Developing indices of relative abundance for monitoring cave and ground wētā (Orthoptera) in southern beech forest, New Zealand

Figures & data

Figure 1. Examples of wētā metatarsal footprints recorded from captive wētā: A, Tallitropsis sedilloti, B, Pleioplectron sp., C, Hemiandrus sp. The metatarsal prints are circled, showing the key differences between the species: Pleioplectron sp. only track two of the metatarsal pads, while T. sedilloti and Hemiandrus sp. lagging metatarsal pads are shaped differently (triangular for T. sedilloti and oval for Hemiandrus sp.).

Figure 2. Mean (±SE) percentage footprint tracking rate (A), and mean number of cave wētā, Pleioplectron sp., per spotlight transect (B), on four sampling grids during three sampling sessions, Eglinton Valley, November 2012 to February 2013. Transects in Grid 2 were not sampled in December.

Table 1. Indices of dispersion with associated chi-squared statistics of cave wētā, Pleioplectron sp., measured across transects (at 25 m spacing) and points within enclosures (at 1 m spacing), over three monitoring periods.

		Transects			Enclosures
Time	Grid	Index of dispersion	χ^2 (df = 23)	Significance	Index of dispersion	χ^2 (df = 24)	Significance
November	1	3.6	86.4	<0.001
	2	2.9	70.8	<0.001
	3	2.7	64.2	<0.001
	4	3.1	73.6	<0.001
December	1	3.7	87.9	<0.001
	2
	3	2.6	62.8	<0.001
	4	2.9	70.6	<0.001
February	1	12.2	281.3	<0.001	1.1	27.0	0.304
	2	3.2	74.2	<0.001	1.0	23.0	0.519
	3	3.1	71.6	<0.001	1.0	24.3	0.445
	4	4.8	111.2	<0.001	1.7	41.1	0.016

Notes: Enclosures were not run in November or December; transects were not run on Grid 2 in December.

Figure 3. The relationship between mean percentage footprint tracking rate and mean number of cave wētā, Pleioplectron sp. on spotlight transects (all data combined; each point represents a different grid × sampling session comparison).

Figure 4. The predicted numbers of cave wētā, Pleioplectron sp., under the temperature conditions experienced during spotlight transects in February.