Hi all, I read the recent Bobolink comments and wanted to chime in. I have a long-term study of Bobolinks and Savannah Sparrows nesting in agricultural fields in the Champlain Valley of Vermont. Over the last 15 years we have monitored >2500 nests relative to the timing of hay harvest or rotational grazing. A lot has come of this work--but a few things are important in this conversation. First, Bobolinks decline between 2-3% in most states in New England. So indeed, if you are comparing long-term numbers of birds, there probably are fewer birds in the fields you know so well. Second, Bobolinks tend to prefer (yes prefer) fields that are mowed early and often. When they arrive in the spring these fields are green and lush. They begin breeding in them 3-5 days earlier than in fields that are under a late-haying plan.
Sarah is quite right that dairy farmers hay early for good reason--higher protein levels, which produces more milk from dairy cows. Therefore, asking a dairy farmer to delay mowing is unfair to him/her, as it is economically impossible. Given this constraint, we have worked hard to find a solution that balances early hay-harvest with bird needs--and with success. Working with Vermont NRCS (Natural Resources Conservation Service), a branch of the USDA, we created a program for intensive dairy farms where we ask them to hay as absolutely early as possible in May. All activities on these fields must be done by 31 May (but preferably earlier). Once the field is mowed, they take the second harvest 65 days later (the typical interval between harvests is 35-40 days). If a field is mowed early enough, this 65 day window is long enough for birds to recolonized the field, pair, build a nest, lay eggs, incubate, feed chicks, and feed fledglings. Under this scheme, reproductive success is nearly as high as on field that are mowed after the breeding season. Farmers that enroll in this program are compensated per acre enrolled for a three year period, and participants that we surveyed all stated that they were able to adjust their feeding programs to the changes in feed. While this is a Vermont-specific program, a number of other states has created models around it. I'm sure something similar could be successful in Maine.
Even with this improved reproductive success, it is important to note that late-haying is the best scenario for these birds. The persistence of grassland habitat in New England depends on continuing cow-based agriculture throughout the landscape. Therefore, successful conservation can only happen through multiple strategies. If you have specific questions feel free to email me directly (nperlut@une.edu).
Enjoy those Bobolinks (and Savannah Sparrows, Meadowlarks, Grasshopper Sparrows, and if you are super lucky, Upland Sandpipers)!
noah perlut
On Friday, June 3, 2016 at 6:58:07 PM UTC-4, Geoffrey Ives wrote:
As usual we have multiple nesting pairs of bobolinks however, I'm pretty sure the counts are low. Last year they were higher - I counted up to 12 males at one time. This year the most I've seen at once are 4. Worried.
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