2 - Principles of sampling
Published online by Cambridge University Press: 05 September 2012
Summary
Before one starts
Objectives
The definition of objectives is particularly important in studies of the abundance of animals or plants because it will determine whether one needs to make a full count of the individuals present in an area (or, at least, an estimate of that number) or whether an index of numbers is satisfactory. By an index, we mean a measurement that is related to the actual total number of animals or plants – such as the number of eggs of an insect species found on a sample of leaves of its host plant (as an index of numbers of adult insects) or the number of rabbit droppings in a sample area (as an index of the number of rabbits). Because accurate counts are extremely difficult to make, one may have to make do with an index even when a count would be preferable. Indeed, so long as an index is sufficient for one's purposes, a reliable index is preferable to an unreliable count.
The objectives will also determine the extent to which a population should be divided by sex, age or size in one's study: some work on the structure of communities may require only that total numbers of each species are known, whereas population dynamicists will often need to know the composition of the population by sex and age.
Information
- Type
- Chapter
- Information
- Ecological Census TechniquesA Handbook, pp. 11 - 86Publisher: Cambridge University PressPrint publication year: 2006
References
Atkinson, P. W., Austin, G. E., Rehfisch, M. M. et al. (in press). Identifying declines in waterbirds: the effects of missing data, population variability and count period on the interpretation of long-term survey data in the UK. Biological Conservation.
, & (2004). WeBS Alerts 2000/2001: Changes in Numbers of Wintering Waterbirds in the United Kingdom, its Constituent Countries, Special Protection Areas (SPAs) and Sites of Special Scientific Interest (SSSIs). BTO Research Report No. 349. Thetford, British Trust for Ornithology.Google Scholar
, , et al. (2005). Breeding Birds in the Wider Countryside: Their Conservation Status 2004. BTO Research Report No. 385. Thetford, British Trust for Ornithology (http://www.bto.org/birdtrends).Google Scholar
, , & (2002). Integrating mark–recapture–recovery and census data to estimate animal abundance and demographic parameters. Biometrics 58, 540–547.CrossRefGoogle ScholarPubMed
, & (2005). The potential of integrated population modelling. Australian and New Zealand Journal of Statistics 47, 35–48.CrossRefGoogle Scholar
, , et al. (2001). Introduction to Distance Sampling: Estimating Abundance of Biological Populations. Oxford, Oxford University Press.Google Scholar
, , et al. (2004). Advanced Distance Sampling – Estimating Abundance of Biological Populations. Oxford, Oxford University Press.Google Scholar
& (2002). Declining farmland birds: evidence from large-scale monitoring studies in the UK. British Birds 95, 300–310.Google Scholar
, , , & (2000). Analysis of populations trends for farmland birds using generalised additive models. Ecology 81, 1970–1984.CrossRefGoogle Scholar
, , et al. (1995). Population declines and range contractions among lowland farmland birds in Britain. Conservation Biology 9, 1425–1441.CrossRefGoogle Scholar
, , & (2005). Recent declines in populations of woodland birds in Britain: a review of possible causes. British Birds 98, 116–143.Google Scholar
(1978). Standing crop and pattern in pure stands of Mercurialis perennis and Rubus fruticosus in mixed deciduous woodland. Oikos 31, 351–357.CrossRefGoogle Scholar
& (1997). Estimation of the population trajectories from count data. Biometrics 53, 488–97.CrossRefGoogle Scholar
& (1998). Estimating population change from count data: application to the North American Breeding Bird Survey. Ecological Applications 8, 258–268.CrossRefGoogle Scholar
(1997.) Randomization, Bootstrap and Monte Carlo Methods in Biology. 2nd edn. London, Chapman and Hall.Google Scholar
& (2001). TRIM 3.0 for Windows (Trends and Indices for Monitoring Data). Voorburg, Statistics Netherlands.Google Scholar
, & (2003). Overlopping confidence intervals or standard error intervals: what do they mean in terms of statistical significance?Journal of Insect Science 3, 34–39.CrossRefGoogle ScholarPubMed
, & (1993). Estimating the impact of past persecution and habitat changes on the numbers of badgers Meles meles in Britain. Mammal Review 23, 1–15.CrossRefGoogle Scholar
, & (2004). Modeling abundance effects in distance sampling. Ecology 85, 1591–1597.CrossRefGoogle Scholar
& (1999). Trend detection in repeated surveys of ecological responses. Journal of Agricultural, Biological and Environmental Statistics 4, 404–414.CrossRefGoogle Scholar
Accessibility standard: Unknown
Why this information is here
This section outlines the accessibility features of this content - including support for screen readers, full keyboard navigation and high-contrast display options. This may not be relevant for you.Accessibility Information
Accessibility compliance for the PDF of this book is currently unknown
and may be updated in the future.
- 22
- Cited by