Showing posts with label moth. Show all posts
Showing posts with label moth. Show all posts

Wednesday, 26 September 2012

Learning to See

This isn't so much a post about ecology, but a couple of times now in both my hobbies and whilst out on bat walks and such I've noticed that people assume that they can't see in the dark.

I've been guilty of it in the past.  For years I was told by my mother that I was night blind.  I had this all but confirmed by both a doctor and an educational psychologist when I was diagnosed with Irlen Syndrome.  Irlen Syndrome sounds terrible, but it's just a perceptual disorder that means I see after images a lot.  It also means that I'm a bit clumsy, I like low contrast lighting conditions and I suck at reading graphs, music or anything that's lined or with high contrast patterning.  It can also mean that you are night blind.

About five years ago, I started doing hobbies that meant that I had to be outside at night, without artificial light and for long periods of time.  It was really difficult at first, I won't lie.  I felt unable to do much and even a bit helpless on occasion.  But in time, I learned how to see and it made me realise something -- sure, I struggle in the dark at night, but I wouldn't call it blind (anymore).  I've had to learn how to see in the dark though; it's not been easy and sure, I still have some problems that other people don't.  It still takes me several minutes more than my friends to adjust to the lighting levels, for example; but I can do it if I hang in there and I use the following coping strategies:
  • Peripheral vision!  I all but ignore most of my central vision at night.  If you're looking for movement in the dark, you'll see it in the peripheral vision first.  You'll also see things like trees and branches in your periphery first.  This can be demonstrated pretty well with stars -- there are several stars that are so faint that you can't see them if you look straight at them.  If you look with your peripheral vision though, you suddenly can. 
  • Lose the torch or go for a torch with a red light option.  Red light means you can still see to write without losing your night vision or affecting anyone else's.  Carry a white light torch though in case you really need it (emergencies, ID purposes, etc).
  • If you're cordoning off an area for safety with glowsticks, use red spectrum glowsticks for the same reason.
  • Don't just assume that because it's dark, you can't see!!!  On a night with a moon -- especially a full moon -- it can be bright enough to cast shadows.  Sure, there are some nights that are moonless, where you are out in the middle of nowhere, with no city light glow or perhaps there is no cloud cover to reflect light down from neighbouring cities.  Maybe you're in a wood and it's too dark to move.  Fine.  But give your night vision a chance first.  Give it 10 minutes.  Move slowly.  Your own eyes will surprise you.  Only use a torch if you really need to. 
  • If someone is blinding you,  politely say something.  Usually they'll be pretty apologetic.  And don't hesitate to preserve your night vision by looking away or shielding your eyes.  Edit:  A friend of mine suggested the pirate trick of covering your dominant eye in order to preserve night vision.  I forgot that I do this too as it's now fairly instinctive.  He also suggested closing your eyes for 60 seconds in order to acclimatise to the dark.  It works for him, but I know I'd fall over!
Night vision can be really quite an important thing to have if you're doing nocturnal surveys.  Some bats actively avoid light (even the red lights) and you've little hope of looking at that moth if you shine a torch at it.  I've seen folks do this and the moths usually fly into the torchlight.  Use a jar to collect the moth and then bring it into the light -- you'll have much more success with your ID.

As I said, learning to see in the dark is a learned skill for me.  It probably is for a lot of people, whether or not they've got night vision issues.  Keep an open mind about it.  Sure, I still stumble often and it takes me a while to get going in the dark, but if I can do it, so can others.

Friday, 21 September 2012

Moths at Delamere (or Why I find Moths Uninteresting)

I'm interested in most things, but moths are apparently where I draw the line.  I don't like them.  Don't get me wrong though; I don't hate them either.  I'm indifferent to them, which is somehow worse.  It's not because moths are invertebrates or that they're not charismatic (because some are).  I just don't find them interesting.  Part of the problem is that there is a large group of moths that even the experts call SBMs (Small Brown Moths) that cannot be identified without microscopic examination of their genitalia.  One of the things that was discussed on the moth night at Delamere was the difference between micro moths (mainly SBMs) and macro moths, and of course the difference between moths and butterflies.  So, here is a brutally quick summary of what I learned:

  • Butterflies have slender, filamentous feelers with clubs on the end.  Moths, on the other hand, have either feathery or comb-like feelers.  If the feelers are clubbed, they won't be filamentous.  Usually, anyway.
  • There are a few technical morphological wing differences.  I tend to think of them being that butterflies look more hinged, whereas many moths look more like the wings are "back-triangles".  
  • Butterflies are slender and sleek bodied.  Moths are sturdy and often a bit hairy or furry of body.
  • Butterflies tend to be more colourful -- but not always.  Some day flying moths are really very colourful indeed, especially if they're toxic.  This chap below is a five-spot burnet moth (Zygaena lonicerae) that I saw on Lundy:


Pretty colourful for a moth, eh?  Apparently the French name for moth translates to "Butterflies of the Night".

Some moth traps were set out during the day and were of two types -- wine traps and actual traps.  Wine traps are pieces of string soaked in "nectar" comprised of molasses, brown sugar, honey and red wine.  These are then left in hedges or trees to attract the moths, to do their work, like so:



Apparently, this is a copper underwing moth on a wine trap.  I was lucky to get the picture as a lot of folks were shining torches at it, which sadly made many a moth leave the traps.

The other trap involves setting up a light rig and a moth maze made out of egg cartons.  The light pulls the moths in, which you can then scoop out to examine.  These traps are also excellent for catching craneflies!  However, these traps are not so practical to cart about as they require either a plug socket or a genny.  The chap giving us the demonstration mentioned how he'd actually had one of his generators stolen from a site too.

I hate to say it, but after seeing some of these chaps up close, some of the bigger, easier to identify moths are winning me over a bit, if only because the camouflage is top rate -- and no wonder, given they fill the ecological niche of pollinator and bat food.  However, I seriously doubt I'll ever get the urge to study SBMs.