Friday, October 31, 2014

Ammodramus Drama

Quiz Bird! What's this blending into the grass?
No one would accuse the sparrows in the genus Ammodramus of being flashy. They are quintessentially "birder's birds": while a sighting can make a birder ecstatic, a non-birder wouldn't give them a second glance. Of course, a non-birder probably wouldn't even get a first glance. Sibley refers to all 7 Northern American species as "secretive" (including the "very secretive" Henslow's), and it is precisely this that makes them so sought after: they are usually really hard to find! And managing to track one down is a classic thrill of birding. 

In the US, we have the coastal marsh specialist Seaside and Saltmarsh Sparrows, both United States endemics, the grassland-dwelling Grasshopper Sparrow, the Nelson's Sparrow, with both coastal and inland populations, and three inland species, all very hard to find: Le Conte's, Henslow's, and Baird's. I had seen the first four, but the latter three have eluded me. Baird's isn't even really on the radar of an East Coast birder, and Henslow's is an impressive rarity. Le Conte's, however, I had chased once, at Milford Point in Connecticut. Someone saw the bird fly into a small clump of marsh grass: us birders peered in, carefully searching for the slightest movement. Impossibly, the bird snuck out without anyone getting so much as a glimpse. 
The Ammodramus I've seen most: Saltmarsh Sparrow. I took this while
kayaking in Green Harbor, MA this past summer
So when I woke up Thursday for class, and saw an email saying that a birder had found a Le Conte's Sparrow in Danehy Park, less than a 20 minute walk away in the northern part of Cambridge, I quickly switched my plans for the morning. I could always catch up on the lecture material. And it was an evolutionary biology class anyway: I was just taking a more field-based approach! So I swapped books for binoculars and walked to the park.

When a got to the cattail marsh where the bird had been seen, there were two birders there, who pointed to the exact grassy edge where they had seen the bird 30 minutes previously. I started searching. 

And searching. And searching some more. There were plenty of sparrows around: mostly White-throated, Song, and Swamp, but with a nice Field Sparrow mixed in too. That was a good pickup: a new bird for my college "public transport" list: all of the species I've seen with only my legs and the MBTA. 
The top Cambridge birding sites and the core of my public transport list: Danehy Park is in blue,
Alewife Brook is green, Fresh Pond orange, and Mount Auburn Cemetery red. 
After about 40 minutes of pacing the same 50 foot stretch of grass searching for the bird, I tried a different part of the marsh. No success on the Le Conte's, but I picked up another nice bird for the day and for my state and local lists: an Orange-crowned Warbler preening on a distant branch, which briefly flew close and posed, and then disappeared. Palm and Yellow-rumped Warblers were also around in abundance. 

But as nice as they were, there weren't the reason I was cutting class. I returned to the sparrow spot to continue the search. A few more scans of the reeds and sedges yielded nothing new. But then a sparrow flew up from the grass practically at my feet. Even in flight I instantly knew what it was: it was strikingly small, pale, and short-tailed: the Le Conte's! 
Le Conte's Sparrow!
Fortunately it didn't go far, landing only a few feet away, though slightly hidden. Then it scurried into the open, and briefly gave fantastic looks perched in plain view on a fallen reed: a perfect view of a very pretty sparrow. 
Such a nice sparrow
As sparrows go, the Le Conte's Sparrow is a beautifully plumaged bird: intricately patterned in cream, yellow, brown, with pale streaking on the back and an pastel orange face. When it was in the open in was striking, but it could quickly blend and fade back into the undergrowth as it moved behind vegetation. After getting a couple great looks I ran to the edge of the field to call over the other birder looking for it (who happened to be big year champ Neil Hayward). By the time we returned, the bird had vanished.
A more typical look at a Le Conte's, partially hidden by vegetation
A few more scans along the spot where it had been were fruitless, but again the bird suddenly flew up from the very edge of the marsh, this time actually perching in the open in the lower branches of a shrub. It stayed there, posing, for a few seconds before again dropping into the sedges. This time, though, we were close enough to be able to follow its progress as it snuck through the grass, moving as if it were a mouse: occasionally it popped into view, but even though we were only feet away it was hidden for much of the time. After another brief but good unobstructed view, I had to leave the bird to its skulking and head back to school. But I think I made the right decision on how to spend my morning!
"Bird Quiz" Revisited: Obviously it's the Le Conte's Sparrow. But check out how the
intricate back and face pattern, so striking when it is in the open,
allow it to disappear into the reeds. What a bird!

Friday, October 3, 2014

The Deep Blue Sea

This past few years the Brookline Bird Club has run what they call "extreme pelagics," overnight boat trips from Hyannis, on Cape Cod, to the canyons on the edge of the continental shelf to look for birds that can only be seen in the warm deep waters of the gulf stream. These trips have been fantastically successful, with records of lots of rare warm-water species, including Barolo's Shearwater, White-faced Storm-Petrel, and tropicbirds. The most popular trip general runs in late August, but this year they ran an additional late September trip, and I jumped at the opportunity. Lacking a car of my own, I asked to get a ride down with Naeem, who generously agreed. After some dicey weather reports, we received word that the trip was a go, and so last Saturday morning 40 or so birders boarded the Helen H in Hyannis Harbor, eager to see what was out there in the open ocean. Unlike a lot of birding trips there were a bunch of young birders on board, including Jacob and Brendan from New York and Alex and James from Connecticut, and 12 members of the Cornell Birding Club.

The boat left Hyannis Harbor at 7am , and we soon were seeing flocks of  White-winged Scoters, a few Common Eiders, and a handful of Northern Gannets in the waters off the Cape. Not long afterwards we passed Nantucket and entered the region known as the Nantucket Shoals, where currents create shallows and odd wave-breaks. It's also a productive marine ecosystem, and we quickly spotted a couple of spouting whales, which turned out to be Humpbacks, and got good looks at one of them. A Sanderling in the wake briefly tricked us into thinking it was a phalarope, but we eventually started getting our first real pelagic birds: first few Great Shearwaters, then a Cory's or two, and then a very nice flock of 20-30 shearwaters sitting on the water that contained both of those species as well as 8 Manx Shearwaters, giving us good comparisons. Groups of gulls contained a few Lesser Black-backed Gulls: we would see them on occasion for the whole trip.

Great Shearwaters (With a couple Manx in the back)
Shearwater assortment: Cory's, Manx, Great
Then someone spotted a large dorsal fin in our wake: it looked sharklike, but flopped back and forth comically, as if the shark was really drunk. It was an Ocean Sunfish, or Mola Mola, a very large species of bony fish (the largest in the world), which basks on its side near the surface and occasionally flops up its dorsal fin.

Suddenly there was the call of "Jaegers!" followed immediately by the shout of "Sabine's Gulls!" We rushed to the side to see two Parasitic Jaegers harassing two small gulls with striking black-and-white wing patterns. But they were not the hoped-for Sabine's but Black-legged Kittiwakes, a nice if more common species. The jaegers, sleek bullies of the bird world, put on quite a show, chasing down the kittiwakes and attacking a small songbird (which photos showed to be a Song Sparrow) that had ended up over the open water.
Blurry dark Parasitic Jaeger
As we continued out through the shoals there were some phalaropes (which were seen only briefly and remained unidentified), a couple more whale spouts,  a surprisingly far offshore Osprey, a distant pod of dolphins (probably Common Dolphin), and another Parasitic Jaeger. By around noon we had left the shoals are were well on our way towards the shelf edge. As we approached the drop-off the water got deeper, warmer, and much bluer. The bird life changed as well. I spotted a small shearwater flying away from the boat with choppy wingbeats: an Aububon's Shearwater, a warm-water species and a lifer for me! Soon after the call came through the loudspeakers again: "Jaeger!" The captain sped the boat in pursuit, and we got good looks at a Long-tailed Jaeger, the smallest of the family and a second lifer for me.

As the water warmed clumps of floating Sargassum seaweed began to appear, and with it came storm-petrels. We searched some larger groups carefully but all seemed to be the expected Wilson's Storm-Petrel. Then someone suggested that they may have seen a White-faced Storm-Petrel in the distance, and we all went on high alert: that rare and charismatic species would be a trip highlight. Not long after there was a cry from the side of the boat: "White-faced Storm-Petrel!!!" I rushed to the rail and got binoculars on the bird, flying away. Unlike all other Atlantic storm-petrels it has a gray back, and as it flew off it extended its long legs and bounced, kangaroo-like, across the tops of the waves: one bounce, two, three, and it vanished into the distance and glare of the sun. What a bird!

Adrenaline already high from that sighting, we were ecstatic when a sea turtle surfaced not far off the port side. Not only was it a sea turtle, it was a Leatherback, prehistoric-looking sea monsters that look like nothing else on earth. It came right up to the boat, giving killer looks to all on board.
Leatherbacks are the only sea turtles without scute or plates on their shells-- hence the name
They also have crazy-looking heads
We had only just arrived at Hydrographer Canyon, and already it was shaping up to be a fantastic day. Unfortunately, after the initial flurry of activity bird sightings slowed down considerably. There were still Wilson's Storm-Petrels and the occasional Aububon's Shearwater, but little else bird-wise, probably because there was very little wind, which many seabirds harness to fly more easily.

While there may not have been many true flying creatures, I was very happy to see a handful of flying fish, most only a few inches long, gliding through the air next to the boat. One glided for a surprising distance, started down, then caught a gust and made it probably 10 feet further: I estimated a total flight distance of around 30 feet, for a fish not much larger than a dragonfly.

As evening approached with still no new avian sightings, we tried "chumming": tossing overboard large amounts of fish guts and fish oil in the hopes of attracting birds. Our chum slight was frequented by dozens of Wilson's Storm-Petrels, but none of the rarer species were in evidence. Around this time we did have a very nice sighting: a small group of Offshore Bottlenose Dolphins, which jumped alongside the boat and put on a good show.

As the sun set we tried another round of chumming, also without much success. As the sun slipped below the horizon many onboard saw the famous "green flash" of light that sometimes accompanies sunset over the ocean, but despite watching the sun I somehow missed it.

Sunset over the Atlantic
Soon after, there was a shark spotted briefly near the boat. A few minutes later, one of the crew came up to the top deck and asked one of the girls on board, "Have you ever caught a shark before?" They had quickly hooked the shark we saw before, and Sarah reeled it in right to the side of the boat. It was a Blue Shark, and a decent sized one too, probably about  seven feet long. After getting a good look, they cut it loose: having a shark on board didn't seem like a good idea.

As night fell, and the moon too set, the horizon disappeared and everything beyond the lights of the boat was blackness. We stayed up for a while watching the crew fishing, and those lights would prove the source of another good sighting. Occasionally, Wilson's Storm-Petrels would swoop by the lights, possibly confused by the brightness, and swoop low over the deck before flying off. This would happen every 10 minutes or so. As one approached, Brendan quickly spotted that it was different: bigger, with longer wings. As it banked and flew over us I got a look at the forked tail: it was a Leach's Storm-Petrel, and a life bird for me! There are a lot of birds that are more often seen or heard in the dark: nightjars, owls, and some herons and rails, but I never expected to get a lifer storm-petrel at night.

Storm-petrels aside, our main show for the night were the efforts of the crew, fishing for tuna. The Helen H is usually chartered as a tuna boat and so the crew are very good sportfishermen. They were chumming and also using a long-handled dipnet to catch some bait for the rods. Most abundant were squid, which inked when captured. But over the next hour or so they captured a menagerie of open-water fish. Unfortunately many (though not all) of them were destined for the hook as baitfish. But still, we were able to see a small striped juvenile Mahi Mahi, a Planehead Filefish that had hid in sargassum, some young Jacks, and most impressively a two foot long Atlantic Needlefish.

But there weren't just small fish. Another shark appeared, either a blue or mako, and we were dazzled when the chum was approched by an adult Mahi Mahi, also known as a Dolphinfish. In the lights from the boat it absolutely glowed blue, yellow, and green. The fishermen were unsucessful in try to nab that fish, but they did hook another impressive one: a Sharksucker, which is a species of remora. Their dorsal fin is highly modified into what is basically a suction cup, which it uses to attach to sharks and other large marine animals. It was also an unusual catch: despite fishing here very regularly, this was the first that they had caught. After we got a good look, they released it back into the ocean.

The "suction cup" on top of the head can be seen here
I was almost ready to go to sleep, but there was still some excitement to be had. Brendan came up to the top deck with one hand behind his back. He revealed the mystery object: a Wilson's Storm-Petrel! It had gotten disoriented by the lights and had ended up in the cabin. After carefully and enthusiastically studying the adorable little guy and his tubed nose and yellow feet, he was liberated back into the night, and flew off safely.
Check out the salt glands that give the "tubenose" family their name
Jacob checking out Storm-Petrel Molt
Then it was time for bed. I slept in a sleeping bag on the deck: the rocking took a little getting used to, but soon it was dawn, and everyone was gathered on the back of the boat for the morning chumming, hoping for some new birds.

Sunrise over the Atlantic
Unfortunately, this chum slick was no more successful than the previous ones had been: lots of storm-petrels, little else. In the pre-dawn we saw another shark: one of the guys in the crew tossed in a big chunk of tuna on a hook and it immediately took the bait, giving us more great looks at these stunning predators. This one turned out to also be a blue shark, not a species that is common eaten, so it too was cut free.
Blue Shark on the line

They hadn't caught any tuna overnight, but shortly after dawn we spotted a big school of gorgeous yellowfin tuna leaping out of the waves not far away. One cast, and there was a tuna on the boat too. That took a turn for the brutal when its head was bashed in--though I do eat tuna, so I can't claim any moral superiority on that front.
RIP Tuna :(
After searching the chum slick, we headed west over Hydrographer Canyon again, and past it along the shelf edge. The water was very calm, and bird diversity pretty low. There were, however, lots of Audubon's Shearwaters. We really didn't realize how many until mid-morning, when the announcement came that we were already approaching the all-time Audubon's Shearwater high count for Massachusetts, which was just under 50, and was set last month. It's been a great year for them in Massachusetts waters! We checked each one in hopes of finding a mega-rare Barolo Shearwater, but to no avail.
One of 158 Audubon's
We did have one very nice sighting for the morning: a dark juvenile Long-tailed Jaeger that stayed with the boat, ate some chum, and gave unbeatable views for and extended period of time. I snapped a bunch of photos, and got exactly zero good ones: I never mastered the art of taking photos of moving birds from a moving boat. So the photos don't show it, but this was about as good a view of a Long-tailed Jaeger (which I had never seen before this trip) as it is possible to get.

Dark Juvenile Long-tailed Jaeger
 Other than that though, the rest of our time on the shelf edge was all Audubon's Shearwaters and Wilson's Storm-Petrels, the latter a common species in general and the former a rare species turned unexpectedly common for this trip. They were even in flocks of up to 8-- unprecedented groups for this area. Our day total steadily climbed, reaching triple-digits before noon. Audubon's Shearwaters really were the bird of the day.

Eventually the announcement came that we had to begin the long voyage back towards land. We were sad to leave the warm water with many targets still unseen, but shortly thereafter we were more than consoled with what may have been the highlight of the whole trip.

A pod of dolphins were spotted, and as they approached the boat we were able to identify them as Common Dolphins. Then they approached closer and closer, soon were "bow-riding": keeping pace with the boat and riding along the wave at the front of the bow, seemingly just for fun. There were around a dozen of them, including two calves, and from our vantage point in the bow of the boat they were practically within an arms-length! It was absolutely incredible to watch as they easily kept pace with us and seemed to be having a fantastic time. We certainly were, watching them. They stayed with us for probably 15 minutes, before eventually peeling off and swimming away, and our days were made.

Dolphin Calf!
Between the shelf edge and the Nantucket shoals is often a slow region for pelagics, but as we moved through this area we had some more fantastic sightings. The water was incredibly calm, almost glassy, and we were able to see small fish, jellyfish, and other invertebrates in the sargassum and below the surface. We found our last Audubon's, in 65 degree water, surprisingly chilly for this species. That was the 158th individual of the day, more than 3 times the previous Massachusetts high. Then in the distance, someone spotted a big flock of phalaropes. In contrast to the small groups of up to ten that we had seen fleetingly the previous day, this was a massive flock of close to 200 birds. They were mostly Red-necked Phalaropes, but looking carefully turned up a number of larger, paler birds: around 20 of them were Red Phalaropes, my 5th life bird of the trip.

The ocean was incredibly still-- even glassy
Phalarope Flock
As we neared the birds we passed through an odd line of water color, and realized that it was not caused by wind or currents or seaweed but by millions upon millions of tiny jelly-like animals. They covered the surface not just in this line but, less densely, across the whole surface of the ocean. This must be what the phalaropes were eating. One of the fishermen dipped a net into the slick, and pulled it out full of the jelly-like creatures. We identified them as salps, which are a rapidly-reproducing member of the group of invertebrates called tunicates. They have an odd reproductive strategy with both sexual and asexual stages, and, most interestingly, are actually a member of the phylum Chordata. This means that they are much more closely related to humans or any other vertebrates than they are to jellyfish. Examining them closely, we could see the notochord, the primitive version of our own spinal chord.
The band of darker water stretching off into the distance is all salps
Moving through the glassy, salp-filled seas towards the phalaropes, someone suddenly spotted a huge dorsal fin in the distance--  a basking shark. Leaving the phalaropes for the moment, we move closer. It seemed to have vanished, but then again broke the surface. The captain slowly piloted the boat closer, and we got an excellent look at this gigantic fish right by the side of the boat. It was probably 13 feet or longer! While they're often mistaken for great white sharks, basking sharks are harmless, and eat only plankton, which they filter out of the water. This guy was almost certainly having a salp feast.
Ominous fin
Basking Shark!
Almost immediately after the shark another Leatherback Sea Turtle surfaced nearby, giving us a brief look. We then returned to the phalaropes, and honed our skills trying to pick our Red Phalaropes from the flock. It got easier as we got closer, and eventually we had very good views of the whole mixed flock.
Phalaropes in flight. The right bird in the left clump is a Red Phalarope, the rest are Red-necked Phalarope
When we reached the shoals the bird activity was pretty low, and some exhausted birders (including myself) flirted with sleep, but just off Nantucket we were re-energized by a gorgeous pair of full adult Parasitic Jaegers, with long central tail streamers still intact. As we got closer to the harbor scoters and gannets became more common, and just before five we reentered Hyannis Harbor after 34 hours at sea. The harbor had oystercatchers, Black-bellied Plovers, and a nice Merlin trying (unsuccessfully) to catch pigeons bigger than it was. We docked, tried to adjust to the odd sensation of the ground not moving, and those who wanted tuna steaks got them. I said goodbye to the Cornell contingent, and sunburnt and exhausted but very happy with the trip, headed home.
Land Ho! By the time we saw Nantucket, we had been out of sight of land for more than 24 hours