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The Birding Side of Whale Watching.
On any day between April and October, the adventure of walking aboard a Dolphin Fleet Whale Watch vessel brings anticipation and excitement to the experienced and amateur Naturalist alike. Families in wonder of what lies ahead, as the vessel rounds Long Pont and begins a journey into Cape Cod Bay and the North Atlantic Ocean, a realm that few people ever experience. The open ocean is indeed like another world to most people. We live our lives on solid ground and rarely think about the great variety, the Biodiversity of plants and animals in the open ocean. The average depth of the worlds oceans is over six-thousand (6000) feet deep, and while those depths are far offshore here on the east coast, the depth of the water below us on our whale watch may range from 100 to 400 feet deep. Deep enough for it to be pitch black on the sandy bottom where animals, including the great whales, swim in darkness. It is the rich phytoplankton (plant plankton) of the western North Atlantic that blocks out the sunlight and makes the water appear a rich green. This is the foundation of the marine food web, microscopic plants that feed tiny zooplankton (animal plankton) which in turn are fed upon by larger animals throughout the marine food webs of this complex system. The open ocean is rich in animal life, swimming in clear view of curious observers aboard vessels of the Dolphin Fleet. First and foremost we search for the great whales; Humpback Whales and Finback Whales, smaller Minke Whales and the representative of the toothed whale group, the Atlantic White-sided Dolphin. Rarer cetacean species may occur, as well as a variety of fish species like the Ocean Sunfish, Basking Shark and numerous other fin fish. Remember though, what you see on this day at sea is directly proportionate to how hard you look. Anything, anytime, is the mantra of many ocean observers.
Above the waters surface on any given day a rich diversity of avian life occurs. Species of birds representing some of the most fascination avian life on the planet may be observed throughout the whale watching season. These are the pelagic birds of the northern and southern hemispheres. Free-roaming oceanic birds that live in perpetual summer, making long trans-equatorial migrations from the great southern oceans, Antarctica, southern South America, and numerous remote islands of the coasts of these continents. Remember that the seasons are opposite in the northern and southern hemispheres, so that while we may be on a July whale watch observing the tiny Wilson’s Storm Petrel flying and feeding in uncountable numbers around the great whales, that same tiny three ounce bird will be nesting in a penguin colony on the continent of Antarctica while we are celebrating New Year’s Day! Summer here, winter there……..Winter here summer there. On some days, depending on wind and tide, we see huge numbers of pelagic birds, while on other days they are absent. There is just too much water, millions of square miles of Atlantic Ocean to the north and east of Cape Cod. Leaving Provincetown inner harbor look for the dark, upright standing Double-crested Cormorants on the breakwater. These fish-eating birds can often be seen standing with wings spread as they stand in the sun drying out. They lack an oil gland at the base of their back that most other families of birds possess, so they cannot spread “water proofing” oil over their feathers. The orange gular pouch (throat) identifies them a double-crested Cormorants and not the larger northern cousin, the Great Cormorant, which shows white on the throat and cheek. Throughout the trip, Herring and Great Black-backed Gulls can be observed, from the harbor to the open ocean. The Herring Gull is our common gray and white “seagull” while the Great Black-backed Gull is larger, with a white head, breast and belly, and as the name implies, black on the back and upper wings (mantle). Both species can be represented y immature birds, appearing mottled brown. One of the smaller gull species often seen throughout the whale watch trip is the Laughing Gull. This is a gull named for its loud, laughing call and is easily identified by its completely black head, in sharp contrast with a gray back and white breast and belly. A smaller relative of the gull is the tern. This graceful, gray above, white below, “sea swallow”, black capped with a deeply forked tail is likely the Common Tern. It is the most often seen tern and can be found throughout the trip, calling loudly keee-err, keeee-err, diving for fish or swooping over the water. The rarer, endangered Roseate Tern, more silvery than the common, with a pure white very long tail, occurs in late August and early September. Listen for its distinct call, chi-vek, chi-vek. Least Terns nest on the beaches that we pass by in June and July on our way to deeper water, and are often seen flying close along the beach or diving for small fish. The Least Tern, as its name implies is smaller than the aforementioned species and calls crisply, ki-dik-ki-dee, ki-dik-ki-dee. Most people on the boat are looking for spouts. Suddenly a small white-rumped, black bird flies past the bow of our vessel, a Wilson’s Storm-petrel. A Cardinal-sized visitor from as far away as Antarctica, roaming the open seas, pattering over the surface as it feeds on small crustaceans and other zooplankton. Often occurring in hundreds or even thousands, this small pelagic wanderer is considered be one of the most abundant birds on the planet. Keep an eye out for two other widely observed pelagic species, Sooty Shearwater and Greater Shearwater. Both of these are southern hemisphere nesters and have migrated north across the equator to the our waters, and will return to their nesting grounds in September, when it will be spring in the southern hemisphere. The Sooty Shearwater is named for its brown, dusky, overall color, and shows a pale, silvery shade on the under wings. This species can also be extremely abundant, and during times when feeding whales are observed, the birds may flock in great numbers as part of the frenzy, taking advantage of small fish driven to the surface. The Greater Shearwater is the largest and most common species of shearwater observed, although the sooty often claims the distinction of most abundant. Greater Shearwaters are brown above and white below, with three prominent field marks; a brown belly smudge, a white rump patch, and a dark cap. A less common to rare species of shearwater, the Manx Shearwater, is a dark chocolate-brown above and pure white below with a rapid wing beat and flight. Manx Shearwater is uncommon but certainly may be present among large flocks of the other shearwater species, so always keep an eye out. Certain species of oceanic birds make their living by stealing from other birds or downright bullying birds into dropping or disgorging their food. These are the Jaegers and they are characterized as kleptoparasites. Two species are commonly found on whale watching trips usually during July and August; the Parasitic Jaeger and the Pomarine Jaeger. Look for a dark bird that seems to be a cross between a falcon and a tern, with a white flash near the end of the wings, The easiest way to identify a jaeger is to spot a winged rocket chasing, whirling, streaking, harassing a common tern that’s carrying a fish. The chase continues until the tern drops the fish, which the Parasitic Jaeger often catches in mid-air. The Pomarine Jaeger is a larger species and tends to be less often observed, although most observers simply record the sighting as Jaeger sp., meaning “some species of jaeger” was observed. Field guides show longer, blunt, central tail feathers on the Pomarine Jaeger, while the parasitic shows pointed central tail feathers. These are the avian pirates of the open sea, behavior often identifies a Jaeger. Rarely seen anywhere along the northeast coast is the South Polar Skua. An identification occurred in 2002 and is one of only a handful ever seen on Stellwagen Bank. This is the baby penguin eater of Antarctica, and though it migrates to the North Atlantic Ocean during our summer, it stays far out to sea. With the stiff-winged flight of a shearwater and the color pattern of a gull, the gray above, white below Northern Fulmar may be observed most often during spring and fall on the open sea. This species nests in the north from Europe to arctic Canada and ranges south to Cape Cod when not on the breeding grounds. Northern Fulmar may be a tough bird to find, but don’t count them out! Note that on the fulmar, as with the shearwaters and petrels, you observe a tube like structure on the upper mandible extending from the base of the bill. This is the method by which these ocean-going birds excrete salt from their bodies. All of these species are able to drink salt water but must get rid of the excess salt that they ingest in their daily routine. A gland near the forehead removes the high salinity content from the birds system and simply secretes a mucous like substance from these modified nostrils on a regular basis, there by preventing the build up of excess salt in the birds blood and tissues. During spring and fall, huge flights of a large white bird called a Northern Gannet may be seen. Larger than any gull, and closely related to pelicans, the Northern Gannet appears pure white, with black wing-tips and a very subtle shade of yellow-green on the nape and neck. This impressive bird is a champion diver and often rockets from as high as one-hundred feet above the water, plunging arrow-like into the water, often surfacing with a fish in its beak. The Northern Gannet is unmistakable, migrating past Cape Cod to and from its nesting grounds in eastern Canada, most notably the Gaspe Peninsula in eastern Quebec. Immature gannets, like gulls, are a variety of blotchy browns and white.
Whale watch trips provide an opportunity to observe a high diversity of ocean-going birds that my never be observed otherwise. The ocean is a huge environment, vast and unpredictable. Don’t be discouraged if you see only a few birds, some days and on any given trip. Thousands may be observed, while later the same day, none. Just remember, look at every bird and have fun.