Estimating the proportion of Archey’s frogs in the Wharekirauponga mine vibration footprint 2 Most (94%) of the Archey’s frog records are from the main block of almost contiguous native habitat ≥200 m above sea level (a.s.l.) covering the Coromandel Peninsula’s axial mountain ranges (Figure 1). This block of habitat extends over 108 km, with a 5 km wide gap at its northern extent, and encompasses an area of 893 km2 with altitudes ranging from ≥200 m to 890 m a.s.l.. In the southern half of the main habitat block, there is a twenty kilometres long section, 314 km2 area, without Archey’s frog records, leaving 578 km2 of the main habitat block with Archey’s frog records. It is uncertain whether absence of Archey’s frog records from the twenty kilometres section is a result of the absence of frogs or lack of search effort. However, the habitat section without Archey’s frog records includes a much higher proportion of manuka-kanuka scrub (45% cf. 15%) and a lower proportion of mixed podocarp-hardwood forest (3% cf. 15%) than the rest of the block (Table 1; Figures 2 a & b). Table 1. Areas of dominant NZ Land Resource Inventory (NZ LRI) vegetation types above 200 m a.s.l. in the main contiguous block of frog habitat in the Coromandel Peninsula with and without records of Archey’s frog sightings (Figure 1). NZLRI Vegetation Type Areas With Records Areas Without Records Combined (km2) (%) (km2) (%) (km2) (%) Manuka/kanuka scrub M 1 89.2 (15.4%) 140.5 (44.7%) 229.7 (25.7%) Fern M 4 0.4 (0.1%) 0.0 (0.0%) 0.4 (0.0%) Subalpine scrub M 5 7.1 (1.2%) 0.0 (0.0%) 7.1 (0.8%) Mixed native scrub M 6 0.0 (0.0%) 3.3 (1.0%) 3.3 (0.4%) Kauri forest N 2 301.4 (52.1%) 127.0 (40.4%) 428.5 (48.0%) Lowland podocarp-hardwood forest N3a 87.5 (15.1%) 9.6 (3.0%) 97.0 (10.9%) Mid-altitude podocarp-hardwood forest N3b 6.8 (1.2%) 4.5 (1.4%) 11.3 (1.3%) Hardwood forest N 5 28.6 (4.9%) 17.5 (5.6%) 46.1 (5.2%) High producing pasture P 1 11.7 (2.0%) 0.7 (0.2%) 12.4 (1.4%) Low producing pasture P 2 45.7 (7.9%) 11.4 (3.6%) 57.1 (6.4%) Areas of all vegetation types (km2) 578.4 314.5 892.8 Within the 578 km2 area of habitat with Archey’s records, there was no relationship between Archey’s frog records and average soil moisture deficit, rainfall or temperatures, but altitude and vegetation type both affected the numbers of records. Most Archey’s frog records (31%) were in the ≥400<500 m elevation band (Figure 3a). However, the density of records (i.e. the number of records per square kilometre) increased steadily with elevation from to 0.29 records/km2 in the ≥200<300 m a.sl. band to 7.85 records/km2 in the ≥800 m elevation band (Figure 3b).
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