Home Range

Methods for estimating characteristics (e.g., areal extent, size) of animal home ranges continue to evolve, yet kernel density estimators and minimum convex polygons remain popular due to their ease of implementation. Practitioners need common sense advice to discern which methods are most appropriate for specific research questions. With this goal in mind, I have written papers that clarify the interpretation of kernel density estimators when applied to autocorrelated data [2], allow for stratified sampling designs through the use of weights [3], and that compare methods of calculating home range overlap [1,4]. I have also helped coauthor review papers that discuss the use of home-range estimators in applied and theoretical research [5-6, 8].  One important finding is that estimates of relative differences in home-range size (e.g., among animals or over space/time) may be relatively insensitive to estimator choice despite large differences in absolute estimates of home-range size [8,9].  Yet, it is important to also recognize that different methods for estimating home-ranges have different estimation targets [7].  When in doubt, it is always best to evaluate the sensitivity of your conclusions to the choice of estimator. With that goal in mind, Johannes Signer and I recently published a paper in PeerJ that demonstrates a "tidyverse" workflow for comparing estimators [9]. 

1. Fieberg, J. and C. O. Kochanny. 2005.Quantification of home range overlap: the importance of the utilization distribution. Journal of Wildlife Management 69:1346-1359.

2. Fieberg, J. 2007. Kernel density estimators of home range: smoothing and the autocorrelation red herring. Ecology 88:1059-1066.

3. Fieberg, J. 2007. Utilization distribution estimation with weighted kernel density estimators. Journal of Wildlife Management 71:1669-1675.

4. Kochanny, C. O., G. D. DelGiudice, and J. Fieberg. 2009. Comparing winter home ranges of white-tailed deer using GPS and VHF telemetry. Journal of Wildlife Management 73:779-787.

5. Kie, J. G., Matthiopoulos, J., Fieberg, J., Mitchell, M.S., Powell, R. A., Cagnacci, F., Gaillard, J-M., and P. Moorcroft. 2010. The home-range concept: are traditional estimators still relevant with modern telemetry technology? Philosophical Transactions of the Royal Society, Series B 365:2221-2231.

6. Fieberg, J. and L. Borger. 2012. Could you please phrase home range as a question? Journal of Mammalogy 93:890-902.

7. Horne, J.S., J. Fieberg, L. Börger, J. L. Rachlow, J. M. Calabrese, and C. H. Fleming.  2019. Animal Home Ranges: Concepts, Uses, and Estimation. Book Chapter in Population Ecology: Underused, Misused, and Abused Methods. D. Murray and B. Sandercock Eds.

8. Signer, J., Balkenhol, N. Ditmer, M. and J. Fieberg. 2015.  Does estimator choice influence our ability to detect changes in home range size?  Animal Biotelemetry 3(1), 1-9.

9. Signer, Johannes, and John R. Fieberg. 2021. A fresh look at an old concept: Home-range estimation in a tidy world. PeerJ 9 (2021): e11031.

Figure 4. from Fieberg and Kochanny (2005)