Geology topics

Corinna Pinzari

Publications and source records attributed to Corinna Pinzari.

3 recordsLinked to original sources

USGS2026

Dietary composition and diversity in an endemic island bat, the Hawaiian hoary bat (Lasiurus semotus)

Due to the importance of sufficient diets, conservation practices for endangered bats often involve protection and restoration of foraging resources. For insectivorous (or arthropodivorous) bats, detailed knowledge of prey consumption can inform effective management. In this study, we used metabarcoding techniques to investigate the diet of Lasiurus semotus , a primarily insectivorous, solitary foliage-roosting endangered bat endemic to the Hawaiian Islands. To determine diet composition and how it relates to sex, reproductive condition, and habitat, we analyzed 141 guano samples collected from across the Hawaiian archipelago between 2010–2021. We detected 424 arthropod prey items, with Lepidoptera — the most common order (found in 100% of all samples), followed by Blattodea (85%), Coleoptera (42%), Orthoptera (47%), Diptera (33%), and Hemiptera (25%). Coleoptera were more frequent in guano collected from females. Prey richness and evenness at the family-level were similar across sex, reproductive condition, elevation, and land cover type. High variability among samples, and the dominance of Lepidoptera and Kalotermitidae (Blattodea), indicates that local prey abundance may influence L. semotus diet more strongly than prey richness and evenness. Lasiurus semotus consumed both native and non-native arthropods, including several invasive agricultural pests. Our study demonstrates that hoary bats in the Hawaiian Islands consume a wide variety of prey types, likely sought over an extensive range of habitats.

Hawaii↗

USGS2023

Genetic diversity, structure, and effective population size of an endangered, endemic hoary bat, ʻōpeʻapeʻa, across the Hawaiian Islands

Island bat species are disproportionately at risk of extinction, and Hawaiʻi’s only native terrestrial land mammal, the Hawaiian hoary bat ( Lasiurus semotus) locally known as ʻōpeʻapeʻa, is no exception. To effectively manage this bat species with an archipelago-wide distribution, it is important to determine the population size on each island and connectivity between islands. We used 18 nuclear microsatellite loci and one mitochondrial gene from 339 individuals collected from 1988–2020 to evaluate genetic diversity, population structure and estimate effective population size on the Islands of Hawaiʻi, Maui, Oʻahu, and Kauaʻi. Genetic differentiation occurred between Hawaiʻi and Maui, both of which were differentiated from Oʻahu and Kauaʻi. The population on Maui presents the greatest per-island genetic diversity, consistent with their hypothesized status as the original founding population. A signature of isolation by distance was detected between islands, with contemporary migration analyses indicating limited gene flow in recent generations, and male-biased sex dispersal within Maui. Historical and long-term estimates of genetic effective population sizes were generally larger than contemporary estimates, although estimates of contemporary genetic effective population size lacked upper bounds in confidence intervals for Hawaiʻi and Kauaʻi. Contemporary genetic effective population sizes were smaller on Oʻahu and Maui. We also detected evidence of past bottlenecks on all islands with the exception of Hawaiʻi. Our study provides population-level estimates for the genetic diversity and geographic structure of ‘ōpeʻapeʻa, that could be used by agencies tasked with wildlife conservation in Hawaiʻi.

Hawaii↗

USGS2020

Hawaiian hoary bat (Lasiurus cinereus semotus) acoustic monitoring at Hawaii Army National Guard (HIARNG) installations statewide

Acoustic sampling for occurrence of the endangered Hawaiian hoary bat (Lasiurus cinereus semotus) was conducted at 18 “long-term” acoustic monitoring stations on 12 Hawai‘i Army National Guard (HIARNG) installations across the islands of Hawai‘i, Maui, Moloka‘i, O‘ahu, and Kaua‘i between 2012 and 2018. Bats were confirmed as present at 10 of these installations: Kealakekua Armory, Keaukaha Military Reservation (KMR), Hanapēpe Armory, Kekaha Firing Range (KFR), Pu‘unēnē Training Facility, Ukumehame Firing Range (UFR), Kaunakakai Armory, Bellows Regional Training Institute, Kalaeloa, Barber’s Point, and the 487th Military Parking Facility, Wahiawā. Seasonal frequency of bat detection was similar to previous acoustic studies for the islands of Hawai‘i, Maui, and O‘ahu. Hawaiian hoary bats were recorded at HIARNG installations during periods of pregnancy, lactation, and pup fledging. Our acoustic sampling did not record bat vocalizations at Fort Ruger and Waiawa Armory. Foraging activity was observed at nine acoustic monitoring stations on the islands of Hawai‘i, Kaua‘i, O‘ahu, and Maui. No foraging activity was observed on Moloka‘i and a single station on O‘ahu recorded one feeding buzz in September 2017 at Kalaeloa, Barber’s Point. Within-night detections showed bat activity was mostly confined to the first six hours of the night but was also variable among stations. In addition to long-term bat acoustic monitoring at HIARNG installations, Hawaiian hoary bat insect prey sampling with paired acoustic monitoring was conducted at KMR on Hawai‘i Island from May through August 2018. Insect abundance and bat activity were sampled within areas where goats and sheep were used to control weeds to determine if grazing by these ungulates attract and support potential prey for the insectivorous Hawaiian hoary bat. The assessment focused on types of flies that are often associated with livestock (muscoid flies, including house flies [Muscidae], blow flies [Calliphoridae], flesh flies [Sarcophagidae], and biting midges [Ceratopogonidae]), and moths that may be impacted by changes in the availability of grass. Insect abundance was found to vary in both space and time across the study area, with numbers of muscoid flies and biting midges increasing in the presence of livestock at some stations. Although these insects appeared to respond to livestock grazing in some instances, we did not find statistically significant responses in bat foraging as measured by echolocation activity between grazed stations and the ungrazed reference station. Thus, we found no evidence that suggested bats are drawn to foraging resources in grazed areas. This result may be influenced by several factors, including the size of Hawaiian hoary bat foraging ranges compared to the scale of study area, the type of ungulate and their dung, and the timing of insect activity. Hawaiian hoary bats use KMR and forage seasonally as evidenced by long-term acoustic studies and their presence in the ungulate grazing areas; however, the relatively small size of the ungulate herd and the area that they graze may not be able to support enough prey to have a significant influence on bat foraging rates.

Hawaii↗