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http://mtnhp.org. 15 October 2013. Acoustic Assessment of Bat Species Presence and Activity Levels at the Signal Peak Mine in the Bull Mountains. Collaborators: Bryce Maxell and Susan Lenard, Montana Natural Heritage Program
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http://mtnhp.org 15 October 2013 Acoustic Assessment of Bat Species Presence and ActivityLevels at the Signal Peak Mine in the Bull Mountains Collaborators: Bryce Maxell and Susan Lenard, Montana Natural Heritage Program Michael Glenn and Chris Yde, Montana Department of Environmental Quality Ellen Pfister Ranch, Bull Mountains, Montana Sean Ellington, Signal Peak Mine QUESTIONS? Please contact, Bryce Maxell at: (406) 444-3655 (office) (406) 461-1279 (cell) bmaxell@mt.gov
Bats of Montana - 5 Species of Concern - 4 Potential Species of Concern ? ?
Major Conservation Issues • White-Nose Syndrome caused by the introduced fungus Pseudogymnoascusdestructanswhich is spreading westward • Loss of natural roost habitats in trees and cracks and crevices in rock outcrops • Wind turbine collisions and barotrauma • Drowning hazards at artificial watering sites • Loss of prey species (pesticides)
Establishment of Long-term Passive Bat Acoustic Detection Array Funders/Status 2 detectors were deployed within the bounds of the Signal Peak Mine’s mineral rights on 23 August 2012
Image from Joe Szewczak Library of Bat Calls of Known Species Identity Used in Automated Analysis Software SONOBAT 3.0
Analysis Process • Convert compressed WAC files into WAV format and archive original WAC files for potential future analysis • Compensate for SMX-US weatherproof ultrasonic microphone using Sonobat Batch Compensator • Eliminate nonbat noise files using Sonobat Batch Scrubber and, if necessary, by hand review • Auto-analyze files using Sonobat Batch Analysis Utility (MT South Version for plains and MT Mountains Version for mountains) • Hand check automated analyses using Szewczak and Weller (2006) acoustic key. a. confirm species monthly presence b. check all calls below 4 degrees Celsius c. check other calls of interest (e.g. activity pulses) • Analyze results of automated and hand analyses in site specific Microsoft Access databases • Archive WAV files for potential future analysis
What We Have Learned from Passive Acoustic Monitoring of Bats at the Signal Peak Mine so far?* *Although current results have greatly expanded our knowledge of bat species temporal distribution and activity patterns, automated analyses procedures are still being refined and only a small portion of the data has been reviewed by hand. Thus, other than hand confirmations, results should be regarded as tentative. It is very possible that future automated analyses of the same data may document additional species or species during time periods where they have not yet been documented.
Bat Species Present or Potentially Present in the Bull Mountains
Deployment History and Analysis Status • 23 August 2012 – Detector installed. • Memory Card Download Dates • 5 November 2012 • 28 January 2013 • 20 May 2013 • 13 June 2013 • 5 August 2013 • 12 September 2013 • 15 October 2013
Files (Bat Passes) Processedthrough 15 October 2013 • 44,050 Total number of bat passes(perhaps 1-2% are noise files that make it through scrubbers) • 5,718 (13%) identified to species by auto-analysis • 756 reviewed by hand (1.7% of total and 13% of those identified to species by Sonobat 3.0)*
Detector Status as Measured byPercent of Calls Auto-Identified to Species * Microphone sensitivity appears to be satisfactory throughout deployment
Species Identified by Automated Analysis (black) and Hand Confirmations (red) 1 Species is relatively quiet and often does not trigger recordings on bat detectors. 2 Silver-haired Bat, Big Brown Bat, and some Hoary Bat calls overlap and definitive differentiation to species is often not possible. 3 Spotted Bat calls may be present, but there identification will requirement refinement of the automated analysis procedures. 4 Long-legged Myotis call recordings often lack the definitive call characteristics needed to definitively identify the species.
2012 Total Passes Per SpeciesPer Month from Automated Analysis
2012 Total Passes Per Species Per Month from Auto Analysis for Hand Confirmed Species Only
2013 Total Passes Per SpeciesPer Month from Automated Analysis
2013 Total Passes Per Species Per Month from Auto Analysis for Hand Confirmed Species Only
Total Passes on Sampling Nights with DataWinter / Spring 2013
Total Passes on Sampling Nights with DataSummer and early Fall 2013
Timing of “Winter” Bat Activity 2012-2013Total No. Bat Passes by Hour After Sunset
Timing of Active Season Bat Activity 2012-2013Total No. Bat Passes by Hour After Sunset
Nightly Background and Bat Pass Temperatures Summarized by Month * Temperature at the detector is recorded every 5 minutes each night and each bat pass is assigned the nearest recorded temperature. Some low temperature passes still need review.
Highlights • First documentation of Fringed Myotis in the Bull Mountains • First winter flight activity records of Western Small-footed Myotis in region. • Dozens of first month records for species and first documentation of flight temperatures with bats flying at temperatures as low as minus 15 °C. • Bat activity between June and September is 10 to 100 times the level of bat activity between October and April and reaches a peak from mid July to late August. • Bat activity at Busse Water Reservoir is up to 5 times higher than it is at Reservoir 1 between May and September. • Bat activity from September through May is generally greater from sunset to the middle of the night than it is in the early morning hours while there are two nightly peaks of activity(a greater peak early in night and a lesser peak late in the night) in June, July, and August.
Recommendations • Continue year round acoustic assessment at both Busse Water Reservoir and Reservoir 1 through at least the fall of 2014 and ideally through the fall of 2015 in order to better document inter-annual variation in bat activity. • Refine automated analysis in order to look for the presence of Spotted Bats. • Conduct automated analysis with alternative software (i.e. Kaleidoscope) and compare results for individual species with Sonobat 3.0 software which has been used for over a decade as the standard bat call analysis software. • Examine correlations between bat activity and barometric pressure and wind speed. • Compare landscape patterns of bat activity at the Busse Water Reservoir and Reservoir 1 sites with levels of bat activity recorded on other bat detectors that are currently deployed across Montana.