Related Experiment Video
Updated: Jun 3, 2026

A Method for Quantifying Foliage-Dwelling Arthropods
Published on: October 20, 2019
Influence of sampling effort on the estimated richness of road-killed vertebrate wildlife
Alex Bager1, Clarissa A da Rosa
1Road Ecology Research Group, Setor de Ecologia, Departamento de Biologia, Universidade Federal de Lavras, Campus Universitário, Brazil. abager@dbi.ufla.br
Abstract:
Road-killed mammals, birds, and reptiles were collected weekly from highways in southern Brazil in 2002 and 2005. The objective was to assess variation in estimates of road-kill impacts on species richness produced by different sampling efforts, and to provide information to aid in the experimental design of future sampling. Richness observed in weekly samples was compared with sampling for different periods. In each period, the list of road-killed species was evaluated based on estimates the community structure derived from weekly samplings, and by the presence of the ten species most subject to road mortality, and also of threatened species. Weekly samples were sufficient only for reptiles and mammals, considered separately. Richness estimated from the biweekly samples was equal to that found in the weekly samples, and gave satisfactory results for sampling the most abundant and threatened species. The ten most affected species showed constant road-mortality rates, independent of sampling interval, and also maintained their dominance structure. Birds required greater sampling effort. When the composition of road-killed species varies seasonally, it is necessary to take biweekly samples for a minimum of one year. Weekly or more-frequent sampling for periods longer than two years is necessary to provide a reliable estimate of total species richness.
Related Concept Videos
Habitat Fragmentation
Conservation of Small Populations
Stratified Sampling Method
To choose a stratified sample, divide the population into groups called strata and then take a...
Conservation of Declining Populations
What are Populations and Communities?
Testing a Claim about Mean: Known Population SD
Estimating a population mean requires the samples to be distributed normally. The data should be collected from the randomly selected samples having no sampling bias. The sample size needed to be higher than 30, and most importantly, the population standard deviation should be already known.
In most realistic situations, the population standard deviation is often unknown, but in rare circumstances, when it...

