National Wildlife and Fish Refuge
Data recently compiled by the Upper Mississippi River National Wildlife and Fish Refuge (UMRNWFR), McGregor District’s Wildlife Biologist, Lisa Maas, confirms Refuge bald eagle nesting populations have hit an all-time high. One hundred seventy-four active bald eagle nests were discovered on navigational Pools 9, 10, and 11. Bald eagle nesting activity is surveyed annually by District staff. In recent years nesting densities have increased to a point where staff needs assistance to complete the surveys. This is especially true in Pool 9, which has the highest concentration of active nests on the entire Refuge. The Friends of Pool 9 have taken on this challenge to help Refuge staff accomplish the survey. Clyde Male, Assistant District Manager for the McGregor District, indicated that nesting bald eagles have been increasing steadily since 2001. “We have come a long way since the first recorded nest on the Upper Mississippi River was discovered in 1969 in the area just north of New Albin, Iowa. A second nest was found in 1973 in the McCartney Bay area south of Cassville, WI in 1973.”
Male went on to say that “history has been made not only with the number of active nests on the Refuge this year, but also the fact that the nesting territory in McCartney Bay has been active since 1973. There is not another location in the U.S., besides Alaska, that can approach these kinds of nesting densities or longevity of use.” However, it is unlikely that the same eagle pair used this territory for 39 years because they have a 20 year reproductive window and a life expectance of 25-30 years. Bald eagles mate for life but what probably occurred was that one of the older birds died and the remaining bird selected a much younger mate, only to die later and the cycle has continued over the years. Bald eagle nests by Pool were as follows: Pool 9 had 92 active eagle nests and produced an estimated 134 eaglets this year; Pool 10 had 39 active nests and produced an estimated 42 eaglets; Pool 11 had 43 active nests and produced an estimated 73 eaglets, for a total of 174 nests, and an estimated 249 eaglets. Previous nests counts were 2011-167 nests, 2010 – 152, 2009 – 136, followed by 2008 – 124 nests. As we look to the future for bald eagles on the Refuge, the nesting numbers will probably continue to increase because of several factors. We know from banding returns that eaglets general return to within 100 miles of their birth place to nest. In addition the Refuge provides an undeveloped landscape with plentiful prey items.
Male ended with this, “We are extremely fortunate to live along the banks of such a diverse and magnificent river. We should all take pride that our forefathers thought enough about the future to set aside the Refuge as a special place for wildlife and plants to thrive for countless generations. You don’t have to look very hard to find an eagle nest on your own these days.”