Herons in Wisconsin die from hailstorm – 05/08/2004

  • September 30, 2013 at 8:29 pm #469


    HAYWARD, Wis. – A hail storm killed more than 100 great blue herons
    on a Chippewa Flowage island, but the loss shouldn’t affect the
    statewide population of the graceful wading birds, state game
    managers say.

    Still, it demonstrates how susceptible wild birds that live in large
    colonies can be to the severe weather, according to workers with the
    Department of Natural Resources.

    The storm hit April 18 and the deaths were discovered on Little
    Banana Island on April 30 by the DNR wildlife staff following up on a
    citizen report.

    In the rookery, or colony of nests, workers found 106 dead herons and
    another 11 injured birds. About 50 herons at the site were unharmed.

    The DNR crew managed to capture the 11 injured herons and deliver
    them to a local wildlife rehabilitator.

    Laine Stowell, one of the DNR biologists who visited the site,
    estimated that at least 100 heron eggs were smashed on the ground.

    The storm that hit the area included hail and high winds that damaged
    homes, cottages and vehicles and stripped needles from pine trees.

    The DNR staff made an aerial survey of the flowage April 20 to check
    on the rookery but observed little damage, with most of the nests
    still intact. However, the citizen report about injured herons along
    the island’s shore caused the DNR staff to investigate and find the
    dead and injured birds.

    “The structural damage to the rookery was less than expected
    considering the loss of all those birds,” Stowell said.

    He said biologists believe about two-thirds of the rookery population
    was killed.

    Bill Volkert, a DNR wildlife educator at Horicon Marsh State Wildlife
    Area, has worked extensively with colonial nesting birds.

    He said the incident underscores the natural risks faced by many such

    “With colonial nesting birds, there is always the risk of losing a
    whole breeding population in one major natural event, such as a major
    thunderstorm with high winds,” Volkert said. “While building nests in
    trees protects them from predators, it makes the rookeries vulnerable
    to severe weather.”

    He said it could take two or three years for the rookery to rebound.
    Some of the remaining herons will probably try to resume nesting, but
    they probably will produce fewer offspring.

    While the event will affect the local heron population, it won’t have
    a significant statewide impact, Volkert said, noting that a recent
    survey showed great blue herons nest in all of Wisconsin’s 72

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