Hierarchical spatial decisions in fragmented landscapes: Modeling the foraging movements of woodpeckers
Authored by Pablo M Vergara, Gerardo E Soto, Christian G Perez-Hernandez, Santiago Saura
Date Published: 2015
DOI: 10.1016/j.ecolmodel.2015.01.006
Sponsors:
FONDECYT (Fondo Nacional de Ciencia y Tecnologia of the Chilean Government)
Platforms:
R
Model Documentation:
ODD
Flow charts
Mathematical description
Model Code URLs:
Model code not found
Abstract
The ability of animals to collect and use environmental information in
fragmented landscapes may considerably decrease as the spatial scale at
which they search for feeding resources increases. Here, we used an
individual-based model to assess the scale-dependent movement patterns
of woodpeckers when searching for their main foraging resources
(wood-boring larvae). Two movement strategies for woodpeckers were
compared in simulated landscapes where resources were spatially
clustered at two hierarchical levels (trees and forest patches): (1)
``top-down{''} foragers, whose movement decisions respond primarily to
memorized information on forest patches; and (2) ``bottom-up{''}
foragers with random, purely exploratory movements that result from
tree-scale foraging experiences. Top-down foragers were able to find
more resources than bottom-up foragers, except in landscapes with very
few and poor quality patches. Thus, the combined use of spatial memory
and random exploration should considerably benefit woodpeckers that
forage in landscapes with low fragmentation levels. Contrary to our
expectations, bottom-up foragers had larger connectivity values by
visiting more patches across the landscape. Thus, model results support
the idea that as the landscape becomes fragmented the home-range size of
woodpeckers increases. We conclude that landscape planning must aim at
maintaining habitat quality and quantity above critical thresholds below
which woodpeckers both lack enough resources and the ability to make
efficient use of memory-based decisions. (C) 2015 Elsevier B.V. All
rights reserved.
Tags
Habitat fragmentation
Animal movement
Memory
information
Forest
Random-walks
Spotted woodpecker
Behavioral
ecology
Multiple scales
Range