By now I hope you understand the complex history that’s happen to get to where we are today. Farms and birds associated with them are under attack from many different directions, but have garnered little attention from environmental groups.
In this segment we will examine 5 of the most troubled field species and take a more detailed look as to why they are in this position.
Henslow’s Sparrow has put its self into a difficult corner. This species has such specific habitat requirements that their colonies are scattered about and so widely separated its a wonder the birds find each other. Henslow’s Sparrow prefers a slightly woody field, usually with scattered shrubs. The grass cannot be too high, too short, too woody or too grassy, like Goldy Locks, they need it just right. If not they won’t nest and if it grows or gets mowed, they won’t come back, they are that picky.
However it is very difficult to find field which meet their requirements these days. It often takes a couple of years to see the changes in plant life to get them to come. This wasn’t too difficult for them in the past, when crop rotations meant that some fields were empty for a couple of years and there were also more of them. These days with artificial fertilizers and other bio-chemical methods, there is not the need for crop rotation and active farms rarely have fields empty for more than a year or two, not enough time for the plants to grow for Henslow’s Sparrow. Also many farmers hay empty fields, meaning the fields never get a chance to age. While abandoned farm land is good for a couple of seasons, eventually the fields become too woody and the birds move on, but they have very few places left to go. This leads to high competition and vulnerability to birds such as Crows and Brown-headed Cowbirds.
The male Bobolink in the breeding season is a sight to behold. His striking black and white (with a bit of yellow) plumage and his long bubbly drawn out song as he flutters around his territory, make him one of the most enjoyable of our breeding birds. The females and off-season males, are quiet and a buff brown color. They are also a long distance migrant flying all the way to South America.
Bobolink’s like hay fields, which is not good. In the past there were many Hay fields and fields were cut later in the season (generally late July into August). This allowed Bobolinks to have at least one brood before the mower came. With the advent of fertilizer and irrigation practices, coupled with a slightly warmer climate, hay is able to start growing earlier in the season. As a result many fields are ready to be mowed in early June, just as the Bobolinks start their nesting. As a result farmers have (For the most part) unknowingly put this species into serious decline. Bobolink’s fail to nest have trouble finding suitable fields and those that are suitable are often already at capacity. Thus Bobolink’s have shown some of the steepest declines of any song bird in the Northeast. Their future however is much more manageable than say Henslow’s Sparrow, because hay fields can grow back in as little as one season, as opposed to several years to get the right growth for Henslow’s, even then they have to be around to find it.
I can’t think of a bird whose call (often called a ‘wolf whistle’) gives me shivers like the Upland Sandpiper. Unlike many Sandpipers this one likes tall grass fields, often near a damp area or farm yard. Unlike Bobolink, Upland Sandpiper requires a large amount of acreage to nest. It is becoming increasing difficult to find wide open grass lands that are suitable these days. This species used to often nest at Airports, but anti-terrorist measures in a lot of areas have prompted airport officials to keep everything mowed to prevent any hiding spaces.
Upland Sandpiper faces a similar problem to Bobolink. Fields are mowed early in the season and this species is a late arrival. As a result many pairs are not successful in their nesting attempts. Also few farms have 100 acres of hay fields, since it is not profitable in anyway, with less crop rotation and fields planted for cash crops more regularly, the habitat isn’t there any more. In many areas Upland Sandpiper has become extirpated, in New York State two of the best areas to find this species is in Ft. Edward, Washington County and in the Town of Ames, Montgomery County. Ames, Montgomery County is one of the few remaining areas of New York State that is predominately grasslands and all the species listed here can be found, often in good numbers.
The buzzy song of this species is how it got it’s name. Although they sound very similar to Savannah Sparrow (And the two are often found in the same field). Like Bobolink this species likes open grassy fields, but do not require as large a parcel of land as Upland Sandpiper. Grasshopper Sparrow faces the same issues as Bobolinks and Upland Sandpiper, early mowing and the loss of nests, nestlings and suitable habitat. Because they will accept smaller areas, they (along with Bobolink) have a high manageable upside.
Harrier’s have to be my favorite hawk. They way the show little effort in gilding at times only a few feet off the ground over a frozen field in winter. One of my fondest birding experiences was on a very foggy day, watching a male Harrier glide silently out of the fog and over my head, close enough so that I can feel the wind from its wings as it went past.
It can be hard at times to imagine this bird in trouble. I have seen over 30 birds at one time coming in to roost and on a good day in winter it is not uncommon to count this species in the dozens. But this species faces the same issues, all the birds in this segment have. Harriers, nest on the ground and as a result they need to have lots of cover. Hay fields provide such cover as well as the food sources they need to support a growing family. Like nearly all of the species here, early mowing destroys a lot of Harrier nests. Because they are such a big bird, farmers do tend to notice them more and in some cases farmers have mowed around Harrier nests to try and give them a good chance, but those cases are sadly few and far between. Harriers are also susceptible to pesticides, because of their wide diet, which has been linked to nesting failures. Harriers also need large tracts of open land (similar to Upland Sandpiper) and it is becoming increasing difficult to find these places and often due to a lack of space, you can find high concentrations of this species in small areas.
We could have examined several other species in this segment including, Horned Lark, Vesper Sparrow, Eastern Meadowlark, American Woodcock, Ring-necked Pheasant, American Kestrel, Short-Eared Owl, Loggerhead Shrike, Barn Owl (which was never very common in Upstate NY to begin with), Eastern Kingbird, Field Sparrow and Red-tailed Hawk. Each of those species also rely heavily on the habitat created by farmers and farms and each is negatively impacted by common farming practices.
For more information I encourage people to read anything done on field birds by Cornell professor Charles R. Smith. Here is sampling of sites (many are PDF’s so you will need Adobe Acrobat Reader):
As you can see there is an extensive wealth of information available on the internet. A suggested search is ‘Grassland Bird Management (your state or location)’.
The final segment tomorrow we will take look at how farmers can make simple changes, that won’t affect their production or incomes, yet can be very beneficial to providing habitat and achieving long term stable populations for many grassland species.