Wednesday, June 30, 2010

Canada Geese - predator of grass

     "The balance of nature is not a status quo; it is fluid, ever shifting in a constant state of adjustment. Man, too, is part of this balance. Sometimes the balance is in his favour; sometimes – and all too often – it is shifted to his disadvantage" Rachel Carson in “Silent Spring”

     Canada geese are a truly beautiful, majestic bird known for their annual migrations marked in the fall and spring by the “V” formations in the sky. Prior to the 1960’s Canada geese sightings were rare treats and Canada geese did not spend their winters here, but now they are commonly seen year round, and are more numerous each year. According to a recent evaluation by the U.S. Department of Agriculture and Fish and Wildlife Service, the Canada goose population in North America has risen fivefold since 1970, primarily due to a 15-fold increase in the number of geese living in urban areas. The resident non-migratory geese made up 18 per cent of the North American total in 1970; now they account for 67 per cent. So what has happened?
     Since the early ‘70’s Canada geese numbers have been increasing significantly due to a perfect storm of events. A successful conservation program was launched across North America in the 1960’s by various wildlife agencies to restore numbers of geese reduced through years of hunting and habitat loss. The program was also intended to boost Canada geese numbers for recreational hunting purposes. In Canada there are 11 subspecies of Canada goose and eight of these live in B. C., but the two subspecies that were introduced through this program were resident, or non-migratory, geese not common to this area. The parallel increase in growth of urban and suburban communities with manicured lawns, golf courses and airports and lovely ponds made for the perfect Canada goose habitat. When we add restrictive hunting and firearm regulations and a lack of predators we have created the perfect storm of events.
     The incredible crash of a passenger airliner into the Hudson River of New York recently was caused by such a group of resident Canada geese. The number of Canada goose-aircraft collisions in North America quadrupled between 1990 and 1998, and that trend continues.
     Farmers have noticed the effects of the Canada geese, also. Forage producers watch as hay and grain fields are demolished in a feeding frenzy by these foragers, which consume up to 4 lbs of grass each day, depositing 2-3 lbs of fecal material. Last year we planted two fields with oats and millet, and watched as hundreds of Canada geese ate the crop while it was trying to grow. I finally gave up and turned the sheep in to compete with the geese, and now we have two bare fields ready to plant again this year. The ground next to the ponds is especially lacking in vegetation, and the ground is compressed. This is only compounded by the fact that the federal government has been encouraging farmers over the past few years to dig more ponds.
Pender Island Golf Course in December with some resident Canada Geese on putting green enjoying sun
     Now, some might suggest that golf course managers might think a bit about working with these lawn mowers with wings, since they produce fertilizer and keep the grounds manicured. But they are in fact viewed as an unappealing nuisance since the fertilizer tends to be slippery underfoot and muck up the golf balls. One cold day while driving by our golf course I counted over 125 Canada geese, not much less than this years Christmas bird count of 148. In fact this year’s count was much less than the record breaking 466 of 2007, according to Gerald McKeating, a bird specialist who lives on Pender and is retired from many years with the Canadian Wildlife Service. This was probably due to the harsh weather that kept birds hanging out at the beach on count day. In fact McKeating said he saw at least 300 on the golf course just a few days earlier.
     There are also public health concerns since Canada geese can contribute to Giardia, Cryptosporidium and Campylobacter outbreaks. It has been reported that communities with increased resident Canada geese populations also have increased rat populations, because rats like to eat the eggs and the young.
     So what can we do? Increasing populations of Canada geese have prompted several communities to control resident flocks. In the 1970s, the wildlife service began to issue permits to property owners whose crops were being ravaged by foraging Canada geese.   In 2007, Kelowna and Osoyoos applied for wildlife service permits to reduce goose numbers through egg addling (shaking), habitat modification and scare techniques.
     With resident Canada geese populations growing at a rate of 12% per year, doubling in numbers every 4-5 years, we had best be thinking about what we should do. Perhaps the Capital Regional District, like other Regional Districts, should also apply for wildlife service permits for our community.

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