While there is growing awareness in ecology of spatial dependency, the application in avian ecology of spatially explicit statistical methods is rare in areas such as habitat—reproduction relationships. We compared nonspatial vs. spatially explicit tests of correlation between a measure of reproduction and a habitat attribute associated with Northern Flicker (Colaptes auratus) nests. While nonspatial tests showed a significant positive correlation between nest productivity and canopy cover of conifers, Dutilleul's modified t-test, which reduces the effective sample size by accounting for dependence among sampled nest trees, showed no significant correlation. These results may be due to spatial autocorrelation of both canopy cover of conifers and nest productivity at the scale of <1 km. Low localized nest productivity appears to have been driven by nest predation rather than by conifer cover. Our results illustrate the utility of this simple modification for examining ecological correlations in the presence of spatial structure. We encourage further use of this and other spatially explicit statistical tests in avian ecology. Failing to do so risks potentially spurious and overstated conclusions, as we demonstrate here.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 112 • No. 2