Signs of spring on Cape Cod
Spring, that cold, wet joke played on us Cape and Islands folk, begins in less than two weeks. Though it has felt pretty wintry recently, we’ve already ticked off several of our “spring can’t be far away” bird migration milestones. The first Killdeer, those large plovers that nest in grassy and gravelly places, were reported weeks ago - I saw five loudly interacting at the Chatham airport last week. Red-winged Blackbirds are now back in certain swamps and marshes, males loudly proclaiming their territories. Here on the Outer Cape, a few Turkey Vultures are back and fighting with the Great Black-backed Gulls over the various dolphin carcasses in the saltmarshes. Woodcocks have been heard giving their complicated terrestrial and aerial displays a few places, as is possible any time starting in late February.
But perhaps no late winter arrival is more anticipated, more heralded, than the first of the Osprey. Well, other than when the first Piping Plovers send headline writers into a hyperbolic state. Many report Ospreys starting in January and February, their vision clouded by hope. There are few if any good records of Osprey in those months – these invariably turn out to be Red-tailed Hawks, Great Black-backed Gulls, and, increasingly, Bald Eagles. I know of at least four reports of Bald Eagles sitting on Osprey nests in recent weeks, in one case the exhibitionist eagles copulated a stone’s throw from downtown Falmouth.
This year’s first Cape Osprey was genuinely quite early - March 4th, a full two weeks early. It’s still the only Osprey reported anywhere in New England this year. This bird was seen by many on a very visible nest by the Orleans rotary on Rt. 6. Typically, St Patrick’s Day is a reliable target date for the first arrivals, and the first birds are usually further west – the Outer Cape’s sparser Osprey population arrives noticeably later. This Orleans male must have been really motivated to get back and defend his nest.
The males are almost always first – they need to make sure their nest site hasn’t been usurped. These birds live a long time, mate for life, and vigorously defend their territories, which they keep from year to year. Ospreys will even drive off much larger Bald Eagles who dare take over their nest during the winter. Females arrive a leisurely four days later than the males, then prepare to be pampered for the next five months. Well, sort of. It’s possible that some females don’t catch their own fish for the entire breeding season - they stay at the nest through the egg and nestling stages while the male does all the fishing. I know of several human households where the male does all the fishing, like my brother’s, but it has little to do with providing for the family.
In any case, these females aren’t eating bon-bons and watching their stories, they are incubating the eggs, feeding the chicks, and helping in the defense of the nest. With age comes wisdom and privilege – older Ospreys arrive earlier, lay eggs sooner, and have greater nest success as a result. It takes a long time to go from egg to fledged young, four months, so starting earlier is an advantage - chicks won’t be flying on their own until July, and a few late bloomers will still be bugging their parents, usually the male, into September. After that, it’s back to Venezuela or beyond for the winter.
With probably close to 500 nesting pairs, we’re lucky to have the biggest Osprey population in the state here on the Cape and Islands. In places like Bourne and Falmouth people are practically swatting them away like huge mosquitoes. Which reminds me - we shouldn’t forget that aerial spraying of the pesticide DDT almost drove them to extinction and by 1970 we were down to a handful of pairs in the whole state. When you do finally see your first Osprey in the coming weeks, take a minute to remember that this isn’t just a sign of spring, or a pretty cool bird, it’s one of the biggest environmental success stories of our time, in the flesh.
This piece first aired on March 10, 2021.