Saturday, August 13, 2022

CAPE VERDE SHEARWATER off Cape Cod, MA - August 12, 2022

For the past couple months, Ian Davies and I had been eyeing this week for a little summer Cape Cod birding adventure. The feasibility of this plan would depend largely on the weather, as I wanted to trailer the boat to the Cape for access to pelagic waters and Monomoy NWR. After a rather uncertain and oft-changing forecast thanks to a stationary front passage, a brief weather window opened for the second half of the week. Julian Hough was free to join me for the mini vacation, so we left CT on Tuesday evening. Wednesday was spent shorebirding; Ian had to work that day, but Pete Trimble and Phil Rusch filled out the boat. Thursday found us rained out, but we regrouped for a full Friday on the water.

At sunrise on Friday the 12th, Ian, Julian, and Pete & Jeremiah Trimble and I left the harbor and headed around the tip of Monomoy to the productive waters east of Chatham. I had been out there a handful of times prior between my boat and a friend's, and there has always been at least something to see between pelagic birds and cetaceans. At their best, these waters are teeming with marine life. Friday's experience was very bird-centric. Hundreds of shearwaters, storm-petrels, gulls and terns were scattered over a broad piece of water about 3-5 miles offshore. There were no massive tight flocks. Rather, the tubenoses were following scattered topwater feeding fish. Based on what I was seeing, I suspected most of the predatory fish were Striped Bass, though I did see a schoolie Bluefin Tuna leap out of the water at one point. The calm waters were perfect for spotting whales, dolphins, or sharks, but surprisingly we had none of those. Just one Mola Mola.

As we were pulling out of the harbor earlier that morning, we threw together a wish list of rarities we could find out there. Some more outrageous than others, though all were incredibly unlikely. Jeremiah's request for the day was Cape Verde Shearwater - a lofty goal! Well wouldn't you know it if Jeremiah didn't point out a small, dark Cory's-type shearwater with a dull bill around 7:20 am. Wow. That's double points for calling your own shot.

The fun part about observing pelagics from a small boat is that you can get quite close to the birds, as the spectre of a 20-foot boat is nothing compared to the large vessels we charter for typical pelagic trips. We were already quite close to this individual, which was in a loosely scattered line of Great Shearwaters.

Once Jeremiah pointed it out, bins and cameras were raised. Unfortunately our time with the bird was all too brief. One by one the Great Shearwaters and the Cape Verde Shearwater lifted off the water and flew dead away. We gunned the boat in pursuit as best we could, but the birds effortlessly motored away from us, which is saying something since we were doing 30mph.

Following a group huddle and back-of-camera photo sharing, we quickly came to a consensus on the ID, though it did take a few moments to shake off the shock. Cape Verde Shearwater is a species that has been recorded off the East Coast at least once before (a well-documented August 2004 record by Patteson et al. off Hatteras, NC), so we had all been geared up for this ID for years. Despite nobody on board having field experience with the species, this bird clearly checked all the boxes in textbook fashion with good views and photos to boot. A life bird for everyone on board.

Description:

Initially seen sitting on the water near a few scattered Great Shearwaters, naked eye this bird appeared small and dark for a Cory's type. Similar in size to the nearby GRSH. After changing the path of the boat slightly to put the bird more broadly on the port side, I got bins on it briefly, and a thin, anemic grayish bill with a darker tip was apparent; certainly not the clear yellow bill you see on Cory's/Scopoli's. Then pulling up the camera, I got only two frames with the bird on the water before it picked up, started towards us, then turned away and continued in this fashion until out of view while we pursued. Its flight style seemed much less deliberate/lumbering than Cory's to me, not surprising given the bird's apparent size and narrow wings. Photo review revealed a lack of any white bleeding onto the under-primaries. Thin white eye arcs stood out against a subtly dark face/cap.






Per usual, click any of the above images for a higher resolution version.

Cape Cod is well-known as a seabirder's paradise, and this bird's occurrence only reinforces that fact. Given how many birds work this area on a regular basis, perhaps it should come as no real surprise that a mega rarity like this would pop up just a few miles offshore.

photo courtesy Jeremiah Trimble

photo courtesy Jeremiah Trimble


red pin marks the location of the CVSH, 4.5 miles due east of Chatham Light

Just an awesome day on the water with great people among one of the region's finest wildlife spectacles. It is tough to beat late summer birding on Cape Cod!

- Nick

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