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Full-Text Articles in Life Sciences

Accelerated Hatching Of Southern Leopard Frog (Rana Sphenocephala) Eggs In Response To The Presence Of A Crayfish (Procambarus Nigrocinctus) Predator, Daniel Saenz, James B. Johnson, Cory K. Adams, Gage H. Dayton Jan 2003

Accelerated Hatching Of Southern Leopard Frog (Rana Sphenocephala) Eggs In Response To The Presence Of A Crayfish (Procambarus Nigrocinctus) Predator, Daniel Saenz, James B. Johnson, Cory K. Adams, Gage H. Dayton

Faculty Publications

Phenotypic plasticity, such as morphological and behavioral changes in response to predators, is common in larval anurans. Less is known about inducible defenses in the embryonic stages of development. We investigated the predation risk imposed by crayfish (Procambarus nigrocinctus) on southern leopard frog (Rana sphenocephala) eggs aud whether crayfish presence induces a change in the timing of hatching of R. sphenocephala eggs. We found that crayfish significantly reduce the hatching success of R. sphenocephala eggs by eating them and that eggs hatch significantly faster in the presence of crayfish than when crayfish are not present. We …


The Influence Of Predator Threat On The Timing Of A Life-History Switch Point: Predator-Induced Hatching In The Southern Leopard Frog (Rana Sphenocephala), James B. Johnson, Daniel Saenz, Cory K. Adams, Richard N. Conner Jan 2003

The Influence Of Predator Threat On The Timing Of A Life-History Switch Point: Predator-Induced Hatching In The Southern Leopard Frog (Rana Sphenocephala), James B. Johnson, Daniel Saenz, Cory K. Adams, Richard N. Conner

Faculty Publications

We tested the hypotheses that potential egg predators, crayfish Procambarus nigrocinctus and dytiscid Cybister sp. larvae, would accelerate the timing of hatching and that a larval predator, dragonfly naiad Anax junius, would delay hatching in the southern leopard frog (Rana sphenocephala). We also tested the hypothesis that differences in response would be proportional to predator lethality. Our results indicate that our hypotheses were partially supported. The presence of an efficient egg predator (crayfish) induces hatching faster than a less efficient predator (dytiscid larvae). However, the presence of a larval predator (naiads) did not delay hatching. Eggs that …


Fire Climate Interactions And Predicting Fire Season Severity In The Mediterranean Climate Areas Of California, Southern Oregon, And Western Nevada, Alan H. Taylor, Carl N. Skinner, Andrew M. Carleton, Scott L. Stephens, Valerie Trouet, Bernd Haupt, Andrew Pierce Jan 2003

Fire Climate Interactions And Predicting Fire Season Severity In The Mediterranean Climate Areas Of California, Southern Oregon, And Western Nevada, Alan H. Taylor, Carl N. Skinner, Andrew M. Carleton, Scott L. Stephens, Valerie Trouet, Bernd Haupt, Andrew Pierce

JFSP Research Project Reports

• We identified annual area burned for 37 National Forests in Washington, Oregon, and California between 1929 and 2004 from annual fire reports. Variation in area burned each year on National Forest lands is strongly related (r2 = 0.87) to total area burned in California. This indicates area burned in National Forests is a good indicator of total area burned in a state. • Four large groups of National Forests were identified that had similar temporal patterns of fire extent. Three of these groups were spatially coherent and included mainly: 1) Washington and northern Oregon; 2) northern California and California …


Planning For Population Viability On Northern Great Plains National Grasslands, Fred B. Samson, Fritz L. Knopf, Clinton W. Mccarthy, Barry R. Noon, Wayne R. Ostile, Susan M. Rinehart, Scott Larson, Glenn E. Plumb, Gregory L. Schenbeck, Daniel N. Svingen, Timothy W. Byer Jan 2003

Planning For Population Viability On Northern Great Plains National Grasslands, Fred B. Samson, Fritz L. Knopf, Clinton W. Mccarthy, Barry R. Noon, Wayne R. Ostile, Susan M. Rinehart, Scott Larson, Glenn E. Plumb, Gregory L. Schenbeck, Daniel N. Svingen, Timothy W. Byer

USDA Forest Service / UNL Faculty Publications

Broad-scale information in concert with conservation of individual species must be used to develop conservation priorities and a more integrated ecosystem protection strategy. In 1999 the United States Forest Service initiated an approach for the 1.2 x 106 ha of national grasslands in the Northern Great Plains to fulfill the requirement to maintain viable populations of all native and desirable introduced vertebrate and plant species. The challenge was threefold: 1) develop basic building blocks in the conservation planning approach, 2) apply the approach to national grasslands, and 3) overcome differences that may exist in agency-specific legal and policy requirements. Key …


Utah Forest Health Report : A Baseline Assessment 1999 - 2001, Colleen Keyes, Paul Rogers, Leon Lamadeleine, Vick Applegate, Dave Atkins Jan 2003

Utah Forest Health Report : A Baseline Assessment 1999 - 2001, Colleen Keyes, Paul Rogers, Leon Lamadeleine, Vick Applegate, Dave Atkins

The Bark Beetles, Fuels, and Fire Bibliography

This report addresses forest health in two ways: by discussion of forest-related issues and by data summaries in several appendices. FHM is a long-term monitoring program and therefore, the data presented in this report must be viewed in that light. This report presents a first-time, or baseline summary. Subsequent reports will address changes over time as plots and other detection surveys are conducted and re-measured.