There has been an explosion in the population of Great Lakes whales in Lake Michigan. Once, nearly driven to extinction from over-harvesting by the whaling industry in the mid-1800’s, the numbers of the inland cetaceans have seen a dramatic increase in recent years. So much so that it has set off a corollary boom in the popular whale watching cruise boat fleet, which enjoyed full occupancy on most of its vessels and waiting lists for bookings this coming weekend, according to tour boat operators in Wisconsin and western Michigan port cities.
The reason for what marine biologists have termed an “exponential increase,” has been identified as an unintended consequence of moving the Memorial Day holiday from its traditional date of May 30th to the last Monday in May, in order to ensure a 3-day weekend. The annual Spring rut of Great Lakes whales was known to 19th century whalers to coincide with the end of May holiday. Extending estrus to three days has naturally had the results we are now seeing in the population.
The phenomenon has not been witnessed on any other of the Great Lakes, presumably because Lake Michigan is the only one of the five lakes that doesn’t straddle the boarder with Canada. Since Memorial Day is uniquely a U.S. holiday, the impact on the breeding season has been neutralized by interbreeding between U.S. and Canadian whales in those waters.
– Gary Tefft – Menomonee Falls, WI May 27, 2016