Thursday, June 16, 2011

Day 28: Platform recon and supertide

I'd been curious about the osprey sighting. Had it been a fluke visit that I just happened to witness, or were they actually considering moving in? Or, were lusty ospreys simply using the platform as a by-the-hour motel room, never intending to stay? To find out, I mounted a camera trap to the perch post and kept it up there for five days. I programmed the camera to shoot a burst of two photos every time it detected motion, and to wait two minutes before detecting motion again.

Listed in order of how frequently they visited, the camera recorded: starlings (big surprise), willets, mourning doves, red-winged blackbirds, and a grackle.

And this.

The osprey leisurely spent three hours dining on a large menhaden, here compressed to 12 seconds:

But it only made this one appearance. I doubt the platform will be occupied this season, but it's nice to know the ospreys are still making use of it.

Another raptor made a cryptic appearance about an hour before I arrived. Leave a comment if you can ID. My guess is that it's a peregrine falcon, based on the wing and tail pattern. They nest on the Marine Parkway Bridge, less than a mile and a half away. But it's hard to imagine the willets would let it stay for long, especially with photos like this circulating the internet. The mystery bird vanished after two shots.

Sarah V. spent her second day at the marsh and her first day of "real toiling." She's already made a lot of progress and hopes to come regularly until classes start.

The two of us cleared a respectable swath of debris.

After Sarah left, photographer Francois Portmann showed up to shoot timelapses of the supertide with me.

The tide was predicted to reach 6.6 feet, and it won't be that high again until April 2012. After setting the cameras to roll we went exploring. This was my first evening in the marsh. By 7:00, the channels had become torrents, ripping the horseshoe crabs from the bottom and tumbling them into the marsh. Once there they droned about in slow circles like so many pool cleaners. Well over 50 were counted.

The females burrowed in to lay eggs and were piled upon by the males, who released their sperm in fizzy trickles. (Excuse the shaky photo, it was dark).

Among the flotsam that floated into the marsh was this egg. It slightly resembles an osprey egg, but it doesn't seem blotchy enough. Then again I'm no egg detective. Leave a comment if you can ID. [update: it's a herring gull egg, thanks Chris and Don]

In with the horseshoes and flotsam poured hundreds of killifish. Meanwhile, the channel banks lined up with anxious beaks. A great egret, a snowy egret, a green heron and three black-crowned night herons took turns spearing the water and coming up with fish. The killifish weren't the only life forms under attack. As the night wore on, a squadron of mosquitoes laid siege to Francois and yours truly. They plunged their syringes into hair and clothes, between the fingers and behind the ears, leaving me just enough blood to make it home. But it was a small price to pay to experience the marsh at its most dynamic hour.

Here's the three hours of peak tide in 17 seconds:

High of 84, average wind NNW @ 8 MPH, 6.6 high tide @ 08:20 PM. Moon 98% visible.
Water level recorded at 26 inch mark (record high).
Birds seen in marsh: cardinal, red winged blackbird, willet, green heron, great egret, snowy egret, black-corwned nigh heron, common tern, least tern, oystercatcher, crow, skimmer
Birds seen in bay: red-breasted merganser


  1. Shervin, in my humble, humble opinion that's a gull egg. Probably herring gull. I handled a few in my time...