Hairy Eared Bat!

24th January 2018

Hairy Eared Bat (Micronycteris megalotis)


I found out from another member of the team that a large fallen tree that was hollow inside was discovered during the clearing of a new trail, and someone took a peek inside and noticed bats flying around. Intrigued, I took a walk into the forest today to investigate it. I found a large hollowed out log that looked close to the length of the first one we found. The inside diameter was roughly the same size as it looked like I could easily fit into it if crawling on my hands and knees. The log wasn’t as thick and solid as the first one, and there were cracks here and there where you could see small amounts of light shining through. There was also a lot of leaf litter on the floor of the log, from the entrance to a few meters back, and it was damp underneath. It wouldn’t be as easy or safe to crawl into as I would have to be more careful of snakes and insects hiding underneath all of that. As soon as I knelt down by the entrance I could see numerous small bats flying around. There was a long crack along the side of the log for the first meter or so, and the leaves on the floor of the log were easy to see due to the light shining through. Right beyond that was darkness so I aimed my headlamp inside and saw a cluster of bats roosting there. I took my machete and carefully pushed the leaves away from the entrance, keeping an eye out for snakes. Then I slowly crawled in about a meter or so and stopped. Multiple bats flew back and forth, coming very close to where I was sitting before turning around and heading toward the back of the log. The cluster of bats I had seen roosting was still there so I took some photos of them. There seemed to be slightly more room in this log to move around, compared to the other log. I had to sit hunched over but was able to turn around more easily. I didn’t have time to stay any longer at that point but I managed to get a few good shots; I’m curious to find out if these are the same species as what we found in the first tree. I’m also really curious to see what the other end of the log looks like, will have to explore that another day!



I made another visit to the new bat site today, intending to take more photos and explore the entire log some more. There actually is a bit more room to sort of crouch down low and ‘walk’ through the entrance, compared to the other log, so that’s what I did, dragging a pillow plus my camera and flash unit with me. I positioned myself several meters into the entrance and sat on the pillow.  I could see some bats flying back and forth further inside where there was no intrusion of outside light. I turned on the headlamp and aimed it to where I could see a cluster of bats roosting maybe 3-4 meters back. A few others flew close to me and I attempted some in flight shots. After they turned around and flew back however there was little movement from any of them. I waited for a little while but they didn’t move and none of them came any closer. So I carefully backed out of the log and decided to do some exploring. I cleared a small path with my machete from the trail over to approximately the center of the log. There was a large dead branch lying along side of it; I walked over that and climbed up onto the log. I intended to walk across the rest of the log down to the other end but there were a  number of cracks and openings along the top and sides. At first I hesitated, wondering if it would be safe to walk across or would I fall through? So I moved slowly, testing each step with one foot and found that, although it was more rotted out than the first log, it was still very strong. I had to clear away some leaves and branches hanging low over the top of the log so I could make my way across. I ended up being able to walk all the way to the end, where I discovered that this tree appears to have fallen naturally, unlike the first tree that Mark and I found that was evidently cut down. I climbed down and around the base to the ground, then walked around to the right side, clearing a bit of a path with the machete. The log was much wider here and there was a huge opening right at the base, it looked very much like the entrance to a cave! I shined my light inside and scanned the area for snakes and other interesting creatures. Seeing nothing but some crickets, I stepped inside. For a short distance I was actually able to bend over and walk through, going deeper inside. The floor of the log back here was somewhat muddy with no leaf litter. Up ahead, on the opposite side from which I entered, was a large opening that let some light through. Beyond that the space appeared to narrow down to approximately the diameter of the rest of the log. I saw a few bats flying here and there but it seemed that most of them were roosting toward the other end.

After comparing photos of the bats from the first log to photos of these bats I could see we had a different species. I noticed differences in the face, particularly the eyes and ears. I consulted our mammal guide book and I believe they may be a type of Spear-nosed bat, possibly the Round-eared Bat (Tonatia bidens) or a similar species. I counted roughly 20 bats on this visit, though there could have been a few more further back. There appears to be a smaller number of them in this particular log compared to the other one. According to what I read regarding the Round-eared Bat species they normally roost alone or in small groups. I climbed out of the log and made my way back to the trail as the sky overhead steadily grew dark. I heard thunder in the distance and put the camera in my waterproof bag. Halfway back to camp I got caught in a major downpour, but such is life during the rainy season….



It was a beautiful sunny day so I took a walk to the log again. The bats were not quite as cooperative today and I moved back and forth from one end of the log to the other multiple times. I managed to get more photos of them from either end of the log, but they didn’t stay in one place for very long before flying to the opposite end. I started off at the entrance from the trail; I crawled in slowly and sat on a pillow just a couple of meters inside the entrance. I noticed that there was one spot where 5-6 of the bats liked to roost all clustered together. As long as I moved very slowly and kept my light turned off until I was positioned to take photos, they didn’t move from that spot. Part of the log up to that section was broken away, letting in enough light so that I didn’t need my head lamp to see what I was doing. I took more photos of them and occasionally one would fly back and forth and attach itself to the cluster, or just fly further back in the log. After about 10 minutes they suddenly all flew off toward the back. I waited for another 10 minutes or so but they didn’t return. I crawled back out of the log and traveled to the other end, where I entered the cave-like opening and very slowly made my way deeper inside until I could see several clusters of bats up ahead. There was a large opening in the side of the log between where I was standing and where the bats were roosting. It was light where I stood but dark where the bats roosted, although I could make out their shapes. So without turning on my light I slowly moved forward, crouched down low to the muddy floor of the log. A few bats flew off but another 5 or 6 didn’t budge. When I had my camera ready I turned on the light, shining it toward the bats. I took some more photos from that position and that worked out for a little while. Then the bats became restless and started flying around more. Within another 5 minutes they all flew to the other end and stayed there. So I made my way back up to the entrance again and repeated this twice. After about two and a half hours of that they appeared to get more agitated by my head lamp so I turned it off and called it a day. Time to head back to camp to take a closer look at my photos.

Story written by Mark Fernley