Thursday, 4 December 2014

If Humans migrated.

Being off work with a shoulder injury for a few weeks now, has allowed me to spend time pondering a question that has floated around inside my head for a little while.
A question. A curiosity. I'm not sure which best defines it, nor the best way to word it?..

"How far could migratory animals migrate, if they were the size of Humans?"

"How far could Humans migrate, under the same abilities as those animals which migrate?"

"Pound for pound, which animals' migration is most impressive?"

I'm still not sure which of those sums it up best but, I'm sure you get the idea of what it is, that I've been contemplating.
Please bear with me, there are a lot of numbers and calculations below. I'm no biology or maths professor but at the same time, I've been as thorough as possible, without dedicating the rest of my life to studying every variable to what is not exactly, the easiest question to answer.
Working out a simple weight equivalant is not hard to do, get an average Human weight and divide by the weight of say, a Reed Warbler, will lead you to how far that Warbler would migrate if it were the weight of a Human. Or would it?.. I looked at few options to compare, to see what appeared to be the most accurate and going by weight actually seemed to be the most inaccurate.
For example, that would make a Barn Swallow (Hirundo rustica) weighing that of an average Human, capable of migrating 9.3 million miles. As impressive as migration is, that figure is just not accurate. The variables I referred to earlier are complex studies that to be quite honest, are beyond me but I feel it only fair to mention which factors I have purposely steered clear of.

Things that would be have to be considered to improve accuracy would have to include factors like different species' metabolism, aerodynamics at a greater size, even how the compostion of each body would affect results. ie: A Human body is made of 50-60% water, but what about say, a Cuckoo? How different would the compostion then be?
So far I'm doing a good job of explaining how NOT to be incredibly accurate but I wanted to show how much I have considered, when working out any kind of answer, and not wanting to sound like a vague school book that simply states "if you could jump as high as a grasshopper, you could jump over the Eiffel Tower" or similar inaccuracies like how a snake is 'poisonous'.
It's not.
It's VENOMous! (Sorry, a real bugbear of mine!)

I researched the length, weight and migration distance and then worked out the BMI of a select few species, which I think gives a slightly more accurate result, as opposed to height or weight alone.
I did this for five different species, those being;

Arctic Tern (Sterna paradisaea)
Avg weight - 100g
Avg length - 34cm
Avg BMI - 0.8650
Migration distance - Pole to pole, apprx 12,500 miles (one-way).

Arctic Tern - photo courtesy of Stewart Sexton
Arctic Tern - photo courtesy of Stewart Sexton
Arctic Tern - photo courtesy of Stewart Sexton

Barn Swallow (Hirundo rustica) 
Avg weight - 40g
Avg length - 16cm
Avg BMI - 1.5625
Migration distance - Various locations in Africa/S.Africa, I used a point at about mid-way of thier range: Gaborone, Botswana. Apprx 6,000 miles (one-way).

Taking a well deserved rest after a perilous journey from Africa

European Eel (Anguilla anguilla)
Avg weight - 1kg
Avg length - 55cm
Avg BMI - 3.3057
Migration distance - Sargasso Sea, near the Bahamas, apprx 5,100 miles (one-way).

European Eel (AKA Silver Eel) are said to not eat at all when on migration! 
(Photo courtesy of

Silver Y moth (Autographa gamma)
Avg weight - 100mg
Avg length - 24mm
Avg BMI - 0.1736
Migration distance - Origins vary from just over the Channel in France, Portugal etc, to possibly even sub-Saharan Africa. Again I made a mid-way estimate point, which was Tunisia, apprx 1,400 miles (one-way).

Silver Y - known for thier high altitude migration, often hundreds of meters up to make use of fast airstreams for assistance

Diamond-back Moth (Plutella xylostella)
Avg weight - 4mg (Pupal weight, but closest I could find and not too dissimilar)
Avg length - 8mm
Avg BMI - 0.0625
Migration distance - Migratory range thought to be very similar to that of the Silver Y, apprx 1,400 miles.

Diamond-back. Some do reside in the UK, those which are migratory share a similar range to the Silver Y.

Human (Homo sapiens)
Avg weight (globally) - 62kg
Avg height (globally) - 167cm (m+f combined avg)
Avg BMI (globally) - 22.2309
Migration distance - Nil. 0 miles.

Human...and a fine specimen at that. OK, maybe not.

Now, down to the business end of all this - my 'findings'. As I mentioned above, I'm still undecided on the best way to word THAT question, but my answer to it, will be stated below, as 'Human Equivalent' for ease.


To help scale some of the distances mentioned below, bear in mind that:
  • The circumference of the Equator = c25,000 miles.
  • Distance to the moon from Earth = c239,000 miles.


Calculating the human equivalent to these migrant species, by comparing the above BMI, results in this:

  • European Eels' journey = 5,100 miles.
  • Human Equivalent        = 34,298 miles!

  • Barn Swallows' journey = 6,000 miles.
  • Human Equivalent        = 85,367 miles!

  • Silver Y moths' journey = 1,400 miles.
  • Human Equivalent        = 179,281 miles!

  • Arctic Terns' journey = 12,500 miles.
  • Human Equivalent    = 321,256 miles!

  • Diamond-back moths' journey = 1,400 miles.
  • Human Equivalent                = 497,972 miles!

What does this all mean? 

These figures are accurate in giving an approximate answer. That sounds a contradiction in itself, however, what it has proven, is that this is exactly why there isn't an exact, definitive answer anywhere, to "THAT" question. 
Maybe someone is spending their lifetime on it now? Maybe not?

Either way I hope, that at the very least, this reaffirms what an incredible feat these animals undertake and what a wonder migration actually is.

Tuesday, 4 November 2014

M.M.A.B.P - Micro Moth Appreciation Blog Post!

Refered to quite simply as: the Micros.

I'm not quite sure why I felt the need to write this up, but if you are one who enjoys the seemingly endless array of Lepidoptera that we have in the UK, then you will most likely also have (believe it, or not!), an appreciation for the Micros amongst them.
Likewise, if you're not a Micro fan, or not even much of a moth fan in general, then maybe you'll just scroll down this page, taking a quick glance as you go and at the very least, think to yourself - "actually, they're pretty damn nice!"

I'll be the first to admit, that although I always loosely enjoyed moths, when I really got into it a couple years back, I would avoid the "little ones" like the plague! My macro ID skills without a book, were limited to a Brimstone, Herald and a Small Magpie so the thought of even trying to ID any micros was laughable! It was a natural progression though, that as I could ID more and more of the Macro moths, either with or without a field guide, that curiosity that simmers in the psyche of all naturalists, showed itself and I just...well... needed to know what they were!
As you start giving them more time and appreciating the colours and detail that a lot of the micros have, that curiosity just can't be contained! Of course, as with macros and indeed, other invertebrates, there are plain and indistinct examples which would barely catch your eye, HOWEVER - the ones that aren't are straight up wonders of a tiny world! Surrounding us most of the time, yet hardly noticed without an effort to purposely seek them out.

I've chosen a few of my photos (quite a few, really!), to show below and hopefully they will share my enthusiasm for Micros without me babbling on for too much longer. Although most guides bare just the Latin names for the micros, and I tend to only use the Latin, the common names are out there and I will include them with the photos as the Latin doesn't go down well with everyone and can take a little longer to digest. Some of them are rather creative though!
If you are curious to know the common name to any micros you have ID'd, I'd recommend a quick search on the NBN Gateway website. Also very good for listing the common names of micros is the Norfolk Moths website.

So, on to some fine examples from the micro world!
One of the first micros I ever ID'd is still a favourite of mine and is known for its resting position of standing up on its front legs at quite an angle. That, along with just being really rather pretty, is the Rosy Tabby - Endotricha flammealis...
Rosy Tabby - Endotricha flammealis
the typical resting position the species is known for.

 Another 'Tabby' I'm fond off is a little more subtle yet still rather smart. If I could though, I would change its common name to 'Chocolate Orange!' (it just springs to mind with the colours!)
Double-striped Tabby - Orthopygia glaucinalis

This one you will recognise as a celebrity micro, as it features on the front cover of Sterling, Parsons & Lewingtons' Field Guide to the Micro moths of Great Britain and Ireland. I real highlighter pen amongst pencils, is Carcina quercana, the Long-horned Flat-body:
Long-horned Flat-bodyCarcina quercana

Although not having as many colours as quercana, the Hook-marked Straw Moth (Agapeta hamana) is equally as bright:
Hook-marked Straw Moth - Agapeta hamana

This next moth is another of the firsts, whos name actually stuck in my brain and it's presence in the UK is thought to be down it hitching a lift in plants, from Australia! The common name not as attractive as the actual moth, in this instance:
Ruddy Streak - Tachystola acroxantha (on £1 coin for scale)

Now for a couple of 'Fanners'. Both of these disturbed whilst walking through long grass and in good numbers. A fine example of being overlooked as this micro really is small, but if you stop and get a close look, you can see the beauty:
Speckled Fanner - Glyphipterix thrasonella
A bit unfair to call the next one Plain, as it's actually Gold all over and not cardboard box brown as first appearances suggest:
Plain Fanner - Glyphipterix fuscoviridella

While we're looking at the smaller of the micro moths, I can't ignore the next few. All truly tiny and only really appreciated with a magnifying glass or macro lens, a few of the 'Argents':
Triple-barred Argent - Argyresthia trifasciata
Gold-ribbon Argent - Argyresthia brockeella
Golden ArgentArgyresthia goedartella

Knot-horns. No, that's not some kind of Viking medical condition, but a nice group of micros that, with the exception of one below, are not as loud but are rather detailed.

Grey Knot-horn - Trachycera advenella
Ash-bark Knot-horn - Euzophera pinguis
Beautiful Knot-horn - Rhodophaea (Pempelia) formosa
Rosy-striped Knot-horn - Oncocera semirubella

Rosy-striped Knot-horn - Oncocera semirubella

Be it birds or moths, migrants and vagrants always make that grin grow a little bigger when you set eyes upon one. Knowing that they have come from god knows where, and travelled well beyond what we would be capable of, if we were a matter of milimeters wide, is surely nothing short of a wonder in the natural world. One of the migrant highlights for me this year was Cydia amplana with the very apt common name of Vagrant Piercer. Not known to actively breed in the UK, this little trooper of moth most often visits the South coast, in particular, Dorset and was only first recorded in 1990, which, in the grand scheme of things, is pretty darn recent.

Vagrant Piercer - Cydia amplana

Another micro moth known for its migratory behaviour and more commonly found, is the Diamond-back Moth - Plutella xylostella. There is a fascinating article HERE, which explains what research has been done to study the high altitude migration of Diamond-backs in the UK. Very interesting and incredible to imagine something so small joining us in our moth traps, after a trip from mainland Europe. Hats off to Plutella xylostella, I say!
Diamond-back Moth - Plutella xylostella

Diamond-back Moth - Plutella xylostella

Last of the few migrants I wanted to show is without doubt, one of the most elegant moths I've had the pleasure to catch:
Olive-tree Pearl - Palpita vitrealis

Tubics, anyone?..
A couple of lookers here, you'd have to wonder why it is so difficult to see these flying around:
Sulphur Tubic - Esperia sulphurella
New Tawny Tubic - Batia lunaris

New Tawny Tubic - Batia lunaris

On the contrary, these next few aim to do the opposite of the 'Tubics' and be as inconspicuous as possible. The aim is camouflage and more specifically, to look like bird droppings when resting in the open, or on foliage. Evolution at its best, if you ask me:
Acorn Piercer - Pammene fasciana
Birch Marble - Apotomis betuletana
Bud Moth - Spilonota ocellana
Little Conch - Cochylis dubitana
Poplar Shoot - Gypsonoma oppressana
Triple-blotched Bell - Notocelia (Epiblema) trimaculana

As tough as they can be to ID, I though it only fair to add a couple of the Plume moths. What they lack in bright colours, they make up for with intricate detail. I like 'em!
Beautiful Plume - Amblyptilia acanthadactyla

Yarrow Plume - Platyptilia pallidactyla

Just for comparison, I wanted to show a selection of the Grass moths (Crambidae) - in particular, the Grass Veneers. Wandering through most meadows and fields at the right time of year, will disturb literally thousands of these, which inevitably all look the same as they fly off away the size 10's! Again, the variation is remarkable when studied up close. Here are a few:
Chequered Grass-veneer - Catoptria falsella

Elbow-stripe Grass-veneer - Agriphila geniculea

Hook-streaked Grass-Veneer - Crambus lathoniellus

Inlaid Grass-veneer - Crambus pascuella

Pale-streak Grass-veneer - Agriphila selasella

Pearl Grass-veneer - Catoptria pinella

Yellow Satin Veneer - Crambus perlella f. warringtonellus

Lastly, here's a little collection that are here because -!

Bramble Shoot Moth - Epiblema uddmanniana

Bramble Shoot Moth - Epiblema uddmanniana

Ok, so this is a 'little brown job' of sorts, but I love the patterning on it and it has a great common name too:

Bulrush Cosmet - Limnaecia phragmitella

A little Codling moth, nothing much from afar but the blotch that covers the apex corner of the forewing has such a metallic shine to it, looks almost like real metal:

Codling Moth - Cydia pomonella

No matter how many of these fly around the MV light in the garden, I can't help but still catch them for another look. A cracking, show-off of a moth:

Gold Triangle - Hypsopygia costalis

A tad more on the subtle side of things but again, I do like the detail:

Hoary Belle - Eucosma cana

These two caused me a bit of a headache before realising they are in fact, the same species but in different colour forms:

Marbled Piercer - Cydia splendana (dark form)

Marbled Piercer - Cydia splendana (light form)

This example has been through the mill a bit but the distinct shape to wing is worth a look and with another common name to fit the description:

Notch-wing Button - Acleris emargana
What a great common name:
Pied Smudge - Ypsolopha sequella

This was a nice find this year and a first for the garden too. It favours Teasel and I don't think a coincidence that this year was the first year, Teasel had been planted. If you build it, they will come?..perhaps?
Rosy Conch - Cochylis roseana

Very lastly, the Twenty-plume moth. The wings remind me of arrow feathers and to look at you could wonder how it gets airborne!

Twenty-plume Moth - Alucita hexadactyla

Thanks for hanging in there. If you do like micros, then I hope you enjoyed. If you still dont like micros, I hope you can at least appreciate them in their own, frustrating, hard-to-ID, headache giving way ;)