By Leeanne Seaver
The sound of sandhill cranes often wakes me as the flock descends to forage in a field nearby. Their primordial chorus is utterly unique and evocative. Something deep within me feels the instinct to call back. Maybe some elemental aspect of my DNA recognizes their ancient voices. Cranes make an almost prehistoric noise that would have been familiar to early humans living in wetland areas from Canada to Florida. Indeed, these birds have been around longer than our ancestors.
Factoid: Sandhill cranes are the oldest living bird species in the state. Their fossil record goes back 2.5 to 10 million years. If the pterodactyl and heron had a baby, it would probably look like these big gray birds. Both adult males and females sport a bright red splotch on their heads. Standing four to five feet tall with an average wing span of six to eight feet, they are also Michigan’s largest bird. Those wide wings are designed for soaring – as high as a mile up – which is a distinct advantage over strenuous flapping. Cranes can easily remain aloft for hours riding thermal currents and staying out of harm’s way on the ground. They’ve been clocked in flight at 50 mph, and have been known to cover nearly 500 miles a day.
The crane’s long-necked, spindly-legged presence is an important indicator of Michigan’s climate – both environmental and political. There are lots of marshy plants, seeds, insects and small amphibians to eat. Plus, every legislative proposal to legalize hunting sandhill cranes dies a swift death by committee at the Capitol.
Hunting sandhill cranes has been illegal in Michigan since 1916. Although they’re not considered an endangered species here, these magnificent birds still face significant threats from environmental pesticides, loss of habitat and foraging areas, plus the usual predators with an appetite for cranes and their eggs. Then there’s the human factor – cranes are famously intolerant of people. Approaching or encroaching on cranes is likely to prompt the nervous crane couple to abandon its nest entirely, which doesn’t bode well for the future of the species.
Left to their own devices, the monogamous breeding pair will set up housekeeping on the ground near marshes or bogs where there’s plenty of nesting material and good things to eat. April marks the beginning of the brood season. Both parents take turns incubating their brown-speckled eggs for up to 32 days. One to three babies hatch with eyes wide open. These downy-covered “colts” (not chicks) require a few weeks of intense feeding, although they begin exploring beyond the nest just 24 hours outside the egg.
Against all odds, one colt usually survives and hangs out with its feathered folks for a year – until the next brood hatches – which is why sandhill cranes are often seen in groups of three. Newly independent juveniles join in nomadic “survival” flocks until four to seven years of age when they start looking for love.
Cranes clearly like being with other cranes. Their social nature may be the key to their longevity – both as a species and as individual birds that have been known to live nearly four decades. A chatty lot, we can often hear sandhill cranes even if we can’t see them trilling and squawking and sounding at times like they just can’t clear their throats. Group trumpeting is part of a communication exchange that may help with locating food and roosting places, whereas “unison calling” between males and females is all about romance. Factoid: The female calls twice for every one male response. Make what you will of that.
While I can’t find anything to verify this theory, I believe some of that boisterous noise is announcing the location of their next dance. Wherever there are cranes, there’s going to be a dance. Crane couples will be doing an exuberant, leaping, twig-tossing, bouncing, beak-swishing dance. This is one of the most astonishing and beautiful things about sandhill cranes, but admittedly, their dancing is about more than courtship.
“Dancing facilitates pair bonding and allows rivals to assess one another and parents to educate their young chicks by dancing with them. Pre-adult cranes practice dancing for years before they select a mate. Courting cranes stretch their wings, pump their heads, bow, and leap into the air in a graceful and energetic dance.” (About Sandhill Cranes (songbirdprotection.com)
With amazing spectacles like that in mind, the Michigan Audubon Society has hosted the Sandhill Crane Festival every second weekend in October at the Baker Sanctuary near Bellevue. The event celebrates all things crane, and is timed to catch sight of the migration. This remarkable process begins in late summer and early fall when sandhill cranes by the thousands from Canada down through southern Michigan start their journey to warmer climes. The stunning exodus continues through late November, and the return begins in March.
Except for those few sandhill cranes that are content to stay here year-round.
You’ve seen them and heard them – the stalwart few who over-winter here. There’s usually enough roosting, food, and open water sources to maintain a small sandhill population in South County. And to all four seasons of my great delight, one of those hospitable locations is the stubble field within earshot of my morning.
By Leeanne Seaver