[by Pam Hunt] Now that our recent April showers have provided a needed boost to spring blossoms and leaf-out, it’s time to get ready for the peak of spring bird migration – and just in time for New Hampshire Audubon’s Birdathon! As announced in the last eNews, we are once again encouraging birders of all skill levels to observe birds on Saturday, May 8, and report what they see to New Hampshire Audubon. Last year we focused on single town birding – or even just participants yards – and despite miserable weather managed to collectively record 160 species over the weekend. And at the same time, since Birdathon is a fund-raiser, we also collected $6,000 from generous participants and donors. To register for Birdathon, please go to our Birdathon page and you’ll receive further information, including an online checklist that you can fill out at the end of the day. There’s also a link to donations, and all are encouraged to spread the word to family and friends.
Birdathon and the other events on May 8 are all part of a greater celebration of bird migration, a phenomenon that’s had people fascinated – and sometimes perplexed – for centuries. We no longer think swallows spend the winter in the mud of ponds, or that hummingbirds ride north on swans and geese, but the real stories of migration are sometimes just as far-fetched. How DOES “your” Eastern Phoebe find its way back to your garage each spring, after flying hundreds of miles south to its winter range and back? How do warblers only 2-3 months old find their way from the White Mountains to tropical winter sites where they’ve never even been before? On the broadest scale, we have a pretty good idea of how birds orient – meaning know which way is north and move accordingly – and are always improving our understanding of navigation – how they know where they actually are relative to where they need to be. They use the sun, stars, and earth’s magnetic field for the former, and landforms and internal mental “maps” for some of the latter. In addition, they accomplish their marathon flights thanks to a remarkable physiology that allows for extremely efficient breathing, off-season atrophy of multiple organs, and rapid accumulation and burning of fat for fuel. Human beings can at least orient and navigate in much the same ways as birds (minus the magnetic field component!), but we mere mammals can never match birds’ prowess when it comes to traveling long distances under our own power. For starters, we can’t fly.
Flight aside, imagine for a moment that you are one of the thousands of warblers moving into New Hampshire right now. Chances are that only a couple of weeks ago you were still in the Caribbean or Central America, perhaps filling up on tasty insects in a mangrove forest. You ate enough to increase your weight by perhaps 50%, with this added fat ready to serve as fuel for a many-hours-long flight. At some point, the calendar in your head, likely combined with a bit of a south wind, spurred you to launch over the Caribbean or Gulf of Mexico and head north shortly after sunset. Many hours and hundreds of miles later you begin your descent back to the ground, ready to rest, refuel for a couple of days, and continue onward. Sometimes ornithologists try scaling this sort of feat of avian endurance and adaptation into human terms: how much would you need to eat, how far would you have to run, and so forth. But the reality here is that there really isn’t a valid way to do this – we simply can accomplish anything remotely similar without damaging our bodies, or at best, becoming completely exhausted well before the comparison is over.
And thus we marvel anew each spring as colorful clumps of feather and muscle arrive in our yards and forests and announce the mornings with song. They’ve made it through two long flights and months in foreign lands, but the chances of doing this successfully are actually rather low. Migration is a hazardous time, and most young birds don’t survive their first complete journey. They may succumb to poor weather, go off course, or be eaten by a predator, and those are just the dangers that they’ve dealt with for millennia. Human beings have added all manner of new threats to the gauntlet these birds face: windows, towers, free-ranging cats, and our seemingly unstoppable conversion of natural habitat into farmland, roads, and buildings. Given all this, perhaps it’s no surprise that North America has lost roughly three billion birds in the last 50 years, and even less of a surprise that the species most likely to have declined are those that migrate the farthest.
Can we reverse these declines? The answer to that question is as varied as the species and threats it encompasses, but in many cases it’s a hopeful “yes.” The hope lies in the ongoing efforts of conservation biologists, environmental organizations, and local communities to understand and protect birds and the natural systems on which they depend. Make no mistake, these are daunting challenges, but not insurmountable ones, and only by acting together can those of who care about birds move us all toward enacting meaningful change. Think about this as you enjoy the returning migrants. They will keep on repeating their journeys – generation after generation – largely oblivious the their world changing beneath their wings. It is us who have the perspective and means to observe these changes, and in turn try to do something about it. A great place to start is New Hampshire Audubon’s new “State of the Birds” publication.
Photo: Eastern Phoebe, by Walter Keane.