Habit Species Model Descriptions

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Olive-sided Flycatcher HABIT@ Model

Input grids

Covercond - Cover-condition grid

Cond - Condition grid

Model description [click here for APL script]

Habitat quality for Olive-sided Flycatchers depends upon both nesting and foraging habitat, which are treated as separate local resources. Nesting habitat depends on cover type and condition, while foraging depends on cover type and condition, as well as the proximity to high-contrast edges.

Local Resource Availability

Nesting habitat is based on the local resource index (LRInest) for cover-condition class (Table 1) of the focal cell.

Foraging habitat is based on minimum of the local resource index for foraging (LRIforage) determined by the cover-condition class (Table 1) and the edge index, representing proximity to high-contrast edges. The edge index is the maximum of the product of the contrast between the two cover types that make up the edge (Table 2) and a logistic function (Fig. 1) of the distance to each nearby edge. The edge that gives the maximum value is used—for instance, if there is an edge between SI and SE at 50 m from the focal cell (0.05  logistic100,–20[50] = 0.05  0.924 = 0.046), and an edge between SE and SM at 100 m (0.75  logistic100,–20[100] = 0.75  0.5 = 0.375), the resulting edge index would be 0.375.

Home Range Capability

The home range capability for nesting is defined as a threshold relationship of the proportion of a 150 m diameter circular home range that contains high-quality nesting habitat. Optimal habitat for nesting (1.0) is achieved when at least 10% of the home range has an LRInest 0.75. Suboptimal nesting habitat (0.6) occurs when at least 10% of the home range has LRInest 0.5 (Fig. 2). Both values for HRCnest decline linearly below 10% of the home range.

The home range capability for foraging is defined as the mean of local foraging within a circle of 150 m radius, inversely weighted by the distance squared.

Landscape Capability

Landscape capability (LC) is based on the number of 150 m radius home ranges that can be placed on the landscape by tiling non-overlapping home ranges starting with the cells with the highest HRC. Home ranges are then dropped by using the HRC as the probability of retaining each home range (e.g., a home range centered on a cell with a HRC of 0.85 will have a 15% chance of being dropped). LC is the total number of home ranges in the landscape for that time step.

Table 1. Local resource index for each cover-condition class for Olive-sided Flycatcher for nesting (LRInest) and foraging (LRIforage).

Table 2. Edge contrast values for Olive-sided Flycatcher, used in LRIforage.