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Status Of The Common Snook (Centropomus Undecimalis) In Texas, Kevin L. Pope, David R. Blankinship, Mark Fisher, Reynaldo Patiño Nov 2006

Status Of The Common Snook (Centropomus Undecimalis) In Texas, Kevin L. Pope, David R. Blankinship, Mark Fisher, Reynaldo Patiño

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Catch data are summarized for common snook (Centropomus undecimalis) from 1975 through 2004 from the lower Laguna Madre, the only area along the Texas coast where common snook are routinely captured. Catch rates of common snook were low < 1 common snook per gill net set) and varied among years, as did size structure. Based on the catch rate and size structure data, the adult common snook population is characterized by low abundance and erratic recruitment (i.e., missing or extremely weak year-classes are common). Additional comments on the status of common snook in Texas are provided.


A Framework For Spatial Risk Assessments: Potential Impacts Of Nonindigenous Invasive Species On Native Species, Craig R. Allen, Alan R, Johnson, Leslie Parris Jan 2006

A Framework For Spatial Risk Assessments: Potential Impacts Of Nonindigenous Invasive Species On Native Species, Craig R. Allen, Alan R, Johnson, Leslie Parris

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Many populations of wild animals and plants are declining and face increasing threats from habitat fragmentation and loss as well as exposure to stressors ranging from toxicants to diseases to invasive nonindigenous species. We describe and demonstrate a spatially explicit ecological risk assessment that allows for the incorporation of a broad array of information that may influence the distribution of an invasive species, toxicants, or other stressors, and the incorporation of landscape variables that may influence the spread of a species or substances. The first step in our analyses is to develop species models and quantify spatial overlap between stressor ...


Sprawl And The Resilience Of Humans And Nature: An Introduction To The Special Feature, Craig R. Allen Jan 2006

Sprawl And The Resilience Of Humans And Nature: An Introduction To The Special Feature, Craig R. Allen

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Human-driven change in land use and land cover is an accelerating global phenomenon with farreaching implications for food production, forest and water resources, the climate, and biogeochemical cycles (Foley et al. 2005). It affects the amount and configuration of habitat available for animals ranging from soil nematodes to elephants. It affects the provision of ecological goods and services for human beings. It affects the processes and function of ecosystems. “Sprawl”, as it has been termed, is exurban human land use change with a footprint exceeding the minimum required for the activity developed. It is that disproportionately large footprint that defines ...


Multimodel Inference And The Understanding Of Complexity, Discontinuity, And Normadism, Craig R. Allen, Denis A. Saunders Jan 2006

Multimodel Inference And The Understanding Of Complexity, Discontinuity, And Normadism, Craig R. Allen, Denis A. Saunders

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Nomadism has received surprisingly little attention in the ecological literature, and further work in this area is needed. The results of Woinarski’s reanalysis of our research findings are broadly similar to our own, and they support our original interpretation. However, his presentation is confusing and difficult to interpret.We used an information-theoretic approach to multimodel selection. We a priori defined plausible candidate models relating the variables described in our original paper or Woinarski’s reanalysis to the phenomenon of nomadism. We tested models that investigate nomadism as a function of nectivory, granivory, diet diversity, mixed diet, distance to body ...


Life-History And Ecological Correlates Of Geographic Variation In Egg And Clutch Mass Among Passerine Species, Thomas E. Martin, R. D. Bassar, S. K. Bassar, J. J. Fontaine, P. Lloyd, H. A. Mathewson, A. M. Niklison, A. Chalfoun Jan 2006

Life-History And Ecological Correlates Of Geographic Variation In Egg And Clutch Mass Among Passerine Species, Thomas E. Martin, R. D. Bassar, S. K. Bassar, J. J. Fontaine, P. Lloyd, H. A. Mathewson, A. M. Niklison, A. Chalfoun

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Broad geographic patterns in egg and clutch mass are poorly described, and potential causes of variation remain largely unexamined. We describe interspecific variation in avian egg and clutch mass within and among diverse geographic regions and explore hypotheses related to allometry, clutch size, nest predation, adult mortality, and parental care as correlates and possible explanations of variation. We studied 74 species of Passeriformes at four latitudes on three continents: the north temperate United States, tropical Venezuela, subtropical Argentina, and south temperate South Africa. Egg and clutch mass increased with adult body mass in all locations, but differed among locations for ...


Multiple Hypotheses Testing Of Fish Incidence Patterns In An Urbanized Ecosystem, Christopher J. Chizinski, C.L. Higgins, C.E. Shavlik, Kevin L. Pope Jan 2006

Multiple Hypotheses Testing Of Fish Incidence Patterns In An Urbanized Ecosystem, Christopher J. Chizinski, C.L. Higgins, C.E. Shavlik, Kevin L. Pope

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Ecological and evolutionary theories have focused traditionally on natural processes with little attempt to incorporate anthropogenic influences despite the fact that humans are such an integral part of virtually all ecosystems. A series of alternate models that incorporated anthropogenic factors and traditional ecological mechanisms of invasion to account for fish incidence patterns in urban lakes was tested. The models were based on fish biology, human intervention, and habitat characteristics. However, the only models to account for empirical patterns were those that included fish invasiveness, which incorporated speciesspecific information about overall tolerance and fecundity. This suggests that species-specific characteristics are more ...


Predictors Of Introduction Success In The South Florida Avifauna, Craig R. Allen Jan 2006

Predictors Of Introduction Success In The South Florida Avifauna, Craig R. Allen

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Biological invasions are an increasing global challenge, for which single-species studies and analyses focused on testing single hypotheses of causation in isolation are unlikely to provide much additional insight. Species interact with other species to create communities, which derive from species interactions and from the interactions of species with the scale specific elements of the landscape that provide suitable habitat and exploitable resources. I used logistic regression analysis to sort among potential intrinsic, community and landscape variables that theoretically influence introduction success. I utilized the avian fauna of the Everglades of South Florida, and the variables body mass, distance to ...


Parent Birds Assess Nest Predation Risk And Adjust Their Reproductive Strategies, J. J. Fontaine, T. E. Martin Jan 2006

Parent Birds Assess Nest Predation Risk And Adjust Their Reproductive Strategies, J. J. Fontaine, T. E. Martin

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Avian life history theory has long assumed that nest predation plays a minor role in shaping reproductive strategies. Yet, this assumption remains conspicuously untested by broad experiments that alter environmental risk of nest predation, despite the fact that nest predation is a major source of reproductive failure. Here, we examined whether parents can assess experimentally reduced nest predation risk and alter their reproductive strategies. We experimentally reduced nest predation risk and show that in safer environments parents increased investment in young through increased egg size, clutch mass, and the rate they fed nestlings. Parents also increased investment in female condition ...


Temperature-Caused Fish Kill In A Flowing Great Plains River, Bart W. Durham, Gene R. Wilde, Kevin L. Pope Jan 2006

Temperature-Caused Fish Kill In A Flowing Great Plains River, Bart W. Durham, Gene R. Wilde, Kevin L. Pope

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

On 9 July 2002, while sampling a flowing segment of the North Fork Ninnescah River 10 km upstream from Cheney Reservoir, Reno County, Kansas, we observed and collected dead and dying specimens of 5 fish species. We attribute the fish kill to high water temperature, which reached 38.0°C on this day.


When Landscaping Goes Bad: The Incipient Invasion Of Mahonia Bealei In The Southeastern United States, Craig R. Allen, Ahjond S. Garmestani, Jill A. Labram, Amanda E. Peck, Luanna B. Prevost Jan 2006

When Landscaping Goes Bad: The Incipient Invasion Of Mahonia Bealei In The Southeastern United States, Craig R. Allen, Ahjond S. Garmestani, Jill A. Labram, Amanda E. Peck, Luanna B. Prevost

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

Woodlots are forest islands embedded within an urban matrix, and often represent the only natural areas remaining in suburban areas. Woodlots represent critical conservation areas for native plants, and are important habitat for wildlife in urban areas. Invasion by non-indigenous (NIS) plants can alter ecological structure and function, and may be especially severe in remnant forests where NIS propagule pressure is high. Woody shrubs in the Family Berberidaceae have been well documented as invaders of the forest–urban matrix in North America. Mahonia bealei (Berberidaceae) is a clonal shrub native to China, and is a popular ornamental in the Southeastern ...


Firm Size Diversity, Functional Richness, And Resilience, Ahjond S. Garmestani, Craig R. Allen, John D. Mittelstaedt, Craig A. Stow, William A. Ward Jan 2006

Firm Size Diversity, Functional Richness, And Resilience, Ahjond S. Garmestani, Craig R. Allen, John D. Mittelstaedt, Craig A. Stow, William A. Ward

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

This paper applies recent advances in ecology to our understanding of firm development, sustainability, and economic development. The ecological literature indicates that the greater the functional richness of species in a system, the greater its resilience – that is, its ability to persist in the face of substantial changes in the environment. This paper focuses on the effects of functional richness across firm size on the ability of industries to survive in the face of economic change. Our results indicate that industries with a richness of industrial functions are more resilient to employment volatility.


Habitat Selection Responses Of Parents To Offspring Predation Risk: An Experimental Test, J. J. Fontaine, T. E. Martin Jan 2006

Habitat Selection Responses Of Parents To Offspring Predation Risk: An Experimental Test, J. J. Fontaine, T. E. Martin

Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications

The ability of nest predation to influence habitat settlement decisions in birds is widely debated, despite its importance in limiting fitness. Here, we experimentally manipulated nest predation risk across a landscape and asked the question, do migratory birds assess and respond to variation in nest predation risk when choosing breeding habitats? We examined habitat preference by quantifying the density and settlement date of eight species of migratory passerines breeding in areas with and without intact nest predator communities. We found consistently more individuals nesting in areas with reduced nest predation than in areas with intact predator assemblages, although predation risk ...