Is energy in nectar a good predictor of hummingbird activity at landscape scale?

Abstract

Hummingbirds are excellent models to test the relationship between animal activity and resource availability, because their primary food source is conspicuous and easily quantified. However, after three published studies done at landscape scale, there is no conclusive evidence of a positive relationship between the activity of a hummingbird species and nectar energy. Here we explore the relationship between the activity of White-eared Hummingbird (Hylocharis leucotis) and the energy contained in nectar in a landscape located in a temperate region of central Mexico. We did not find significant correlation pooling the data of 9 1-ha plots. However, there was not a significant difference between the regression statistical slopes of observed activity–nectar availability and expected individuals–nectar availability, which suggests to us that the relationship hummingbird–energy is occurring in the landscape.