Mute swan no scapegoat for Chesapeake's ills
In a recent op-ed ("Speaking Up for the Bay's Mute Swans," May 12) an animal rights advocate decries the killing of invasive mute swans as an unnecessary "slaughter" of a scapegoat for the Chesapeake Bay's myriad ills. The writer belittles the decades of science that formed the basis for the difficult decision to reduce the Chesapeake's feral mute swan population.
There is in fact little real divergence of opinion among scientists and conservationists as to the danger that this non-native species poses to the Chesapeake and its wildlife. Decades of research here and across the continent have demonstrated the mute swan's propensity to drive native species from their nesting areas and destroy aquatic habitat, all the while reproducing at an astounding rate in the absence of significant competition.
The charge that the mute swan is a scapegoat for the Chesapeake's problems is preposterous. Everyone realizes that the Chesapeake Bay's troubles come from a wide front of assaults from human activities. Mute swans are just another aspect of the problems that are facing the bay. As unpalatable as it may be to all of us concerned with animal welfare, recent research has shown that addling/oiling of eggs and similar measures directed at reducing nesting success are not by themselves effective mute swan population controls. Removal of adults is absolutely required as part of a comprehensive program.
Wayne H. Bell, president of the Maryland Ornithological Society
Invasive species displaces natives, consumes grass
Mute swans are non-native birds and compete directly with native species, including the smaller tundra swan which winters (or used to) in large numbers on the Chesapeake. Mute swans aggressively defend winter feeding areas from these smaller birds, and it is no surprise that wintering tundra swan numbers have declined as mute swan numbers have climbed. I personally have seen mute swans attack and drive away the smaller native birds from winter feeding areas.
Be assured that these birds eat a great deal of SAV [submerged aquatic vegetation]. Examination of stomachs of mute swans from two regions of the Chesapeake Bay found that 70-100 percent of their summer diet consisted of these bay grasses. What is worse, mute swans do not migrate and thus feed on bay vegetation during its critical summer blooming/seeding period.
