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Tam Metin
Abstract: The use of non-destructive and non-invasive monitoring methods is often necessary for species of high conservation status. Developing monitoring methods to maximise numbers of individuals found is important, given that rare species can be difficult to locate. Artificial refuges called 'weta motels' have been used for monitoring tree weta (Orthoptera: Anostostomatidae) since 1992, but poor occupancy for Hemideina ricta and H. femorata necessitated an improved design and assessment of placement to encourage tree weta use. Modification to a basic design of weta motel was tested on New Zealand's rarest tree weta, H. ricta, on Banks Peninsula, Canterbury, New Zealand. Possible lures such as peanut butter or frass from male and female H. ricta were placed in motels in an attempt to improve occupancy. We recorded high occupancy rates with an improved weta motel design and found that motels containing female frass had significantly higher levels of occupancy than controls, with the former reaching 80% occupation after 6 months. Weta motels were more likely to be used by tree weta in areas with low subcanopy density and patchy or little canopy cover, with H. ricta found to prefer higher altitude sites. Occupation of weta motels was compared with results from a previous hand search survey, finding very similar distributions of tree weta species with the two survey methods. We conclude that this modified refuge is effective for monitoring tree weta, including the range-restricted Banks Peninsula tree weta H. ricta.
Keywords: conservation; distribution; Hemideina femorata; restoration; weta motels
Introduction
Monitoring rare or threatened species non-destructively is a problem encountered by conservation managers and researchers worldwide (e.g. Sherley 2001; Venette et al. 2002; Thompson 2004; Hedgren & Weslien 2008; Evangelista et al. 2009; Singh et al. 2009; de Tores & Elscot 2010). Due to the relatively small size and fragility of most invertebrates, successful monitoring has necessitated designing techniques that avoid laborious hand searching or the destruction of natural refuges (e.g. Sherley 2001; Bowie et al. 2006; Hodge et al. 2007). As a result, artificial refuges are often utilised in species conservation for a variety of taxonomic groups (commonly birds, lizards and invertebrates) and can be used to monitor important parameters such as population size, density, demographics, and to provide organisms for critical field and laboratory...