What the flock? Gulls take over lawns, hoover up scourge of Winnipeg worms

They're the bane of cyclists' existence and leave smears across vehicle windshields, but now a scourge of worms that has been eating its way through Winnipeg treetops has met a formidable winged foe.

Birds get wise, leave water behind for smorgasbord of forest tent caterpillars, elm spanworms, cankerworms

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      They're the bane of cyclists' existence and leave smears across vehicle windshields, but now a scourge of worms that has been eating its way through Winnipeg treetops has met a formidable winged foe.

      Gulls usually stick to the water, but they recently wised up to an infestation of three different worm species in Assiniboine River-adjacent Wolseley and West Broadway. Flocks of the white birds have begun waddling across area sidewalks and lawns in search of squishy meals.

      "Doing what they're doing, it's pretty unusual,'" said Paula Grieef, a naturalist at Oak Hammock Marsh.

      A worm infestation in Winnipeg's Wolseley and West Broadway neighbourhoods has caught the attention of gulls. The birds normally stick to waterways but have made an exception for the worms, which are wriggling around lawns 0:20

      The first wave of forest-tent caterpillars in May was followed closely by elm spanworms and cankerworms. The wriggling trio has hung from treetops and scattered droppings on the ground below.

      The birds have hopped from street to street and stopped on Palmerston Avenue and Spence Street this week to chow down.

      Grieef said it's likely one or two gulls first discovered the worms and couldn't keep the smorgasbord a secret for long.

      The city has been spraying some Winnipeg neighbourhoods for forest tent caterpillars in recent days. (Star Tribune, Joel Koyama/Associated Press)

      "Gulls are one of those kinds of birds that will eat just about anything and take advantage of whatever is available," Grieef said. "I would think lots of little birds are eating them, but we don't notice them like we would notice the gulls."

      Grieef said the birds will help bring the overall worm number down but can't single-wingedly exterminate the pests.

      A gull catches a worm on the street in Winnipeg's West Broadway neighbourhood on Tuesday. (Trevor Brine/CBC)

      Winnipeg is in the midst of its worst elm spanworm invasion in 20 years, the city's insect control branch says. The city expects the invasion to last another two to three weeks.

      Elm spanworms that evade the gulls will morph into pale white moths this August, while cankerworms will turn into grey moths. Taz Stuart with pest-control company Poulin's said last week that forest tent caterpillars will take on a golden-brown colour in their moth phase in July. 

      City crews sprayed for worms from The Forks west through West Broadway and Wolseley on the weekend.

      Gulls are now a common sight on lawns and boulevards in West Broadway and Wolseley. (Trevor Brine/CBC)
      Worms have invaded some parts of Winnipeg. And now so have birds. CBC's Marjorie Dowhos braved the streets following flocks of gulls through our city. 1:20

      About the Author

      Bryce Hoye

      Reporter

      Bryce Hoye is an award-winning journalist and science writer with a background in wildlife biology. Before joining CBC Manitoba, he worked for the Canadian Wildlife Service monitoring birds in Manitoba, the Northwest Territories, Nova Scotia and Alberta. Story idea? Email bryce.hoye@cbc.ca.

      With files from Information Radio