Case Study
Nesting Gull Colony Presence Reduced by 75% with Egg Removal Plan
The Problem
In 2014, a Ring-billed Gull colony of approximately 6,000 birds moved into the heart of a Milwaukee-based University campus during the nesting season. Rooftops were so congested with feces, feathers and dead birds that air ducts, air return filters and drains were all clogged. Much of the feces and debris also made its way down to the ground level, putting staff and students in harm’s way. The condition was so bad that maintenance staff could not access many components on the rooftops, requiring pressure washing multiple times a week.
Our Solution
In 2015, Migratory Bird Management (MBM), Wild Goose Chase’s sister company in Wisconsin, was hired for egg depredation at the University, with the goal of removing all the eggs over the duration of the nesting season. MBM acquired the federal permit needed to remove eggs for the University and submitted the gull egg depredation permit report after the season concluded. In that first year, MBM successfully removed over 8,000 Ring-billed eggs and nearly 450 Herring Gull eggs.
In 2016, the Ring-billed colony returned, however, the population was heavily diminished. MBM removed just over 1,800 eggs that year, and the colony took off earlier than in the previous year. In 2017, the number of eggs removed again drastically dropped to 444. 2018, the last year of any trace of Ring-bills, saw only 252 eggs and an early departure in May. The Ring-billed colony has not returned since.
Herring gull numbers, while not nearly as high as the Ring-billed colony to start with, were harder to reduce. Herring gulls are a bigger, more aggressive, and more resilient species of gulls. They will pursue nesting opportunities in different locations, potentially bouncing from rooftop to rooftop to avoid harassment. As such, their presence was also more spread out all over the University’s campus, increasing the risk of attacks towards student and faculty. However, MBM persistently treated Herring gull nests through the same population control solution implemented for Ring-billed gulls, expanding service across more buildings throughout campus over time.
Wild Goose Chase's Impact
Over 6 years of gull management, gull nest and egg counts dropped over 75%. Ring-billed Gull egg depredation proved to be successful within the first 2 years, as most of the colony did not return the following year after egg removal began. Herring Gull species, while harder to control, has also seen a steady decline year-to-year as egg depredation service continues across the University’s campus.