Neotropical Migrants and White-tailed Deer
We in Audubon attach a special value to neotropical migrants. These species are experiencing general, and in some cases, serious declines. For example, both the Wood Thrush and the Black-billed Cuckoo are on the Audubon Watchlist for Connecticut. The Connecticut forests are an important habitat for these birds; this is where they breed. For successful breeding, however, a healthy, multi-layered forest is essential.
Here is where the White-tailed Deer come into the picture. With a deer population of over 75,000 in 1999 (compared to virtually none in 1900), Connecticut's deer are causing a host of ecological problems, from loss of plant diversity to fewer nesting songbirds.
In areas of deer overpopulation, herds can eat some plants out of existence and the intermediate canopy can disappear, replaced by carpets of ferns. Wood Thrush and Black-billed Cuckoos don't nest in ferns; they nest in the intermediate canopy.
So, while the obvious results of the excessive deer population in Connecticut are the number of road-kills, the damage done to our gardens (including mine in New Haven), and the role of deer as a vector in the spread of Lyme Disease, they also play a part in the decline of some of the neotropical songbirds.
Sources- Connecticut DEP (www.dep.state.ct.us/burnatr/wildlife/ factshts/wtdeer.htm), Pennsylvania Audubon (pa.audubon.org/Deerfactsheetrev1.htm), (www.audubon.org/chapter/pa/ pa/Dunn.htm).