Measuring landscape connectivity:: The challenge of behavioral landscape ecology

The recognition of behavior as a link between process and pattern in landscape ecology is exemplified by the concept of functional connectivity: the degree to which the landscape facilitates or impedes movement among resource patches. In this paper, I first argue that the actual operational definitions of this concept as applied to animal movement are not fully consistent with its formal definition. For instance, I question that a high likelihood of movement among the different points of primary habitat implies a high connectivity and contend that such a view can lead to misinterpretations. I also address two more hurdles to the measurement of functional connectivity: the fact that functional connectivity may not be equal along all axes and directions of movement and individual variation in functional connectivity within a given landscape. These points bring me to suggest that the concept of functional connectivity be bridged to the one of travel costs used in behavioral ecology. This would help define unequivocal operational definitions of functional connectivity as its measurement would then be dictated by its ecological role within specific models (e.g., travel costs within group membership models of foraging theory). I argue further that this ecological role shall in. turn determine the motivation underlying the movement of individuals, implying that the latter should preferably be standardized when measuring functional connectivity in the field. I finally present some methods to do so. These include translocation and playback experiments, food-titration and giving-up densities experiments, and manipulating feeding and breeding site locations and success.