By Jeb Barzen
On Dec. 6, 59 eagles were counted through 28 hours of volunteer effort by Ferry Bluff Eagle Council volunteers. Two weeks later, on Dec. 20, 90 eagles were counted through 30 hours of volunteer effort. That is a good start to our eagle winter season.
For the Dec. 6 count, most eagles were distributed downriver at the Lone Rock Roost. The weather was mild, which reduces the probability that eagles will use a traditional roost. Instead, often eagles perch and roost over night near where they were last feeding. By Dec. 20, we counted 45 percent more eagles and those birds were distributed further upstream (at Black Hawk and Ferry Bluff Roosts) while also continuing to use the primary downstream roost at Lone Rock.
Counting 90 eagles by mid-December provides hope for a good eagle season as that total is near our winter maximum count for the last six years. It was still warm for the Dec. 20 count, so we likely failed to count eagles that didn’t fly into roost, leading to an under-estimation of the eagles currently occupying our area. If there are good numbers of shad in the river, we might get large numbers of eagles using the Lower Wisconsin River winter area.
Anne Lacy, who counted at Leland, watched two adult eagles from a nest chase a third eagle out of the roosting area. As with last year, we have two roosts that now contain eagle nests in them (Ferry Bluff and Leland) and territoriality is being expressed at least late in the winter season and perhaps early in the winter season. No aggressive encounters between territorial and non-territorial eagles were noted at Ferry Bluff on Dec. 20, the only count day where we could observe the roost itself. Generally, if large numbers of eagles do winter here, it will be interesting to see if that territoriality is maintained to mid-February.
Jeb Barzen is president of the Ferry Bluff Eagle Council, ferrybluffeaglecouncil.org.