Steve Blumenshine | California State University, Fresno (original) (raw)

Papers by Steve Blumenshine

Urbanization presents novel challenges to native species by altering both the biotic and abiotic ... more Urbanization presents novel challenges to native species by altering both the biotic and abiotic environment. Studies have attempted to make generalizations about how species with similar traits respond to urbanization, although existing results are idiosyncratic across cities and often fail to account for seasonality. Here, we present a comparative study in three US cities: Fresno, California; Tucson, Arizona; and Phoenix, Arizona. Using presence-absence data to define regional bird species pools and urban assemblages in non-breeding (winter) and breeding (spring) seasons, we tested whether urban avian assemblages were a random subset of regional assemblages on the basis of both traits and phylogeny, and whether urbanization was associated with homogenization among avian assemblages. We found evidence for non-random trait filtering into urban assemblages, including of diet guilds, migratory status, and primary habitat, but filtering differed across cities and seasons, being strongest for diet and in Fresno. There was no evidence for non-random phylogenetic-based filtering in urban avian assemblages. Dissimilarity in species and diet guild composition within each season was higher between cities than between regional species pools. These findings show the potential for biotic differentiation as opposed to homogenization as the outcome of environmental filtering processes operating on species traits across cities and seasons.

Ecosystems, 2015

Rose Abramoff D.J. Abson Michael Acreman Andre Amado Ron Amundson David Angeler Niels Anten Ichir... more Rose Abramoff D.J. Abson Michael Acreman Andre Amado Ron Amundson David Angeler Niels Anten Ichiro Aoki Christina Aponte Júlio Araújo Ernesto Arias Gonzalez Anna Armitage Stefan Arndt Chelsea Arnold Kevin Arrigo Isabel Ashton Owen Atkin Amy Austin Patricia Backwell Dan Baird Troy Baisden Ronald Baker Elisabeth Bakker Ashley Baldridge Jennifer Baltzer Joel Daniel Barker Paul Barnes Rebecca Barnes Noelia Barrios-Garcia Marissa Baskett Ryan Batt Sarah Batterman Robert Baxter Pieter Beck Justin Becknell Asmeret Asefaw Berhe Melody Bernot Andrea Bertolo Sukaina Bharwani Bopi Biddanda Lori Biederman Michael Billett Michael Bird Rich Birdsey Robert Bjork Jaap Bloem Steve Blumenshine Patrick Bohlen Ben Bond-Lamberty Richard Bowden David Bowman Luz Boyero Martin Braakhekke Mark Bradford Bethany Bradley Kari Anne Bråthen Sarah Bray Michael Brett Nick Brokaw Barry Brook Peter Brown Linda Brubaker Lee Bryant Michaela Buenemann Amy Burgin Douglas Burns Matthew Burns Ryan Burrows David Butman Gilbert Cabana Colin Campbell Zoe Cardon Pedro Cardoso Joel Carr Marco Carrer Analı́a Carrera Tancredi Caruso Pere Casals Peter Casper Xavier Cavard Silvia Ceausu Oliver Chadwick Jeanne Chambers Samantha Chapman Robin Chazdon John Cheeseman Beth Cheever Weixin Cheng Chelsea Chisholm Norm Christensen Lynn Christenson Natalie Cleavitt Mark Clegg Elsa Cleland Karina Clemmensen Cory Cleveland Jonathan Cole David Coleman Marta Coll Jana Compton Rich Conant Georgina Conti Caren Cooper Joseph Craine John Crawford Susan Crow Katherine Crowley Jennifer Crumsey Christopher Curtis P. Jeff Curtis Paolo D’Odorico Loı̈c D’Orangeville Jeffrey Dambacher Etienne Dambrine Michael Dannenmann Anthony Darrouzet-Nardi Francesco de Bello Nathan De Jager Martin De Kauwe Guillaume de Lafontaine P.C. de Ruiter Donald DeAngelis Maire Lise Delgard John DeLong Thomas DeLuca Jennie DeMarco Raphael Didham Mike Dietze Feike Dijkstra Ecosystems (2015) 18: 359–362 DOI: 10.1007/s10021-015-9840-6

A goal of the San Joaquin River Restoration Program is to restore self-sustaining populations of ... more A goal of the San Joaquin River Restoration Program is to restore self-sustaining populations of the southern-most fall and spring runs of Chinook salmon in North America. One of the main criteria for success is the availability of suitable rearing habitat for juvenile salmonids, including seasonal floodplains. Historically, juvenile Chinook salmon life stages coincided with storm and snowmelt-driven flood pulses, which inundated thousands of Central Valley floodplain acres. But now water supply and pulses are largely managed for human uses. This talk will address our collaborative approach to this important local issue of how apparently conflicting water demands can be ameliorated. For example, some project goals have been modified in response to the recent drought in a rather opportunistic way. This year we monitored juvenile salmon ecology in the absence of floodplain habitats due to the drought. This will allow us to address the conventional wisdom that juvenile Chinook require ...

Oecologia, 2000

The cascade model successfuly predicts many patterns in reported food webs. A key assumption of t... more The cascade model successfuly predicts many patterns in reported food webs. A key assumption of this model is the existence of a predetermined trophic hierarchy; prey are always lower in the hierarchy than their predators. At least three studies have suggested that, in animal food webs, this hierarchy can be explained to a large extent by body size relationships. A second assumption of the standard cascade model is that trophic links not prohibited by the hierarchy occur with equal probability. Using nonparametric contingency table analyses, we tested this "equiprobability hypothesis" in 16 published animal food webs for which the adult body masses of the species had been estimated. We found that when the hierarchy was based on body size, the equiprobability hypothesis was rejected in favor of an alternative, "predator-dominance" hypothesis wherein the probability of a trophic link varies with the identity of the predator. Another alternative to equiprobabilty is that the probability of a trophic link depends upon the ratio of the body sizes of the two species. Using nonparametric regression and liklihood ratio tests, we show that a size-ratio based model represents a significant improvement over the cascade model. These results suggest that models with heterogeneous predation probabilities will fit food web data better than the homogeneous cascade model. They also suggest a new way to bridge the gap between static and dynamic food web models.

North American Journal of Fisheries Management, 2004

Aquatic Invasions, 2012

The Chinese mitten crab is an invasive catadromous species that has populated many European estua... more The Chinese mitten crab is an invasive catadromous species that has populated many European estuaries. However, despite repeated 'introductions', the only known established North American population is in the San Francisco Bay Delta, along with recent populations discovered in Chesapeake Bay and the Hudson River. In established populations, adult mitten crab numbers oscillate dramatically, and large numbers of crabs can have severe environmental impacts. Extremely little is known about the biology and ecology of juvenile stages, but understanding the factors behind new cohort survival is crucial for understanding the dynamics of newly-established populations. In this study, we use the only known long-term life-history data set to assess the relative importance of reproductive potential and environmental factors in regulating mitten crab population dynamics in San Francisco Bay. Both exploratory regression tree and bivariate data analyses support the hypotheses that concentrations of planktonic zoeae are strongly influenced by interactions between the number of breeding female crabs, the timing of reproduction, and water temperature. Additional studies are needed in other estuaries invaded by mitten crabs to test the generalities of these relationships and further evaluate the potential of these relationships to inform predictions about the extent and magnitude of mitten crab populations.

In 2007, a comprehensive long-term river restoration project was initiated on the San Joaquin Riv... more In 2007, a comprehensive long-term river restoration project was initiated on the San Joaquin River. This project was implemented in order to rehabilitate the river habitat as well as in reintroduces a selfsustaining population of naturally reproducing Chinook salmon (Oncorhynchus Tshawytscha) (FMP, 2010). A significant problem with any reintroduction project is the overestimation of available habitat, which can lead to unrealistic reintroduction goals (Geist, 2000). Currently there is limited knowledge of the use of available rearing habitat by the juvenile Chinook salmon on the San Joaquin River; due to the extirpation of the species over 60 years ago (Yoshiyama, 1996). In normal wet years, juvenile Chinook salmon rear in floodplains to gain weight and strength before their migration to the sea. However, due to the persistent drought that has engulfed the San Joaquin Valley there is a lack of floodplain habitat. . Therefore, we set out to investigate the mainstem river (four locat...

Growth of juvenile salmonids is a critical variable affecting survival and recruitment to success... more Growth of juvenile salmonids is a critical variable affecting survival and recruitment to successive life history stages, essentially affecting the strength of subsequent cohorts. Consumption and temperature are key variables affecting growth for fishes in general. Temperature dictates the metabolic efficiency of prey conversion to production, and is thus a primary variable affecting growth. However, temperature optima and thresholds are variable for Pacific salmon populations. Yet many researchers using bioenergetic approaches to understand growth use temperature-dependent equations and coefficients for Chinook Salmon published in Steward & Ibarra (1991), which is based on adults from Lake Michigan, and uses coefficients from other salmonid species. To address this problem, we are using an approach using several lines of evidence to better understand relationships between temperature and growth. We focus this effort on juvenile Chinook Salmon used in the San Joaquin River Restorati...

Frontiers in Ecology and Evolution

Scaling Relations in Experimental Ecology, 2001

Environmental Science & Technology, 2014

Environmental Biology of Fishes, 2006

Environmental Science & Technology, 2014

Aquatic Invasions, 2012

Oecologia, 2000

The cascade model successfuly predicts many patterns in reported food webs. A key assumption of t... more The cascade model successfuly predicts many patterns in reported food webs. A key assumption of this model is the existence of a predetermined trophic hierarchy; prey are always lower in the hierarchy than their predators. At least three studies have suggested that, in animal food webs, this hierarchy can be explained to a large extent by body size relationships. A second assumption of the standard cascade model is that trophic links not prohibited by the hierarchy occur with equal probability. Using nonparametric contingency table analyses, we tested this "equiprobability hypothesis" in 16 published animal food webs for which the adult body masses of the species had been estimated. We found that when the hierarchy was based on body size, the equiprobability hypothesis was rejected in favor of an alternative, "predator-dominance" hypothesis wherein the probability of a trophic link varies with the identity of the predator. Another alternative to equiprobabilty is that the probability of a trophic link depends upon the ratio of the body sizes of the two species. Using nonparametric regression and liklihood ra-tio tests, we show that a size-ratio based model represents a significant improvement over the cascade model. These results suggest that models with heterogeneous predation probabilities will fit food web data better than the homogeneous cascade model. They also suggest a new way to bridge the gap between static and dynamic food web models.

North American Journal of Fisheries Management, 2004

Fisheries managers seldom have adequate information to assess their stock losses to avian piscivo... more Fisheries managers seldom have adequate information to assess their stock losses to avian piscivores, which function as apex predators in many aquatic food webs. Our primary objective was to estimate the number of stocked rainbow trout Oncorhynchus mykiss consumed by great blue herons Ardea herodias on the Bull Shoals and Norfork tailwaters of north-central Arkansas. Between November 2000 and December 2001, we periodically surveyed great blue herons along 150.7 river km on the tailwaters of the Bull Shoals and Norfork dams. Heron density (number/km) in or along the river ranged from 0 to 4/km per survey, with the highest mean number located near the Bull Shoals Dam (2.31 herons/km). We recorded 467 prey captures by herons during 202 observation hours. Sculpin Cottus spp. were the most common prey (N ϭ 120). Most prey (87%) measured 14 cm or less in length, and most captured live trout (85.4%) fell between 10.5 and 28.0 cm in length. While live trout represented only 48 of 359 identifiable prey items (13%), they comprised an estimated 62.8% of heron diet biomass. We developed a bioenergetics model that combined our observations with published metabolic coefficients and relationships to estimate heron energy demand during breeding and nonbreeding seasons. This analysis revealed that trout comprised an estimated 67% of heron daily energy demand in the study area. Heron daily energy demand peaked during the breeding season (March-May). Based on a mean monthly population estimate of 227 great blue herons requiring 156 million kJ of total energy/year, we calculated that herons consumed just under 50,000 catchable-sized stocked trout annually. This loss to great blue herons represents an estimated 2.4% of the approximately 2 million trout stocked in the study area. Thus, great blue heron predation likely represents only a minor source of trout mortality in the Bull Shoals and Norfork tailwaters.

Aquatic Invasions, 2012

Ecosystems, 2015

Oecologia, 2000

North American Journal of Fisheries Management, 2004

Aquatic Invasions, 2012

Frontiers in Ecology and Evolution

Scaling Relations in Experimental Ecology, 2001

Environmental Science & Technology, 2014

Environmental Biology of Fishes, 2006

Environmental Science & Technology, 2014

Aquatic Invasions, 2012

Oecologia, 2000

The cascade model successfuly predicts many patterns in reported food webs. A key assumption of t... more The cascade model successfuly predicts many patterns in reported food webs. A key assumption of this model is the existence of a predetermined trophic hierarchy; prey are always lower in the hierarchy than their predators. At least three studies have suggested that, in animal food webs, this hierarchy can be explained to a large extent by body size relationships. A second assumption of the standard cascade model is that trophic links not prohibited by the hierarchy occur with equal probability. Using nonparametric contingency table analyses, we tested this "equiprobability hypothesis" in 16 published animal food webs for which the adult body masses of the species had been estimated. We found that when the hierarchy was based on body size, the equiprobability hypothesis was rejected in favor of an alternative, "predator-dominance" hypothesis wherein the probability of a trophic link varies with the identity of the predator. Another alternative to equiprobabilty is that the probability of a trophic link depends upon the ratio of the body sizes of the two species. Using nonparametric regression and liklihood ra-tio tests, we show that a size-ratio based model represents a significant improvement over the cascade model. These results suggest that models with heterogeneous predation probabilities will fit food web data better than the homogeneous cascade model. They also suggest a new way to bridge the gap between static and dynamic food web models.

North American Journal of Fisheries Management, 2004

Aquatic Invasions, 2012