Wednesday, March 26, 2008

Grouse News

Karen Johnson sent me this report on Monday:

"I got a call from Brian this morning at 10:30- he had a Ruffed Grouse in Dividing Creek! This is the 3rd report of Ruffed Grouse that I have heard in the past month ." [Brian is Karen's husband - DF]

This is exciting stuff, given that grouse have all but disappeared from southern NJ. In fact, for several years birders in NJ have been talking about the steep decline in Ruffed Grouse statewide. Consider this graph created on Birdsource (the collaborative web site of Cornell and National Audubon.) It is derived from Christmas Bird Count info over the last 30 years:

The decline begs the question, why? My personal opinion is that natural succession is the primary cause, though other factors like overabundant white-tailed deer and invasive non-native plant species also likely play a role. Grouse favor young-age stands of trees, especially during the winter when buds of trees like aspens and birches become extremely important winter food sources. These species disappear as forests mature, which is what has happened in much of NJ as abandoned farm fields first became brushlands, then young forest, then mature second growth forest. Barring intervention, either human (= forestry or other management practices to set back succession,) or natural (=fire), grouse are unlikely to recover to their former numbers in the state.

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