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Biases in the literature on direct wildlife mortality from energy development

Comparing environmental impacts of different energy sources can inform energy investments and environmental conservation. Direct wildlife mortality from energy development receives substantial public and scientific attention, but it is unclear whether rigorous comparisons of mortality among energy sources are possible. To address this question, we compared availability of mortality studies among energy sources, wildlife groups, and regions, and assessed comparability of mortality indicators measured. Whereas wind and hydropower have received substantial mortality research exceeding their proportional contributions to global energy production, coal, oil and gas, and bioenergy have received fewer studies and are underrepresented relative to their contributions. Furthermore, research is biased toward birds and fish and North America and Europe, and there are inconsistencies among energy sources and limited replication of most indicators measured. These results indicate that rigorous comparisons of direct wildlife mortality among energy sources are not currently possible and highlight research needs for improving understanding of energy's environmental impacts.

BioScience

Status of the California condor (Gymnogyps californianus) and efforts to achieve its recovery

The California Condor ( Gymnogyps californianus ; hereafter "condor"; Fig. 1) has long been symbolic of avian conservation in the United States. Its large size, inquisitiveness, and association with remote places make it highly charismatic, and its decline to the brink of extinction aroused a continuing public interest in its plight. By 1982, only 22 individuals remained of this species whose range once encompassed much of North America. The last wild bird was trapped and brought into captivity in 1987, which rendered the species extinct in the wild (Snyder and Snyder 1989). In the 1980s, some questioned whether viable populations could ever again exist in the natural environment, and whether limited conservation funds should be expended on what they viewed as a hopeless cause (Pitelka 1981). Nevertheless, since that low point, a captive-breeding and release program has increased the total population by an order of magnitude, and condors fly free again in California, Arizona, Utah, and Baja California, Mexico (Fig. 2). At this writing (summer 2009), more than 350 condors exist, 180 of which are in the wild (J. Grantham pers. comm.). The free-living birds face severe challenges, however, and receive constant human assistance. The intensive management applied to the free-living populations, as well as the ongoing monitoring and captive-breeding programs, are tremendously expensive and become more so as the population grows. Thus, the program has reached a crossroads, caught between the financial and logistical pressures required to maintain an increasing number of condors in the wild and the environmental problems that preclude establishment of naturally sustainable, free-ranging populations.

The Auk

Apapane ( Himatione sanguinea )

The 'Apapane is the most abundant species of Hawaiian honeycreeper and is perhaps best known for its wide-ranging flights in search of localized blooms of ō'hi'a ( Metrosideros polymorpha ) flowers, its primary food source. 'Apapane are common in mesic and wet forests above 1,000 m elevation on the islands of Hawai'i, Maui, and Kaua'i; locally common at higher elevations on O'ahu; and rare or absent on Lāna'i and Moloka'i.

Birds of North America

Iiwi ( Vestiaria coccinea )

The ‘I‘iwi is one of the most spectacular of extant Hawaiian birds, with vermilion plumage, black wings and tail, and long, decurved bill. In pre-European Hawai‘i, beautiful feather capes, sometimes containing hundreds of thousands of ‘I‘iwi feathers, were a symbol of power and prestige among native Hawaiians. The ‘I‘iwi is a bird of the Hawaiian forests. Its decurved bill seems well adapted to exploit nectar from the similarly shaped flowers of lobelioid plants (Campanulaceae). ‘I‘iwi and ‘Apapane ( Himatione sanguinea ) are well known for their long flights over the forests in search of the flowers of the ‘öhi‘a ( Metrosideros polymorpha ) tree, their primary food source. Probably as a consequence of their high flights, ‘I‘iwi, ‘Apapane, and ‘Ö‘ü ( Psittirostra psittacea ) are the only 3 species of endemic Hawaiian honeycreepers in which the same subspecies occurs on more than one island. Contemporary interisland movements have not been documented.

Birds of North America

Ou ( Psittirostra psittacea )

The ‘Ö‘ü and the Läna‘i Hookbill are plump, predominantly olive green, thick-billed Hawaiian honeycreepers. The ‘Ö‘ü is now very rare and restricted to remote, high-elevation native forest, and the Läna‘i Hookbill is extinct. They are closely related species, belonging to a specialized tribe, Psittirostrini, consisting of nine historically known Hawaiian species with heavy, finchlike to parrotlike bills. Because of their taxonomic affinity and the paucity of information on the Läna‘i Hookbill, we are treating the two species in a single account.

Birds of North America

Hawaiian Goose ( Branta sandvicensis )

Evolving in the remote Hawaiian Archipelago and having the smallest range of any living goose, the Hawaiian Goose, or better known by its Hawaiian name—Nënë, is among the most isolated, sedentary, and threatened of waterfowl. The Nënë is also highly terrestrial, and several structural features demonstrate its adaptation to life on islands with limited freshwater habitat: It stands taller and more upright than geese of similar weight, enabling it to reach high to browse the fruits, seeds, and foliage that constitute its herbivorous diet; its legs and padded toes are long and strong, promoting swift, sure walking and running over rugged terrain; webbing is reduced between the toes; and though it is a capable swimmer and readily uses freshwater habitats when available, the Nënë does not require freshwater or oceanic habitats in the same way that many other waterfowl do.

Birds of North America