Publications
Filter Total Items: 1493
Vegetation response of a dry shrubland community to feral goat management on the island of Moloka‘i, Hawai‘i Vegetation response of a dry shrubland community to feral goat management on the island of Moloka‘i, Hawai‘i
The Hawaiian Islands are well known for their unique ecosystem assemblages that have a high proportion of endemic flora and fauna. However, since human colonization of this archipelago—starting with the arrival of Polynesian sailors approximately 1,200 years ago, and particularly following western contact in 1778—thousands of non-native species have been introduced to the Islands and...
Authors
James D. Jacobi, Jonathan D. Stock
Recreation economics to inform migratory species conservation: Case study of the northern pintail Recreation economics to inform migratory species conservation: Case study of the northern pintail
Quantification of the economic value provided by migratory species can aid in targeting management efforts and funding to locations yielding the greatest benefits to society and species conservation. Here we illustrate a key step in this process by estimating hunting and birding values of the northern pintail (Anas acuta) within primary breeding and wintering habitats used during the...
Authors
Brady J. Mattsson, James A. Dubovsky, Wayne E. Thogmartin, Kenneth J. Bagstad, Joshua H. Goldstein, John B. Loomis, Jay E. Diffendorfer, Darius J. Semmens, Ruscena Wiederholt, Laura Lopez-Hoffman
Reply to the discussion of Pinter et al. on ‘Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California’ by Schumann et al. (2016) Reply to the discussion of Pinter et al. on ‘Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California’ by Schumann et al. (2016)
We appreciate the thoughtful discussion offered by Pinter et al. (2017) because it gives us an opportunity to elucidate some of the main points of our study, address some apparent misinterpretations, and recapitulate one of our conclusions. Pinter et al.’s discussion emphasizes and reinforces some of the important concepts we presented but also raises questions regarding specific aspects...
Authors
R. Randall Schumann, Jeffrey S. Pigati
A paleomagnetic age estimate for the draining of ancient Lake Alamosa, San Luis Valley, south-central Colorado, U.S.A. A paleomagnetic age estimate for the draining of ancient Lake Alamosa, San Luis Valley, south-central Colorado, U.S.A.
In September 2009, a 99.4-m (326-ft) deep well was drilled proximal to Great Sand Dunes National Park and Preserve to explore the history and subsurface geology of the San Luis Valley, Colorado. Of particular interest was deciphering the evolution of ancient Lake Alamosa, which filled much of the San Luis Valley in the Pliocene and Pleistocene. Thick intervals of massive clay, recovered...
Authors
Joshua K. Davis, Mark R. Hudson, V. J. S. Grauch
Domestic cat Domestic cat
The familiar domestic cat is not native to southern California and is considered an invasive spe-cies by biologists and conservation organizations. When owners abandon their cats, wild or feral populations may arise, as they have in San Diego County. Cats’ pelage color, tail length, and hair thickness vary widely, given human fascination with breeding diverse phenotypes, but all have a...
Authors
Jay E. Diffendorfer
Late Quaternary fluvial history of Santa Cruz Island, California, USA Late Quaternary fluvial history of Santa Cruz Island, California, USA
The geologic history of fluvial systems on Santa Cruz Island (SCI) is complex, involving responses to both allogenic and autogenic forcings. During periods of low or lowering sea level, canyons on the island were eroded and sediment was transported off the island onto the exposed marine shelf. When sea level rose, streams aggraded, building a sedimentary wedge that progressed from the...
Authors
R. Randall Schumann, Jeffrey S. Pigati
Broken bones and hammerstones at the Cerutti Mastodon site: A reply to Haynes Broken bones and hammerstones at the Cerutti Mastodon site: A reply to Haynes
Haynes [2017 “The Cerutti Mastodon.” PaleoAmerica 3 (3): 196–199] criticizes numerous aspects of our analysis of the Cerutti Mastodon (CM) site, but central among his points is the claim that heavy equipment broke the bones and stones that we interpret as evidence of ancient human activity. This notion can be discounted primarily because most of the relevant CM fragments were found...
Authors
Steven R. Holen, Thomas A. Demere, Daniel C. Fisher, Richard Fullagar, James B. Paces, George T. Jefferson, Jared M. Beeton, Adam N. Rountrey, Kathleen A. Holen
Late Quaternary uplift along the North America-Caribbean plate boundary: Evidence from the sea level record of Guantanamo Bay, Cuba Late Quaternary uplift along the North America-Caribbean plate boundary: Evidence from the sea level record of Guantanamo Bay, Cuba
The tectonic setting of the North America-Caribbean plate boundary has been studied intensively, but some aspects are still poorly understood, particularly along the Oriente fault zone. Guantanamo Bay, southern Cuba, is considered to be on a coastline that is under a transpressive tectonic regime along this zone, and is hypothesized to have a low uplift rate. We tested this by studying...
Authors
Daniel R. Muhs, Eugene S. Schweig, Kathleen Simmons, Robert B. Halley
Understanding recurrent land use processes and long-term transitions in the dynamic south-central United States, c. 1800 to 2006 Understanding recurrent land use processes and long-term transitions in the dynamic south-central United States, c. 1800 to 2006
Forests have historically been under significant land use pressures that cause periods of degradation, clearance, and recovery. To understand these changes, studies are needed that place trends in a historical landscape context and also examine recent dynamics. Here, we use historical investigation (c. 1800) and an examination of land use and land cover change between 1973 and 2006 to...
Authors
Mark A. Drummond, Glenn E. Griffith, Roger F. Auch, Michael P. Stier, Janis L. Taylor, D. J. Hester, Jodi L. Riegle, Jamie L. McBeth
Taphonomic problems in reconstructing sea-level history from the late Quaternary marine terraces of Barbados Taphonomic problems in reconstructing sea-level history from the late Quaternary marine terraces of Barbados
Although uranium series (U-series) ages of growth-position fossil corals are important to Quaternary sea-level history, coral clast reworking from storms can yield ages on a terrace dating to more than one high-sea stand, confounding interpretations of sea-level history. On northern Barbados, U-series ages corals from a thick storm deposit are not always younger with successively higher
Authors
Daniel R. Muhs, Kathleen R. Simmons
Quantitative tools for implementing the new definition of significant portion of the range in the U.S. Endangered Species Act Quantitative tools for implementing the new definition of significant portion of the range in the U.S. Endangered Species Act
In 2014, the Fish and Wildlife Service (FWS) and National Marine Fisheries Service announced a new policy interpretation for the U.S. Endangered Species Act (ESA). According to the act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range (SPR). The 2014 policy seeks to provide consistency by...
Authors
Julia E. Earl, Samuel Nicol, Ruscena Wiederholt, Jay E. Diffendorfer, Darius J. Semmens, D. T. Tyler Flockhart, Brady Mattsson, Gary McCracken, D. Ryan Norris, Wayne E. Thogmartin, Laura Lopez-Hoffman
Oxygen stable isotopic disparities among sympatric small land snail species from northwest Minnesota, USA Oxygen stable isotopic disparities among sympatric small land snail species from northwest Minnesota, USA
The oxygen isotopic composition (δ18O) of land snail shells can be a valuable paleoenvironmental archive if the climatic parameters that influence the isotopic system are fully understood. Previous calibration studies have examined a limited number of species or individuals, and most have focused on larger (> 10 mm) taxa, which do not represent the dominant shell material in the...
Authors
Yurena Yanes, Jeffrey C. Nekola, Jason A. Rech, Jeffery S. Pigati