Unintended Consequences: How the Recovery of Sea Eagle Haliaeetus Spp. Populations in the Northern Hemisphere Is Affecting Seabirds

Adult seabirds experience predation by many species. At sea, they are taken by predatory fish such as white sharks Carcharodon carcharias (Johnson et al. 2006), and by marine mammals including killer whales Orca orcinus (Dahleim & White 2010), true seals (Penny & Lowry 1967, Cobley & Bell 1998), fur-seals and sealions (McHugh 1952, Long & Gilbert 1997, David et al. 2003, Lalas et al. 2007, Charbonnier et al. 2010), walrus Odobenus rosmarus (Mallory et al. 2004), and sea otters Enhydra lutris (Riedman & Estes 1988). On land, they are taken by native and non-native mammals including rodents (Sealy 1982, Blight et al. 2000, Angel et al. 2009) and carnivores ranging in size from shorttailed weasels Mustela erminea (Cairns 1985) to polar bears Ursus maritimus (Donaldson et al. 1995). In addition, many are taken on land by avian predators, including Giant Petrels Macronectes spp. (Emslie et al. 1995), hawks (Lewis 2003), falcons (Beebe 1960, Booms & Fuller 2003), eagles (Zaun 2009), owls (Morse 1971, Hayward et al. 1993, Velarde et al. 2007), rails (Brothers 1984), gulls (Spear 1993), skuas Stercorarius spp. (Müller-Schwarze & Müller-Schwarze 1973), sheathbills Chionis spp. (Jouventin et al. 1996), and passerines (Verbeek 1982, Ryan & Moloney 1991, Gaston & Elliot 1996).