To the editor:
In the article. “Audubon study finds bird decline” [WWF Aug. 2007], Leslie Clapp, president of the Downeast chapter of the Maine Audubon Society, reported, based on observations by others, that “decks…would be full of 30 to 50 [evening grosbeaks]” and “They’ve always been so common and now they’re not around.”
However, the evening grosbeak was, according to the National Audubon’s website, virtually unknown east of the Mississippi until about 1850, when the species expanded east where its population peaked in the mid 1980s and since has experienced precipitous declines. As an example, the species was reported to have not been observed until 1951 in Londonderry, Vermont…
The article also discusses the recent National Audubon study that documents a population decline of over 50 percent for 20 bird species over the last 40 years. Included in the 20 are the Evening Grosbeak and six grassland/early successional species (Horned Lark, Northern Bobwhite, Eastern Meadowlark, Loggerhead Shrike, Field Sparrow and Grasshopper Sparrow).
According to information on the National Audubon website, the decline of “grassland and… early successional species… is that much of the farmland in northeastern states has been abandoned and is either reverting to forest or being converted to suburbs or other human development. In the rest of the country, farmland is being used more intensively, leaving dwindling habitat for … grass-loving birds.” Translation — as substantial areas of former farmland revert to forest, population levels of grassland birds in those areas are returning to the lower levels that would have occurred prior to clearing land for farms (and lumber) from the 1700s to early 1900s.
Also on the list of 20 are Whip-poor-wills and terns. National Audubon reports that the primary cause of the population decline of the former is fire suppression in eastern deciduous forests. For terns, it appears that the increasing population of gulls has had a negative impact on these birds…
Based on the preceding, the quote in the article “Audubon officials say the sharp decline in bird populations found in the new study should be viewed as a canary in the coal mine; whatever hurts bird populations may soon hurt humans, they warn” is not relevant to at least the birds reviewed above.
Phil Sandine
Stockton Springs