Occupancy as a surrogate for abundance estimation

By D. MacKenzie, James D. Nichols. Animal Biodiversity and Conservation, 2004

283 citations recorded by the source corpus.

In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of detectability must be taken into account in order to make accurate inferences: the non-detection of the species does not imply the species is genuinely absent. Here we review some recent modelling developments that permit unbiased estimation of the proportion of area occupied, colonization and local extinction probabilities. These methods allow for unequal sampling effort and enable covariate information on sampling locations to be incorporated. We also describe how these models could be extended to incorporate information from marked individuals, which would enable finer questions of population dynamics (such as turnover rate of nest sites by specific breeding pairs) to be addressed. We believe these models may be applicable to a wide range of bird species and may be useful for investigating various questions of ecological interest. For example, with respect to habitat quality, we might predict that a species is more likely to have higher local extinction probabilities, or higher turnover rates of specific breeding pairs, in poor quality habitats.

Subfields: Ecology, Epidemiology, Statistics and Probability

View Paper: https://www.semanticscholar.org/paper/8a453435a5d093de194ac4e78900d0a79599133c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology

1. F. Rovero
2. T. O'Brien
3. M. Kinnaird
4. Paul D. Meek
5. F. Zimmermann
6. D. Berzi
7. J. Baillie
8. L. Krueger

In Epidemiology

1. T. O'Brien
2. L. Lawson Handley

In Statistics and Probability

1. T. O'Brien
2. J. Baillie
3. F. Zimmermann
4. L. Krueger
5. D. Berzi
6. Paul D. Meek
7. L. Lawson Handley
8. M. Kinnaird

Citations in the corpus

• The Wildlife Picture Index: monitoring top trophic levels (2010, background): “The WPI can measure trends in occupancy, a surrogate measure of abundance (Royle & Nichols, 2003; MacKenzie & Nichols, 2004), diversity and distribution of a broad range of terrestrial bird and mammal species, providing insight as to whether species populations are being successfully maintained in…”
• "Which camera trap type and how many do I need?" A review of camera features and study designs for a range of wildlife research applications (2013, background): “If the home range diameter of a species is much larger than the distance between camera traps the results should be interpreted as the percentage of area used by a species during the survey period instead of the percentage of an area occupied (MacKenzie and Nichols, 2004).”
• How will the ‘molecular revolution’ contribute to biological recording? (2015, background): “Although this is obviously different to species abundance, the two measures are positively correlated (MacKenzie & Nichols, 2004), so site occupancy can be considered a proxy for abundance.”
• Camera trapping photographic rate as an index of density in forest ungulates (2009, unknown): “Both calibration and modelling might not always be feasible because of lack of data, in which case occupancy models based on presence ⁄absence data may be a useful surrogate (MacKenzie et al. 2002; Mackenzie & Nichols 2004).”
• A picture is worth a thousand words: the application of camera trapping to the study of birds (2008, background): “2002) where occupancy may serve as a surrogate for abundance (MacKenzie and Nichols 2004).”