Landscape History, Fragmentation, and Patch Occupancy: Models for a Forest Bird With Limited Dispersal

Abstract

We developed and tested patch occupancy models for an endemic understory bird with limited dispersal ability, the Chucao Tapaculo (Scelorchilus rubecula), in two South American temperate rain forest landscapes that differed in levels and duration of forest loss. We assessed cover changes since 1961 in each landscape and surveyed patches for Chucao Tapaculo occupancy. We then developed incidence-based predictive models independently for each landscape and tested each model reciprocally in the alternative study area. We thereby assessed the domain of model applicability and identified those predictor variables with general effects and those that varied between the two landscapes. The two models were consistent regarding variable selection, and predictive accuracy of each model was high in the landscape where training data were collected. However, the models differed substantially in the magnitudes of effects related to patch size, with larger unoccupied patches observed in the landscape with the more advanced stage of fragmentation. Due to this discrepancy, each model performed poorly when applied to the alternative landscape, potentially reflecting the contrasting stages of habitat loss. Although it was impossible to dissociate effects of level and duration of forest loss, we viewed the landscapes as representing two extremes along a continuum of fragmentation, providing insights into potential trajectories for portions of the biome where deforestation is occurring. Further, our data suggest that static equilibrium models developed from distribution patterns in recently fragmented landscapes may overestimate persistence when used as a forecasting tool, or when extrapolated to alternative landscapes where fragmentation is more advanced. Thus, we suggest that landscapes used as standards for model building should be selected with caution. We recommend that distribution patterns be obtained from landscapes where fragmentation is advanced, preferably with histories of fragmentation long enough that time-delayed extinctions already would have occurred.

Patch Network Criteria for Dispersal‐limited Endemic Birds of South American Temperate Rain Forest

“…These species are phylogenetically related to understory insectivores of tropical Latin America (Ridgely and Tudor 1994) that are also fragmentation sensitive (e.g., Stouffer and Bierregaard 1995, Sieving and Karr 1997, Stratford and Stouffer 1999. In SATR, Tapaculos are still relatively common, but there are serious signs of decline in highly fragmented areas (Castello´n and Sieving 2006b).…”

“…Fragmentation in the Central Valley of Chile (historically supporting one of the highest levels of diversity and endemism in the biome; Armesto et al 1998) was initiated 100-150 years ago (Donoso and Lara 1995), with ,20% forest cover remaining in the most fragmented portion (Castello´n and Sieving 2006b;Fig. 1).…”

Forest habitat loss and fragmentation in Central Poland during the last 100 years

“…As a consequence, the present distribution of some species in the landscape can be better explained by the historical distribution of the habitat than by the current landscape configuration (Jonsell and Nordlander 2002, Schrott et al 2005, Helm et al 2006. Because of this, knowledge about the historical landscape is necessary to better understand forest distribution in the modern landscape and to explain the occurrence of forest dwelling organisms (Marcucci 2000, Gu et al 2002, Castellon and Sieving 2006, Johansson et al 2008). This topic is especially important in light of recent programs aimed at increasing forest coverage in many European countries.…”

Post-Fledging Habitat Selection by the Slender-billed Parakeet (Enicognathus leptorhynchus) in a Fragmented Agricultural Landscape of Southern Chile

“…Historically, the region was covered by continuous deciduous lowland forest dominated by the trees Nothofagus obliqua, Laurelia sempervirens, and Persea lingue (Donoso 1993, Luebert andPliscoff 2006). However, intensive logging and anthropogenic fires have shaped the landscape for at least the past 100-150 years (Castellón and Sieving 2006, Echeverría et al 2007, Vergara and Armesto 2009. The current landscape is a mosaic of small patches of secondary forest and plantations of exotic trees surrounded by extensive areas of farmland and pastures ( Fig.…”