Conservation and Ecology of Mammals – Chiroptera

Contributed Paper
ROOM: Room 120 – Dona Ana
SESSION NUMBER: 36
 

10:30AM Examining the Effectiveness of the North American Bat Monitoring Program (NABat) Acoustic Survey Protocols.
Kevin A. Parker; Han Li; Matina Kalcounis-Rüppell
The North American Bat Monitoring Program (NABat) is a long-term continental-wide bat sampling effort. It suggests two acoustic survey protocols for summer bat monitoring: mobile transect surveys and stationary point surveys. These two survey protocols were designed based on experts’ recommendations and logistic considerations. However, their effectiveness has not been tested with empirical data. We used NABat field data collected in North Carolina in 2016 to construct occupancy models. Our goals were to examine: 1) whether two survey protocols had the same probability to detect a species across different landscapes; 2) whether species specific detection probabilities varied among multiple nights of surveys in a protocol; and 3) whether stationary point survey site conditions would affect detectability of specific species. Our analysis showed that the mobile transect surveys lacked the ability to collect high numbers of Myotis species calls. Compared to stationary point surveys, mobile transect surveys had the same detection probability for the eastern red bat (Lasiurus borealis), evening bat (Nycticeius humeralis), tricolored bat (Perimyotis subflavus), and Mexican free-tailed bat (Tadarida brasiliensis). Multiple nights of surveys did not show detection probability variations except for the hoary bat (Lasiurus cinereus) in the stationary point surveys. Different detection probabilities for each night fit the occupancy model better than a single detection probability for multiple nights (ΔAIC > 3) for the hoary bat. We also found that the canopy coverage at a stationary point site affected the occupancy probability for the hoary bat, Mexican free-tailed bat, and silver-haired bat (Lasionycteris noctivagans). Whether a site was in urban environments affected the occupancy probability for the Mexican free-tailed bat and northern long-eared bat (Myotis septentrionalis). Our results provide insights on how to effectively and efficiently monitor bats via acoustic methods across different landscapes.
10:50AM Using Non-Invasive Methods to Compare Stress Levels in Urban Bats throughout the Chicago Metropolitan Area
Matthew P. Mulligan; Mary Beth Manjerovic; Katherine Fowler; Rachel Santymire
Researchers of urban wildlife typically study community composition through passive monitoring, but there is an increasing need to understand health and stress factors. Chronic stress can damage individual health through reproductive and immune system suppression. Through extraction of cortisol from fecal material, hair, and nails one can understand target species stress levels 12-24 hours (fecal material) or up to several months (hair and nails) prior to collection. Our objectives were to: 1) develop methods to measure cortisol in bat hair, toenails, and guano; and 2) determine if the degree of urbanization influenced stress levels in bats. We hypothesized that bats located in human-dominated landscapes would have higher cortisol levels due to environmental stressors such as land-use change, resource loss, and sound and light pollution. To develop cortisol analysis methods, we collected guano from active big brown bat (Eptesicus fuscus) and little brown bat (Myotis lucifugus) roosts in four counties around the Chicagoland area verifying species presence using acoustic monitors. Hair and nail samples were gathered from deceased rabies negative bats at the Illinois Natural History Survey from individuals prior to the detection of the white-nose fungus (Pseudogymnoascus destructans) in the region. Cortisol was successfully extracted from hair, toenails, and guano. We found a positive correlation in bat fecal cortisol metabolites and roost proximity to high human density (4.70±1.53 µg/g) compared to low human density (1.05±0.18 µg/g) areas (p=0.05). We also observed an increase in fecal cortisol metabolites early to mid-June (8.72±2.35 µg/g) compared to mid-July (0.92±0.17 µg/g; p=0.014) and late September (1.83±0.36 µg/g; p=0.012), which could be driven by an increased demand on females rearing pups in June. In conclusion, land managers need to consider human presence when installing bat roosts in urban areas to reduce stress and improve resiliency to detrimental diseases such as white-nose syndrome.
11:10AM Understanding the Landscape Factors and Scale That Influence Urban Bat Activity
Elizabeth W. Lehrer; Travis Gallo; Mason A. Fidino; Seth B. Magle
Once considered devoid of wildlife, cities are increasingly recognized as complex, biodiverse ecosystems, in part due to an emerging emphasis on reconciliation ecology in urban planning. To properly manage biodiversity in cities, we need a better understanding of the landscape factors that drive wildlife distributions, and the scale at which species are selecting habitat. Facing many threats, bats are known to occur in cities, but relatively little is known about species-specific responses to urbanization. During 2013-2015, we examined the influence of various landscape variables at several scales on bat activity. Based on calls recorded from acoustic detectors, we used Bayesian occupancy modeling to examine species-habitat relationships for bats in the Chicago metropolitan area, USA. We found that urban bats are responding to habitat characteristics at different scales, likely due to varying roosting requirements and foraging strategies. For example, habitat characteristics at local, mid-sized, and landscape scales were important predictors of silver-haired and eastern red bat activity. We also found a shift in the relative importance of some habitat characteristics at different scales, indicating that local-scale effects may be impacted by broad-scale spatial patterns of land cover. While it is important to understand what habitat characteristics are most important for bats, it is just as important to understand at what scale bats are selecting these habitats. We encourage managers and city planners to consider species- specific habitat requirements beyond the local scale when creating urban habitats for wildlife.
11:30AM Predicting Seasonal Distribution and Migratory Pathways for Neotropical Nectar-Feeding Bats
Rachel A. Burke; Kathryn E. Stoner; Jennifer K. Frey; Christopher P. Brown
Three Neotropical species of nectarivorous bats, the lesser long-nosed bat (Leptonycteris yerbabuenae), Mexican long-nosed bat (Leptonycteris nivalis), and Mexican long-tongued bat (Choeronycteris mexicana), reach their northernmost extent in the southwestern United States. It’s generally accepted that these species migrate along a nectar corridor of columnar cacti and Agave species. Thus, the seasonal distribution of these nectarivores is dictated by phenological relationships with their food resources. However, the precise nature of these relationships is poorly understood. To better understand the seasonal distribution of these bats, we generated a series of models to explore the influence of food resources on the distribution of each species. Using herbarium records of documented food resources, we generated botanical resource distribution models in MaxEnt. We determined the seasonal availability of each resource and seasonal botanical richness using phenology records. We then used botanical models to estimate the seasonal distribution of the bats themselves using presence records from verified museum specimens and from recent studies. Using Circuitscape, we modeled migratory corridors among seasonal habitats. Models highlight the importance of the western Sierra Madre Occidental for L. yerbabuenae and the eastern Sierra Madre Orientals for L. nivalis; models indicate that C. mexicana likely follows a mixture of these routes. Migration models also highlight routes by which L. nivalis may reach southwestern New Mexico, where all three species of nectarivores are sympatric. Based on these models, we recommend surveys in the Davis, Guadalupe, Sacramento, and Gila Mountains, and throughout northern Chihuahua for endangered L. nivalis. While migration modeling is widely used for avian species, this is the first paper that utilizes corridor tools to identify migration routes for bats. These results will provide valuable information to land managers in the U.S. and Mexico, while also providing a toolset with which to inform field surveys for highly mobile migratory bats.
11:50AM Effects of Urbanization on Bat Habitat Use in Phoenix, Arizona: A Multi-Scale Landscape Analysis
Tracy C. Bazelman; Carol L. Chambers; Jianguo Wu; Sam A. Cushman
Abstract:
 Urbanization can have negative effects on bat habitat use through the loss and isolation of habitat. Yet, how bats respond to the changing landscape pattern of urban environments remains poorly understood. The objective of this research is to examine how urban landscape composition and configuration affects bat activity, foraging activity, and species richness (response variables). We used a multi-scale landscape approach and bat acoustic data to create predictive models that identified the key predictor variables across three scales (landscape, home range and site scales). We found the extent and/or the extensiveness of water (corresponding to small water bodies and watercourses) were the most important predictor variables across all response variables. Bat activity was predicted to be high in native vegetation remnants, and low in outlying native desert habitat. Foraging activity was predicted to be high in areas of fine-scale land cover heterogeneity. Species richness was predicted to be high in golf courses, which included the detection of the uncommon pocketed free-tailed bat (Nyctinomops femorosaccus), and low in commercial areas. Overall, bat habitat use was affected by urban landscape pattern at the landscape and site scales. Our results suggested in hot, arid, urban landscapes water is a limiting factor for bats, even in urban landscapes where the availability of water may be greater than in outlying native desert habitat. Also, golf courses may serve as important stop-overs or refuges for rare or elusive bats. Golf courses and urban waterways are novel urban cover types that can serve as compliments to urban preserves, and other green spaces for bat conservation.

 

Contributed Paper
Location: Albuquerque Convention Center Date: September 25, 2017 Time: 10:30 am - 12:10 pm