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Ocean Watch Susan Scott |
Flying home, by
instinct or by choiceAt the end of April, Hawaii's golden plovers left Hawaii to attend to family matters. I did the same. The birds went to Alaska to mate and raise their young. I went to Wisconsin to help my aunt.
Migrations are notable in this part of the country. Day after day, people in my hometown marvel at the fact that I moved to Hawaii. I marvel at the large flocks of Canada geese flying north.
Like me, some of these big birds have reached their northernmost destination. One group, called giant Canada geese, migrates to Wisconsin in the spring and stays here all summer. Although they nest throughout the state, most giant geese set up housekeeping in Horicon Marsh, a state and federal refuge and the largest cattail wetland in the country.
Another group of Canada geese common here is known as the Mississippi Valley Population (MVP). These somewhat smaller geese fly each spring from southern Illinois to Canada's Hudson Bay.
Up to 200,000 of the 1.3 million members of the MVP stop at Horicon Marsh to rest and eat. It takes these travelers 15 hours to fly the 850 miles from Illinois to Horicon, and seven to 10 hours to cover the remaining 450 miles to Hudson Bay.
This traveling is a lot of work, but like our plovers, these migratory birds know what they're doing. Predators are scarce in the spacious Hudson Bay area, and the long hours of daylight make plant food abundant.
Although they look alike to most of us, Canada geese (Branta canadensis) are divided into 12 subspecies. The MVP and the giant Canada goose are two of those. The others are widespread.
Our state bird, the nene, is a descendant of the Canada goose.
Like most of Hawaii's seabirds, these geese mate for life. If one is widowed, however, the bird usually finds a new spouse.
Canada geese begin breeding when they're 2 to 3 years old. Young females lay about five eggs, but older birds have larger broods.
This week, I spotted a super-couple caring for 12 fluffy yellow goslings. As I approached the family to take a picture, the male stepped forward and hissed at me. I saw no teeth in that menacing beak, but the painful pinch that bird might deliver was easy to imagine.
As I hesitated, the mother goose hustled the brood into the water. Dad brought up the rear, and in seconds the family had paddled far from shore, safe from the camera-wielding monster.
Goslings hatch after 25 days and are fully grown in two months. Fast maturing is crucial. When the days begin to shorten, signaling the end of the food supply, the youngsters must follow their parents south. In this way, offspring learn the route, including the breaks at Horicon Marsh.
These stopovers have made the marsh famous worldwide for goose gatherings. About 260 other species of birds also live or stop there.
Canada geese are short-lived compared with the similar-size Laysan albatrosses, which can live up to 50 years. A wild goose is lucky to see eight. In captivity, however, Canada geese have lived more than 30 years.
During my visit to Wisconsin, the geese honking overhead bring to mind our plovers' spring migration and my own upcoming journey across land and sea.
We migrants stay on the move, but we know a good thing when we see it. Trips are good, but Hawaii is the place to call home.
See the Columnists section for some past articles.
Marine science writer Susan Scott can be reached at http://www.susanscott.net.