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Filter Total Items: 3377

Troublesome toxins: Time to re-think plant-herbivore interactions in vertebrate ecology

Earlier models of plant-herbivore interactions relied on forms of functional response that related rates of ingestion by herbivores to mechanical or physical attributes such as bite size and rate. These models fail to predict a growing number of findings that implicate chemical toxins as important determinants of plant-herbivore dynamics. Specifically, considerable evidence suggests that toxins se
Authors
R.K. Swihart, D.L. DeAngelis, Z. Feng, Lee C. Bryant

Seed dispersal and seedling emergence in a created and a natural salt marsh on the Gulf of Mexico coast in Southwest Louisiana, U.S.A

Early regeneration dynamics related to seed dispersal and seedling emergence can contribute to differences in species composition among a created and a natural salt marsh. The objectives of this study were to determine (1) whether aquatic and aerial seed dispersal differed in low and high elevations within a created marsh and a natural marsh and (2) whether seedling emergence was influenced by mar
Authors
T. Elsey-Quirk, B.A. Middleton, C.E. Proffitt

Regeneration potential of Taxodium distichum swamps and climate change

Seed bank densities respond to factors across local to landscape scales, and therefore, knowledge of these responses may be necessary in forecasting the effects of climate change on the regeneration of species. This study relates the seed bank densities of species of Taxodium distichum swamps to local water regime and regional climate factors at five latitudes across the Mississippi River Alluvial
Authors
B.A. Middleton

Site condition, structure, and growth of baldcypress along tidal/non-tidal salinity gradients

This report documents changes in forest structure and growth potential of dominant trees in salt-impacted tidal and non-tidal baldcypress wetlands of the southeastern United States. We inventoried basal area and tree height, and monitored incremental growth (in basal area) of codominant baldcypress (Taxodium distichum) trees monthly, for over four years, to examine the inter-relationships among gr
Authors
K. W. Krauss, J.A. Duberstein, T.W. Doyle, W.H. Conner, Richard H. Day, L.W. Inabinette, J.L. Whitbeck

Interactions between non-native armored suckermouth catfish (Loricariidae: Pterygoplichthys) and native Florida manatee (Trichechus manatus latirostris) in artesian springs

Non-native suckermouth armored catfishes (Loricariidae) of the genus Pterygoplichthys are now common throughout much of peninsular Florida. In this paper, we present preliminary observations on interactions between a Pterygoplichthys species, tentatively identified as P. disjunctivus (Weber, 1991), and endangered native Florida manatees, Trichechus manatus latirostris (Harlan, 1824), in artesian s
Authors
Leo G. Nico, William F. Loftus, James P. Reid

Trend estimation in populations with imperfect detection

1. Trends of animal populations are of great interest in ecology but cannot be directly observed owing to imperfect detection. Binomial mixture models use replicated counts to estimate abundance, corrected for detection, in demographically closed populations. Here, we extend these models to open populations and illustrate them using sand lizard Lacerta agilis counts from the national Dutch reptile
Authors
Marc Kery, Robert M. Dorazio, Leo Soldaat, Arco Van Strien, Annie Zuiderwijk, J. Andrew Royle

The decline of North American freshwater fishes

North America has a broad array of freshwater ecosystems because of the continent's complex geography and geological history. Within a multitude of habitats—that include streams, large rivers, natural lakes, springs, and wetlands—rich assemblages of fishes reside, representing diverse taxonomic groups with unique ecological requirements. They face an unprecedented conservation crisis.1 In the last
Authors
Stephen J. Walsh, Howard L. Jelks, Noel M. Burkhead

The golden rule of reviewing

A major bottleneck in the time required to publish a scientific or scholarly paper is the speed with which reviews by peers are returned to journals. Peer review is a reciprocal altruistic system in which each individual may perform every task—editors, reviewers, and authors—at different times. Journals have no way to coerce reviewers to return their critiques faster. To greatly shorten the time t
Authors
Mark A. McPeek, Donald L. DeAngelis, Ruth G. Shaw, Allen J. Moore, Mark D. Rausher, Donald R. Strong, Aaron M. Ellison, Louise Barrett, Loren Rieseberg, Michael D. Breed, Jack Sullivan, Craig W. Osenberg, Marcel Holyoak, Mark A. Elgar

Perturbation analysis for patch occupancy dynamics

Perturbation analysis is a powerful tool to study population and community dynamics. This article describes expressions for sensitivity metrics reflecting changes in equilibrium occupancy resulting from small changes in the vital rates of patch occupancy dynamics (i.e., probabilities of local patch colonization and extinction). We illustrate our approach with a case study of occupancy dynamics of
Authors
Julien Martin, James D. Nichols, Carol L. McIntyre, Goncalo Ferraz, James E. Hines

Plant community establishment following drawdown of a reservoir in southern Arkansas, USA

Wetland area, function and wildlife habitat value are extensively altered by the construction of freshwater reservoirs. We studied the effects of a temporary drawdown on shoreline vegetation communities of Felsenthal Navigation Pool (“the pool”), an impoundment at Felsenthal National Wildlife Refuge in southern Arkansas that is managed as a greentree reservoir. The pool was permanently flooded fro
Authors
Rebecca J. Howard, Christopher J. Wells

Sexing sirenians: Validation of visual and molecular sex determination in both wild dugongs (Dugong dugon) and Florida manatees (Trichechus manatus latirostris)

Sexing wild marine mammals that show little to no sexual dimorphism is challenging. For sirenians that are difficult to catch or approach closely, molecular sexing from tissue biopsies offers an alternative method to visual discrimination. This paper reports the results of a field study to validate the use of two sexing methods: (1) visual discrimination of sex vs (2) molecular sexing based on a m
Authors
J. Lanyon, H. Sneath, J. Ovenden, D. Broderick, Robert K. Bonde

Local versus landscape-scale effects of savanna trees on grasses

1. Savanna ecosystems – defined by the coexistence of trees and grasses – cover more than one‐fifth the world’s land surface and harbour most of the world’s rangelands, livestock and large mammal diversity. Savanna trees can have a variety of effects on grasses, with consequences for the wild and domestic herbivores that depend on them.2. Studies of these effects have focused on two different spat
Authors
Corinna Riginos, James B. Grace, David J. Augustine, Truman P. Young