Great post Mark,
I agree - when I first took up competitive bushwalking in the early 1990s
everyone walked at night by moonlight. Now everyone's gone all technogadgetry
and they shine lights all over the place. Most are stunned when you come
walking out of the dark telling them to shine that headlamp elsewhere cause
you're ruining our night vision! :)
Regarding red filters - just a thought - if most nocturnal mammals produce red
eyeshine, is this an indication that the red light is being reflected back (and
so not absorbed by the eye)? If so, then is this the reason for choosing red
(i.e. because the animal generally isn't affected by that colour anyway)?
Chris.
________________________________
From: Mark Carter <>
To:
Sent: Tuesday, 22 September, 2009 9:30:30 AM
Subject: [Birding-Aus] Re: LED light
I may as well add more anecdotal evidence as that seems to be all we have to go
on! After years of spotlighting mammals, reptiles and birds in various
locations around the world I have drawn the conclusion that red filters over
very bright lights seem no better than simply using white lights dimmed to the
equivalent brightness. I find filters main use is in maintaining my own
night-vision! In terms of responses I have also noticed that there can be as
much variation among individual animals in their responses as there is between
species which makes generalisations difficult. Also, reptile ID with a red
filtered light is a nightmare (but I guess thats not so important to this
forum!).
Here in the outback I suspect most animals are accustomed to periodic bright
illumination- lightning is not uncommon and the full moon on a cloudless night
is car-headlight bright (seriously- you can easily read and see colour by it
some nights). Spotlights and flashes used with common sense are unlikely to be
a big deal for outback critters.
But all of the above is just opinion.
I strongly agree with other posts calling for more scientific research-
there seems to be very little structured scrutiny of this activity
which is a bit weird considering the importance of nature spotlighting products
to the
ecotourism industry. Is it just that studying the
impacts of spotlighting nocturnal birds 'n' beasts is not as 'sexy' as
studying tourism impacts on whales or dolphins (something which has been
studied to death!)?
One concern I would have about any studies that may occur is that narrow
studies of tourism 'impacts' can be problematic if they don't account for wider
benefits that the 'impact' can have. For example, dolphin watching from boats
inevitably 'impacts' on dolphin behaviour but the economic and conservation
benefits that flow mean that those impacts must be seen in perspective and, in
a wider sense, are probably negligible. Conservation of nocturnal creatures
suffers from an 'out of sight, out of mind' effect: spotlighting is one of the
few ways we have to enthuse the public about our awesome nocturnal wildlife. It
would be a shame and lead to a greater harm if a narrow finding of slight
negative impacts were used to shut down spotlighting across the board. If
impact studies could focus on finding best practice techniques then I think
that could be very beneficial.
Coming back to LEDs vs gas bulbs, I think in a few years the old halogen gear
will only be seen in museums. On energy conservation alone LEDs are a massive
step forward. There are also huge portability and dependability advantages to
the new technology. My 3 watt LED headlamp which fits in my pocket and gives
50hrs of light means that everytime I go bush I can be prepared for a bit of
impromptu spotlighting. Viva LED!
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