A mass mortality occurred in 1983, killing 95-99% of the Diadema antillarum Philippi in the Caribbean. This study, conducted in Lameshur Bay, Saint John, U.S. Virgin Islands, reports the impact of the mass mortality on Diadema population density, algal biomass, and Diadema body size. Census dates were 6 months before and 6, 12, 18, 26, 30, and 42 months after the mass mortality. There was an in...

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales...

1. Reproductive costs can affect survival and future reproduction. In winter and in short photoperiods, some individuals within populations of temperate-zone rodents inhibit reproduction and decrease food intake, while others do not. 2. Two lines derived from a natural population of White-Footed Mice and selected to maintain or inhibit reproduction in short photoperiod were tested for two poten...

BACKGROUND Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (lambda) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of lambda-Jensen's Inequality implies that even when the estimate...

When the megalopa stage of estuarine crab species becomes competent for settlement and metamorphosis, it responds to specific chemical and physical cues from the adult environment. Delayed metamorphosis in the absence of such cues is beneficial insofar as it increases the probability of finding a suitable habitat, and it may also enhance the genetic exchange between separate populations. Howeve...

A hypothesis testing and an interval estimation are studied for the common mean of several lognormal populations. Two methods are given based on the concept of generalized p-value and generalized confidence interval. These new methods are exact and can be used without restriction on sample sizes, number of populations, or difference hypotheses. A simulation study for coverage probability, size ...

The exact critical points for selected sample sizes and significance levels are tabulated for the two-sample test statistic which is a combination of the Wilcoxon and the Mood test statistic. This statistic serves for testing the null hypothesis that two sampled populations have the same location and scale parameters.

These experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the apple snail, Marisa cornuarietis. The overall objective of the program is to identify suitable husbandry conditions for maintaining multi-generation populations of this species in the laboratory for use in ecotoxicological testing. In this article, we focus on th...

Evaluating the practicality, economic, and sampling efficiency of potential monitoring programs is a first step in validation. Thus, we established a system of nest boxes in southeast Ohio to evaluate the feasibility of using a system of nest boxes to monitor changes in southern flying squirrel (Glaucomys volans) populations. We recorded the time of box placement until first usage and types of ...