Sunday, 31 March 2013

Barn owls!

Well down here in good old Suffolk, winter's grip is still strong and a fantastic photo, taken by my good friend Em Johnson of the wonderful Iken Barns (a really nice place to stay if you ever think of visiting Suffolk), brought home to me how it's not only us that suffer during this very prolonged bleak spell. 
A powerful image caught in Iken, Suffolk.  © Em Johnson.
Barn owls are crepuscular birds, they prefer or are more active around dawn and dusk. They're not daytime hunting birds and seeing one hunting in the daylight is a sign that all is not well. Owls, like most birds of prey, fly for only one reason, to hunt and they only hunt when they're hungry or have chicks to feed. They do not fly or hunt for pleasure, flying in the daylight leaves them vulnerable to attack from larger birds such as seagulls, rooks, etc (known as mobbing). Also, trying to hunt in these conditions will be extremely hard for the bird whose primary hunting technique is based primarily on sound. The face of the owl on photo above shows the heart shape of the face of a barn owl. The heart shape is not for looks, it serves a purpose, which is to direct any sound that the owl is facing directly to the ears. Notice how the perimeter of the face is 'pinched' around the level of the eye. This is where the ears are and this pinch is the deepest set part of the face, all sound is directed to this point. Here's another interesting fact, the ears are asymmetrical. This means that unlike us, the are not level, one ear is higher than the other and again there is a purpose behind it. The ears being off kilter help the owl to triangulate exactly where a sound is coming from, so that even in total darkness, it can pin point its prey. The eyes are also unusual in that, unlike us, they cannot move in the eye socket, they are always pointing straight ahead. This means that when the owl hears a sound, its head turns to pinpoint exactly where the sound originated from, which means its eyes are looking directly at it. If they can see their prey as well as it hear it, the chance of capture is much higher than just by sound alone.
Their hearing is very sensitive, so much so, that trying to hunt in the rain is a bit like listening to the constant hiss on an untuned radio. It would be very hard to hear the rustle of a field/bank vole or mouse amongst all that noise. The same goes with snow, sounds become incredibly muffled and the chances of a successful hunt are low compared to precipitation free times.
So the picture above paints a very bleak picture for our owls, in fact 2 days after this pic was captured, I too saw an owl hunting in broad daylight at 3pm in the afternoon, not good. This obvious lack of food caused by the prolonged winter we're having, could also have an effect on the breeding cycle of the owls. Owls will only lay as many eggs that they feel they can cater for, i.e. if food is plentiful, they could lay up to and around 8 eggs, yet if food is scarce then only a couple of eggs might be laid.
This picture also highlights other issues, such as the lack of food. The weather has also affected the vole and mice, the crops, grasses and insects they feed on, are still deep in the ground and therefore they are not breeding too. Again, it's all about 'interrelationships' (I love that word) and how everything is interlinked and dependant on other organisms for its survival. When an imbalance occurs, such as the prolonged bad weather, this has a knock on effect with the plants and insects, which affects those reliant on the plants and insects and so forth and so on. So, it's important at times like this that our feeders are kept topped up and water trays are kept defrosted. It doesn't help all of nature, but it gives it just a helping hand.
Although saying that, it's funny how we don't have feeders for birds of prey. But then I don't think several live mice hanging from your bird feeder would go down well with most garden lovers, nor the RSPCA for that matter (I'm just kidding, please DO NOT try this at home). 

Just for the record

Moth trap was set last night. Last year I caught 53 moths of 9 different species and the minimum temp was 6ºC.
Last night I caught nothing, but then the minimum temp was a very unseasonal -3.2ºC (yes, MINUS).

Not good.

Have a good easter peeps.

Till next time.

Saturday, 23 March 2013

It's lovely out there!

Well what can I say, the weather's awful, everything is still tucked up in dormancy with temperatures around freezing and my moth trap is still empty. It's not good considering that this week was the vernal equinox, the point when day and night are equal but the days now begin to get longer than the nights of winter, yes, SPRING!
So why hasn't it sprung??? Answer, I have no idea. However, I'm sure it has something to do with that dreaded jet stream that was responsible for our wet miserable summer last year. But enough about the weather, for when it's like this it's time to be getting on with other things. One of those other things was looking at a book that's just been released, Britain's Hoverflies by S Ball & R Morris.

An excellent book for ID'ing hoverflies.

I ordered this book last year sometime and was disappointed when I got an email saying that the release date had been put back till March this year. But hey, it arrived this week and I've been perusing its pages and can only say, what an excellent book!
With over 296 pages covering 165 (yes, I didn't know there was that many either) species and over 500  colour photos. It also has maps, charts, glossary, biology, a detailed section on all the parts that make up a hoverfly and so much more. I just can't wait for the season to begin now, which is even harder as it states in the book that:
"The field season really starts in March once the Goat Willow, Blackthorn and Cherry Plum come into flower."
 There's only one more week of March left and as I look out my window all I see is snow falling heavier and heavier with each passing minute. Don't quote me on this, but I think the season is going to start later this year. I just have this funny feeling lets say.
So yes, I would thoroughly recommend this book to anyone with a passing interest in the cute little hoverfly or with just an interest in insects in general, especially if your new to all this. The naming the parts section gives a simple, yet detailed account of all of the hoverfly from its ocelli to its claws. It will certainly be handy for me as I'm booked up on another course this year at the wonderful Field Studies Council studying these little creatures, yay!

 On TV

No, not me. But did anyone catch the insect season on BBC4? It started with The Incredible Story of the Monarch Butterfly which showed this butterfly's amazing journey from the North of America down to its wintering grounds in the forests of Mexico. One thing that truly amazed me was how roughly the Americans handled them when they had Monarch catching events. At one point, they even got kids to put stickers on them! Not only has this butterfly got to fly thousands of miles, which is a feat in itself, they have to avoid getting caught in a net, being manhandled and then having a sticker placed on your delicate flying apparatus. Truly amazing.
Then there was the Insect Dissection, which definitely IS NOT for the squeamish, as you can imagine. I had to wait until wifey was snugly tucked up in bed before I could watch it. Very interesting, especially the bit where one of the presenters gets stung by a very powerful stinging insect. If you ever want to see what a 'cool dude' looks like when he's trying to hide the pain he's actually in, this is the moment (sorry, it must be my evil streak). 

Courses

As previously mentioned, I'm off on another course this year studying Diptera (two winged flies) and also a day course on spiders with the Field Studies Council. This place is excellent, they have locations all over the UK and courses to suit everyones needs whether it's for the individual, family or professional development, you're bound to find something of interest. If there's one thing that's worth doing, booking up a course with the FSC is a must.
Of course, the FSC isn't the only place that offers courses. There are many groups, societies and organisations that also offer courses and workshops. Some useful organisations to mention just a couple are the British Entomological and Natural History Society and the Amateur Entomologists Society. You could also just look up your local naturalists society using Google and see what workshops and courses they have to offer. I'm sure you'll find something of interest.

Murmurations

This week found me stumbling on a murmuration of starlings Sturnus vulgaris. It really was by complete accident as after some car trouble in the household, me and the wifey had a little running around to do dropping off and picking up car from the menders. This involved me getting home a little later than usual and via a different route. The route involved me driving past Ransomes Industrial Estate in Ipswich and as I approached the roundabout, glancing to my right I saw the murmuration. I immeadiately pulled up (once I got off the roundabout of course) and watched this fantastic natural phenomenon. I sent a text to wifey who was driving ahead of me only to get the reply, 
"Yeah seen it before, Their there most evenings." 
We've lived here for nearly 7 years and wifey has not once mentioned it to me that this occurs on a regular basis. Don't worry though, we are speaking again.
Anyway, you can see my rather bad footage of the event (it was taken on a mobile) here.

Citizen science

Yes, there's still more CS stuff to get into. There's a new one especially for Easter called The Great Easter Newt Hunt and for those of you living in the Norwich area, The Norwich Bat Group still have some squares left for surveying once it's warm enough for the bats to come out.

Sorry there's not much top report on this post, but as you well and truly know, the weather is awful. Lets hope that it gets its act together very soon and then we can start having some fun.

Be careful peeps, till next time.

Sunday, 17 March 2013

Bad science, good science and ocelli.

Hello again. Many of you seemed to like my last post and Tawcabout asked a very good question regarding what use the scales on Lepidoptera are for. So I done some delving and come up with some interesting stuff and some dodgy science too. Here's what I found:

  • Some sources seem to theorise that the scales are predominately for defence and sexual purposes. Just looking at some butterflies such as this Peacock Inachis io below. You will clearly see its fake eye spots, and when the butterfly feels threatened by a predator, it will flash these by closing and opening it wings rapidly and, in this particular species, it gives an audible squeak at the same time, thus emphasising the perceived threat to the predator. The bright colours also make it noticeable to a passing mate. As is often seen in nature, specimens often try to show off their colours in courtship displays. Colouration of  scales also give the benefit of camouflage to hide from predators. This is specially helpful to moths who need to hide up in the daytime. Unfortunately, I don't have any pictures of moths in camouflage that I can show you. But hopefully this year, I'll get plenty that I can share with you and you'll get the idea. If you can't wait till then, type Buff tip moth into a google image search and you'll see a moth that resembles a small broken silver birch twig, it really is amazing!
Peacock Inachis io butterfly taken last year clearly showing fake eye spots.
  • Another theory on the use of scales was again as a defence mechanism and works on the idea that as the scales come off easily, when a moth/butterfly flies into a spiders web the scales that stick to the web come away from the moth allowing the moth ability to fly away at the cost of a few scales. 
  • Then came the idea that the scales were to aid flight by trapping dead air under the scale. This article was looking interesting until it made the following statement:                                    "Scales in butterflies, typically, come in a variety of colors, while those of moths, as a rule, do not. This accounts for a basic difference between butterflies and moths. Butterflies tend to be gaudy, while moths, more often than not, are drab. There are exceptions to the rule, provided for instance by moths that fly by day and are colorful like butterflies, or that rest by day and depend on color for camouflage. But on the whole the difference holds."                                                               This statement more or less makes the whole article worthless. Is a baseless statement and no         evidence is given to back up their claims. However, anyone who has trapped moths will know that the majority of moths are more colourful and more beautifully patterned than some butterflies. Always question what you read!
  • The next theory was in complete contrast to the previous statement in that it was backed up with good hard science. The theory was that the scales help defend Lepidoptera, especially moths, by absorbing ultrasound from bats making it harder for bats to locate them. You can see the paper here and for those of you who haven't got time to read the whole thing (spoiler alert, look away now if you don't want to know the outcome), it turns out that of the species of moth and butterfly studied, moth scales did reflect weaker echoes than butterfly wings and with the scales removed, the wing absorbed less ultrasound, yet that did not happen in butterflies! This ultrasound absorption gave the moths 5-6% advantage in distance that a bat can detect them from. It may only seem a small advantage, but in the wild 5-6% can be the difference between life and death.
So there you have it, there are some theories out there as to there use and I also believe their primary use is for defence whether it be mimicry, camouflage, spiders webs or ultrasound absorption. 

On the subject of moths.

This morning I went down to the moth trap to find 0 moths again. Again, I didn't expect much as it had been raining during the day and the temperature was only a chilly 4ºC. Yet, when I checked my records from last year, I found that on the same date I had trapped 83 moths of 9 different species and the temperature was only 5ºC. So why the lack of moths???



Moths trapped

2012
2013
2nd March
3
0
10th March
110
0
16th March
83
0
Total
196
0


Min Temperature/ºC

2012
2013
2nd March
Not taken
0
10th March
6
1
16th March
5
4

As you can see from the above tables, the amount of moths recorded in 2012 are markedly contrast to 2013's records. Yet the temperature differences are not significantly different. Although I didn't take the temperature on 2/3/12, the met office website data states the mean for East Anglia was 3.5ºC, so it would be safe to assume that there were no temperature irregularities there either. A Twitter friend pointed out that maybe last years awful wet weather may have taken its toll on this years moths, and unfortunately, I believe she may be correct. All the rain would have meant that caterpillars wouldn't have been able to feed properly as they would have been washed off the leaves. The lower temperatures would have seen less breeding opportunities occurring, all significant factors. 
However, with a little digging, I've found some other interesting factor through local weather recorders.
According to Phil Holmes weather page, the rainfall for February 2012 was 11.6mm. For the same month this year it's 33.2mm. That's three times as much and I feel could also play a significant part in the lack of moths so far. It would be interesting to find out other recorders findings to see what impacts they've recorded.

More microscopy

Yes, I've been busy playing with the microscope again and looking at last years found dead bugs. Last year I discovered a dead wasp and whilst looking at its head under the microscope I came across three little bumps on the top of its head in between its eyes. It turns out these are called 'ocelli' which basically means 'little eye' in latin. However, it's not an eye used for vision, oh no. It seems that it is used as a light receptor and aids navigation. 
The said wasp head.

The same wasp from the top.

Wasps are not the only creature to have them either, I've also found them on the head of a bee, although I did have trouble getting a clear shot of these (Bees are hairy creatures as you can see).

Taken from above the head, bee facing upwards.
I've also found them on the top of a fly head. To give you an idea of scale, the fly's head is 2mm across, so the ocelli are extremely small.

Although not a great shot, you can still see the ocelli arrowed.
Again, I find this quite amazing that creatures so small have this built in GPS system that allows them to navigate by the position of the sun to help them find a little hole in the ground. Really is truely amazing.
I've also found out that damselflies have them too, which look quite weird. If I come across a dead specimen, I will have a look and share my findings with you. I know, you can find pics of damselfly ocelli on the internet, but there's nothing quite like discovering for yourself either.
Till next time, have fun!

Sunday, 10 March 2013

Under the microscope


I was going to start this blog with the ongoing saga of culling now that deer are in the spotlight. But then I thought (yes, it happens occasionally), there's enough politics going on regarding the environment and as important as it is, I don't want this blog to get too involved and tangled up in it. This blog is about learning and sharing new experiences with you, my loyal, wonderful follower. The politics of environment can be seen everywhere and there really isn't much more I can add to it except to quote what others have said. So, I'm keeping this blog relatively politics free.

Something new

So now that's out of the way, let me point you in the direction of something new on the blog. If you cast your eyes to the right, you'll see a new column titled 'Citizen Science' and here you will find a clickable list of surveys you, yes you, can get involved in. Please check it regularly as I'm often adding more to it when I find a new survey to add. I hope you like it.
If you have a project or know of one that isn't listed here, please let me know, I'll be only to happy to add it.

Microscopy

As you may be aware, wifey has now got a workshop of her own down the bottom of the garden and I've moved my office from the broom cupboard to the much larger spare bedroom. Oh the joy of being able to spread ones arms properly, bliss. So I'm now getting more settled in my spacious office and able to get on with stuff. One thing I enjoy is a bit of microscopy (looking through microscopes would you believe) and I'm often picking up dead insects, putting them in small containers so I can have a look in closer detail at a later date, much to wifey's dismay I might add. That later date has arrived and I've been looking at a dead butterfly I found in my mothers garden last year. It's a female Orange-tip butterfly Anthocharis cardamines. Butterflies and moths belong to the order of Lepidoptera, which is derived from ancient greek as "scale" & "wing", and it isn't until you look under the microscope at the wing of a butterfly or moth, that you really see what the ancient greeks were talking about. They're covered in them, the whole wing pattern is made up of, it must be thousands, of tiny little scales. Have you ever seen a butterfly bounce of your windscreen and leave behind a patch of dust? Well that dust is in fact all the little scales that adorn the butterfly.
Here's some shots to give you an idea to the size of the scales on a butterfly/moth:
The wing of a female Orange-tip. Don't worry she didn't feel anything, she's been dead for over a year.



Zooming a little closer now at 20x magnification

As close as my digital microscope will take me. I estimate there to be around 330 scales in
this photo.

Unfortunately, these are the best shots I can get, but you should be able to see that it is these scales the give the butterfly the patterns and colours on their wing. As you can also see, each scale is minute and held in place by an even smaller stalk called a pedicle. Every time a butterfly bumps into something, it will knock off some scales. As far as is known, this doesn't harm the butterfly but if it loses to many scales, it's flight is affected. Some mornings I've come down to the moth trap to find a moth that is so battered and worn that the majority of its scales are missing which makes ID'ing it next to impossible.

Simple USB digital microscope. They're not bad for the money.

It always amazes me when I see these creatures in flight, how delicate they are and yet how much control they have in their flight. Next time you see a Comma Polygonia c-album sitting on the ground, just sit and watch it. The ones I've seen seem to be quite territorial and are quick to chase off any other butterfly that invades its airspace and the ariel chase can be quite impressive. Apparently, Purple Emperor Apatura iris are so aggressive, they even chase off birds would you believe. I've never seen this butterfly, but I hope I can remedy that this year.

In case you're wondering what equipment I used to photograph the scales, it's a simple USB digital microscope that plugs into your laptop/computer you can pick up on that well known auction site for about £20. For the money, they're a handy little tool that can give you an introduction to the miniature world and maybe fuel your passion to get something better.
Here's one more shot I took of one of the underwings. Note the hairs, yes, butterflies have hairs as well as scales.

Yellow, black and white scales and some hairs too.


Of course, I only use this microscope when I want to take pictures of whatever I'm looking at. In the main, I use a stereo microscope which is more suited for looking at and examining things in more detail.


Stereo microscope with my little pouch of dissecting tools.

The magnification isn't any greater on it than my USB microscope and it's not all about the magnification either. Don't think you need to get the highest possible magnification you can afford, it doesn't work like that. Say you had the leg of a bee (not personally, that'd be weird) that you wanted to look in greater detail at. If you were to use a magnification of say 1000x, it would be a bit like looking at the white cliffs of Dover from 2 inches away. Yet, if you used something of about 200x, you would see the detail and structure of all the beautiful hairs along its leg and the detail of the foot. The high power stuff is ideal if you want to start looking at cells and bacteria and the like, but too powerful for anything else.
My stereo microscope was a little more dearer at around £60 from that site again and although there is no name on it, I think it's a Brunel MX-6. It lights from the top or/and from underneath too, allowing you to see through some of the finer objects.

And for those of you who don't have the funds for the above or just don't have the time or space for it, well you can't go much wrong with a good old hand glass. I carry mine with me everywhere and it's shown me so much that I never knew existed that I would never be without it. Sometimes, it's the simpler things in life that give the greatest pleasure.

My trusty loupe, great in the field.

I think that's all for now and I hope this has been of some benefit to you. For the more educated amongst you who think I might have got something wrong, please feel free to point it out to me, I won't be upset, honest.
Till next time, have fun.        







Wednesday, 6 March 2013

Rare moths to be found!

Not quite there yet.

Well this weekend saw the moth trap out for the first time this year. Can't wait to start recording moths this year, especially as my lovely wifey bought me a very nice note book to record stuff in, for Xmas.

Hawk Honey
A very nice Xmas pressy from the wife.
I've decided it'll be just for recording moths, or no moths, as the case was this weekend. Yes, with the overnight temperature dropping to a roaring 0ºC, the moths, or any flying insect for that matter, was not going to happen. But, it's still a record as are all nil results. So it went in to the new book as: 
"no moths recorded".
For those of you who are new to mothing and maybe threw caution to the wind and built yourself a moth trap like mine, you will be doing nature and your local natural history recording unit a big favour. As I've said before, it's through records that we see changes in the environment, and through those changes, we are sometimes able to act and stop unnatural declines in species and their environments. Our observations can also monitor positive change, such a case happened to me last year when on two separate occasions I trapped a moth called a Small Ranunculus Hecatera dysodea which was more or less made extinct in the early part of the 20th century. However, it has become re-established recently down in Kent and is slowly making it's way further northwards. I think my recording was about the 9th in Suffolk last year, so was quite chuffed. Luckily, the second time I caught it was the day before I was going to a naturalists 'taster day' (no, it didn't involve people walking round licking naturalists). I knew that my local county moth recorder was going to be present and I took the moth down to him to verify it. After a few minutes looking at it, he conceded that it was in fact Small Ranunculus, something which has never caught in his trap, and he lives just up the road from me. So there you go, my recording of this species being found in my moth trap goes towards plotting the species' return from extinction.

Copyright of Les Hill
Small Ranunculus Hecatera dysodea © Les Hill

I did take a photo of the little fellow, but unfortunately can't find it now (damn!). However, fear not. Here's a link to UK Moths which shows a great photo of the moth and Les Hill who took the photo, has kindly given me permission to use his photo here. Thanks Les.

I also can't wait to find the wonderful large Hawkmoths. I had a few of these last year including a Lime Hawkmoth Mimas tiliae which was a lovely surprise and one morning I came down to find 10 made up of 4 different species in the trap. Fantastic. Every morning is like Xmas when you go down to see what's in the trap, you never know what you're going to get.


Hawk Honey
Lime Hawkmoth Mimas tiliae taken through perspex of moth trap.

Hawk Honey
Four species at once. Clockwise from top right Elephant Hawkmoth Deilephila elpenor,  Privet Hawkmoth Sphinx ligustri, Pine Hawkmoth Hyloicus pinastri and Lime Hawkmoth Mimas tiliae.





Well it continues, the debate that is. Yes, Fred Titmus left a comment pointing me in the direction of a letter to British Wildlife magazine from Matt Shardlow, Chief Executive of Buglife. In it, Mr Shardlow points out the damage that can be done by Buddleia in the wild and what other people in environment circles think about the plant (all against it). 
Unfortunately, there is no web link to the letter and I only have a scanned copy. I have sent an email to British Wildlife magazine asking for permission to reproduce the letter here, but they haven't replied.

I've spotted a few more things this week, one of which was too close for my liking under the circumstances. It was a Muntjac deer Muntiacus reevesi which run out in front of me whilst driving my truck along the A14 near Wherstead. As you can see from the still from the dash-cam video below, it was a close call and I only just missed it. However, the van overtaking me at the time didn't and this video turned out to have captured the deer a second before its sad demise.

It may not look close, but this is a 120º wide angle cam and at this point it's about 3 metres away and I'm doing 50mph.

A taste of spring!

Did anyone else spot it? Down here in beautiful Suffolk on Tuesday 5th March, spring gave us a short preview with beautiful sunshine, temperatures in double figures (14-16ºC). I managed to see a small brown butterfly whizz past me whilst driving past Bury St Edmunds and a bumbler in Felixstowe. Couldn't get ID's as I was driving at the time (not best practice). If only I could've put the moth trap out that night, I would be sure of getting something, but an early start (4am) means I don't get the time until the weekend. Twitter was literally a buzz with sightings of Comma's and brimstones, but alas, not for me whilst I'm stuck at work. If only my work was on a nature reserve/woodland/country park/wildlife trust etc. Hey-ho, never mind, could always be much worse! :)


So here's the latest additions to the list so far:
              

21
Turdus viscivorus
Mistle thrush
Home
09/02/2013
Bird
22
Fringilla coelebs
Chaffinch
Home
09/02/2013
Bird
23
Troglodytes troglodytes
Wren
Home
09/02/2013
Bird
24
Erithacus rubecula
Robin
Home
11/02/2013
Bird
25
Carduelis carduelis
Goldfinch
Home
11/02/2013
Bird
26
Buteo buteo
Common buzzard
Melton Park
21/02/2013
Bird
27
Phalacrocorax carbo
Cormrant
Barham
25/02/2013
Bird
28
Columba livia
Feral pigeon
Stowmarket
25/02/2013
Bird
29
Corvus frugilegus
Rook
Stowmarket
25/02/2013
Bird
30
Muntiacus reevesi
Muntjac
Ipswich
25/02/2013
Mammal
31
Tadorna tadorna
Shelduck
Trimely marshes
28/02/2013
Bird
32
Haematopus ostralegus
Oystercatcher
Trimely marshes
28/02/2013
Bird
33
Anser anser
Greylag goose
Ingham
28/02/2013
Bird