Understanding the extent to which habitats function as sources or sinks for populations is of increasing interest to ecologists as we try to predict how species will respond to rapidly changing landscapes.  American three-toed (Picoides dorsalis) and black-backed (P. arcticus) woodpeckers are cited as among the birds most vulnerable to intensified management of northern forests.  They specialize on post-fire and, to a lesser extent, old-growth conifer forests -two habitats expected to become increasingly rare under current harvesting and salvage-logging practices.  Both species occur in old-growth, but reach markedly higher abundances following fire, leading some to suggest that recent burns may function as critical, but temporary, source habitat.  To test this hypothesis, we compared demographic measures of three-toed and black-backed woodpeckers over three years within a recent (2003) un-salvaged, conifer-dominated burn, and in unburned, >100 year old, conifer-dominated forests in west-central Alberta, Canada.  We also combined these data with landscape simulation models to assess population responses to varying fire and management regimes.  For three-toed woodpeckers, field estimates of breeding densities, nest success, fledging production and residency were surprisingly similar in burned and unburned sites, with both habitats classed as sources.  Black-backed woodpeckers, a known burn specialist, were found breeding only in burn sites.  However, their densities and reproductive rates were lower than previous reports, and so low that burn sites functioned as sinks by the third year after fire.  We are examining how variation in habitat quality (e.g. burn intensity), both among and within burns, may explain our results, as overlooking this variation could lead to overly conservative management recommendations.  To illustrate, we show how population projections from models vary under alternate habitat-quality and management assumptions.