DOI: 10.5061/dryad.jm63xsjcs
title: Climate change and alpine-adapted insects: modelling environmental envelopes of a grasshopper radiation

description: Mountains create steep environmental gradients that are sensitive
 barometers of climate change. We modelled the environmental envelopes of
 twelve predominantly alpine, flightless grasshopper species in Aotearoa
 New Zealand, using current conditions and two future global climate change
 scenarios: representative concentration pathway (RCP) 2.6 (1.0 °C raise)
 and RCP8.5 (3.7 °C raise). Two thirds of our models suggested a reduced
 potential range across species by 2070, but surprisingly, for six species
 we predict an increase in potential suitable habitat under mild (+1.0°C)
 or severe global warming (+3.7°C). However, when we consider the limited
 dispersal ability of these grasshoppers, all twelve species studied are
 predicted to suffer extreme reductions in range, with a quarter likely to
 go extinct due to a 96-100% reduction in suitable habitat. Alpine species
 are particularly vulnerable to the impacts of climatic shifts, and species
 that have limited migratory ability will be particularly at risk of
 habitat loss, fragmentation and local extinction. Here we present the
 predicted outcomes for an endemic radiation of alpine taxa as an exemplar
 of the challenges that alpine species, both in New Zealand, and
 internationally, will face in light of anthropogenic climate change
description: <strong><em>Collection of species location
 records</em></strong> For 12 grasshopper species location records were
 collated from insect collections, journal articles, theses, books and
 Crown Pastoral Lease Tenure Reviews (Supplementary material 1) published
 between 1967 and 2016. These 12 endemic New Zealand grasshoppers consist
 of ten high elevation species: <em>Alpinacris
 crassicauda</em>, <em>Alpinacris
 tumidicauda</em>,
 <em>Brachaspis
 collinus</em>,
 <em>Brachaspis
 nivalis</em>,
 <em>Paprides dugdali</em>,
 <em>Paprides
 nitidus</em>,
 <em>Sigaus
 australis</em>,
 <em>Sigaus
 campestris</em>,
 <em>Sigaus piliferus, </em>and
 <em>Sigaus
 villosus</em>, and two low
 elevation relatives: <em>Sigaus
 childi</em> and
 <em>Sigaus
 minutus</em>. Given the
 range of sources used to obtain location data our sample does not suffer
 from the common bias of only collecting from sites close to access roads.
 In particular, our location data benefit from the use of Crown Pastoral
 Lease Tenure Reviews (CPLTR) that are produced by Land Information New
 Zealand (LINZ) and contain conservation reports and ecological surveys
 carried out by the Department of Conservation on pastures throughout Te
 Waipounamu (South Island) New Zealand. Additional
 records were retrieved from our specimen collections at Massey University.
 World Geodetic System 1984 (WGS84) coordinates (latitudes and longitudes)
 were obtained for each location record using NZ Topo
 Map. Location records for two additional
 endemic lowland grasshopper species (<em>Phaulacridium
 marginale</em> and <em>Phaulacridium
 otagoense</em>) were
 included in the dataset, but not modelled in this
 study. Both of these species have low
 elevation distributions and provided additional location searches and
 absence data that increase the accuracy of the ENMs. Coordinates were
 reduced to two decimal places and duplicate records within species were
 removed, in order to ensure only one record per ~ 1km
 2 for each species. Coordinates were also
 mapped for each species to ensure there were no outliers due to incorrect
 species identification. Following filtering, a total of 949 location
 records were available for our analysis (manuscript fig. 1). All location
 records and their sources can be found in Supplementary material 1 (of the
 manuscript).