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- Invasive species (8)
- Scale (6)
- Florida (5)
- Nest predation (5)
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- Solenopsis invicta (5)
- Adaptive management (4)
- Growth (4)
- Biodiversity (3)
- Birds (3)
- Black crappie (3)
- Body mass (3)
- Clutch size (3)
- Morone americana (3)
- Predation (3)
- Red imported fire ant (3)
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- Allometry (2)
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- Everglades (2)
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- Habitat selection (2)
- Life history (2)
- Micropterus salmoides (2)
- Papilio aristodemus (2)
Articles 61 - 90 of 101
Full-Text Articles in Other Environmental Sciences
Yellow Jackets May Be An Underestimated Component Of An Ant-Seed Mutualism, Megan T. Bale, Jennifer A. Zettler, Bradford A. Robinson, Timothy P. Spira, Craig R. Allen
Yellow Jackets May Be An Underestimated Component Of An Ant-Seed Mutualism, Megan T. Bale, Jennifer A. Zettler, Bradford A. Robinson, Timothy P. Spira, Craig R. Allen
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Yellow jackets (Hymenoptera: Vespidae) are attracted to the typically ant-dispersed seeds of trilliums and will take seeds from ants in the genus Aphaeogaster. To determine if yellow jacket, Vespulla maculifrons (Buysson), presence interferes with seed foraging by ants, we presented seeds of Trillium discolor Wray to three species (A. texana carolinesis Wheeler, Formica schaufussi Mayr, and Solenopsis invicta Buren) of seed-carrying ants in areas where vespids were present or excluded. We found that interspecific aggression between yellow jackets and ants is species specific. Vespid presence decreased average foraging time and increased foraging efficiency of two of the three …
Adaptive Inference For Distinguishing Credible From Incredible Patterns In Nature, C. S. Holling, Craig R. Allen
Adaptive Inference For Distinguishing Credible From Incredible Patterns In Nature, C. S. Holling, Craig R. Allen
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Strong inference is a powerful and rapid tool that can be used to identify and explain patterns in molecular biology, cell biology, and physiology. It is effective where causes are single and separable and where discrimination between pairwise alternative hypotheses can be determined experimentally by a simple yes or no answer. But causes in ecological systems are multiple and overlapping and are not entirely separable. Frequently, competing hypotheses cannot be distinguished by a single unambiguous test, but only by a suite of tests of different kinds, that produce a body of evidence to support one line of argument and not …
Biodiversity Of Fungi In Red Imported Fire Ant (Hymenoptera: Formicidae) Mounds, Jennifer A. Zettler, Thomas M. Mcinnis Jr., Craig R. Allen, Timothy P. Spira
Biodiversity Of Fungi In Red Imported Fire Ant (Hymenoptera: Formicidae) Mounds, Jennifer A. Zettler, Thomas M. Mcinnis Jr., Craig R. Allen, Timothy P. Spira
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The red imported fire ant, Solenopsis invicta Buren, became established in North America more than 70 yr ago, and it currently occupies most of the southeastern United States. Fire ants change the physical and chemical components of soil, which likely infuence soil fungi in ant mounds. To determine the effects of fire ants on soil fungi, we sampled soil from fire ant mounds and the surrounding nonmound soil. In addition, we sampled soil from the nests of the native ant Aphaenogaster texana carolinensis Wheeler. We found that both fire ant mounds and native ant nests had greater fungal abundance but …
Cross-Scale Structure And Scale Breaks In Ecosystems And Other Complex Systems, Craig R. Allen, C. S. Holling
Cross-Scale Structure And Scale Breaks In Ecosystems And Other Complex Systems, Craig R. Allen, C. S. Holling
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The five articles in this special feature extend the discovery of regular patterns of deviation from scaling laws and from continuous distributions of attributes in ecosystems and other complex systems. These patterns suggest that these systems organize over discrete ranges of scale and that organization abruptly shifts with changes in scale. If this is so, scaling laws (for example, see West 1997, 1999; Zipf 1949) serve only as the baseline from which to measure those departures, and those departures indicate “scale breaks” (transitions) between scales of structure in complex systems. Patterns in the deviations from a scaling-law baseline may provide …
Variability Between Scales: Predictors Of Nomadism In Birds Of An Australian Mediterraneanclimate Ecosystem, Craig R. Allen, Denis A. Saunders
Variability Between Scales: Predictors Of Nomadism In Birds Of An Australian Mediterraneanclimate Ecosystem, Craig R. Allen, Denis A. Saunders
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Nomadism in animals is a response to resource distributions that are highly variable in time and space. Using the avian fauna of the Mediterranean-climate region of southcentral Australia, we tested a number of variables to determine if they predicted nomadism. These variables were species body mass, the distance in body mass terms to the edge of a body mass aggregation, and diet (for example, seeds, invertebrates, nectar, or plants). We utilized two different classifications of the avifauna that diverged in their definition of nomadic to build two different predictive models. Using both classifications, distance to the edge of a body …
Cross-Scale Morphology, Craig R. Allen, C.S. Holling
Cross-Scale Morphology, Craig R. Allen, C.S. Holling
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The scaling of physical, biological, ecological and social phenomena has become a major focus of efforts to develop simple representations of complex systems. Much of the attention has been on discovering universal scaling laws that emerge from simple physical and geometric processes. But there are regular patterns of departures both from those scaling laws and from continuous distributions of attributes of systems; these departures often demonstrate the development of self-organized interactions between living systems and physical processes over narrower ranges of scale. Cross-scale morphology refers to morphological attributes of animals that are influenced by interaction with ecological structures and patterns …
Influence Of The Proximity And Amount Of Human Development And Roads On The Occurrence Of The Red Imported Fire Ant In The Lower Florida Keys, Elizabeth A. Forys, Craig R. Allen, Daniel P. Wojcik
Influence Of The Proximity And Amount Of Human Development And Roads On The Occurrence Of The Red Imported Fire Ant In The Lower Florida Keys, Elizabeth A. Forys, Craig R. Allen, Daniel P. Wojcik
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
We examined the influence of both the proximity and extent of human developments and paved roads on the presence of the predatory, non-indigenous, red imported fire ant (Solenopsis invicta). This species was inadvertently introduced into the United States at the port of Mobile, Alabama, around 1930 and rapidly spread to many southeastern states, including Florida. More recently, S. invicta colonized the Florida Keys, an area with a high proportion of rare and endemic vertebrate and invertebrate species. We placed bait transects in transitional salt-marsh, pineland, and hardwood hammocks on 13 of the lower Florida Keys and compared habitat …
Implications Of Body Mass Patterns: Linking Ecological Structure And Process To Wildlife Conservation And Management, Jan P. Sendzimir, Craig R. Allen, Lance H. Gunderson, Craig A, Stow
Implications Of Body Mass Patterns: Linking Ecological Structure And Process To Wildlife Conservation And Management, Jan P. Sendzimir, Craig R. Allen, Lance H. Gunderson, Craig A, Stow
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The unprecedented scale of problems affecting wildlife ecology today overwhelms many managers. Challenges are no longer local in origin, but rather a tangle of local, regional and even global externalities often interacting in unpredictable ways. Previously isolated ecosystems have become increasingly connected at global, hemispheric and regional levels, eroding their integrity. Endocrine-disrupting compounds applied in Mexico have changed avian sexual development in the Great Lakes (Colborn et al. 1996). Chamois (Rupicapra rupicapra) reproduction in the Carpathian mountains falters when the color of newborns is no longer cryptic because climate change prematurely melts snow cover (K. Perzanowski, Polish Academy …
Assessing State-Wide Biodiversity In The Florida Gap Analysis Project, L. G. Pearlstine, S. E. Smith, L. A. Brandt, C. R. Allen, W. M. Kitchens, J. Stenberg
Assessing State-Wide Biodiversity In The Florida Gap Analysis Project, L. G. Pearlstine, S. E. Smith, L. A. Brandt, C. R. Allen, W. M. Kitchens, J. Stenberg
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The Florida Gap (FI-Gap) project provides an assessment of the degree to which native animal species and natural communities are or are not represented in existing conservation lands. Those species and communities not adequately represented in areas being managed for native species constitute 'gaps' in the existing network of conservation lands. The United States Geological Survey Gap Analysis Program is a national effort and so, eventually, all 50 states will have completed it. The objective of FI-Gap was to provide broad geographic information on the status of terrestrial vertebrates, butterflies, skippers and ants and their respective habitats to address the …
Initial Mortality Of Black Bass In B.A.S.S. Fishing Tournaments, Gene R. Wilde, Calub E. Shavlik, Kevin L. Pope
Initial Mortality Of Black Bass In B.A.S.S. Fishing Tournaments, Gene R. Wilde, Calub E. Shavlik, Kevin L. Pope
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
We studied the initial mortality of black bass Micropterus spp. that were captured, weighed in, and released in fishing tournaments conducted by the Bass Anglers Sportsman Society between 1972 and 1998. Mean annual initial mortality (i.e., mortality before weigh-in and release) ranged from 1% to 30%. Initial mortality was greatest during the 1970s (15.2%) and decreased during the 1980s (5.7%) and 1990s (1.9%). Because initial mortality was uniformly low ( ≤5%) after 1982, we used results for 1983–1998 to assess relationships involving initial mortality. Initial mortality was correlated with bag size, mean fish weight per angler, and number of fish …
Functional Group Change Within And Across Scales Following Invasions And Extinctions In The Everglades Ecosystem, Elizabeth A. Forys, Craig R. Allen
Functional Group Change Within And Across Scales Following Invasions And Extinctions In The Everglades Ecosystem, Elizabeth A. Forys, Craig R. Allen
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Cross-scale resilience theory predicts that the combination of functional diversity within scales and functional redundancy across scales is an important attribute of ecosystems because it helps these systems resist minor ecological disruptions and regenerate after major disturbances such as hurricanes and fire. Using the vertebrate fauna of south Florida, we quantified how the loss of native species and invasion by nonnatives may alter functional group richness within and across scales. We found that despite large changes in species composition due to potential extinctions and successful invasions by nonnative species, functional group richness will not change significantly within scales, there will …
Ant–Seed Mutualisms: Can Red Imported Fire Ants Sour The Relationship?, Jennifer A. Zettler, Timothy P. Spira, Craig R. Allen
Ant–Seed Mutualisms: Can Red Imported Fire Ants Sour The Relationship?, Jennifer A. Zettler, Timothy P. Spira, Craig R. Allen
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. …
The Spatial Distribution Of Diversity Between Disparate Taxa: Spatial Correspondence Between Mammals And Ants Across South Florida, Usa, Craig R. Allen, L. G. Pearlstine, D.P. Wojcik, W.M. Kitchens
The Spatial Distribution Of Diversity Between Disparate Taxa: Spatial Correspondence Between Mammals And Ants Across South Florida, Usa, Craig R. Allen, L. G. Pearlstine, D.P. Wojcik, W.M. Kitchens
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Gap Analysis takes a proactive landscape-level approach to conserving native species by identifying nodes of high biological diversity. It uses vertebrate species richness as an index of overall biological diversity. However, it remains unknownwhether or not the spatial distribution of vertebrate diversity correspondswith the diversity of other taxa. We tested whether landscape-level diversity patterns corresponded between a vertebrate and an invertebrate taxon, mammals and ants, across the southern half of the Florida peninsula, USA. Composite digital maps with a 30-m spatial resolution were produced for each taxon. Spatial correspondence between the taxa was determined by normalizing and then subtracting the …
Modeling Viable Mammal Populations In Gap Analyses, Craig R. Allen, L. G. Pearlstine
Modeling Viable Mammal Populations In Gap Analyses, Craig R. Allen, L. G. Pearlstine
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Gap analysis is an approach to conserving biological diversity that maps species richness and identifies sites that ought to be protected but are not in conservation networks. Gap analyses based on species richness may have high error rates when species models are based solely on species-habitat association, because patches too small to support populations are still considered to be potential habitat. We incorporated information on the home range and dispersal distances of the mammals of Florida to estimate minimum critical areas (MCA) to support minimum viable populations for each mammal species. Incorporating MCA decreases the area occupied by the highest …
Potential Fire Ant (Hymenoptera: Formicidae) Impact On The Endangered Schaus Swallowtail (Lepidoptera: Papilionidae), Elizabeth A. Forys, Anna Quistorff, Craig R. Allen
Potential Fire Ant (Hymenoptera: Formicidae) Impact On The Endangered Schaus Swallowtail (Lepidoptera: Papilionidae), Elizabeth A. Forys, Anna Quistorff, Craig R. Allen
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The Schaus swallowtail, Papilio aristodemus ponceanus, historically occurred in tropical hardwood hammocks from South Miami to the upper Florida Keys and is currently listed as federally endangered. Much of the remaining hardwood hammock habitat is fragmented by roads and human development that may alter the microhabitat within the hammocks and increase the probability of invasion by non-native predators and competitors. One non-indigenous species that has recently invaded the Florida Keys, and that may impact the Schaus swallowtail is the red imported fire ant (Solenopsis invicta Buren). We estimated abundance of red imported fire ants in Schaus swallowtail habitat …
Potential Fire Ant (Hymenoptera: Formicidae) Impact On The Endangered Schaus Swallowtail (Lepidoptera: Papilionidae), Elizabeth A. Forys, Anna Quistorff, Craig R. Allen
Potential Fire Ant (Hymenoptera: Formicidae) Impact On The Endangered Schaus Swallowtail (Lepidoptera: Papilionidae), Elizabeth A. Forys, Anna Quistorff, Craig R. Allen
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The Schaus swallowtail, Papilio aristodemus ponceanus , historically occurred in tropical hardwood hammocks from South Miami to the upper Florida Keys and is currently listed as federally endangered. Much of the remaining hardwood hammock habitat is fragmented by roads and human development that may alter the microhabitat within the hammocks and increase the probability of invasion by non-native predators and competitors. One non-indigenous species that has recently invaded the Florida Keys, and that may impact the Schaus swallowtail is the red imported fire ant ( Solenopsis invicta Buren). We estimated abundance of red imported fire ants in Schaus swallowtail habitat …
A Caloric-Based Evaluation Of Diet Indices For Largemouth Bass, Kevin Lee Pope, Michael Lee Brown, Walter Gilbert Duffy, Paul Herbert Michaletz
A Caloric-Based Evaluation Of Diet Indices For Largemouth Bass, Kevin Lee Pope, Michael Lee Brown, Walter Gilbert Duffy, Paul Herbert Michaletz
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Selection of methods for quantitative description and assessment of food habits is a concern for trophic investigations. We used diet data for largemouth bass Micropterus salmoides, to compare a caloric-based approach with eight diet indices: percent frequency of occurrence, percent total number, percent total weight, mean relative number, mean relative volume, relative importance index, prey-importance index, and mean stomach fullness. Mean caloric contribution of stomach contents for each prey taxon was used as a standard to compare diet indices. Temporal differences in composition and caloric contents of largemouth bass stomach contents were apparent. Most diet indices provided similar assessments …
Anglers Tagging And Marking Fish: Provincial And State Fishery Agency Views, Kevin L. Pope
Anglers Tagging And Marking Fish: Provincial And State Fishery Agency Views, Kevin L. Pope
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
In recent years, the involvement of anglers in fish tagging programs has begun to capture the interest of managers. I conducted a mail survey of provincial and state fishery agencies to discern where anglers could legally tag, mark, or attach telemetry devices to fish. In addition, I documented current provincial and state agency views toward fish tagging or marking by anglers. Anglers were allowed to tag or mark fish in most provinces and states; however, more restrictions were placed on marking and telemetering fish than on tagging. Of the issues covered in this survey, respondents indicated that fish mortality and …
The Likely Cause Of Extinction Of The Tree Snail Orthalicus Reses Reses (Say), E.A. Forys, A. Quistorff, Craig R. Allen, D.P. Wojcik
The Likely Cause Of Extinction Of The Tree Snail Orthalicus Reses Reses (Say), E.A. Forys, A. Quistorff, Craig R. Allen, D.P. Wojcik
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The Stock Island tree snail, Orthalicus reses reses, went extinct in its native range in the Florida Keys in 1992. Fortunately, O. r. reses has been introduced elsewhere and further reintroductions are currently planned. Before these reintroductions are implemented, it is important to try and determine which factors were most likely to have caused the decline and extinction. While habitat destruction was probably the ultimate reason why there were so few tree snails, it is likely that an interaction of habitat fragmentation and the invasion of an exotic predator caused the final decline that lead to the extinction in …
The Non-Indigenous Ant, Solenopsis Invicta, Reduces Loggerhead Shrike And Native Insect Abundance, Craig R. Allen, R. Scott Lutz, Tim Lockley, Sherman A. Phillips Jr., Stephen Demarais
The Non-Indigenous Ant, Solenopsis Invicta, Reduces Loggerhead Shrike And Native Insect Abundance, Craig R. Allen, R. Scott Lutz, Tim Lockley, Sherman A. Phillips Jr., Stephen Demarais
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The red imported fire ant (Solenopsis invicta Buren) is an aggressive, non-indigenous species that is a threat to native biota in the southeastern United States. We determined the effect of S. invicta on loggerhead shrike (Lanius ludovicianus L.) abundance and investigated a possible mechanism of impact, which is a reduction in insect prey availability. We used a fire ant bait (hydramethylnon) to reduce fire ant populations on one randomly chosen member of each of five pairs of 202-ha study areas in the Texas coastal Bend region, and also measured shrike relative abundance and a volumetric index of insect …
Red Imported Fire Ants: Impact On Biodiversity, Daniel P. Wojcik, Craig R. Allen, Richard J. Brenner, Elizabeth A. Forys, Donald P. Jouvenaz, R. Scott Lutz
Red Imported Fire Ants: Impact On Biodiversity, Daniel P. Wojcik, Craig R. Allen, Richard J. Brenner, Elizabeth A. Forys, Donald P. Jouvenaz, R. Scott Lutz
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The red imported fire ant, Solenopsis invicta Buren (hereafter referred to as imported fire ant), long considered a regional problem, is receiving renewed attention nationwide, with infestations found in Arizona, Maryland, Nevada, New Mexico, and Virginia (Mitchell 1996). Recently, infestations discovered in several regions of California caused great public concern (Brennan 1999, Schrader 1999). Initially, infestations appeared to be isolated in almond groves in Kern County; presumably these infestations originated from bee hives transported interstate for the purpose of pollinating crops. Separately, ornamental plants arriving in Las Vegas, NV, were infested with fire ants, and records showed that the point …
Nonlethal Methods Of Examining Fish Stomach Contents, Jan F. Kamler, Kevin L. Pope
Nonlethal Methods Of Examining Fish Stomach Contents, Jan F. Kamler, Kevin L. Pope
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Several nonlethal methods have been developed to determine the stomach contents of fish, including gastroscopes, tubes, stomach suction, stomach flushing, emetics, forceps, and chronic fistulas. By reviewing the literature on this subject, we found that the effectiveness (ability to remove all stomach contents) of the different methods depends on size, age, species of fish, and the size of the food items in the stomach. Overall, various methods of stomach flushing were the most effective method of recovering stomach items from a variety of fishes. Mechanized pressure appeared to be the most efficient method of stomach flushing for most large fishes. …
Assessment Of Outputs From Smith-Root Model-5.0 Gpp And Model-7.5 Gpp Electrofishers, Kevin L. Pope, Brian E. Van Zee, Michael C. Mayo, Mohammed Rahman
Assessment Of Outputs From Smith-Root Model-5.0 Gpp And Model-7.5 Gpp Electrofishers, Kevin L. Pope, Brian E. Van Zee, Michael C. Mayo, Mohammed Rahman
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
We evaluated the outputs from eight Smith-Root electrofishers (two factory-rigged model-5.0 GPP boats, four biologist-rigged model-5.0 GPP boats, and two biologist-rigged model- 7.5 GPP boats), using an oscilloscope to determine the actual waveforms (voltage as a function of time), current, and power produced for various settings. Differences were found in average power outputs among the six model-5.0 GPP electrofishing boats. In terms of average power output, biologist-rigged electrofishing boats using generators and control boxes purchased from Smith-Root were as or more effective than those rigged by Smith-Root. However, factory-rigged boats generally contained additional safety features that should be considered when …
Shrinkage Of Inland Silverside Larvae Preserved In Ethanol And Formalin, Mandy K. Cunningham, William F. Granberry, Kevin L. Pope
Shrinkage Of Inland Silverside Larvae Preserved In Ethanol And Formalin, Mandy K. Cunningham, William F. Granberry, Kevin L. Pope
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Length measurements of preserved larval fish are necessary in many types of larval fish surveys. If the fixative causes significant shrinkage, then the preserved lengths cannot be used to indicate accurate live lengths. The objective of this study was to determine how preservation in two different concentrations of formalin and ethanol affects the total length of larval inland silversides Menidia beryllina. Larvae were measured (nearest 0.1 mm) and individually fixed in one of four fixative treatments (80% ethanol, 100% ethanol, 5% buffered formalin, and 10% buffered formalin). Fish were remeasured (nearest 0.1 mm) at 15 min; 4 h; and …
Parental Care And Clutch Sizes In North And South American Birds, Thomas E. Martin, P. R. Martin, C. R. Olson, B. J. Heidinger, J. J. Fontaine
Parental Care And Clutch Sizes In North And South American Birds, Thomas E. Martin, P. R. Martin, C. R. Olson, B. J. Heidinger, J. J. Fontaine
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
The evolutionary causes of small clutch sizes in tropical and Southern Hemisphere regions are poorly understood. Alexander Skutch proposed 50 years ago that higher nest predation in the south constrains the rate at which parent birds can deliver food to young and thereby constrains clutch size by limiting the number of young that parents can feed. This hypothesis for explaining differences in clutch size and parental behaviors between latitudes has remained untested. Here, a detailed study of bird species in Arizona and Argentina shows that Skutch's hypothesis explains clutch size variation within North and South America. However, neither Skutch's hypothesis …
Body Mass Patterns Predict Invasions And Extinctions In Transforming Landscapes, Craig R. Allen, Elizabeth A. Forys, C. S. Holling
Body Mass Patterns Predict Invasions And Extinctions In Transforming Landscapes, Craig R. Allen, Elizabeth A. Forys, C. S. Holling
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Scale-specific patterns of resource distribution on landscapes entrain attributes of resident animal communities such that species body-mass distributions are organized into distinct aggregations. Species within each aggregation respond to resources over the same range of scale. This discontinuous pattern has predictive power: invasive species and extinct or declining species in landscapes subject to human transformation tend to be located at the edge of body-mass aggregations (P < 0.01), which may be transition zones between distinct ranges of scale. Location at scale breaks affords species great opportunity, but also potential crisis.
Development And Evaluation Of A Standard Weight (WS) Equation For Blue Catfish, Maurice I. Muoneke, Kevin L. Pope
Development And Evaluation Of A Standard Weight (WS) Equation For Blue Catfish, Maurice I. Muoneke, Kevin L. Pope
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
Using a data set composed of 33 populations from six states, we employed the regression-linepercentile technique to develop a standard weight equation for blue catfish Ictalurus furcatus and validated it with an independent data set composed of 43 populations from 10 states. The equation is log10Ws=-6.067+ 3.400 log10TL, where Ws is standard weight in grams and TL is total length in millimeters. The English-unit equivalent (pounds and inches) is log10Ws=-3.950+ 3.400 log10TL. The equation is valid for blue catfish 160 mm (approximately 6 in) TL and longer. …
Earlj Life Historj And Recruitment Of Black Crappie (Pomoxis Nigromaculatus) In Two South Dakota Waters, K. L. Pope, D. W. Willis
Earlj Life Historj And Recruitment Of Black Crappie (Pomoxis Nigromaculatus) In Two South Dakota Waters, K. L. Pope, D. W. Willis
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
We compared the early life history of black crappie (Pomoxis nigromaculatus) in Richmond (an impoundment) and Brant (a natural lake) lakes during 1994-1996. We expected variable recruitment (i.e., missing year classes) in the natural lake and more consistent recruitment in the impoundment. Larval black crappie abundance was always higher in Richmond Lake than Brant Lake. Peak abundance of larval black crappie was highest during 1994 in both waters. However, peak larval abundance did not correspond with fall trap-net catch per unit effort (CPUE) of age-0 black crappie, which was highest during 1995. Thus, recruitment of black crappie was …
Ecological Resilience, Biodiversity, And Scale, Garry D. Peterson, Craig R. Allen, C. S. Holling
Ecological Resilience, Biodiversity, And Scale, Garry D. Peterson, Craig R. Allen, C. S. Holling
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
We describe existing models of the relationship between species diversity and ecological function, and propose a conceptual model that relates species richness, ecological resilience, and scale.We suggest that species interact with scale-dependent sets of ecological structures and processes that determine functional opportunities. We propose that ecological resilience is generated by diverse, but overlapping, function within a scale and by apparently redundant species that operate at different scales, thereby reinforcing function across scales. The distribution of functional diversity within and across scales enables regeneration and renewal to occur following ecological disruption over a wide range of scales.
Larval Black Crappie Distribution: Implications For Sampling Impoundments And Natural Lakes, Kevin L. Pope, David W. Willis
Larval Black Crappie Distribution: Implications For Sampling Impoundments And Natural Lakes, Kevin L. Pope, David W. Willis
Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications
An understanding of larval fish distributions is essential for developing an appropriate sampling design to monitor larval abundances. We monitored abundance of larval black crappie Pomoxis nigromaculatus to assess spatial differences in Richmond Lake (a 336-ha impoundment) and Brant Lake (a 405-ha natural lake), South Dakota, during 1994–1996. Age-0 black crappies were collected with a 500-µm mesh ichthyoplankton trawl from fixed sites within each water body. In the impoundment, larval black crappies were collected over a longer period at the upper site than at the dam site during 1994 and 1995. In the natural lake, larval black crappie abundances were …