Top 20 Most Threatened Bird Habitats in the U.S. - American Bird ...

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2Open Ocean/SeabirdNesting IslandsA T A G L A N C E :Priority Species: Laysan and BlackfootedAlbatrosses, Xantus’s Murrelet,Hawaiian Petrel, Black Storm-Petrel,Ashy Storm-Petrel, Whiskered Auklet,Black-capped PetrelThreats: Invasive species, marinepollution, overfishing, global warmingGeographical area: Atlantic andPacific Oceans, Gulf of MexicoLaysan Albatrosses. Photo: Breck TylerIn conservation terms, the seabirdsof the open ocean are caughtbetween a rock and a wet place!Roving far and wide across the mostisolated seas, these birds rarely touchland. When they do, it is to breed onoceanic islands that can be hundreds,if not thousands of miles from themainland. Neither land animals nortrue ocean denizens, these birds haveoften been overlooked by conservationistsdealing with either mainlandor ocean habitats, and so they slippedthrough the cracks. Today the problemsfacing alcids (such as murreletsand auklets), tubenoses (includingalbatrosses, shearwaters, and petrels),and other ocean wanderers, such asfrigatebirds, are well understood—namely introduced species on theirbreeding islands, overfishing, fisheriesbycatch, and pollution of the seas.In the United States, the main breedinggrounds for seabirds are theHawaiian, Channel, Farallon, andAleutian Islands, but other islands,such as the Dry Tortugas off theFlorida Keys and Petit Manan off thecoast of Maine also play an importantrole.Although their remoteness has affordedthese islands a high degree of protectionagainst development, they havenevertheless felt the impact of humancivilization. The threat of unregulatedhunting and egg collecting has nowpassed thanks to the enactment ofstrict wildlife protection laws (thoughtoo late to save the Great Auk fromextinction), but seabirds, including theLaysan, Black-footed, and Short-tailedAlbatrosses, are still being killed inadvertentlyon longline fishing hooks inU.S. and international waters. Conservationgroups, including ABC, havepushed hard to have proven mitigationmeasures for limiting seabird bycatchmandated in all longline fisheries.Like other island species, seabirdsevolved in isolated environments, andover the millennia, became specializedand highly sensitive to change. The introductionby humans of alien predators,including cats, rats, mongooses,and foxes, has caused declines in thepopulations of a number of seabirdspecies, such as the Hawaiian Petrel,Xantus’s Murrelet, Black Storm-Petrel,and Whiskered Auklet. Guam has lostall three of its populations of breedingseabirds (Brown Noddy, White Tern,and White-tailed Tropicbird) due tothe introduction of the brown treesnake.Page 44 of 48
Introduced ungulates can be asdevastating as the predators. Leftunchecked, introduced goats, sheep,cattle, and horses can wreak havoc onnative habitat and trample groundnests. Even introduced plant speciescan compromise seabird nesting colonies,such as golden crown-beard onMidway Atoll (see below).One advantage of islands is that theyare, by definition, enclosed ecosystems,and are frequently relatively small.This can make removal of invasivespecies easier than on the mainland.The National Park Service successfullyremoved rats from Anacapa and otherCalifornian Channel Islands to aid inthe recovery of the Xantus’s Murreletand Ashy Storm-Petrel; and on WakeIsland, between Hawaii and Guam, acoalition of groups removed feral catsto protect Wedge-tailed Shearwaters.Removal of the brown tree snake fromGuam will be considerably harder,however, despite recent legislation thatprovided much needed federal funding.Conservationists are desperatelyXantus's Murrelets: Glen Tepkeguarding against the possible spreadof this invasive predator to Hawaii,where it could devastate remainingnative bird populations.While at sea, ocean-going birds facea mounting barrage of threats. Withthe introduction of double-hulledtankers, oil spills are decreasing, butmany operators still risk catastropheby using old, single-skinned vessels.Tanker spills only account for 10-12%of marine oil pollution, however.An estimated 550,000 tons of oil isreleased into the oceans each year frompipeline ruptures and the continuousdischarge emanating from ships andland-based sources. An ever-growingaccumulation of plastic trash drifts onocean currents to the furthest reachesof the globe. Mistaking these items forsmall fish, albatrosses consume bottlecaps, cigarette lighters, toothbrushes,and all manner of household objects,often with fatal consequences.Ultimately, seabirds are reliant onocean-based food chains for survival.Overfishing has changed the compositionof ocean life almost beyond comprehension,with far reaching effects.Some U.S. fisheries are beginningto come under better management,but without significant changes toglobal fishing practices, seabirds willcontinue to feel the effects of decliningfood supplies. These effects arelikely to be compounded by globalclimate change, the extent and impactof which is becoming ever more apparent.While we cannot predict howseabirds will fare with rising temperaturesand sea levels, it is likely thattheir current population declines andsensitivity to habitat change will notdispose them favorably.HABITAT CONSERVATION SPOTLIGHTMore than two million seabirds live on Midway Atoll in theHawaiian chain, including the Black-footed Albatross andthe world’s largest populations of the Laysan Albatross. Introducedrats that once plagued the island have now beeneradicated, but other invasives, most notably two species of plants,are now wreaking havoc.Ironwood (a large tree that invades open areas) and golden crownbeard,have overrun parts of Midway. Golden crown-beard (a relativeof the sunflower) out-competes native vegetation, growing well evenin sand and in cracks in asphalt, and forms dense stands wherealbatrosses cannot nest. It also grows so rapidly that chicks canbecome enclosed by thick walls of vegetation while still in the nest.Unable to extricate themselves or be reached by their parents, somechicks starve.Beginning in the late 1990s, the U.S. Fish and Wildlife Service initiateda golden crown-beard management program on Midway, whichwas intensified in 2003. The program has included control by handpulling,mowing, and herbicide application. In areas where goldencrown-beard has been eradicated, native plants are propagated toprevent the invasive from recolonizing. In 2006, the National Fishand Wildlife Foundation’s Pulling Together initiative awarded a grantto the Friends of Midway Atoll National Wildlife Refuge to help withpropagation of native plants and provide volunteers to help removegolden crown-beard. ABC and the Biological Conservation AssistanceProgram are also assisting in this effort.Conservationists hope that the recent designation of the NorthwestHawaiian Islands as a National Monument will promote new sourcesof funding to help rid Midway of its most harmful invasive species, aswell as financing the removal of lead-based paint from former Navybarracks on the island. Hundreds of curious young albatrosses havebeen poisoned after eating peeling paint that affects their nervoussystems. With an estimated cost of $6 million, the cleanup will requirea substantial commitment from federal regulators, but ABC, withsupport from Lynn White and the LannanFoundation, is pushing hard to ensure thatthe buildings are made safe for futuregenerations of Laysan and BlackfootedAlbatrosses on Midway.—Christy Finlayson, Friends ofMidway and Jennifer Arnold, ABCLaysan Albatross chick in golden crown-beard: Christy FinlaysonPage 45 of 48
Page 2 and 3: Table of ContentsMap of the Top 20
Page 4: Wetlands photo: USDA Natural Resour
Page 7 and 8: The Economic Contribution of BirdsM
Page 9 and 10: However, the beauty and wonder ofth
Page 11 and 12: Hooded Warbler: Barth Schorrewhen t
Page 13 and 14: Historically, oak savannah was afir
Page 15 and 16: Williamson's Sapsucker: Peter LaTou
Page 17 and 18: lower and wetter ground for less an
Page 19 and 20: Grasshopper Sparrow: Bill Hubickpro
Page 21 and 22: While the northernmost chaparralhab
Page 23 and 24: esident and migratory bird species,
Page 25 and 26: It is not simply habitat loss that
Page 27 and 28: The Prairie Potholes are rightfully
Page 29 and 30: in longleaf. Likewise, many species
Page 31 and 32: Many endemic plants and animalsevol
Page 33 and 34: The large mammals, such as bison,an
Page 35 and 36: of miles of varied shoreline, inclu
Page 37 and 38: conditions for John Deere’s newly
Page 39 and 40: significant role in maintaining rip
Page 41 and 42: limestone bedrock that forms thepla
Page 43: dense layer of shrubs. Early ranche
Page 47 and 48: emained. From the seed-eating Palil

Top 20 Most Threatened Bird Habitats in the U.S. - American Bird ...

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