Bat phobia

[SuckinOnSodaStraws]

Okay so I'm not phobic, and less and less worried by close-encounters with our trogloxene friends, the bat. But when I see pictures of huge colonies in caves, I wonder how they get around without disturbing them. I have heard of speaking in low tones, and have myself been successful in slowly and quietly crawling past a sleeping one. I've also had my freak-out moments in my first few encounters. I learned to love all trogs, but does anyone out there really have a phobia? If not, what are some techniques you've used to keep bats undisturbed? Any photography technique advice would be appreciated as well.

[Chads93GT]

Easy. Don't touch them. I shine my lights at them, talk, etc who cares. Whomever gave you the impression that the slightest peep will disturb a bat gave you the wrong impression.

[graveleye]

I've heard that whispering disturbs them more than talking. Something about the higher frequencies and sibilance of whispering is more audible to them.
If there is a large colony, you probably shouldn't be in there anyway. And if you were, you would want to move along very quickly for a variety of reasons (your health, the bats health and and many more).

Solitary bats that roost alone usually don't seem bothered if you just walk on by them. In warmer weather you might wake one up or encounter one with insomnia and they have to fly around and check you out. The rest just sleep through it.

My wife and I only communicate in hand signals when we are checking on our bats in order to disturb them as little as possible. In the winter we try to leave them alone for the most part and stay away from their preferred hibernation roost.

In any case, folks need to do whatever they can to keep from disturbing them, especially these days.

(edited from my first post...more thoughts on the subject.)

[batshitcrazy]

I live in Indianapolis and most of the caves we frequent are in southern IN and have very healthy bat populations. We always look very closely at the bats to check for WNS and I can tell you from my experience bats are hard to disturb. One of the caves have a section that they are so thick they are hard not to bump into and we walk within inches of them and talk , shine lights etc. and they never seem to mind. I personaly have never had a bat touch me in a cave and I've been in tunnels so tight they couldn't get around me and they would fly right up to my face and turn around over and over waiting on a chance to get past me. Bats are not my phobia when it comes to caves. I worry more about snakes in the entrances than any other animal in a cave. I have several caves that I have designated as winter only caves, lol,, Lost Boy cave is one of those. If anyone has ever done Lost Boy they will know what I'm taking about. Looks like a great spot to get a copperhead bite. lol

[Chads93GT]

Ive had them land on me and crawl over me while surveying several times. Its no big deal, they are harmless, after a minute of crawling on me the little guy flew away, it was pretty damn cool.

[GroundquestMSA]

I have also wondered how cozy one could/should be with bats. In one cave I frequent, a few dozen bats are always sleeping in a low crawl. Should I avoid that part of the cave if it means I have to get very close to or possibly even brush against them? I worry about these things because I once, as a kid in the back of the group, clandestinely prodded a bat. I was devastated when it fell off the ceiling into the stream, thrashed around a little, and expired. I don't think that's typical but I've been worried about accidently killing something since.

[SuckinOnSodaStraws]

From experience, I have had some solo roosting bats flap in my face. And that involved some amateur kick and scream work. Since then, as I said, I've developed a liking for all cave creatures. I think my initial fears of bats strengthened my liking for them in the long run. As for large colonies of bats, I've never run into that. But I guess I was being a little too weary of bats in general. My thoughts were they must be like any other wild animal, they attack when they feel threatened. The only reason I would want to be close to a colony is photographic documentation.

[Chads93GT]

I've never had bats attack me.
I have had them in my face in a crawl way or tight narrow
Passage simply because they want to get past and I'm plugging
The hole.

[Pippin]

If you ever see a large colony of clustering bats, you should leave the cave immediately. Seriously. Especially in the era of WNS, nobody should be disturbing large bat colonies. Most bat species that cluster in large colonies are easily disturbed, even talking in low voices bothers them. Lights will disturb them too. Photography and flashes will really disturb them! Taking quick photos of solitary pips (tri-colors) is ok because it's super hard to wake them up, but I wouldn't take a bunch of pictures of one using a flash because I'm sure that would really annoy the bat. Taking pictures of any large colony of bats would be really really bad for the bats! Don't do it!

I see solitary bats all the time, but they never wake up when I encounter them. Just walk by carefully and make sure you don't touch it. If you have to actually touch a bat to make your way through a passage, I wouldn't go down that passage. The bat was there first and touching and bumping it will disturb it and maybe even injure it.

I've had bats land on me a couple times. Once was when I was watching a summer emergence at a big bat cave one of the bats landed on me. Another time I was going through a small crack and a bat smacked into me while I was plugging up the passage and landed on my shirt. They both just flew away after a few seconds. If that happens to you, don't freak out and start waving your hands and screaming. You'll probably injure the bat! Just wait and see if it flies away. I love encountering bats in caves. They usually just hang there and pay no attention to people! Bats do not attack people. If you bump them or talk so loud that you wake them up, they'll simply fly away and try to find a more quiet location. If you're in the way they may land on you. If you accidentally stick your hand on them and squish them, then yes they will probably try to bite you, but that would totally be your fault.

[caverdan]

Alex,
As you have already noticed......the bats around here tend to sleep alone and not in large groups. As long as you leave them alone, they will remain hanging there and looking cute. Mines are where our bats like to congragate as our caves tend to be tight and crawly. If you do find a colony of bats in your travels, please let us know so the proper people can study them.

[SuckinOnSodaStraws]

Cool. I really hope I never come across a colony. I don't wanna disturb anything! And it sounds like a few are familiar with the orient mine bat emergence. Pretty cool to see? They ever let anyone in the cave anymore?

[nathanroser]

I've got a crazy story from a trip years ago that I unfortunately did not get to witness. A group was climbing up some narrow passage when someone accidentally bumped a sleeping bat from the wall. The bat then fell down into the open mouth of the person below him. The unlucky guy that had the bat fall in his mouth kept it open until the bat woke up and flew out. No one actually believed a bat fell in his mouth but he went for rabies shots after that anyway.

[tncaver]

Easy. Don't touch them. I shine my lights at them, talk, etc who cares. Whomever gave you the impression that the slightest peep will disturb a bat gave you the wrong impression.

Pippin is correct. Certain bats are easily disturbed while others are not. Bats that cluster in large numbers are usually the ones you need to avoid
the most. Not only are they endangered and protected by the FEDS, they are also the easiest to disturb, which is especially bad this time of year
while it's cold outside and their source of food is gone.

[PYoungbaer]

I've been reading through this thread with interest, and find some surprising statements from some experienced cavers. I might suggest that some of the initial observations don't tell the whole story. Please bear with this post - it may be a little long.

There are quite a few studies on disturbance of bats by humans and the effects on bats, and portions of other articles relating to the same subject. I will skip the obvious detrimental effects of intentional vandalism. Here are a few generalized points, and then some citations/abstracts:

1. Hibernating bats of any kind, regardless of colony size, should not be disturbed. This causes bats to arouse and burn up precious stored fats. Bats go into hibernation prepared for a certain number of normal torpor bouts, but little room for error.

2. How bats respond to disturbance, both tactile (touching or handling as may occur during banding or other direct studying of the bats) or non-tactile (such as simply passing by, talking, sound of footsteps, light from passing headlamps or photography) varies. The effects vary by species, type of disturbance, and even the timing of it during the year (e.g. hibernation vs. maternity vs. day roost).

3. What may initially appear to be no effect by what a caver thinks is minimal disturbance, such as quietly passing by bats or shining a headlamp momentarily at a bats, or even whispering, often does result in full arousal by the bat. Depending on species and level of torpor, this can occur fairly quickly or even a half hour or much more later, when the caver is long gone. It's not unusual for bats passed on the way into a cave to be seen flying when passed on the way out. In the Little Brown bat, for example, the Brown Adipose Tissue (ironically named BAT), is the "engine starter" for arousal from torpor. This fuel initiates the process until White Adipose Tissue (WAT) takes over and bat finishes "powering up." Justin Boyles' thermal imaging research shows some amazing visual examples of this in another species, the Indiana bat:

http://www.flickr.com/photos/jboyles/3262743977/

Here's an excerpt of what Gary McCracken, University of Tennessee, Knoxville said in an article published in the NSS Bulletin 51:49-51 in 1989:

Although intentional disturbance of roosts is well documented, unintentional disturbance often poses an even greater threat. In the temperate zone, aggregations of bats which cavers typically encounter are either hibernating groups that occur in late fall, winter, and early spring, or maternity colonies that occur in late spring or summer. There is no question that disturbances as seemingly trivial as merely entering a roost area, or shining a light on hibernating bats or on a maternity group of females and their pups, can result in decreased survival, perhaps outright death, and possible abandonment of the roost site. Although there is some controversy about the significance of this apparently "innocent" disturbance, my own experience and reading of the literature lead me to the opinion that it can be extremely significant. however, there is no question that the impact of such disturbances are somewhat species-specific, and that the timing of the disturbance is very important.

The results of "innocent" disturbance of a maternity colony can include the following> (1) It can cause individuals to abandon roost sites, particularly early in the reproductive season when females are pregnant. This may result in females moving to other, perhaps less ideal, roosts were their success at reproducing is reduced. (2) disturbance raises the general level of activity within roosts. This may result in greater expenditure of energy and less efficient transfer of energy to nursing you. This, in turn, may cause slower growth of young and increase the foraging demands on females, thus increasing the time females are outside of the roost and vulnerable to predation. (3) Disturbance can cause outright death of young that lose their roost-hold and fall to the cave floor. (4) maternity aggregations often result in thermoregulatory benefits. Clustering bats gain thermal benefits from being surrounded by other warm bodies However, individuals also may receive thermal benefit because the accumulated body heat of all individuals present serves to raise temperatures within the roost area. Therefore, if the size of a colony decreases, the accumulated thermal advantes to the individuals in that colony may likewise decrease, and it may become energetically less advantageous, or perhaps even energetically impossible for females to raise pups in that roost. Thus, there may be a "threshold," where after a population reaches a certain lower size, roost temperatures cannot be raised sufficiently for rearing young and that roost must be abandoned as a maternity site. (Peter's note: with WNS severely depleting bat populations, we're seeing much smaller maternity roost sizes begging this question. Dr. Tom Kunz is experimenting with simple wooden baffle systems in several New England buildings that are historical maternity roosts to re-create levels of heat formerly maintained by larger maternity colonies in order to help assist reproductive rates of WNS survivors and the recovery of the species.)

Problems caused by disturbing hibernating bats also relate to their energy requirements. During winter, temperate zone bats go long periods without eating, and allow their body temperatures to drop, often to near freezing. the energy reserves that bats accumulate prior to hibernation are often close to what is needed to survive the winter. disturbance during hibernation may cause bats to arouse prematurely, elevating their body temperatures and utilizing stored energy reserves which should not be spared. The bats may go back into torpor after the disturbance, but then they may not have sufficient energy to survive the rest of winter. this may not be apparent to the person causing the disturbance."

Here are abstracts from two additional papers on the subject:

Hibernating Bats Are Sensitive To Nontactile Human Disturbance, Donald W. Thomas, Journal of Mammology, Vol. 76, No. 3, August 1995 (Full article available here: http://www.jstor.org/pss/1382764

Abstract
I measured natural baseline activity and the response of hibernating bats to human presence in a hibernaculum containing ca. 1,300 bats of the species Myotis lucifugus and Myotis septentrionalis. Infrared detectors registered baseline flight movements in the hibernaculum over 62 days in January to March and over 8 days in April, when no observer was present, and they also registered the increase in flight movements following six visits of 1-2 h each to the hibernaculum. Visits to the mine resulted in a dramatic increase in flight activity of bats beginning within 30 min of the visit, peaking 1.0-7.5 h later, and remaining significantly above baseline level for 2.5-8.5 h. These results show that, contrary to previously published studies, hibernating bats are sensitive to nontactile stimuli and arouse and fly following human visits. To avoid increased mortality due to the premature depletion of fat reserves, human visits to hibernacula should be kept to a minimum.

Effects of Disturbance on the Energy Expenditure of Hibernating Bats, J.R. Speakman, et al, Journal of Applied Ecology, Vol. 28, No. 3, Dec., 1991

Abstract
(1) We investigated the effects of a range of stimuli, associated with disturbance by visitors to caves, on the energy expenditure of hibernating bats. (2) Twenty-five individual bats of six species were exposed to 206 separate applications of non-tactile stimuli (head torch, photographic flash, sound, speech, temperature increase). This resulted in only nine significant increases in energy expenditure (4.4%). In contrast, nineteen out of nineteen tactile stimuli, applied to ten individuals of four species, resulted in significant increases in energy expenditure. The difference in frequency of response to the two types of stimulation was highly significant. (3) The extra energy expended by bats in a response following a non-tactile stimulation was low (mean = 49 J). Tactile stimulation resulted in much greater energy expenditure (mean = 2038 J). (4) Neither the degree nor the frequency of response to non-tactile stimulation was affected by species, body mass, ambient temperature, season, or metabolic rate during torpor. Degree of response to tactile stimulation increased significantly with increasing body mass. (5) Energy expenditure during torpor (pre-stimulation) was significantly affected by temperature in Natterer's bat (Myotis nattereri Kuhl), Daubenton's bat (Myotis daubentoni Kuhl), brown long-eared bats (Plecotus auritus L.), and by body mass in these species and pipistrelles (Pipistrellus pipistrellus Schreber). The mean energy expenditure across all species was 6.17 mW. (6) By combining the measured energy expenditure in torpor before stimulation with the increase in energy requirements which accompanied non-tactile and tactile disturbance, the mean maximum reduction in potential duration of hibernation resulting from a non-tactile disturbance which elicited a significant response was 4.5 h, and was 104 h for each tactile disturbance. (7) Each non-tactile disturbance was predicted to decrease fat stores by 0.001 g. Each tactile disturbance was predicted to decrease fat stores by 0.05 g.

In this era of WNS and management strategies looking to minimize the potential effects of the disease on bats, including the Eastern Pipistrelle, or Tri-colored, and especially to assist in conservation recovery efforts in already decimated areas, I think it prudent that cavers should take extra care to avoid any disturbance of hibernating bats, no matter how innocent or inadvertent we may believe it is.

[pub]

Thank you Peter, a very informative post. I too was surprised by some of the replies here. Hopefully cavers will take heed to your bottom line.