A few simple actions can help property owners protect their parking lots — and the local water supply — from gulls.
ANYONE WHO OWNS or manages a large surface parking lot along the East Coast has probably encountered gulls perched on light poles or resting on the ground. These birds create numerous problems for property owners. Gulls defecating in parking lots can damage building roofs, soil cars and potentially spread disease. Aggressive birds may also harass employees, shoppers and other parking lot users.
Why do gulls gravitate to parking lots? Recent research by biologists with the Massachusetts Department of Conservation and Recreation, Division of Water Supply Protection (DWSP), has provided some interesting insights into this common occurrence.
From 2008 to 2013, DWSP conducted an intensive research project on the winter ecology of gulls in central Massachusetts, which focused on bird activities in relation to water supply reservoirs. The research team captured and wing-tagged over 2,500 gulls; satellite transmitters were placed on an additional 30 birds. Data from 6,000 tagged gull sightings and 50,000 satellite locations indicated that gulls were spending a lot of time in urban and suburban parking lots during the day, then spending most nights on DWSP’s reservoirs, where their feces contaminated the water. While the perception was that gulls were in lots eating garbage and “dumpster diving,” researchers wanted to see if that perception was accurate.
During the winters of 2011 to 2013, the team intensively studied gulls — counting them and observing and documenting their foraging behavior — at eight urban and suburban shopping center parking lots at least 30 miles from the ocean in central Massachusetts. Almost all (98 percent) of the gulls counted were ring-billed gulls. The results were striking, and not what researchers expected.
The team observed about 600 gull-food interactions. The vast majority (over 550) of these were human-provisioned feedings; the rest involved gulls scavenging garbage. People offered a variety of food to gulls, including bread, baked products, french fries and cereal. While some people offered very little food, such as a few fries from their own lunch, many came to parking lots with large quantities of food specifically to feed gulls. On average, gulls were fed by people once every hour.
The research team then attempted to persuade people to stop feeding gulls through education and outreach, by erecting “DO NOT FEED” signs in the parking lots and by directly asking people to stop feeding. Signage alone appeared to have little impact on the number of people feeding gulls; when asked, most individuals said they had not seen the signs. When approached, however, many feeders indicated that they were unaware of the negative implications of feeding gulls and agreed to stop after being educated.
This research suggests that feeding gulls is a common activity not only in Massachusetts parking lots but throughout the range of ring-billed gulls; tagged gulls have been sighted in parking lots from Newfoundland to Florida. DSWP strongly encourages parking lot owners who have a gull problem to discourage people from feeding gulls, and offers the following advice:
1. Post “DO NOT FEED” signs in visible areas. While signs alone may not stop feeding, they can be an important component in an education campaign. Detailed signs that describe the negative consequences of feeding gulls may be more effective than simpler ones. (See, for example, the sign above.)
2. Adopt a zero tolerance policy for feeding. Because most parking lots are private property, owners can take an assertive stance toward people who feed gulls. In many places, placing old food on the ground can be considered littering.
3. Coordinate efforts with those of other property owners. If feeding is discouraged over a large area, research suggests that gulls will abandon the area in search of a more natural diet. Work with other property owners, local municipalities, environmental groups and government agencies to spread the word that feeding won’t be tolerated.