A couple weeks ago, I posted a request for information about flexible
inspection scopes for peering down rather small mouse burrows. I got
responses from readers of the Ecolog-L list and the Mammal-L list
which were very helpful and I have cut and pasted many of those
comments here. Someone posted a really interesting video of an
examination of vole burrows in Oregon. That opened a few more doors
to high-end optics which we are still looking at, but may not be able
to afford. Getting straight forward pricing on various models of
these things is not so easy it seems.
Anyway, a summary of the replies is listed below.
* I use the burrow cams from sandpiper... for gopher tortoise
burrows and I love them (once you get the hang of twisting and
coaxing the camera down the tunnels). You have to be careful of the
wiring as it can get a bit touchy with continued use in the field
(and it can get heavy to carry). The headset allows you to see
inside the burrow with remarkable detail. But they are pricey... and
I am currently in the process of writing one into my research grants
as I have been borrowing one that is no longer available to me. I
have attached a pic of it in use..
* My airplane mechanic uses a television camera with a flexible
probe about one meter long and 6 mm diameter. It produces a very
nice picture. I suggest you look around before making your purchase.
* Please see the attached publication. I know the probe was only
good in ground squirrel burrows to about 3 meters, then it had
problems with dirt building up in front of the lens and also became
hard to direct. Also see the attached paper on ground squirrel
burrow structure that was performed by manual excavation. Please
feel free to contact me directly if I can be of further
assistance. Berentsen, A.R. and Salmon, T. P. 2001. The structure
of California ground squirrel burrows... Transact. West. Sect.
Wildlife Soc. 37: 66-70.
* In response to your Ecolog post about burrow scopes, I spent
several months last year as a technician scoping gopher tortoise
burrows in Georgia with a couple different cameras. I haven't used
the Peep-A-Roo, but I have used the Peeper by Sandpiper which is
pretty similar. Some thoughts to consider:
* A) The head mounted video display is nice when it's
really sunny out because you won't get a glare on the screen, but the
down side to the headset is that only one person can see what's going
on as opposed to cameras that connect to a small monitor that
multiple can watch at the same time (but which reflect the sun's glare).
* B) With the Peeper, the cord wasn't very rigid. It's
important that you find the right balance between rigidity and
flexibility in a cord to match what you hope to use the camera
for. The non-rigid cord became a problem for me with longer burows
(>3m) that flattened out in the back. As long as the burrows kept
getting deeper the farther back they went it wasn't a problem, but
after a few meters on level ground (and especially if there are forks
in the burrow) it can be like trying to push a wet noodle.
* C) My field season with the Peeper was its 3rd intense
field season. It held up pretty well, but over the years it slowly
went a little out of focus.
* D) I guess I'd say of the few cameras I used for
scoping, the Peeper was the most reliable one. That said, eventually
any camera is going to have problems after banging around in sandy
sometimes wet burrows for multiple field seasons.
* Have not tried these with rodents, but I had grad students try
something similar (perhaps same, or 1 size larger - Peeper?)) from
Sandpiper when we were trying to view otter dens. We found them very
hard to maneuver in the large and complex dens we were dealing
with. If your tunnel/burrow is small and only one tunnel (no large
cavities or side burrows to try and turn into), it may work
fine. However, cost is high, as you know. We are now experimenting
with other, much cheaper, devices for viewing underground tunnels
and/or tree cavities used by fisher and marten. In one case, we
bought an AquaVu underwater fish camera used by ice-fisherman (~$300
I recall), took off the plastic fish that the lens is mounted in (to
make it smaller), and just attached some wire to it to push it in the
tunnels or tree cavity. But I think after taking the plastic fish
cover off, it's still ~ 2" diameter (which is fine for us, but sounds
like too big for you). It's black and white, and comes in a
convenient field-ready design with the screen (see
www.aquavu.com/store/ ). We also just bought a color/waterproof
video probe that is commonly used for general surveillance monitoring
(www.microvideo.ca/2120wp.htm). I think ours was only $100, plus
another 2-$300 for the software - it plugs into a laptop. I believe
the probe is ~ 1.5 inch diameter, and may require a small
rechargeable battery. But all gear, with laptop, easily fits in a
backpack. Again, the main issue is just rigging up something to
attach to the probe to help push it in and maneuver. We're still
experimenting, and anyone with a little creativity should be able to
come up with something to meet their needs. They have other models
as well, including some less than 1" (need to be sure they are ok for
rougher field use). Picture quality for both was fine, though the
microvideo probe is color if that matters. They just require a
little creativity to design an attachment to push and control the
probe - the video cord is not real strong for this purpose. But my
experience with the Sandpiper probe is that it wasn't any easier to
control, unless they've changed something. $400 vs $6,000 is a big
difference. Just some ideas to consider. No doubt there are other
companies out there as well selling surveillance video probes that may work.
* My advice would be try one out on a loan from them and see if
it consistently suits your needs. I have one that I bought for
prairie dog burrows and found that it was not as easy to use as I
expected, at least for deep (>1 m), wider burrows. It takes some
practice to navigate once the camera is outside your normal reach,
where you have to twist the cable like a plumber's snake. I also
found that, if the soil is loose on the sides, the camera and IR
lights would fill up with soil (for some reason the small lights are
recessed into the end, so I had to retrofit a plastic bag to keep
them from filling with dirt). They may work great for shallower
crevices where the camera can bounce off the rock or stiff walls, but
for a convoluted burrow, especially one with sharp right turns and
sub-burrows, or where some are closed off, it wasn't as useful as I
had hoped. It would be nice if someone could build one that could be
'driven' around within a deeper burrow, aka a mini Mars lander but
that was outside my budget and engineering abilities.
* I've never dealt with burrow cams, but have built systems for
continuous recording at bird nests and helped others put together a
peeper-cam system for woodpecker cavities. In my experience it is
MUCH cheaper to buy the components to build your own systems. I've
built or help others build nest-monitoring systems for ~$500 that are
sold by companies such as Sandpiper or Fuhrman for thousands of
dollars (I think the Sandpiper peeper-cam costs more than the burrow
system). I've always bought components from
<http://www.supercircuits.com>www.supercircuits.com and Radio
Shack. You could probably get a small camera for ~$100 and small TV
for ~$100; they probably don't sell cameras that small with built in
infrared LEDs (for vision in the dark), but you could buy these at
Radio Shack (there was a similar issue with the peeper cams). I
guess the main challenge/unknown is the stout cable to help guide the
system through a burrow, but I'm guessing that you could come up with
something. Just thought I would raise this possibility, because $6k
is a lot of money!
* I have used the peeparoo for burrowing owl nests for a couple
of years now - they have some limitations - the smaller diameter
model you are looking at has a relatively flimsy (very flexible)
cable which is good and bad - good because it can get into fairly
tight spaces, bad because it has almost no tensile strength for
pushing it into burrows - around corners, through debris, etc.. I
think that for peromyscus sized burrows it would be a very expensive
item with limited application. - even for burrowing owl burrows - we
use the larger diam. Model and have a heck of a time getting back the
3 - 4 meters where the nests are located
This video clip was posted on the Mammal-L list serve and it shows a
really excellent video
(http://www.opb.org/programs/ofg/videos/view/48-Voles) of a vole
burrow system (and some pretty interesting biology going on as
well). The system being used is an Everest VIT and it made or sold
by GE. This is not a model name per se, but a product line that
includes really huge flexible camera scope costing as much as $20k
(there is a used one for sale on ebay right now for $2k). I do not
know what the model in this video cost, but it appears to be in
the $14-15K range. Well out of our ballpark. It may be rentable
for a reasonably affordable rate, but again, getting this info seems
to be unnecessarily difficult for some reason.
Here is another scope that is also made or sold via GE
http://www.geinspectiontechnologies.com/download/products/rvi/GEIT-65023EN_fiberscope-brochure.pdf
Costs of these can be in the $1500 range, but I am not clear on which
models might be in this price range.
My graduate student is looking into building a system from parts. He
thinks this can be done for $500 or less. I suppose there will be a
lot of trial and error but even so, it may be much cheaper and better
suited to our specific needs. If he is successful, we will have
something more concrete to offer in the way of assistance.
In the meantime, thanks very much for all of your input. It has been
a great help in getting us started.
Brent
Brent Danielson
Ecology, Evolution, and Organismal Biology
253 Bessey Hall, Iowa State University, Ames Iowa, USA 50011-1020
Telephone 515.294.5248
website: http:\\www.public.iastate.edu\~jessie
