Hawaiian Hoary Bat 

Acoustic and Thermal IR Monitoring Project for Tree Removal at Nehelani on 

Schofield Barracks 17‐29 June 2015 

Data prepared by C. Pinzari, for OANRP, July 2015 

Survey Goals 

Establish whether or not Hawaiian Hoary bats (Lasiurus cinereus semotus) are roosting with pups on four trees that are required to be removed for a construction project.  The trees to be removed are (1) Mango (Mangifera indica), (1) Coconut palm (Cocos nucifera) and (2) Chinese Banyans (Ficus microcarpa)  If bats present, discuss with regulatory agency possible mitigation measures to continue project or postpone removal of trees until pupping season is completed. 

Survey Map 

Figure 1. Map of the Nehelani construction project site which received bat acoustic survey. Green dots indicate location of the two acoustic detectors at the site. 

Appendix 4-1 Bat Report Results

Map removed to protect rare resources. Available upon request

Survey Methods 

Acoustic surveys for bats were conducted from 17‐29 June 2015 at the proposed tree cutting site for a 

total of 12 nights. Two SM2Bat+ ultrasonic “bat detector” (Wildlife Acoustics) were placed about 80 

meters apart, on either end of the row of trees proposed to be removed (Figure 1).    

Bat detectors were set to record bat echolocation calls or “pulses” from dusk until dawn, and a bat 

“event” was triggered, recorded as a sound file, and logged for each pass a flying bat made by the 

microphone of a detector during the night. The number of bat events and number of echolocation 

pulses within an event can be used to confirm bat presence and describe bat activity levels. Bat events 

can also contain information on foraging activity, by the presence of characteristic echolocation pulses 

that form a “feeding buzz”. Files collected during the recordings were scanned and filtered for bat 

presence using the program Kaleidoscope (version 1.1.22, Wildlife Acoustics) and visually inspected by 

sound and sight to confirm and count bat echolocation pulses. Foraging activity was also noted in call 

events containing feeding buzzes. Bat detectability (p), signifying presence or absence of the species for 

each survey was calculated using the program Presence (version 6.2, J.E. Hines, USGS).  These acoustic 

surveys can detect whether bats are actively using the area within the range of the detectors with any 

frequency.  The effective range of these detectors is upwards of about 50 m (C. Pinzari pers. comm.)  A 

high detection rate could indicate the presence of a roost tree within the detection range.  Whereby 

further surveys with a thermal imager would be required. 

Visual surveys for bats were conducted on 29 June 2015, the day of the scheduled tree removal.  A Fluke 

Ti400 thermal imager was employed to scan the tree for any roosting bats as well to confirm no 

presence.  Scanning commenced from about 05:40 and completed around 07:00 from the ground 

scanning from different angles and locations around the two trees.  An aerial bucket was also on site as 

an extra resource to scan higher in the tree. 

Results and Discussion 

Survey results show no measure of bat detectability at this location during the acoustic survey period.  

No bats were recorded passing through or utilizing the site during this time.  The visual thermal IR 

survey detected no bats at all.  Multiple species of birds were observed with the thermal IR, with visual 

confirmation, in and around the area. It was determined that there would be ‘No Effect’ to bats if the 

trees were removed.  

Recommendations 

Continue to utilize acoustical surveys to determine bat presence in these small well defined areas with 

low numbers of trees.  Bat detectors can be placed within 40 meters of each other so that there is 

overlap in effective detection distance.  If a bat is using the area around the detector frequently it is 

expected that there would be more activity, more passes, longer files, more than 1 per night, or more 

than 1 night.  If bat activity is higher in a specific area then the thermal IR should be used to verify bat 

roosting. 

Hawaiian Hoary Bat 

Thermal IR Monitoring Project for Tree Removal at Vought Street on Wheeler 

Army Airfield 25 June 2015 

Data prepared by C. Pinzari, for OANRP, June 2015 

Survey Goals 

Establish whether or not Hawaiian Hoary bats (Lasiurus cinereus semotus) are roosting with pups on two Coconut palm trees (Cocos nucifera) that are required to be trimmed for safety reasons. The trees were not trimmed prior to the pupping season so they still contained falling coconuts directly over residences. If bats present, discuss with regulatory agency possible mitigation measures to continue project or postpone removal of trees until pupping season is completed. 

Survey Map 

Figure 1. Map of the Vought Avenue project site which received bat acoustic surveys. Green dots indicate location of the trees to be trimmed at the site. 

Map removed to protect rare resources. Available upon request

Survey Methods 

Visual surveys for bats were conducted on 25 June 2015, the day of the scheduled tree trimming.  A Fluke Ti400 thermal imager was employed to scan the tree for any roosting bats as well to confirm no presence.  Scanning commenced at about 05:50 (#824 Vought Avenue.) and completed around 07:00 (#762 Vought Avenue) from the ground scanning from different angles and locations around the two trees. 

Results and Discussion 

The visual thermal IR survey detected no bats at all.  Multiple species of birds were observed with the 

thermal IR, with visual confirmation, in and around the area.  It was determined that there would be ‘No 

Effect’ to bats if the trees were removed.  

Recommendations 

Work with DPW to better monitor the contractors work so that trees that need trimming are not missed 

prior to the pupping season.   

Hawaiian Hoary Bat

Acoustic Monitoring Project for Tree Removal at Maili Street on Schofield Barracks 01-14 July 2015

Data prepared by C. Pinzari, for OANRP, July 2015

Survey Goals

Establish whether or not Hawaiian Hoary bats (Lasiurus cinereus semotus) are roosting with pups on two trees that are required to be removed for a construction project. The trees to be removed are (1) Kukui nut (Aleurites moluccanus) and (1) Eucalyptus spp. If bats are present, discuss with regulatory agency possible mitigation measures to continue project or postpone removal of trees until pupping season is completed.

Survey Map

Figure 1. Map of the Maili Street project site which received bat acoustic survey. Green dots indicate location of the two trees to be removed at the site.

Map removed to protect rare resources. Available upon request

Survey Methods

Acoustic surveys for bats were conducted from 01-14 July 2015 at the proposed tree cutting site for a total of 13 nights. One SM2Bat+ ultrasonic “bat detector” (Wildlife Acoustics) was placed between the two trees proposed to be removed (Figure 1). The trees are only about 5 meters apart.

Bat detectors were set to record bat echolocation calls or “pulses” from dusk until dawn, wherein each bat “event” is triggered, recorded as a sound file, and logged for each pass a flying bat makes by the microphone of a detector during the night. The number of bat events and number of echolocation pulses within an event can be used to confirm bat presence and describe bat activity levels. Bat events can also contain information on foraging activity, by the presence of characteristic echolocation pulses that form a “feeding buzz”. Files collected during the recordings were scanned and filtered for bat presence using the program Kaleidoscope (version 1.1.22, Wildlife Acoustics) and visually inspected by sound and sight to confirm and count bat echolocation pulses. Foraging activity was also noted in call events containing feeding buzzes. Bat detectability (p), signifying presence or absence of the species for each survey was calculated using the program Presence (version 6.2, J.E. Hines, USGS). These acoustic surveys can detect whether bats are actively using the area within the range of the detectors with any frequency. The effective range of these detectors is upwards of about 50 m (C. Pinzari pers. comm.) A high detection rate could indicate the presence of a roost tree within the detection range. Whereby further surveys with a thermal imager would be required.

Results and Discussion

Survey results show an extremely low measure of bat detectability at this location during the acoustic survey period. A single bat pass was recorded on 2 July at 20:22:26. It was a very short file, with three pulses of echolocation. This type of flight is considered a fly by, whereby the animal is just flying through to visit another site (C. Pinzari pers. comm.). It was determined that there would be ‘No Effect’ to bats if the trees were removed.

Recommendations

Continue to utilize acoustical surveys to determine bat presence in these small well defined areas with low numbers of trees. Bat detectors can be placed within 40 meters of each other so that there is overlap in effective detection distance. If a bat is using the area around the detector frequently it is expected that there would be more activity, more passes, longer files, more than 1 per night, or more than 1 night. If bat activity is higher in a specific area then the thermal IR should be used to verify bat roosting.

Hawaiian Hoary Bat 

Thermal IR Monitoring Project for Tree Removal at Schofield Barracks Building 

684 on 28 July 2015 

Survey Goals 

Establish whether or not Hawaiian Hoary bats (Lasiurus cinereus semotus) are roosting with pups on a Chinese arbovitae (Platycladus orientalis) that is infested with termites so requires removal for safety reasons.  If bats present, discuss with regulatory agency possible mitigation measures to continue project or postpone removal of trees until pupping season is completed. 

Survey Map 

Figure 1. Map of the SB Bldg 684 project site which Fluke thermal imager surveys. Green dot indicates location of the tree to be removed at the site. 

Map removed to protect rare resources. Available upon request

Figure 2.  Chinese arbovitae (Platycladus orientalis) on site 

Survey Methods 

Visual surveys for bats were conducted on 28 July 2015, the day of the scheduled tree trimming. A Fluke Ti400 thermal imager was employed to scan the tree for any roosting bats as well to confirm no presence.  Scanning commenced from 05:30‐05:43 from the ground from different angles and locations. 

Results and Discussion 

The visual thermal IR survey detected no bats at all.  Multiple species of birds were observed with the 

thermal IR, with visual confirmation, in and around the area.  It was determined that there would be ‘No 

Effect’ to bats if the trees were removed.  

Recommendations 

Work with DPW to better monitor the contractors work so that trees that need trimming are not missed 

prior to the pupping season.   

Hawaiian Hoary Bat 

Thermal IR Monitoring Project for Tree Removal at Schofield Barracks Credit 

Union and Warrior Transition Battalion on 28 July 2015 

Survey Goals 

Establish whether or not Hawaiian Hoary bats (Lasiurus cinereus semotus) are roosting with pups on two Mexican fan palms (Washingtonia robusta), two Coconut palms (Cocos nucifera), 16 Royal palms (Roystonea regia), eight Loulu palms (Pritchardia spp.) and five queen palms (Syagrus romanzoffiana) that require trimming for safety reasons.  If bats present, discuss with regulatory agency possible mitigation measures to continue project or postpone removal of trees until pupping season is completed. 

Survey Map 

Figure 1. Map of the SB Credit Union and Warrior Transition Battalion project site which Fluke thermal imager surveys. Red dot indicates location of the site. 

Map removed to protect rare resources. Available upon request

Figure 2.  Map of palm locations 

Survey Methods 

Visual surveys for bats were conducted on 28 July 2015, the day of the scheduled tree trimming. A Fluke Ti400 thermal imager was employed to scan the tree for any roosting bats as well to confirm no presence.  Scanning commenced from 05:45‐06:30 from the ground from different angles and locations. 

Results and Discussion 

The visual thermal IR survey detected no bats at all.  Multiple species of birds were observed with the 

thermal IR, with visual confirmation, in and around the area.  It was determined that there would be No 

Effect to bats if the trees were removed.  

Recommendations 

Work with DPW to better monitor the contractors work so that trees that need trimming are not missed 

prior to the pupping season.   

Figure 3.  Photo samples of the palms on site