Contributed Papers: An Experimental Test of Matrix Permeability and Corridor Use by an Endemic Understory Bird

Because of widespread habitat fragmentation, maintenance of landscape connectivity has become a major focus of conservation planning, but empirical tests of animal movement in fragmented landscapes remain scarce. We conducted a translocation experiment to test the relative permeability of three landscape elements (open habitat, shrubby secondary vegetation, and wooded corridors) to movement by the Chucao Tapaculo (Scelorchilus rubecula), a forest understory bird endemic to South American temperate rainforest. Forty-one radio-tagged subjects were translocated (individually) to three landscape treatments consisting of small release patches that were either entirely surrounded by open habitat (pasture), entirely surrounded by dense shrubs, or linked to other patches by wooded corridors that were otherwise surrounded by open matrix. The number of days subjects remained in release patches before dispersal (a measure of habitat resistance) was significantly longer for patches surrounded by open habitat than for patches adjoining corridors or surrounded by dense shrubs. These results indicate that open habitat significantly constrains Chucao dispersal, in accord with expectation, but dispersal occurs equally well through wooded corridors and shrub-dominated matrix. Thus, corridor protection or restoration and management of vegetation in the matrix (to encourage animal movement) may be equally feasible alternatives for maintaining connectivity.Original Abstract: Debido a la fragmentacion de habitat generalizada, el mantenimiento de la conectividad en el paisaje se ha convertido en un aspecto principal de la planificacion de conservacion, pero las pruebas empiricas del movimiento de animales en paisajes fragmentados son escasas. Realizamos un experimento de translocacion para probar la permeabilidad relativa de tres elementos del paisaje (habitat abierto, vegetacion secundaria arbustiva y corredores arbolados) al movimiento del Tapaculos de Chucao (Scelorchilus rubecula), una especie de ave de sotobosque endemica al bosque lluvioso templado de America del Sur. Translocamos (individualmente) a 41 aves con radio transmisores a tres paisajes-tratamiento consistentes en pequenos parches de liberacion que estaban completamente rodeados de habitats abiertos (pastizales), completamente rodeados de arbustos densos o unidos a otros parches por medio de corredores arbolados que a su vez estaban rodeados por matriz abierta. El numero de dias en que los sujetos permanecieron e