Raptors on the Hunt at Plum Island
January 23, 2016
By Steve Grinley

     There have been a number of raptors on Plum Island this month including a several Northern Harriers, a Red-tailed Hawk and a Rough-legged Hawk. A couple of snowy owls have been hiding in the dunes most of the time, but a pair of Short-Eared Owls have been seen hunting during the late afternoons over the Hellcat dike. Paul Roberts of Medford ( a.k.a. Mr. Raptors) visited Plum Island a couple of weeks ago, so I thought that I would share his report with you.

     “It was an unusual day on Plum Island. 100% overcast, wind N/NE, temperatures high 30s to 40 degrees. High tide about 9:35 a.m. Cool, but not bone chilling cold until the sea breeze built in late morning. The Salt Pannes and Stage Island pool were ice-covered.

     “With the overcast we hoped we might see a Short-eared [Owl] hunting in the heavily overcast morning with an early high tide, but that was not to be. However, as we approached the marsh south of the Old Pines, we saw a rare, incredibly beautiful sight. That mile-long section of marsh was stuffed – STUFFED– with Black Ducks; more than I have seen in years. The tide was high, but not 9 feet yet, the torsos of almost every duck were high on the water and visible. Even more striking, something had alarmed them. 

     “I had just seen an immature Northern Harrier almost a mile away apparently make a kill on a small duck in a pond just north of Cross Farm Hill. It was so distant that I cannot say for sure, but the harrier dropped down with its wings held high over the head and stood there with legs spread on the prey for a few seconds. It might have captured a rodent or small bird, but it was acting like the prey was large and challenging. I think this strike led to almost every Black Duck within a mile becoming very alert, turning into the wind. The light was poor, but the scene was spectacular. 

     “I did a quick estimate by 20s and came up with 4000 Black Ducks, fearing the opportunity was brief. I then did a sample estimation by 20s of roughly 200 Ducks and found I was 85% accurate. I did a second estimate of the marsh and came up with the same rough number. I was undoubtedly missing a few ducks hidden by the grass, but so many were visible. I’d say I had a minimum of 3000 Black Ducks, likely closer to 4,000. That is one of the highest numbers I have had in years, in decades. And what made this sight so spectacular was that they were all alert and facing into the strong wind. I regretted that I had not gotten my camera out, but the light was so poor that I probably would not have been able to capture much, especially at a distance. Several times small flocks of several hundred Black Ducks lofted into the air nervously, and fluttered down only 50-75 yards away. It was a Currier and Ives print come to life. 

     “This was as many Black Ducks as I have seen in that marsh in probably decades, and I have made a point of checking it at spring tide every month this and every fall. Usually the numbers of Black Ducks [numbers] there peak in late November, and I have always thought they were a major attraction to any passing Gyrfalcon. Many of the Gyrs I’ve seen on Plum have been in that section of marsh, or perched close to large flocks of Black Ducks. Most of the prey I’ve seen Gyrs take on Plum or in Newburyport has been Black Duck (1 Canada Goose). Over the past 15 years, it seems as though our rare Gyrfalcons have a predilection for Herring Gull rather than Black Duck. 

     “Black Duck numbers had been disappointingly low in November and December. Perhaps this number had been driven into this rich section of marsh by the very recent freeze up and the high tide rendering other areas poor for cover or feeding. (We did not hear any gunning after 8 a.m.) We drove down the marsh, and maybe thirty minutes later back drove back up the marsh. The number of Black Ducks visible was a paltry fraction of what it had been. We had been incredibly lucky.

     “Three raptor sightings of note. On our way north to Lot #1, we had a small flock of Tree Sparrows on the verge on a bend in the road by the middens; the only flock of sparrows we saw. While Julie visited the restroom, I had a Sharp-shinned Hawk flying less than a foot high along the edge of the road and across Parking Lot #1. Its wingtips were inches from the asphalt. It had obviously been looking to capture an unwary sparrow but had missed. I’ve seen Merlins hunting this way, but rarely sharpies strafing the ground so low. 

     “Four hours later, as we were leaving the refuge, we had a large but thin sharpie perched on a dead branch just north of the gate. I was able to photograph it briefly before the hawk took off, whirled quickly, and and dropped into a thick bush where it began climbing after prey we never saw. We left it lost through the shrubbery, but I am sure this was the same bird I had seen hours earlier.

     “We had 5-6 Northern Harriers (1 adult female) over the course of the day, and an adult Peregrine Falcon on his favorite perch, the osprey platform at the Old Pines. But the real surprise was as we were driving north of the S-curves, we had a truly miniscule Merlin explode very low out of the shrubbery on the beach side, fly right in front of and below our headlights, and penetrate the thick brush on the bay side of the road. I yelled “sharpie,” but by the time the word had left my mouth I clearly saw falcon shaped wings; narrow and very sharply pointed, slicing between thick shrubbery. I’ve never seen a Merlin flying into such heavy vegetation maybe a foot off the ground. We did not see it come out.

     “With all this bush-whacking, we should note that we saw about 1 Blue Jay, 8 Robins, 8 Horned Larks, a dozen tree sparrows, 1 Cardinal and nary a Mockingbird in six hours on the island. (Also had 50 Sanderlings and 20 Dunlin on the beach at Lot #5.) Hunting had to be tough [for the raptors].”

Steve Grinley
Bird Watcher’s Supply & Gift
Route 1 Traffic Circle
194 Route 1
Newburyport, MA 01950
BirdWSG@Comcast.net 
978-462-0775 
www.birdwatcherssupplyandgift.com 
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