Publications
Below is a list of WERC's peer-reviewed publications. If you are searching for a specific publication and cannot find it in this list, please contact werc_web@usgs.gov
Filter Total Items: 3617
Effects of a non-native biocontrol weevil, Larinus planus, and other emerging threats on populations of the federally threatened Pitcher's thistle, Cirsium pitcheri
Larinus planus Frabicius (Curculionidae), is a seed-eating weevil that was inadvertently introduced into the US and was subsequently distributed in the US and Canada for the control of noxious thistle species of rangelands. It has been detected recently in the federally threatened Pitcher's thistle (Cirsium pitcheri). We assayed weevil damage in a natural population of Pitcher's thistle at Whitefi
Authors
Kayri Havens, Claudia L. Jolls, Julie E. Marik, Pati Vitt, A. Kathryn McEachern, Darcy Kind
Biodiversity loss decreases parasite diversity: theory and patterns
Past models have suggested host–parasite coextinction could lead to linear, or concave down relationships between free-living species richness and parasite richness. I explored several models for the relationship between parasite richness and biodiversity loss. Life cycle complexity, low generality of parasites and sensitivity of hosts reduced the robustness of parasite species to the loss of free
Authors
Kevin D. Lafferty
Effects of the amphibian chytrid fungus and four insecticides on Pacific treefrogs (Pseudacris regilla)
Chemical contamination may influence host-pathogen interactions, which has implications for amphibian population declines. We examined the effects of four insecticides alone or as a mixture on development and metamorphosis of Pacific Treefrogs (Pseudacris regilla) in the presence or absence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Bd exposure had a negative impact on
Authors
Peter Kleinhez, Michelle D. Boone, Gary Fellers
Matrix population models from 20 studies of perennial plant populations
Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage s
Authors
Martha M. Ellis, Jennifer L. Williams, Peter Lesica, Timothy J. Bell, Paulette Bierzychudek, Marlin Bowles, Elizabeth E. Crone, Daniel F. Doak, Johan Ehrlen, Albertine Ellis-Adam, Kathryn McEachern, Rengaian Ganesan, Penelope Latham, Sheila Luijten, Thomas N. Kaye, Tiffany M. Knight, Eric S. Menges, William F. Morris, Hans den Nijs, Gerard Oostermeijer, Pedro F. Quintana-Ascencio, J. Stephen Shelly, Amanda Stanley, Andrea Thorpe, Ticktin Tamara, Teresa Valverde, Carl W. Weekley
More than a meal: integrating non-feeding interactions into food webs
Organisms eating each other are only one of many types of well documented and important interactions among species. Other such types include habitat modification, predator interference and facilitation. However, ecological network research has been typically limited to either pure food webs or to networks of only a few (
Authors
Sonia Kéfi, Eric L. Berlow, Evie A. Wieters, Sergio A. Navarrete, Owen L. Petchey, Spencer A. Wood, Alice Boit, Lucas N. Joppa, Kevin D. Lafferty, Richard J. Williams, Neo D. Martinez, Bruce A. Menge, Carol A. Blanchette, Alison C. Iles, Ulrich Brose
New parasites and predators follow the introduction of two fish species to a subarctic lake: implications for food-web structure and functioning
Introduced species can alter the topology of food webs. For instance, an introduction can aid the arrival of free-living consumers using the new species as a resource, while new parasites may also arrive with the introduced species. Food-web responses to species additions can thus be far more complex than anticipated. In a subarctic pelagic food web with free-living and parasitic species, two fish
Authors
Per-Arne Amundsen, Kevin D. Lafferty, Rune Knudsen, Raul Primicerio, Roar Kristoffersen, Anders Klemetsen, Armand M. Kuris
Shading decreases the abundance of the herbivorous California horn snail, Cerithidea californica
Most of the intertidal zone in estuaries of California, USA and Baja California, Mexico is covered with vascular vegetation. Shading by these vascular plants influences abiotic and biotic processes that shape benthic community assemblages. We present data on the effects of shading on the California horn snail, Cerithidea californica. This species is important because it is the most common benthic
Authors
Julio Lorda, Kevin D. Lafferty
Effects of spatial subsidies and habitat structure on the foraging ecology and size of geckos
While it is well established that ecosystem subsidies—the addition of energy, nutrients, or materials across ecosystem boundaries—can affect consumer abundance, there is less information available on how subsidy levels may affect consumer diet, body condition, trophic position, and resource partitioning among consumer species. There is also little information on whether changes in vegetation struc
Authors
Amy A. Briggs, Hillary S. Young, Douglas J. McCauley, Stacie A. Hathaway, Rodolfo Dirzo, Robert N. Fisher
Cryptic extinction of a common Pacific lizard Emoia impar (Squamata, Scincidae) from the Hawaiian Islands.
Most documented declines of tropical reptiles are of dramatic or enigmatic species. Declines of widespread species tend to be cryptic. The early (1900s) decline and extinction of the common Pacific skink Emoia impar from the Hawaiian Islands is documented here through an assessment of literature, museum vouchers and recent fieldwork. This decline appears contemporaneous with the documented decline
Authors
Robert Fisher, Ivan Ineich
Serologic and molecular evidence for testudinid herpesvirus 2 infection in wild Agassiz’s desert tortoise, Gopherus agassizii
Following field observations of wild Agassiz’s desert tortoises (Gopherus agassizii) with oral lesions similar to those seen in captive tortoises with herpesvirus infection, we measured the prevalence of antibodies to Testudinid herpesvirus (TeHV) 3 in wild populations of desert tortoises in California. The survey revealed 30.9% antibody prevalence. In 2009 and 2010, two wild adult male desert tor
Authors
Elliott R. Jacobson, Kristin H. Berry, James F. X. Wellehan, Francesco Origgi, April L. Childress, Josephine Braun, Mark Schrenzel, Julie Yee, Bruce Rideout
Phenology, growth, and fecundity as determinants of distribution in closely related nonnative taxa
Invasive species researchers often ask: Why do some species invade certain habitats while others do not? Ecological theories predict that taxonomically related species may invade similar habitats, but some related species exhibit contrasting invasion patterns. Brassica nigra, Brassica tournefortii, and Hirschfeldia incana are dominant, closely related nonnative species that have overlapping, but d
Authors
Robin G. Marushia, Matthew L. Brooks, Jodie S. Holt
Ontogenetic and among-individual variation in foraging strategies of northeast Pacific white sharks based on stable isotope analysis
There is growing evidence for individuality in dietary preferences and foraging behaviors within populations of various species. This is especially important for apex predators, since they can potentially have wide dietary niches and a large impact on trophic dynamics within ecosystems. We evaluate the diet of an apex predator, the white shark (Carcharodon carcharias), by measuring the stable carb
Authors
S.L. Kim, M. Tim Tinker, J. A. Estes, P.L. Koch