Multi-state occupancy models of foraging habitat use by the Hawaiian hoary bat (Lasiurus cinereus semotus)

Abstract

Multi-state occupancy modeling can often improve assessments of habitat use and site quality when animal activity or behavior data are available. We examine the use of the approach for evaluating foraging habitat suitability of the endangered Hawaiian hoary bat (Lasiurus cinereus semotus) from classifications of site occupancy based on flight activity levels and feeding behavior. In addition, we used data from separate visual and auditory sources, namely thermal videography and acoustic (echolocation) detectors, jointly deployed at sample sites to compare the effectiveness of each method in the context of occupancy modeling. Video-derived observations demonstrated higher and more accurate estimates of the prevalence of high bat flight activity and feeding events than acoustic sampling methods. Elevated levels of acoustic activity by Hawaiian hoary bats were found to be related primarily to beetle biomass in this study. The approach may have a variety of applications in bat research, including inference about species-resource relationships, habitat quality and the extent to which species intensively use areas for activities such as foraging.

Hawaiian hoary bat responses to habitat, season, and non‐native insectivore suppression

“…This may explain the apparent lack of prey competition between bats and the invasive insectivores. For example, rats, mice, yellowjackets, and ants generally consume larval stages of insects like moths (Lepidoptera) and beetles (Coleoptera) on the ground or vegetation (Cole et al 1992, Gambino 1992, Wilson et al 2009, Shiels et al 2013), whereas hoary bats consume the adult forms of these aerial insects in flight (Todd 2012, Gorresen et al 2018, Pinzari et al 2019). Additionally, because no other bat species are present in Hawaiʻi, hoary bats experience little competition for nocturnal aerial insects, and they are opportunistic insectivores with flexible diets.…”

“…The bat resides on all main islands of Hawaiʻi, USA. They are solitary, tree‐roosting bats that consume aerial insects, primarily moths (Lepidoptera) and beetles (Coleoptera), in open and wooded areas (Belwood and Fullard 1984, Jacobs 1999, Todd 2012, Gorresen et al 2018, Pinzari et al 2019). Despite the preponderance of moths and beetles in their diet, individuals forage opportunistically on a wide range of insect orders in native, non‐native, human‐occupied, and agricultural landscapes (U.S.…”

Response of a remnant marmot population to habitat enhancement yields insights into marmot ecology

“…In particular, to assess whether marmots expanded geographically into enhanced habitat areas, we used a novel approach within a multistate framework. Previous studies have used multistate frameworks to evaluate transition probabilities among age classes ( Ozgul et al 2007 ; Muths et al 2014 ; Prochazka et al 2017 ); among habitats ( Hotaling et al 2009 ; Breininger et al 2010 ; Spurgeon et al 2018 ); to estimate occupancy ( Schmidt et al 2014 ; Gorresen et al 2018 ; Wilson et al 2018 ); and recently to estimate effect of body condition and habitat on survival ( Boulanger et al 2013 ), and cause-specific mortality ( Raithel et al 2017 ). Here, we used a multistate framework to estimate the probability (with estimates of error) that a population moved into enhanced habitat areas post-habitat enhancement.…”

Seasonal and Elevational Differences by Sex in Capture Rate of ‘Ōpe‘ape‘a (Lasiurus semotus) on Hawai‘i Island

“…Four fixed sites were located at elevations above 1,000 m ("high elevation") and four below 1,000 m ("low elevation"). Fixed sites were chosen from locations that offered relatively high levels of bat occurrence and capture success, as determined in previous studies (Gorresen et al 2008(Gorresen et al , 2013Bonaccorso et al 2015) and from opportunistic surveys and scouting in this study prior to 2019. We surveyed each fixed site at least once per 4-month period (January-April, May-August, September-December), with a survey comprising 1 to 3 netting events (mean 2.5 ± 0.6) depending on capture success (i.e., no capture on first night was followed by additional survey effort), project priorities, weather, and available personnel.…”

“…Acoustic and visual observations demonstrate that 'ōpe'ape'a are distributed across all of the major Hawaiian Islands and elevations up to 3,562 m (Tomich 1986;Bonaccorso et al 2016), yet population size is currently unknown with threats including collisions with wind turbines and potentially limited habitat and food resources (USFWS 2021). 'O pe'ape'a activity varies by geographic location and time-of-year, with greater activity associated with forested locations, insect biomass, and lower elevations during summer months (Jacobs 1994;Menard 2001; Gorresen et al 2013). Previous specimen collection and capture-release netting surveys have broadened our understanding of reproductive timing, diet, roosting and foraging behaviors, and population genetics (Menard 2001;Todd 2012;Bonaccorso et al 2015;Bernard and Mautz 2016;Pinzari 2019;Pinzari et al 2019;Montoya-Aiona et al 2023).…”