Please cite this article in press as: Sorensen, A. A., et al. Quantifying overlap in crop selection patterns among three sympatric ungulates
in an agricultural landscape. Basic and Applied Ecology (2015), http://dx.doi.org/10.1016/j.baae.2015.05.001
ARTICLE IN PRESS
BAAE-50888; No. of Pages 9
Basic and Applied Ecology xxx (2015) xxx–xxx
Quantifying overlap in crop selection patterns among three
sympatric ungulates in an agricultural landscape
Anja A. Sorensen
a,*
, Floris M. van Beest
a,b
, Ryan K. Brook
a
a
Department of Animal and Poultry Science & Indigenous Land Management Institute, College of Agriculture and
Bioresources, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
b
Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
Received 9 July 2014; received in revised form 5 May 2015; accepted 10 May 2015
Abstract
Quantifying overlap in habitat selection patterns of coexisting species is a prerequisite for effective conservation and species
management. In the agriculture-dominated landscapes of North America, commercial crops are used extensively by free-ranging
elk (Cervus canadensis), mule deer (Odocoileus hemionus), and white-tailed deer (Odocoileus virginianus), leading to severe
economic losses to agricultural producers. We analysed 19,069 crop damage claims paid to farmers in Saskatchewan, Canada for
confirmed losses of annual crops (cereal grains, oilseeds, pulses) by elk, mule deer, and white-tailed deer during 2000–2012. We
used kernel utilization distribution (UD) to compute core areas of crop damage and overlap among species and the outlying mean
index (OMI) analysis to quantify (dis)similarities in variables influencing agricultural crop selection among species. Overlap in
the distribution of crop damage sites and crop selection patterns was greatest between elk and white-tailed deer, both selecting
for areas close to protected areas with a high proportion of farmland seeded with oats and canola. The distribution of crop damage
sites and crop selection patterns of mule deer was more distinct, favouring pea fields, open grasslands, shrublands, and areas
with a greater density of streams, while avoiding areas where a high proportion of farmland was seeded with oats and canola.
Based on all variables influencing overlap in crop selection patterns among three sympatric ungulates, we created predictive
maps to identify areas where the risk of crop damage was greatest. The results of this study, together with the crop-damage
risk maps, provide valuable tools to direct the development of more effective and targeted mitigation strategies to alleviate
wildlife-agricultural conflicts.
Zusammenfassung
Die Übereinstimmung der Habitatwahlmuster bei koexistierenden Arten zu quantifizieren, ist eine Voraussetzung für
effektiven Naturschutz und das Artenmanagement. In den von Landwirtschaft beherrschten Landschaften Nordamerikas, wer-
den Feldfrüchte ausgiebig von wilden Wapitihirschen (Cervus canadensis), Maultierhirschen (Odocoileus hemionus), und
Weißwedelhirschen (Odocoileus virginianus) genutzt, was zu erheblichen Ertragseinbußen bei den Produzenten führt. Wir
untersuchten 19069 Schadensersatzleistungen, die von 2000 bis 2012 in Saskatchewan, Canada, an Landwirte ausgezahlt wur-
den. Es handelt sich um bestätigte Schäden an einjährigen Feldfrüchten (Getreide, Ölsaaten, Hülsenfrüchte), die von den
drei genannten Hirscharten verursacht worden waren. Wir berechneten die Kernareale der Ernteschäden und die Überlappung
zwischen den Arten mit der Kernel-basierten Nutzungsverteilung. Die Ähnlichkeit bzw. Unähnlichkeit der Variablen, die die
Nahrungswahl der drei Arten beeinflussten, quantifizierten wir mit der Outlying-Mean-Index-Analyse (OMI). Die Überlap-
pung zwischen der Verteilung der Ernteschäden und den Nahrungswahlmustern war bei Wapiti- und Weißwedelhirschen am
*
Corresponding author. Tel.: +1 306 202 8884.
E-mail address: anja.a.sorensen@gmail.com (A.A. Sorensen).
http://dx.doi.org/10.1016/j.baae.2015.05.001
1439-1791/© 2015 Gesellschaft für Ökologie. Published by Elsevier GmbH. All rights reserved.