Wildlife & Waterfowl

DEP wildlife biologists routinely inventory all species of wildlife to estimate population levels, and they compare this data to reservoir water samples to determine if a relationship exists between wildlife defecating in the water and higher fecal coliform bacteria levels. This task is a year-round job, with DEP wildlife biologists beginning as early as 4:00am to conduct bird population surveys and collect/analyze fecal samples from birds and mammals. Certain species of birds have identification tags placed on their legs to track their local movements around the reservoirs during breeding seasons and to distinguish residents from migratory populations.

DEP’s research in the early 1990s discovered that seasonal increases (spikes) in the level of fecal coliform bacteria in the Kensico Reservoir were caused by the presence of large numbers of waterfowl and particularly Canada geese. These birds were prospering at the reservoir because it is virtually a predator-free habitat. However, what’s good for the geese is not good for water quality because elevated fecal coliform levels are a significant threat to public health.

In 1992, DEP launched a Waterfowl Management Program to measure the amount of bacterial pollution that wildlife species contribute to the City’s reservoirs and to correct the problem through well-developed wildlife management practices. Initially confined to Kensico Reservoir, the program has since expanded to include most of the City’s water supply reservoirs.

To address the seasonal spikes in fecal coliform bacteria, DEP’s Waterfowl Management Program strives to eliminate geese, gulls, cormorants, ducks and other water birds from select reservoirs using non-lethal measures. This highly-successful program is labor-intensive but simple: as seasonal changes increase the waterfowl populations, DEP staff use motorboats, hovercraft, pyrotechnics, and bird distress tapes to chase the birds off the water. These federally and State-approved techniques have been critical to the City’s ability to continue meeting federal and State drinking water quality standards.