University of Connecticut OpenCommons@UConn

Wrack Lines University of Connecticut Sea Grant

Winter 2012 Who's Afraid of the Big Bad ? Richard Jay King Williams College, [email protected]

Follow this and additional works at: https://opencommons.uconn.edu/wracklines Part of the Behavior and Ethology Commons, Education Commons, Marine Biology Commons, and the or Avian Science Commons

Recommended Citation King, Richard Jay, "Who's Afraid of the Big Bad Cormorant?" (2012). Wrack Lines. 88. https://opencommons.uconn.edu/wracklines/88 Who’s Afraid of the Big Bad Cormorant?

Svati Narula and Richard King

On an early afternoon last June, we motored through the Mystic River and out into the far eastern edge of Long Island Sound. We paused along the way to notice the that perched on pilings like statues and popped up from underwater like seals. These were . Our mission that day was to visit their home on Gates Island, a little clump of rocks just beyond the mouth of the river. As Gates came into clear view we caught the slightly fishy, sulfuric scent of cormorant , the acidic white excrement the birds deposit all over their nesting grounds. We anchored our boat about fifteen meters away from the island itself. With binoculars we watched the slender black birds and a smaller number of white and grey gulls. We saw only one of cormorant, the Double-crested ( auritus), which is to be expected at this location at this time of year. Of the six species of cormorants native to North America, the Double-crested is the most widespread, and the most common in New England and the Mid-Atlantic. Here in southeastern Connecticut we see Great Cormorants (Phalacrocorax carbo), too, but only during the winter. Both species of cormorants seem to be native to Long Island Sound. Historical records indicate cormorant sightings here and throughout coastal New England as early as 1604. Explorers throughout the 1600s witnessed Native Americans raiding cormorant roosts and eating the birds. A 1776 map of what is today Newport County, Rhode Island, features an outcrop named “Cormorant Rocks.” An 1847 chart shows within twenty miles of Gates

12 • Wrack Lines: A Connecticut Sea Grant Publication ...... Island another “Cormorant Rock,” as well cormorants, even baby ones, to be A pair of cormorants as “Cormorant Reef” and “Cormorant loveable birds. Some have always viewed rests on a rock with Cove.” (See map on page 14). the cormorant with disdain, considering other members of We counted the adult cormorants it an unsightly annoyance, like a crow, the colony swimming close by. we could see with binoculars, then or associating its long snake-like neck Photo by Svati Narula motored around to the other side of the and black with something island to count again from a different sinister. In 1667 famously vantage point. We counted a total of used the cormorant as a symbol for the about 60 individual cormorants on Gates devil in Paradise Lost. Two and a half that day. Official counts usually centuries later, people are still invoking refer to “breeding pairs,” which means fiery language to discuss the birds: local ...... the number of active-looking nests in a writer Charley Soares recently penned a breeding colony, but it was too difficult column about cormorants titled “Black Cormorant nests on Gates island in to see all the nests on the island from Death – The Birds from Hell” in the August 2012. Notice where we had dropped anchor. New England edition of On the Water, a the bits of manmade Had we brought the boat closer magazine devoted to sport fishing.The material that are or stepped on the island, birds’ fishing and swimming abilities go incorporated into the nest, such as the entire colony would unappreciated by most casual observers rope and a piece of a have flown away, leaving and are decidedly not appreciated lobster pot. cormorant chicks by the many recreational fishermen, Photo by Svati Narula vulnerable to as exemplified by Soares and also by from the gulls. Such Charlie Walsh, of Stratford, CT, who a scene plays out complain that the birds steal their catch. almost every time A few years ago Walsh wrote for the CT humans get too Post, “To Long Island Sound’s recreational close to a cormorant fishermen, cormorants are, to put it as breeding colony: gently as possible, evil baby-fish killers.” all the cormorants Looking through our binoculars that away, but the cohabitating day off the island’s shore, we watched gulls, less afraid of people, adult cormorants feed their chicks stay and seize the opportunity amidst the squawks of gulls and the to gobble up cormorant , constant arrivals and departures of other newborns, and chicks that have yet to cormorants. Individuals were flying off fledge. For this reason, it’s best to stay the island, circling back and landing in clear of bird colonies during their nesting the water to fish just a short distance season from February through July. away from the rocks. Few people consider Cormorants start their dives from

continued on next page

Fall/Winter 2012-13 • 13 Fisher’s Island Sound 1847 (includes Cormorant Reef and Gates I.)

...... Co-author Svati Narula collects pellets at Gates Island in August 2012. Photos by Svati Narula

with enhanced federal protection for cormorants through a 1972 revision of the Migratory Bird Treaty Act. continued from previous page understand why many ornithologists As cormorant populations have feel there might be other behaviors grown around the country, often the surface with a simple duck of the connected to this notorious posture. around artificially stocked fish ponds, head and kick of the feet, keeping the The Double-crested Cormorant is lakes, and rivers, so have conflicts wings tucked in to the side of the body found all over the continental United with humans. Cormorant guano, in and elongating the neck to search for States, by the sea and on lakes and addition to smelling foul, can kill trees prey on the way down, the webbed feet rivers. It is the only cormorant in North and shrubs. The U.S. Fish and Wildlife providing propulsion. They grab all America found appreciably inland. The Service has enacted management sorts of fish and in their Atlantic population migrates up and plans around the Great Lakes and thin and swallow them whole, down the entire east throughout the southern states to permit the one at a time, often taking the prey to the year. The cormorants in this cull of cormorant populations or the the surface to toss it around and re- population spend the better half of each destruction of eggs where the birds orient it for easier swallowing. year up north, on the New England appear to threaten fish stocks, critical The cormorant’s strangest trait is and Canadian , and can be found natural habitat, or aquaculture facilities. one it displays out of the water: the anywhere from the Chesapeake to the Here in southeastern Connecticut, statue-like posture of standing still Gulf of and Yucatan Pennisula recreational fishermen have taken with its wings spread. The traditional from late fall to early spring. notice of the big black birds that swoop explanation for this has revolved Cormorants were entirely into the water to feed on small fish around the drying of the wings after extirpated in New England for a period such as flounder and cusk, and have swimming. Cormorant feathers are in the 1800s but recovered slightly wondered if similar population control structurally different from those of by the early 1900s. Populations all measures might be appropriate in the other ; they get wetter faster, over the country took a hit once future. At this point, it is hard to know which helps them dive deeper, like again in the 1940s and 1950s due to exactly what type of impact cormorants a weight belt. The tradeoff is that continued harassment from humans, have on local fish stocks. The impact cormorants then need to hold up their habitat loss, and the widespread use is simply assumed to be relevant but it wings to dry before efficiently taking of pesticides such as DDT. Since then is not well understood. Consider, for flight again. Anyone who has ever seen the species’ numbers have rebounded example, that while cormorants eat a cormorant holding out its wings while thanks to reduced pesticide use and commercially valuable fish, they also standing in the rain, however, will improvements in water quality, along may advance a given fish population by

14 • Wrack Lines: A Connecticut Sea Grant Publication ...... (Left) A cormorant is similar to that of an owl’s, containing bones and other indigestible matter of the fish and crustaceans that the bird recently ate. (Right) Co-author, Rich King, and a Williams-Mystic student on Gates Island in August 2012, collecting cormorant pellets for analysis. Photos by: Svati Narula

thinning their slower individuals and only by slim margins. Diet composition often been painted, but is actually a by eating other fish species that would surely changes throughout the seasons reputable avian citizen, not without be their predators. and seems to also vary from year to intelligence, amiability, and interest.” Over the past eleven years, our year. For example, a Williams-Mystic Cormorant colonies like the one undergraduate students and faculty study in 2002 found cusk and fourspot on Gates Island are not so threatening at The Maritime Studies Program of flounder to occur most frequently in to the local landscape or other species Williams College and Mystic Seaport cormorant diets, yet a largely identical that we need to be hostile toward them. (Williams-Mystic) have conducted study in 2008 identified more scup, It is true that cormorants are capable small research projects on cormorant summer flounder, and mailed sculpin of consuming plenty of fish, with diets in the Mystic River and Long than any other species. their adept diving skills and a wide Island Sound, often dissecting We returned to Gates Island in variety of species upon which they are cormorant pellets and regurgitants August for the opportunity to step willing to feed. Yet, doesn’t it make collected at Gates Island and at ashore and get a closer look at the more sense to admire these creatures other locations. Students have been cormorant nests. Nesting season was for their adaptive survival skills, identifying the bones of fish that show over so there were no chicks that which include not just underwater up in these samples. Cormorants would be endangered by our presence. fishing but migrating long distances everywhere are opportunistic feeders, We collected as many pellets as we and inhabiting both freshwater and which makes sense, given their could find for continuing research on saltwater environments, than to resent expansive range. Because their diets are the bird’s diet. We counted about 75 them for any potential, unknown so diverse, we cannot assume that one intact cormorant nests, which suggests detriment to sport or commercial fish population’s feeding patterns will be that Gates hosts a colony of at least 150 stocks? Cormorants have been part of indicative of another population’s diets. birds. This is a smaller colony than has this region’s ecology for centuries, if not A study of all the cormorant pellets inhabited the island in previous years; millennia. In the natural spaces on and Williams-Mystic students collected in 2001 there were over 200 nests on off the New England coast, there is no between 2002 and 2009 identified over Gates, indicating a colony three times reason to fear the talented cormorant. twenty species of fish. Of those twenty as large as this year’s...... identified species -- bearing in mind Harrison Flint Lewis, who worked Svati Narula studied at The Maritime that the samples also contained many for the Canadian Fish and Wildlife Studies Program of Williams College unidentifiable fish bones -- it appears Service and wrote the authoritative and Mystic Seaport in the Fall of 2011 that benthic species such as American Natural History of the Double-crested and the summer of 2012. Richard King, a faculty member at Williams-Mystic, is , sculpin, cusk, and tautog Cormorant in 1929, concluded his the author of The Devil’s Cormorant: A are the most common components of work by saying that the bird, “though Natural History of the Most Despised cormorant diets in this area. However, unfortunate in some respects, is by Bird in the World to be released later these species are the most common no means as unpleasant as it has this year.

Fall/Winter 2012-13 • 15