Table 1.
Sample sizes and naïve occupancy rates for each subset of data used in analyses of Columbia spotted frog habitat availability, water body-scale occupancy, and threats to persistence
| Analysis | Data subset | Sample size | Naïve Occupancy rate | Data source1 |
|---|---|---|---|---|
| Habitat availability | Spotted frog breeding locations | 145 | 1.0 | USFWS |
| Water body-scale habitat associations2 | ID3survey sites | 78 | 0.28 | IDFG |
| NV3survey sites | 778 | 0.14 | NDOW, USFS | |
| OR3survey sites | 75 | 0.15 | Wente et al. (2005) | |
| Threats to persistence4 | ID survey sites | 78 | 0.28 | IDFG |
| NV survey sites | 1,129 | 0.12 | NDOW, USFS | |
| OR survey sites | 96 | 0.15 | Wente et al. (2004) | |
| Bullfrog GIS observations | 182 | 1.0 | USFWS, USGS NAS, USGS BISON, Wente et al. (2004) | |
| Redband stream vertices5 | 111,561 | 1.0 | (May et al. 2012) | |
| Cutthroat stream vertices5 | 11,428 | 1.0 | USFWS | |
| Available 270-m pixels6 | 412,634 | na | Pilliod et al. (in press) | |
| Chytrid observations | 32 | 0.47 | (Olson et al. 2013), USFWS |
Data source abbreviations are as follows: USFWS: U.S. Fish and Wildlife Service; IDFG: Idaho Department of Fish and Game; NDOW: Nevada Department of Wildlife; USFS: U.S. Forest Service; USGS NAS: U.S. Geological Survey Nonindigenous Aquatic Species program; and USGS BISON: USGS Biodiversity Information Serving Our Nation. BISON records occurring at county centroids were excluded to prevent artificial inflation of bullfrog distributions.
For occupancy modeling, only sites with no missing habitat data were used.
State abbreviations are as follows: ID: Idaho; NV: Nevada; and OR: Oregon.
For threat analyses, all sites where a given variable was recorded were used in analyses of that variable (i.e., includes sites missing other habitat data). Consequently, sample sizes vary with threat variable analyzed. Values shown are maximum possible sample sizes.
Redband and cutthroat trout vertices were derived from GIS data of streams segments categorized as occupied by each fish species. Here, each vertex is assumed to be occupied.
Available pixels are those with ≥0.20 probability of having suitable climate for spotted frog breeding.