Tuesday, 28 March 2017

The Sweet Smell of Rain

Ah, the sweet, rich smell of rain. That distinctive scent wafting up our nostrils comes from a naturally occurring plant oil that is absorbed by soil and rocks during dry periods. When rain falls, the oil is released into the air along with an organic compound called geosmin that's produced by the bacteria in wet soil. It’s this combination that creates that clean, earthy, “just-rained smell”. Rain itself has no odour. Even acid rain looks and smells just like the normal kind.

We’ve had rather a lot of rain recently but before we go down and see what effect it has had on our stream I noticed this little patch of ground when we emerged onto the track last week. It is regularly cultivated later in the spring but let’s have a look and see what’s taken hold before the rotavator moves in. Plenty of Wood Sorrell here at our feet and some stands of White Mustard in front of the Date Palms but just check out these little pink flowers. These are Small Herb Robert and they are certainly attracting the little Bee Flies. As their name suggests they are flies that have evolved to protect themselves by looking like bees. Whenever you come across an animal that seems to have two contradictory names the second name tells you what it is and the first name tells you what it resembles. Thus a Whale Shark is a shark that resembles a whale and a Curlew Sandpiper is a sandpiper that looks like a curlew and not the other way around.

The rain has certainly put a bit more vim and vigour into our stream; it looks as though it can’t wait to get to the sea. Let’s have a dig along the bank and see what turns up. Earthworms – now these are quite exciting for me because I don’t see many in our arid climate out here. The one on the right is an adult Lobworm and the one on the left looks to be a juvenile. How can you tell the difference? Earthworms are hermaphrodite (both male and female) and when they mature they develop a ‘saddle’, technically called the clitellum, which contains the eggs. After two earthworms have mated the sperm from worm 1 is transferred up the body of worm 2 to the saddle (and vice-versa), the clitellum secretes material that forms a ring which the worm then slides out of and injects the eggs and sperm into it. The ring seals itself into a cocoon in which the baby worms develop, emerging as fully formed juveniles two or three months later. Now you know all about the sex life of the earthworm. You’ve always wanted to know that, haven’t you?

I see that we have a diminutive cascade running into our stream from the valley side. Do you fancy a climb? We could do with a change of scene. There are quite a number of White Hedge-nettles about: another totally misleading name as they are not nettles at all and they don’t always grow in hedges as you can see. If you look at the flower shape you can see that they are similar in design to Sage, Rosemary and many of the other culinary herbs and that is because they are in the same family. Nettles are in a completely different family and their flowers are totally dissimilar and very dull in comparison. Mind you, you can eat nettles but as far as I know there are no recipes for White Hedge-nettles despite their family connections. That may be one for our friend Haris Saslis at Forage Crete to investigate.

Here’s another one of those pesky flies trying to look like something it isn’t. It has all the colouring and shape of a wasp but it’s a Hoverfly. This one is male and they usually appear earlier in the spring than the females giving them a chance to mature (you know how long it takes us boys to grow up –I’m not sure I’ve got there yet). How do I know it’s a male? The eyes are set very close together and appear to almost join in the middle. In the female the eyes are set further apart.

Quite a nice view of the opposite side of the valley from up here and we’re almost back to the coast. Look back down to the track a moment. There, sitting on top of that telegraph pole – a kestrel. They often patrol up and down this valley. They’ll be breeding soon, nesting in holes and scrapes in the cliffs or maybe in an old crow’s nest. They can lay up to six or seven eggs and like many birds they are r-strategists. That is they spread their parental care over a number of offspring allowing the strongest to survive. This compares to animals like ourselves who are k-strategists (in the developed world at least) who have fewer offspring but devote considerable care and attention to ensuring that they all survive. I sometimes wonder, from a purely biological rather than a humanitarian viewpoint, whether we in the developed world are correct in imposing our k-strategy thinking on those parts of the world where the r-strategy prevails.

And on that thought I think we’ll call it a day and make our way back down to the track. Watch your footing, going down can be more treacherous than climbing up and I don’t want to pick you up in a heap at the bottom.

The Extra Bit

Just in case these blog posts give you a taste for visiting the Mediterranean I am hosting a new facebook site called Mediterranean Island Insights which features posts from bloggers on various Mediterranean Islands. Here is the link: https://www.facebook.com/groups/1309179912496006/

Naturalists (the facebook page that accompanies this blog)
See detailed pictures at http://www.inaturalist.org/login  (search - people-stevedaniels-observations)
The Nature of Crete  (Flipboard Magazine)

Tuesday, 21 March 2017

Tales of the Riverbank

If we just push our way through these giant canes we should find the…splash!...stream. I’ve found the water; my right foot has at any rate. I’ve also found a rather interesting character wandering over this rock here. An eight legged arachnid but not a spider. She is one of the hard backed ticks (like books, they come in hard back and soft back) and I think that she’s a Brown Dog Tick. Although they prefer dogs as hosts (and we have plenty of hunting dogs in this area) they will take blood from any mammal including us. As she can host bacteria that would result in us catching Mediterranean spotted fever she is best avoided – like the plague as it were. I think we’ll press on.

This looks like a nice spot to sit and rest for a while with a little waterfall gurgling beside us. I don’t see any ticks about and fortunately they are not particularly numerous so let’s probe about in the leaf litter and see who’s at home. Ah, a tiny, bright red, harmless bug. Very small, very colourful and very vulnerable; which is probably why it’s hiding in the leaf litter.  Bugs have to grow up just like we do and this one is just a toddler so to speak. Later on it will moult into new clothing, changing styles (much as our children do when growing up) and finally reaching the full adult livery of our old friend the Soldier Bug. Then, of course, it’s off to find a mate and start the cycle again as we saw last week.

Well, we’d better move on but it looks as though we’ll have to crawl through the undergrowth once again. These magnificent plants with the mottled stems and white patched leaves are Dragon Arums which will throw up a huge purple spathe next month. Very impressive and I’m sure we’ll see some when the time comes. Meanwhile, I’ve just dislodged a piece of bark from a rotting tree stump and a couple of woodlice have rolled out. Some woodlice can roll up into a tight ball like this and, like Ernie Wise’s wig, you can’t see the join. These are commonly known as pill bugs in the family Armadillidiidae. The odd thing about these two are those lumpy bits called tubercles. They’re very pronounced and require a bit more investigation as I don’t think that they’re common woodlice. You may think that a woodlouse is a woodlouse is a woodlouse but there are over 200 species in Greece alone and they’re a fascinating group of animals to study.

The river bank is a great place to find rotting logs and tree stumps and gently peeling away the outer bark can often reveal a kaleidoscope of life going on. Let’s have a look under this one. A worm, but not an earthworm. See the way that it’s anchored its backside to the wood and is swishing away at the front? That is characteristic of a Nematode. They don’t have the ability to crawl like earthworms. Did you know that they can eat up to five thousand bacteria a minute? That is, if they don’t get eaten themselves first. There seems to be a fungus growing up not far from its head and there are such things as nematophagous fungi that prey specifically on nematodes; catching them in glue traps or lassoing them. I don’t think that this is one of those though. I think that it is in far more danger from that little scorpion there. I have an irresistible urge to call “He’s behind you!” in true pantomime tradition. By the way, the nematode is definitely an ‘it’ and not a he or she. Like slugs and snails, nematodes are hermaphrodite with both male and female sexual organs.

I think that we can stand up now and if we push our way through these canes we should get back to the track – eventually. It’s like trying to break out of prison isn’t it? Here we are, scratched, torn but happy, back on terra firma and there’s an inconspicuous little flower down by our feet. A little flower with a big history. It has been used to mummify Egyptian royalty, sail Roman ships,  provide a good night’s sleep for European nobles and oil the bats of the England Cricket team. It is Linum bienne or pale flax, the wild ancestor of the cultivated flax that has been used to make linen for millennia and the source of linseed oil. It also gave us the words line, lining, lingerie and linoleum; and to think I almost trod on it.

The Extra Bit

Flax and linen have gone out of fashion a bit but a couple of years ago I was at the Cotswold Show in England when I came across this flax fabric and flax oil resin canoe from Flaxland. I want one. I wonder if they’ll give me a discount on the strength of this link? (They make lots of other marvellous linen products as well).

Naturalists (the facebook page that accompanies this blog)
See detailed pictures at http://www.inaturalist.org/login  (search - people-stevedaniels-observations)
The Nature of Crete  (Flipboard Magazine)

Tuesday, 14 March 2017

To St. John’s Ford

Algerian Iris, Iris unguicularis
Here we are below the Milonas waterfall and the cataract is still tumbling down through the rocks sounding like a symphony of swirling streams. A veritable jungle of giant cane and oleander surround us and up among the rocks small flowers like this Algerian Iris are taking advantage of every crack and crevice that holds a modicum of soil.  Not only is it a ridiculously pretty little flower but its rhizomes - the underground stems - contain some useful compounds (Kaempferol and 8-Methoxyeriodictyol if you're into phytochemistry), both of which are important in the fight against diabetes and a wide range of cancers[1].

Tropinota beetle and Spilostethus Seed Bugs
It looks as though machetes will be needed to get through this next bit so I think we’ll take a detour up over the bank. With the temperatures now in the upper twenties Celsius and wall-to-wall sunshine the insects are anticipating next week’s spring equinox. The hairy Tropinota Beetles are all over the place and this one is gorging himself on a Cretan Cistus. Some insects, like the bees, flit from flower to flower but he’ll be there for an hour or more availing himself of every last bit of nourishment. Meanwhile the seed bugs are busy making more seed bugs. Unlike the Tiger Beetles who go for the direct mounting technique (see last week) Seed Bugs prefer the back-to-back method of mating. Not particularly romantic but equally effective.

Caddisfly larva, Trichoptera sp.
I can see a light at the end of the tunnel; if we just thrust our way through this bush… ah, we’re back to the stream. Let’s sit and peer into it for a bit and get our breath back. Pass me the net will you, I think there’s something going on down by that rock. Now why do you think that this little nymph is poking his head into that pile of sand? He’s not doing it voluntarily. That pile of sand is hiding a Caddisfly larva. There’s another one down there look. They spin a cocoon of sticky silk around themselves and cunningly cover it with surrounding materials; sand and grit in this case, then lay in wait and ambush unsuspecting prey. Our poor nymph is being eaten head first.

If you look at some of these rocks they’re covered with rather uninteresting looking brown slime. This is the next stage of the biofilm that we saw developing in A Recipe For Life. If you take the sampling kit – yes, that’s it: a screw top container and an old toothbrush. Just half fill the container with water, scrape the rock with the toothbrush and stir item 1 with item 2 – I’ll set up the field microscope and we’ll see what’s lurking within. Look at that, no less than nine species of diatoms; those minute life forms at the base of the food web. Fascinating aren’t they?

Spawn of the Green Toad, Bufotes viridis
Signs of civilisation, a vehicle track. If we were to follow it round to the left we’d find a waymarked path to the waterfall (but it wouldn’t have been as much fun as hacking through the undergrowth). To the right it goes down to Ferma Bay one way and up to Agios Ioannis the other. As I’ve said previously Agios Ioannis translates as St. John so I’ve always called this place St. John’s Ford but you won’t find it marked as such on any map. I see that the Green Toads have been busy. That clump of what looks like spotted snakes coiled around those reeds is toadspawn and the black dots are emerging tadpoles, there are a few swimming around look. You can tell that it’s toadspawn and not frogspawn because toads lay their spawn in long strings whereas frogs lay theirs in a jelly-like mass. Worldwide, amphibians are suffering deaths to the point of extinction in some species from ranaviruses[2] but thankfully I’ve seen no signs of it locally. However, we’ll keep an eye on them on our travels.

 Talking of which, I think we’ll call that it for today and explore downstream next week. Spring will have well and truly sprung by then so it will be ‘eyes everywhere’ to catch all that’s going on.

The Extra Bit

Those diatoms we were looking at under the microscope are interesting enough when they’re still but when you watch them going about their daily business they are absolutely mesmerising. Here’s a short video for you:  https://youtu.be/DWctIwT3dFI 

Naturalists (the facebook page that accompanies this blog)
See detailed pictures at http://www.inaturalist.org/login  (search - people-stevedaniels-observations)
The Nature of Crete  (Flipboard Magazine)

Tuesday, 7 March 2017

The Milonas Waterfall of Crete

Cyclamen creticus, Anacamptis collina, Fumana arabica
We seem to have emerged from the woods unscathed and the waterfall now lies directly ahead of us. We’ve had to take quite a detour to get around those imposing cliffs but it should be quite a gentle stroll today (famous last words) with plenty of opportunities to look about us. Let’s start with a few flowers that are heralding the arrival of spring later this month. In the shade of the rocks among the pine litter we have the white nodding heads of the Cretan Sowbread which is a type of Cyclamen; the yellow Fumana, a type of rock rose which we saw budding a few weeks back, is now in full flower; and our first orchid of the season: The Fan Lipped Orchid. 

Lucilia ceasar visiting Euphorbia dendroides
Many flowers have lovely scents to attract insect pollinators which we greatly appreciate but some, like this tree spurge here, have a pungent odour which we find somewhat off-putting. Some people have likened it to a decomposing corpse. Fortunately I have never had the experience of smelling a three day dead body so I can neither confirm nor deny but it certainly seems to be attracting these Greenbottles. Not everybody’s favourite insect but they’re quite beautiful when you look at them closely and useful too. Not only do they help to cleanse the planet of rotting bodies but their maggots (which feed on dead animal tissue) have been, and still are, used medically in maggot therapy. They are dropped into a wound such as an ulcer where they not only remove all the dead tissue but also secrete antimicrobial fluids that sterilise the wound.

Cicindela campestris mating
Have you noticed these little green beetles scurrying around on the sandy ground? They’re Tiger Beetles, so called because of their predatory nature. Notice the way that they sprint and stop in a series of jerky runs. This is because they run too fast to see where they’re going and they have to stop and visually reorient themselves. They hold their antennae straight out in front of them to stop them bumping into things. There’s a pair mating here look (in graphic detail if you look closely). I hope he wasn’t running at full tilt when he commenced – the female would have got the shock of her life.

Chalcides ocellata, Rumina decollata, Julidae family
We’re nearly there now and I see that we’re into stone flipping territory so let’s see if anyone is at home. Now here’s a strange group of bedfellows. An Ocellated skink, still hibernating by the way he’s remaining immobile and blinking at me sleepily, three Decollate snails and a Julid millipede. I say odd bedfellows because a skink’s diet generally includes snails and millipedes although I believe that this particular species prefers spiders and beetles. I wonder if the snails and millipede know that? It still seems like us cuddling up to a hibernating bear but nature is full of surprises.

Veliidae family

Well, here it is at last, the Milonas Waterfall, at 40m vertical drop it is the highest streaming waterfall in Crete. There’s a lovely pool here at the base that looks ripe for a bit of pond dipping so let’s go for a paddle. That’s rather refreshing isn’t it? We seem to have some small bugs swimming on the surface that may be worth a closer look. They’re rather quick and not easy to photograph but the body shape and size, the fact that they’re not doing the backstroke and the plated appearance of the abdomen make me think that they are Riffle Bugs. These are small predatory water striders typical of this sort of habitat but I’m not 100% sure. What do you think?

The Extra Bit

You know, that pool does look rather inviting, did you bring a towel? Come on then. Let’s go for a dip. Don’t be a sissy, the snow’s melted and there’s not even any ice on the surface.

Time for a dip (short video):  https://youtu.be/RUybOxhLqRg 

Recent Posts