A Marine Biogeographic Assessment of the Northwestern Hawaiian Islands Seabirds Kaylene E. Keller1, Angela D. Anders2, Scott A. Shaffer3, Michelle A. Kappes3, Beth Flint4 and Alan Friedlander5,6 INTRODUCTION The Northwestern Hawaiian Islands (NWHI) provide habitat for an estimated 5.5 million nesting seabirds represent­ ing 22 different species (see Figures 7.1 and 7.2 and Fefer et al., 1984). For many of these species, the Monument provides the majority of available nest­ ing habitat. Nesting occurs throughout the year, varying by species and within species, and by annual food availability (Harrison, 1990). The largest breeding populations occur at Midway Atoll, Lay­ san Island and Nihoa (USFWS, 2005). While the Monument protects seabird breeding and nesting habitat, the for­ aging ranges for most of these species Figure 7.1. A Red-footed Booby. Red-footed Boobies nest on all islands and atolls in the NWHI. Photo: J. Watt. extend beyond the Monument’s bound­ aries, with foraging distances ranging from 3 km to several thousand kilome­ ters (e.g., Fernández et al., 2001). Some seabird species occur year-round in the Monument, while others migrate to oth­ er parts of the Pacific when not breed­ ing. Juvenile birds may also remain at sea for several years before returning to their breeding colonies inside Monu­ ment water. Overall, the NWHI provide high-quality breeding habitat, with low predation risk and low disturbance con­ ditions (Table 7.1). The distribution of seabirds within the Figure 7.2. Brown Noddy Terns and Brown Boobies at Pearl and Hermes Monument reflects, to some extent, the Atoll. Photo J. Watt. nesting habitat currently available on the islands (Tables 7.2 and 7.3). Nesting distribution has also been affected by human disturbance in the late 19th and 20th centuries, including egg and feather hunting, and destruction of habitat due to military activities during and after World War II. For example, populations of many of the seabird species on Laysan Island are likely still recovering after the devegetation of the island by guano miners and hunter-introduced feral rabbits in the early 1900s (Ely and Clapp, 1973). Further habitat losses have occurred from the introduction of non-native plants like golden crown-beard (Verbisena encelioides) and rodent pests like rats and mice. Numbers of nest­ ing adults of some species are also still increasing on Tern and East Islands at French Frigate Shoals after the decommissioning of Naval and Coast Guard stations following World War II (Amerson, 1971). 1. NOAA/NOS/ONMS/Papahanaumokuakea Marine National Monument 2. Clancy Environmental Consultants, Inc. 3. University of California Santa Cruz 4. U.S. Fish and Wildlife Service 5. NOAA/NOS/NCCOS/CCMA Biogeography Branch 6. The Oceanic Institute 235 236 A Marine Biogeographic Assessment oftheNorthwesternHawaiianIslands MarineBiogeographic A Table 7.1. Life history and management Information for selected seabirds of the NWHI. Source: USFWS, unpub. data. BREEDING PERIOD FEEDING ESTIMATED BEHAVIOR FORAGING RANGE FROM COLONIES Common Protection IUCN ESA Primary Months When Fish Fish Cephaopods Ephausi­ Crus­ Feeding Feeding Distance Source Name Status Months of Breeding Eggs (squid, octo­ ids (krill) ta­ Habits Activity Presence pus) ceans Eggs Chicks Procellariiformes (Albatrosses, Petrels and Shearwaters) Laysan Highly Imper­ VU A4bd Nov - Jul Nov-Feb Jan-Jul X X X Surface feed­ Nocturnal 1,000 km Albatross iled and High ing Concern Black- Highly Imper­ EN A3bd Oct - Jul Oct-Feb Jan-Jul X X X Surface feed­ Diurnal 700 km footed iled and High ing Albatross Concern Short-tailed VU D2 Endangered Nov - Feb Oct-Jan Jan-Jun X X X Surface feed­ Diurnal Unknown Albatross ing Bonin Moderate LC Aug - Jun Jan- Feb-Jun X X X Surface feed­ Nocturnal Unknown Petrel Concern March ing Bulwer’s Moderate LC Apr - Oct May-Jul Jul-Oct X X X X Surface feed­ Nocturnal Unknown Petrel Concern ing Wedge- Low or Not LC May - Dec May-Aug Aug- X X Contact dip­ Diurnal 480 km tailed Currently at Dec ping / associ­ Shearwater Risk ated with large predatory fi sh Christmas Highly Imper­ LC Feb - Oct April-Jul Jun-Oct X X Contact dip­ Nocturnal Unknown Shearwater iled and High ping and pur­ Concern suit plunging / associated with large predatory fi sh Tristram’s Highly Imper­ NT Oct - May Dec-Feb Feb- X X Surface feed­ Nocturnal Unknown Storm- iled and High May ing Petrel Concern Pelecaniformes (Tropicbirds, Boobies and Frigatebirds) Red-footed Low or Not LC Jan - Dec Jan - Mar - X X Plunge diving / Diurnal 276 km Flint Booby Currently at Aug Dec associated with Risk large predatory fi sh Masked Moderate LC Dec - Oct Jan - Jul Mar - X X Plunge diving / Diurnal 158 km Flint Booby Concern Oct associated with large predatory fi sh Brown Moderate LC Jan - Oct Feb - April - X X Plunge diving / Diurnal 80 km USFWS, Booby Concern Aug Oct associated with 2005 large predatory fi sh Great Moderate LC Jan - Dec Feb - Jul April - X X Surface feed­ Diurnal 612 km Weim­ Frigatebird Concern Nov ing / associ­ erskirch ated with large et al., predatory fi sh 2004 Table 7.1 (Continued). Life history and management Information for selected seabirds of the NWHI. Source: USFWS, unpub. data. BREEDING PERIOD FEEDING ESTIMATED BEHAVIOR FORAGING RANGE FROM COLONIES Common Protection IUCN ESA Primary Months When Fish Fish Cephaopods Ephausi­ Crus­ Feeding Feeding Distance Source Name Status Months of Breeding Eggs (squid, octo­ ids (krill) ta­ Habits Activity Presence pus) ceans Eggs Chicks Lesser LC Feb - Jul Feb - Jul X X Surface feed­ Diurnal Unknown Frigatebird ing / associ­ ated with large predatory fi sh Red-tailed Moderate LC Feb - Nov Mar - April - X X Plunge diving Diurnal 468 km Flint Tropicbird Concern Aug Nov White- LC Jan - Dec Jan - Jan - X X Plunge diving Diurnal 374 km Flint tailed Dec Dec Tropicbird Charadriiformes (Terns and Noddies) Black Moderate LC year- Nov - Dec - X X X Surface feed­ Diurnal 80 km USFWS, Noddy Concern around Jun Aug ing / associ­ 2005 ated with large predatory fi sh Brown Low or Not LC year- Jan - Oct Feb - X X Surface feed­ Diurnal 163 km Flint Assessment oftheNorthwesternHawaiianIslands MarineBiogeographic A Noddy Currently at around Nov ing / associ­ Risk ated with large predatory fi sh Blue Highly LC year- Jan ­ Jan - X Surface feed­ Diurnal Near- Noddy Imperiled and around May Jun ing shore High Concern White Tern Moderate LC year- Jan - Jan - X X Surface feed­ Diurnal Near- Concern around Dec Dec ing / associ­ shore ated with large predatory fi sh Sooty Tern Moderate LC Mar - Sep Mar - Jul April - X X Surface feed­ Primarily 740 km Flint, Concern Sep ing / associ­ nocturnal 1991 ated with large predatory fi sh Gray- Moderate LC Feb - Oct Feb - April - X X X X Surface feed­ Diurnal 370 km USFWS, backed Concern Aug Oct ing / associ­ 2005 Tern ated with large predatory fi sh Little Tern Moderate LC Feb - Oct Feb - April - X X Plunge diving Diurnal 3 km USFWS, Concern Aug Oct 2005 237 238 Seabirds Table 7.2. Seabird nesting distribution in the NWHI. Source: USFWS, unpub. data. Assessment oftheNorthwesternHawaiianIslands MarineBiogeographic A MIDWAY KURE FRENCH FRIGATE SHOALS PEARL AND HERMES ATOLL ATOLL ATOLL Little GinIsland Eastern Island Disappearing Round Island Green Island Grass Island Shark Island North Island Sand Island Sand Island Seal Kittery Le Perouse Little North East Island Tern Island Tern Bird Island Spit Island Trig Island Trig Southeast MOKU­ Gin Island GARDNER Pinnacle MARO LAYSAN LISIANSKI Island Island Island NIHOA MANA­ Island PINNA­ ISLAND MANA CLES REEF ISLAND ISLAND Black-footed Albatross X X X X X X X X X X X X X X X X X X X Laysan Albatross X X X X X X X X X X X X X X X X X X X Short-tailed Albatross Bonin Petrel X X ? X X X X X X X X Bulwer’s Petrel X X X X X X X X X Wedge-tailed Shearwater X X X X X X X X X X X X X Christmas Shearwater X ? X X X X X X ? X X Tristram’s Storm-Petrel X X X X X X ? X X Red-tailed Tropicbrid X X X X X X X X X X X X X X X White-tailed X Tropicbird Masked Booby X X X X X X X X X X X X X X X X X X X Brown Booby X X X X X X X X X X ? X X Red-footed Booby X X X X X ? X X X X X X X X X Great Frigatebird X X X X X X X X X X ? X Lesser Frig­ X ate Bird Little Tern X X X Grey-backed X ? X X Tern X X X X X X X X X X X X X Sooty Tern X X X X X X X X X X Brown X X X X X Noddy X X X X X X X X X X X X X Black Noddy X X X X X X X X ? X X X Blue Noddy X X X X White Tern X X X X X X X X X A Marine Biogeographic Assessment of the Northwestern Hawaiian Islands Table 7.3. Distribution of seabirds in the Pacific, Main Hawaiian Islands (MHI) and the NWHI. Source: USFWS, 2005. COMMON NAME SCIENTIFIC NAME NWHI MHI USPI Procellariiformes (Albatrosses, Petrels and Shearwaters) Black-footed Albatross Phoebastria nigripes B B B Laysan’s Albatross Phoebastria immutabilis B B B Short-tailed albatross Phoebastria albatrus b Seabirds Hawaiian Petre Pterodroma sandwichensis B Herald Petrel Pterodroma arminjoniana B Tahiti Petrel Pterodroma rostrata B Bonin Petrel Pterodroma hypoleuca B Ex B Phoenix Petrel Pterodroma alba Ex Bulwer’s Petrel Bulweria bulwerii B B B Wedge-tailed Shearwater Puffi nus pacifi cus B B B Christmas Shearwater Puffi nus nativitatis B B B Newell’s Shearwater Puffinus auricularis newelli B1 Audobon’s Shearwater Puffi nus lherminieri B Band-rumped Storm-Petrel Oceanodroma castro B B Black Storm-Petrel Oceanodroma melania B Tristram’s Storm-Petrel Oceanodroma tristrami B B Polynesian Storm-Petrel Nesofregetta fuliginosa B Pelecaniformes (Tropicbirds, Boobies and Frigatebirds) White-tailed Tropicbird Phaethon lepturus