lynnthium 的最愛

The calls are faint but visible. Probably not PESU (tri-colored bats) since they are not strongly inflected but that may be due to attenuation resulting in call fragments. The pulses are rather consistent in frequency which is a trait of PESU. However, I think the calls are more likely from LABO (eastern red bat) or from NYHU (evening bat). With an Fc (characteristic frequency) of 43 and a slight upturn in the call towards the end, it is closer to LABO. However, it could still be NYHU, especially since the pulse duration is about 8 ms.

First record of this species in Mission Trails Regional Park. Acoustic detection made using tripod-mounted Echo Meter Touch 2 Pro microphone and iPad Mini 4 microphone. Left side of split image is screen shot of spectrogram of echolocation call of a hand-released COTO on 9/4/2018 east of El Cajon, CA. Spectrogram on the right side of split image is one of three short COTO sequences recorded overnight from the San Diego River bed. It was recorded at 1137 PM PDT. The other detections were at 7:57 PM on 9/8 and 1:29 AM on 9/9. The second photo shows the recording location. The preponderance of recordings (>680) were of Pocketed-free tailed bats (Nyctinomops femorosaccus). Recording session in this closed area was with permission of MTRP ranger staff.

Recorded with iPhone XS Max and Echo Meter Touch 2 Pro ultrasonic module, the associated EMT bat detector app uses Kaleidoscope identification technology. I added several screenshots to try to portray the entire span of recording.

Recorded at 20:08 local time at Oversite/Ida Canyon confluence, approximately 5950' elevation. Sycamore/oak canyon bottom, recorded at spring where subsurface water comes to the surface and continues downstream approximately 400-500 m. The only water that I know of in the area. I have four recordings of passes to submit, Myev at 20:06, an Anpa at 20:08, a Laxa at 21:50, and a Mysi at 21:51. I was not recording throughout.

For the Anpa:

The fmaxE frequency at greatest amplitude was 32-35 kHz during at least one of the passes. However in general I am skeptical of the software's selection of Anpa and am wondering if this is the same individual that I recorded 1-2 minutes beforehand (https://www.inaturalist.org/observations/56186847). I added the entire recording, I wonder if I happened to record >1 bat and that some of the passes are from the bat linked above.

I've been using Szewczak's Echolocation Call Characteristics of California Bats., which describes Myev calls as potentially spanning 100kHz of bandwidth. The FM sweep can be nearly linear and the signature is shaped like Myth but with higher characteristic frequency (33-36 vs. 23-28 for Myth).

Could be PERSUB (PISU) but the duration (>6 ms) seems to long and most calls have a downward toe which suggests Myotis. The lowest frequency seems slightly too high for MYOVEL but not by much. Auto ID said LASNOC for some reason.

Observations were made with Bat Expert Gerald S. Wilkinson Professor at the University of Maryland Department of Biology. We utilized an echo meter application function on that phone that made recordings of the bat acoustics.

Recorded acoustically while watching for Canyon Bats that have been foraging shortly after sunset the past few evenings. No PAHE but this triggered sequence was recorded while walking back with my tripod mounted tablet and Echo Meter Touch 2 Pro microphone. The second half of the sequence indicates a second TABR was present with slight frequency shift. Note feeding buzz when the first bat captured a prey insect.