the spring.
Since robins don't fly far from Wisconsin in the winter, their migration is primarily influenced by temperature changes in the region. Migratory patterns of species that overwinter farther away are influenced more by changes in daylight rather than temperature.
Climate models for Wisconsin project that springtime temperatures are likely to warm by 3-9°F by the middle of the century, with the largest increases across northern and central Wisconsin. Warmer temperatures will affect the timing of life-cycle events, or phenology, of plants and animals.
Robins may be on the list of winners when it comes to climate change. Species that have short generation times, live and move across wide landscapes and can live most anywhere, including highly populated areas, will survive better than species that are more specialized in their feeding and habitat needs. We can expect to see more gray squirrels, white-tailed deer, European starlings and Canada geese, but fewer, if any, American marten, red-backed salamanders, spruce grouse and common loons.
Peter McIntyre, a member of WICCI's Water Resources Working Group, is looking at how climate change is altering fish migration patterns that flow to the Great Lakes.
"We're using climate forecasting to predict how fish migration patterns might change," says McIntyre. "Great Lakes water temperatures appear to be changing faster than air temperatures."
McIntyre, an assistant professor in the University of Wisconsin-Madison Center for Limnology, is investigating whether stream flow or temperature triggers suckers' impulse to spawn.
Suckers, an important food source for large sport fish, usually start to move when the days are warm and the water is clear but before the trees have leafed out. The eggs and excrement they deposit as they move upstream serve as an important source of nutrients that fertilize the growth of plants and insects in spawning streams.
If peak migration of suckers shifts, their interactions with migrating sturgeon, pike, walleye and redhorse would also be affected. In fact, changing the timing of the nutrient inputs from suckers could alter the dynamics of the entire stream ecosystem.
Like Zuckerberg and his bird-watchers, McIntyre is using citizen volunteers to collect some of the data used in his study. Citizen scientists through the University of Wisconsin Extension — DNR Water Action Volunteers program are monitoring sucker migration patterns on 22 tributaries to Lake Michigan. They devote about 15 minutes at the same time each day for up to five weeks in the spring looking for suckers moving upstream.
DNR research scientist Karl Martin heads WICCI's Wildlife Working Group. His group focuses on developing adaptation strategies for wildlife management that can change along with environmental conditions. At the top of his list is land protection for different types of habitat as migratory, breeding and foraging behaviors change with the alteration of Wisconsin's seasons. Martin says good stewardship, private-public partnerships and citizen involvement can help promote resilience in wildlife habitat and populations.
Wildlife managers and biologists across the state were surveyed by Suzanne Hagell, a research associate on WICCI's Wildlife Working Group. "This group realizes that their hard work might not pay off for a long time," says Hagell, "but they are highly motivated to develop climate change adaptation strategies, not just for birds but for all wildlife."