Juvenile herring gull
They say over the past three weeks, 36 dead juvenile herring gulls have been found at Deering Oaks Park.
Three of these gulls were sent to be tested at the National Wildlife Disease Lab in Wisconsin and the results of these tests are expected in the next 7-10 days.
Inland Fisheries and Wildlife say herring gulls are the only type of dead birds found at the park even though there are many other species there.
Portland's Parks Director though says Deering Oaks is still a safe place to visit.
Comment: Beaver attack reports from across the globe for the last few years: Aggressive beaver attacks 2 swimmers in Killingly, Connecticut
Beaver attacks paddle boarder in Asheville, North Carolina
Beaver attacks man at bus stop in Sweden
Belligerent beaver attacks two Bavarian bystanders in Germany
Woman is savaged by an angry beaver in Russia
Oregon men hospitalized, recovering after rare beaver attack
Animals losing the plot: Couple attacked by beaver in Watchung Reservation, New Jersey
Animals increasingly losing the plot: Vicious beaver attacks snorkeler off Nova Scotia's coast, Canada
Paddling family of three attacked by a beaver in Austria
Vicious beaver attacks and kills man in Belarus