Mid-September. Change is in the air including migrating hawks by day and songbirds by night. There’s no telling what will land in local backyards or pass by overhead.
Audubon’s hawkwatch staffer Katrina Fenton had a busy first week up at the Miller State Park site, not as much “negative data” (no migrants) that typically begins and ends the fall migration season as numbers wax and then wane.
The one hawk species that crowds the skies a handful of days each fall showed up big time last year on Sept. 16, 17 and 21 — well over 3,000 each of those days.
Here’s Katrina’s write-up for September 16:
“It took pep-talks, threats, optimism, pessimism, and chocolate with sea salt to get through a morning filled with anticipation that sank like Cardigan Mountain into the haze. Numbers inched upwards hour by hour: two birds, 40 birds, 90 birds. Not bad but not quite what we were hoping for after [769] yesterday. Then kettles began to grow out of the north, 30 birds here, 70 birds there. Broad-winged Hawk kettles led by Ospreys and Bald Eagles with Sharp-shinned Hawks mixed in billowed out of the north and east, vanishing as the birds entered their glides only to materialize again, closer, when another thermal was reached. Between 1:00 and 4:00, over 3,000 Broad-wingeds were counted, leading to the 4th highest single day total in Pack’s 11 year history.”
Broad-winged hawks evacuate their breeding territories in pulses that surge south on days with good flight conditions, especially following a cold snap. If you want to track their flights to increase chances of looking up at the right time, go to hawkcount.org, click on “Monthly” in the Data Summaries box, then select “Pack Monadnock” as the hawkwatch site.
You’ll be delivered to daily reports including Katrina’s always descriptive narratives that accompany the numbers, as well as a forecast for what the next day’s flights might be.
What’s just down the road for us — the state’s premier hawkwatch site — draws people from afar. Lucky us!
Meade Cadot and I will be up there on Sunday helping interpret the migration. Hike or drive to the Pack Monadnock summit, and come on along. With sea-salted chocolate or without.
There is a tradition of sharing treats among the hawkwatch group. I’ve been known, during lulls, to offer Fig Newmans to the next person to sight a migrant. Crisp apples also are hard to beat this time of year. And yes, Katrina does like chocolate.
I was asked to talk with a book group about hawks and the hawkwatch, and a simple question launched me down an interesting path of inquiry.
The question: Do hawks mate for life?
About 90% of all birds are monogamous, although that term covers a range of pair bonding — from one brood to a lifetime. As a generalization, monogamy works best given that survival of the species is genetically programmed in all animals, humans included.
As with humans, most avian young are born requiring a lot of care. Care and tending by two adults makes sense.
The species accounts for various hawks use words like “generally monogamous,” and “thought to mate for life.”
“Divorce” is mentioned also, but it’s hard to determine whether a mate switch is a response to death of a mate — thought to be highly likely — and not swapping one mate for another.
“Nest-site fidelity” is mentioned a lot for hawks. Many species reuse the same nest rather than starting over each year. That makes sense, too, as some raptor nests are huge.
Over the years I’ve wondered about nest-site fidelity vs. mate fidelity, which comes first, and I knew who to turn to for help sorting things out.
Iain MacLeod, a.k.a. “Mr. Osprey,” conceived of and carried through creation of N.H. Audubon’s hawkwatch at Miller State Park on Pack Monadnock. Although no longer working for Audubon, moving on to head Squam Lakes Natural Science Center, he commutes this way each Monday to spell Katrina as official hawkwatcher.
Here’s my email query to Iain: “I’ve in the past heard more about nest-site fidelity than mate fidelity, which always made me wonder if it’s just our homo sapiens tendency to discount what we consider human attributes/emotion in non-humans. Of course it’s all about evolution and mate fidelity makes more sense for continuation of the species, until it doesn’t …”
Here’s Iain’s response: “High mate fidelity is directly tied with survival. If annual adult [Osprey] mortality is only 10% then chances are very high that pairs will reunite each year. They are drawn by the nest site and there is a distinct advantage to mating with a known/familiar partner. Having watched pairs reunite immediately after one individual has JUST arrived after six months apart, it is amazing how they immediately accept each other and bond. It’s like they pick up where they left off six months earlier.
I have also seen a new male be immediately accepted by an old female. He made the ‘right moves’, was feeding her and her biological drive to mate and make baby Ospreys meant she accepted him. I suspect that it is similar with other raptors.”
It seems that nest-site fidelity greatly assists mate fidelity. A reunited pair on familiar territory start producing the next generation without losing precious time to competition for a mate, courtship and nest building.
In my research, I learned that female adult ospreys head south before the young are independent, about a month before her mate. He takes charge of tending the young.
How curious. I intend to visit Iain up at the hawkwatch to ask him reasons why that makes sense.
Backyard Birder by Francie Von Mertens appears every other week in the Monadnock Ledger-Transcript.