The City of Dubuque has seen an influx of out-of-town tourists fly in this week. They haven’t caused a back up at the airport, but they have in the waters near the eastern Iowa border town. Mark Wagner — the chief naturalist at the National Mississippi River Museum and Aquarium — says the visitors are seagulls. Wagner says it reminded him of the Alfred Hitchcock movie “The Birds” as he says the sky was full of seagulls over the Missisippi River and the ice harbor, and also over the museum.
Wagner says such a large gathering of gulls isn’t the norm — but he’s occasionally seen them move in for a meal. He says a lot of times you’ll see them in spring when people are plowing fields as they descend to eat the insects and grubs that’re stirred up. The gulls in Dubuque were taking advantage of a large number of gizzard shad fish that congregate and die in the ice harbor.
Wagner says the gulls did leave a few droppings, but he says the birds didn’t cause any trouble. He says they didn’t cause any problems, and likely did everyone a favor by eating up the dead fish.
The gulls have started thinning out — and Wayne Buchholtz of the Iowa Department of Natural Resources says most of them will eventually move on. Buckholtz says seagulls are scavengers and once the food supply is depleted, they’ll head out on the river or head north in their spring migration to their nesting sites.
Buckholtz says most of the gulls he’s seen in Dubuque probably won’t be around much longer. He says most are ringbill gulls, which he says may nest in the area, but he says most will just be passing through. Buckholtz says the gizzard shad that lured the seagulls are a non-native fish that can’t take a lot of extremes in temperature and quite a few die off during the spring.