Gary Engberg Outdoors

gengberg February 7th, 2012

Hello Eagle Counters!

What a difference in just seven days! After counting 131 eagles last week, we were down to 54 eagles today, sweltering among mostly bare bluffs. The river has lost most of its ice in the main channels, and snow cover statewide has been reduced substantially. Our count this week mirrors the last time we had such warm weather, when, in early January we counted 45 eagles a week before Eagle Days.From years when we were radio-tracking eagles, we saw similar shifts where, in warm weather that existed statewide, eagles would leave the Sauk Prairie area and shift north to such places as the Chippewa River and Stevens Point. In extensive cold snaps, the opposite would happen and eagles would move to the Mississippi River and drift downriver to southern Iowa. If cold weather returns yet this month, eagles may still return to Sauk Prairie for the remaining winter even though some of our local birds might begin laying eggs in the next three weeks. Eagles that nest in northern Wisconsin or the UP of Michigan still have six weeks or so before they will be laying eggs. One other issue that has been developing this winter involves Ferry Bluff Roost. For several years, the counts of eagles using the main bowl at Ferry Bluff have been relatively low. Discovering why is not such an easy thing, but it now appears that the eagles are using a bowl that faces the Wisconsin River instead of the bowl that faces State Highway 60. Joe Howard, Ferry Bluff Roost Coordinator, has conducted two counts this past winter where two observers were positioned to see what part of the Ferry Bluff State Natural Area was being used by roosting eagles.One observation spot is the traditional pull-off adjacent to Highway 60. Counters have observed eagles using Ferry Bluff Roost from this location since our first counts began in 1988. A second observer has been positioned across the Wisconsin River downstream of the canoe landing where the river side of Ferry Bluff can be observed. This year almost no eagles have used the traditional bowl that faces Highway 60, whereas eagle use of the bowl facing the Wisconsin has been noted each time the roost has been observed from the south side of the river.Why this shift of roosting sites has occurred is unclear. It is possible that the house built just west of the traditional roosting site has been too much of a disturbance, forcing the eagles to move to the river side of the bluff. Other roosts (e.g. Sugarloaf), however, have houses located closer to the perching areas than occurs at Ferry Bluff. The eagles often perch in direct line of sight of houses at Sugarloaf, whereas there is no direct line of site between the house near Ferry Bluff and the traditional roosting bowl at Ferry Bluff. It is also possible that other disturbances, like fallen roost trees, have affected the quality of the traditional roost. There might also be another type of disturbance occurring that we are not aware of.What is clear is that, in the bowl that faces the river, other sources of disturbance may also be problematic for roosting eagles. Though the bluff part of Ferry Bluff State Natural Area has been traditionally closed to human use during winter to protect roosting eagles, enforcing that closure has proven difficult. John Buss, our local Conservation Officer, has made a great effort to enforce the closure over the last quarter century, but his efforts are minimized if the area does not have proper signage. Maintaining proper signage in critical eagle areas like Ferry Bluff and along the Wisconsin River across from the overlook are important tasks that need to continue in the future when economic pressures deprioritize such recurring tasks. Closure signs for Ferry Bluff were not erected this year until the middle of January.

Involvement by FBEC members may be needed to help make sure this conservation activity gets accomplished each year, and it is possible that our role may need to take on greater significance in the coming years. We need to help dedicated DNR staff like John do their job well. Your efforts at monitoring this population represent one enormously helpful thing that we can do. Perhaps there are more tasks that we can take on. Stay tuned…

Collectively you all applied 32 hours of counting effort today and your efforts are much appreciated!If you have any questions or comments, please don’t hesitate to contact me.Jeb BarzenCount Results

Adult

Immature

Unknown

Total

Blackhawk

2

1

-

3

Sugarloaf

6

4

3

13

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