DOI: 10.5068/d1n682
title: Kauai and Maui Lidar derived environmental layers for bird habitat modelling

description: Translocation, often a management solution reserved for at-risk species,
 is a highly time-sensitive intervention in the face of a rapidly changing
 climate. The definition of abiotic and biotic habitat requirements is
 essential to the selection of appropriate release sites in novel
 environments. However, field-based approaches to gathering this
 information are often too time intensive, especially in areas of complex
 topography where common, coarse-scale climate models lack essential
 details. We apply a fine-scale remote sensing-based approach to study the
 'akikiki (Oreomystis bairdi) and 'akeke'e (Loxops
 caeruleirostris), Hawaiian honeycreepers endemic to Kaua'i that are
 experiencing large-scale population declines due to warming-induced spread
 of invasive disease. We use habitat suitability modeling based on
 fine-scale lidar-derived habitat structure metrics to refine coarse
 climate ranges for these species in candidate translocation areas on Maui.
 We found that canopy density was consistently the most important variable
 in defining habitat suitability for the two Kaua'i species. Our
 models also corroborated known habitat preferences and behavioral
 information for these species that are essential for informing
 translocation. We estimated a nesting habitat that will persist under
 future climate conditions on east Maui of 23.43 km2 for 'akikiki,
 compared to the current Kaua'i range of 13.09 km2. In contrast, the
 novel nesting range for 'akeke'e in east Maui was smaller than
 its current range on Kaua'i (26.29 km2 versus 38.48 km2,
 respectively). We were also able to assess detailed novel competitive
 interactions at a fine scale using models of three endemic Maui species of
 conservation concern: 'ākohekohe (Palmeria dolei), Maui
 'alauahio (Paroreomyza montana), and kiwikiu (Pseudonestor
 xanthophrys). Weighted overlap areas between the species from both islands
 were moderate (&lt;12 km2) and correlations between Maui and
 Kaua'i bird habitat were generally low, indicating limited potential
 for competition. Results indicate that translocation to east Maui could be
 a viable option for 'akikiki but would be more uncertain for
 'akeke'e. Our novel multi-faceted approach allows for the timely
 analysis of both climate and vegetation structure at informative scales
 for the effective selection of appropriate translocation sites for at-risk
 species.
description: An Optech HA-500 dual channel airborne lidar system aboard the
 Global Airborne Observatory (GAO) was used to collect the lidar point
 cloud data over east Maui during January 12–14, 2018. During these dates,
 collection conditions were very good with an absolute positional error of
 less than 10 cm given previous collections with the same sensor. Flights
 were performed at an altitude of 2000 m above ground level and a speed of
 130 kt. The lidar was configured to have a combined pulse density 200 kHz,
 scan frequency 34 Hz, and field of view set to 34 degrees. Given these
 parameters, we computed the point and pulse densities for every 2 m pixel
 in the coverage. This resulted in 99% of the coverage having point pulse
 densities between 0.97 and 13.8 pulses m<sup>-2</sup>
 (1.95-37.19 points m<sup>-2</sup>). Less than 0.03% of the
 total number of pixels recorded zero pulse returns in the area of
 interest. Upon visual inspection of these pixels, it was confirmed that
 most were over water bodies. 
description: These ASCII files can be opened in any GIS software tool (ie
 QGIS, ArcGIS Pro, etc). Their intended use is in the maximum entropy
 software (MaxEnt version 3.3.4 k).