Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 15 of 15

Full-Text Articles in Entire DC Network

Fate Of Fish Production In A Seasonally Flooded Saltmarsh, Philip W. Stevens, Clay L. Montague, Kenneth J. Sulak Dec 2006

Fate Of Fish Production In A Seasonally Flooded Saltmarsh, Philip W. Stevens, Clay L. Montague, Kenneth J. Sulak

United States Geological Survey: Staff Publications

Although saltmarshes are thought to enhance the productivity of open estuarine water, the mechanism by which energy transfer occurs has been debated for decades. One possible mechanism is the transfer of saltmarsh production to estuarine waters by vagile fishes and invertebrates. Monthly estimates of fish standing stock, net fish ingress, and predation were used to develop a bio-mass budget to estimates annual production of fishes and the relative yield to predatory fish, birds, and direct migration to the estuary. Annual production of saltmarsh fishes was estimated to 31.0 gm-2 saltmarsh, which falls within the range of previously reported values …


Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak Sep 2006

Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak

United States Geological Survey: Staff Publications

Deep-water (307–697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several centuries old. Bands were delaminated in KOH and analyzed for carbon and nitrogen stable isotopes. Carbon values ranged from _16.4‰ to _15.7‰; the oldest specimen displayed the largest range in values. Nitrogen values ranged from 7.7‰ to 8.6‰. …


Anguilliform Larvae Collected Off North Carolina, Steve W. Ross, Tara L. Casazza, Andrea M. Quattrini, Kenneth J. Sulak Jul 2006

Anguilliform Larvae Collected Off North Carolina, Steve W. Ross, Tara L. Casazza, Andrea M. Quattrini, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999–2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April …


Endangered Species Time Line, Leona K. Svancara, J. Michael Scott, Dale D. Goble, Frank W. Davis, Donna Brewer Jan 2006

Endangered Species Time Line, Leona K. Svancara, J. Michael Scott, Dale D. Goble, Frank W. Davis, Donna Brewer

United States Geological Survey: Staff Publications

The Endangered Species Act (ESA) is embedded in a web of statutes designed to regulate relationships between humans and other species that stretch back nearly a millennium (Goble, this volume; Goble and Freyfogle 2002). This chapter presents a time line of federal actions taken to protect wildlife beginning with passage of the Land and Water Conservation Fund Act in 1963 (Act of May 28, 1963). Earlier laws to protect wildlife are discussed elsewhere (Goble, this volume). The time line emphasizes federal actions that conserve species at risk of extinction and significant events in the course of implementing the Endangered Species …


Isotope Sourcing Of Prehistoric Willow And Tule Textiles Recovered From Western Great Basin Rock Shelters And Caves E Proof Of Concept, L.V. Benson, E.M. Hattori, H. E. Taylor, S.R. Poulson, E.A. Jolie Jan 2006

Isotope Sourcing Of Prehistoric Willow And Tule Textiles Recovered From Western Great Basin Rock Shelters And Caves E Proof Of Concept, L.V. Benson, E.M. Hattori, H. E. Taylor, S.R. Poulson, E.A. Jolie

United States Geological Survey: Staff Publications

Isotope and trace-metal analyses were used to determine the origin of plants used to manufacture prehistoric textiles (basketry and matting) from archaeological sites in the western Great Basin. Research focused on strontium (87Sr/86Sr) and oxygen (18O/16O) isotope ratios of willow (Salix sp.) and tule (Schoenoplectus sp.), the dominant raw materials in Great Basin textiles. The oxygen-isotope data indicated that the willow and tule used to produce the textiles were harvested from the banks of rivers or in marshes characterized by flowing water and not from lakes or sinks. The strontium-isotope …


Renewing The Conservation Commitment, Frank W. Davis, Dale D. Goble, J. Michael Scott Jan 2006

Renewing The Conservation Commitment, Frank W. Davis, Dale D. Goble, J. Michael Scott

United States Geological Survey: Staff Publications

As we write this in early 2005 there are several ESA-related pieces of legislation pending before Congress. Most of the proposed legislation is championed by Republican leaders from western states, who promise to strengthen the use of science or ensure fairer treatment of private landowners. Ir has become a perennial drama on the American political stage: "conservatives" rally to rein in a law that they believe has reached too far and "conservationists" mobilize ro defend the law that they believe offers the best ho pe for protecting biodiversity from relentless economic exploitation. There is much posturing, finger pointing, and, ultimately, …


Taxonomic Considerations In Listing Subspecies Under The U.S. Endangered Species Act, Susan M. Haig, Erik A. Beever, Steven M. Chambers, Hope M. Draheim, Bruce D. Dugger, Susie M. Dunham, Elise Elliott-Smith, Joseph B. Fontaine, Dylan C. Kesler, Brian J. Knaus, Iara F. Lopes, Pete Loschl, Thomas D. Mullins, Lisa M. Sheffield Jan 2006

Taxonomic Considerations In Listing Subspecies Under The U.S. Endangered Species Act, Susan M. Haig, Erik A. Beever, Steven M. Chambers, Hope M. Draheim, Bruce D. Dugger, Susie M. Dunham, Elise Elliott-Smith, Joseph B. Fontaine, Dylan C. Kesler, Brian J. Knaus, Iara F. Lopes, Pete Loschl, Thomas D. Mullins, Lisa M. Sheffield

United States Geological Survey: Staff Publications

The U.S. Endangered Species Act (ESA) allows listing of subspecies and other groupings below the rank of species. This provides the U.S. Fish and Wildlife Service and the National Marine Fisheries Service with a means to target the most critical unit in need of conservation. Although roughly one-quarter of listed taxa are subspecies, these management agencies are hindered by uncertainties about taxonomic standards during listing or delisting activities. In a review of taxonomic publications and societies, we found few subspecies lists and none that stated standardized criteria for determining subspecific taxa. Lack of criteria is attributed to a centuries-old debate …


By The Numbers, J. Michael Scott, Dale D. Goble, Leona K. Svancara, Anna Pidgorna Jan 2006

By The Numbers, J. Michael Scott, Dale D. Goble, Leona K. Svancara, Anna Pidgorna

United States Geological Survey: Staff Publications

The current endangered species list has its administrative beginnings in 1964 when the Department of the Interior's Committee on Rare and Endangered Wildlife Species published a preliminary list of 62 species at risk of extinction (Goble, forthcoming). Following the enactment of the Endangered Species Preservation Act of 1966 (ESPA), the secretary of the interior in 1967 published the first official list of 78 "native fish and wildlife threatened with extinction" (ESPA sec. l(c); U.S. Department of the Interior 1967; Wilcove and McMillan, this volume). By the time the Endangered Species Act (ESA) was adopted in 1973, there were 392 species …


Breeding Biology And Success Of A Reintroduced Population Of The Critically Endangered Puaiohi (Myadestes Palmeri), Erik J. Tweed, Jeffrey T. Foster, Bethany L. Woodworth, William B. Monahan, Jherime L. Kellerman, Alan Lieberman Jan 2006

Breeding Biology And Success Of A Reintroduced Population Of The Critically Endangered Puaiohi (Myadestes Palmeri), Erik J. Tweed, Jeffrey T. Foster, Bethany L. Woodworth, William B. Monahan, Jherime L. Kellerman, Alan Lieberman

United States Geological Survey: Staff Publications

The ultimate success of reintroduction programs for endangered species depends on the ability of reintroduced animals to breed in the wild. We studied the nesting success and breeding biology of a reintroduced population of Puaiohi (Myadestes palmeri) on the island of Kaua‛i, Hawaii. Thirty-four captive-bred Puaiohi were released into the Alaka‛i Swamp in 1999–2001 and monitored using radiotelemetry. Ten females and two males paired with wild and other released birds, including one polygynous trio. From March to September, 31 nests were built. Mean clutch size was 2.0 eggs, daily nest survival was 0.97 ± 0.01 (mean ± SE) …


Introduction To "The Endangered Species Act At Thirty, Volume 2", Frank W. Davis, J. Michael Scott, Dale D. Goble Jan 2006

Introduction To "The Endangered Species Act At Thirty, Volume 2", Frank W. Davis, J. Michael Scott, Dale D. Goble

United States Geological Survey: Staff Publications

More than thirty years after its passage, the Endangered Species Act (ESA) of 1973 continues to be a corners tone of U.S. biodiversity policy and among our most powerful environmentallaws. The ESA set the nation's biodiversity conservation policy on a path that emphasized species-based conservation and triggered action only when a species faced imminent extinction. However, promoting recovery has proven more challenging than the original designers of the law anticipated. The number of listed species has mushroomed from 78 in 1973 to 1,267 in 2005, while in that time only 13 species have recovered sufficiently to be removed from the …


Conserving Biodiversity In Human-Dominated Landscapes, Dale D. Goble, J. Michael Scott, Frank W. Davis Jan 2006

Conserving Biodiversity In Human-Dominated Landscapes, Dale D. Goble, J. Michael Scott, Frank W. Davis

United States Geological Survey: Staff Publications

The two volumes of The Endangered Species Act at Thirty look backward to evaluate the effectiveness of the act over its first three decades (Wilcove and McMillan 2006; Scott et al. 2006, chap. 2; Goble, this volume; Svancara, this volume; Callicott, this volume; Norton, this volume) and also forward to suggest how it can be used as a cornerstone for conserving biological diversity in increasingly human-dominated landscapes (Davis et al. 2006; Bean 2006). The chapters in part 2 of this volume, for example, appraise the science of the 1990s and 2000s at both the large scale (Lomolino, this volume; Naeem …


Introduction To "The Endangered Species Act At Thirty, Volume 1", J. Michael Scott, Dale D. Goble, Frank W. Davis Jan 2006

Introduction To "The Endangered Species Act At Thirty, Volume 1", J. Michael Scott, Dale D. Goble, Frank W. Davis

United States Geological Survey: Staff Publications

This book examines one legislative effoft to resolve the dilemma, the Endangered Speeies Aet of 1973 (ESA 1973). The ESA was an idealistic and perhaps naive attempt to preserve humanity by preserving other species in the ecological support system that makes life possible. In the words of the House report accompanying the bill:

A certain humility, and a sense of urgency seem indicated .... One might analogize the case to one in which one copy of all the books ever printed were gathered together in one huge building. The position in which we find ourselves today is that of custodians …


Reply To The Discussion By F. Lagroix And S.K. Banerjee Of “Geochemical Evidence For The Origin Of Late Quaternary Loess In Central Alaska”, Daniel R. Muhs, James R. Budahn Jan 2006

Reply To The Discussion By F. Lagroix And S.K. Banerjee Of “Geochemical Evidence For The Origin Of Late Quaternary Loess In Central Alaska”, Daniel R. Muhs, James R. Budahn

United States Geological Survey: Staff Publications

We thank F. Lagroix and S.K. Banerjee (2006) for their Muhs and Budahn 1895 interest in our recent paper and welcome this opportunity to clarify our thoughts on the issues they raise. ...

The loess deposits of central Alaska contain a long and detailed record of sedimentation and soil formation. However, we are convinced that this history is a complex one and, therefore, we again thank Lagroix and Banerjee (2006) for the opportunity to articulate some additional thoughts on the geologic record here. We applaud the use of new methods, such as those of Lagroix and Banerjee (2002, 2004), in …


The Agricultural Productivity Of Chaco Canyon And The Source(S) Of Pre-Hispanic Maize Found In Pueblo Bonito, Larry Benson, John Stein, Howard Taylor, Richard Friedman, Thomas C. Windes Jan 2006

The Agricultural Productivity Of Chaco Canyon And The Source(S) Of Pre-Hispanic Maize Found In Pueblo Bonito, Larry Benson, John Stein, Howard Taylor, Richard Friedman, Thomas C. Windes

United States Geological Survey: Staff Publications

Agricultural productivity estimates suggest that the core area of Chaco Canyon could have sustained only a few hundred individuals. Modern analogues of existing Pueblo populations and their domestic habitations with Chaco structures suggest that Chaco at times had a resident population exceeding 2000 people. These data suggest that maize would have had to be imported to feed permanent residents and those visiting Chaco during ritual–political gatherings and those who participated in the accelerated construction and modification of great houses between AD 1030 and 1130. Comparison of strontium-isotope and trace-element ratios of synthetic soil and natural waters from sites within the …


Use Of Mammal Manure By Nesting Burrowing Owls: A Test Of Four Functional Hypotheses, Matthew D. Smith, Courtney J. Conway Jan 2006

Use Of Mammal Manure By Nesting Burrowing Owls: A Test Of Four Functional Hypotheses, Matthew D. Smith, Courtney J. Conway

United States Geological Survey: Staff Publications

Animals have evolved an impressive array of behavioural traits to avoid depredation. Olfactory camouflage of conspicuous odours is a strategy to avoid depredation that has been implicated only in a few species of birds. Burrowing owls, Athene cunicularia, routinely collect dried manure from mammals and scatter it in their nest chamber, in the tunnel leading to their nest and at the entrance to their nesting burrow. This unusual behaviour was thought to reduce nest depredation by concealing the scent of adults and juveniles, but a recent study suggests that manure functions to attract arthropod prey. However, burrowing owls routinely …