Lamberts dome

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Mono lake flies

 Does anyone remember these ads in the back of Archies comics? I do. Those ads were full of unattainable, fascinating stuff . And I always wondered just what creatures these sea-monkeys were. Even to young kid me, papa monkey and mama monkey sounded a bit unlikely. Yet like a pet I could actually keep in our tiny Bombay house. Equivalent to the caterpillars I kept that became pupae and always ecclosed to butterflies when I was at school.

The first time I saw a sea monkey, ultimately was earlier this year in Mono lake. What they are these things, brine shrimp. And Mono has plenty of them. They feed on microscopic plankton which is so plentiful, it turns the lake green.  Another plentiful creature in the Mono lake ecology is the alakine fly, which also feeds on plankton. All of this plenty at the small size scale, converts to high productivity at the higher size scale and millions of water birds visit the lake. We saw the fag-end of the migration. But we did get to see all the little stuff and the big stuff chasing it, successfully or not.

The cool thing about the flies is that they carpet the shore and when you disturb them, the disturbance travels through the carpet and you get these waves of flies, flying off and landing again behind you. Imagine being the exact opposite of magnetic as you walk through nail filings.

C is usually not that repellant to insects.

It take little to set the flies off and even dainty bird steps will do it.

But there really are a lot of the little blighters. Its a blizzard in fact.

This gave some birds some bright ideas. This California gull thought it was enough to simply run through the swarm with his mouth open. The worst thing is, I suspect it worked. Natural selection isn't what it used to be.

Or at least that's what these guys seem to be thinking

 While we didn't get to see the mass congregations of a few million birds, it's not hard to imagine them there. I suppose I could do worse than go back some day to catch that moment. And perhaps a few more gulls having an easy meal.

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Mono lake, Lee Vining, California

The best thing about Mono lake is not that is surrounded by the Sierra's. It is not that it is utterly gorgeous. And not that its a salty terminal lake with spectacular tufa formations. Or with a salt content rivalled only by th dead sea. It is it's ecology. (Next installment)

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Distance

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Foraging and Sleeping

 

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Squiggles

PS: How cool, you cannot make these up! Just today a day after I posted this, I got an email that this book which uses one of my older squirrel images is now out in print! PPS: I get nothing out of this, it's not an ad, just a squiggly coincidence!

Chipmunk: but which one?

 

California ground squirrel

Western grey squirrel

Greased lightening: Golden mantled ground squirrel

Yellow bellied marmot

 I travel, you get a beast list.

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

At the zoo: San Diego

Someone told me / It's all happening at the zoo.

 


Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Half Dome and San Francisco

Half Dome from Olmstead point

San Francisco from Union Square

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Sleeping on the shore

Copyright © Natasha Mhatre 2012 If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Skylarks

There's a grassland on a hill on the border of this city. It's a golf course really, but it doesn't matter to the skylarks that decide to breed there. To hear them singing as they make these beautiful aerial displays is a thing of beauty. The RSPB website has a snippet of song to tempt you with.

Some of them seem to have brood already. This pair seemed to be bringing food to a nest. But some still made displays, possibly the unlucky ones.

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Word beasts: tree crickets break the rules, sort of.

This time its my own work. We just published a paper that I think is important for a couple of reasons. I'll outline the main one here. I've not gone into this detail in any of the popular science articles I've interviewed for, simply because this is a subtle point. (And also because it got lost in trying to explain the work, I'm not practiced at this interviewing thing). But this is my blog, so I can tell you and take the long route, consider this your fair warning! This is not an explanation of the paper, but of why its interesting.

There are very few laws in biology. By laws I mean rules that hold far and wide across a huge phylogenetic range of organisms. Biology is about variation, making oneself distinct, occupying a new niche. So, in the complicated messy world of biology,  it's quite rare and hence, comforting to have a 'law'. Often when such laws exist, they are rooted in physics. For instance, the law that relates thermoregulation capacity to body mass. Since larger animals have a lower surface to volume ratio, they retain heat well and lose it poorly. And vice versa for small animals, loose heat easily and retain it with difficulty. As you can see, this law is very rooted in the physicality of the body. You may even say it is rooted at an even more fundamental level, in geometry itself.

The law that relates to our paper is quite similar. In animals that communicate using sound, the dominant frequency of the sound they produce is correlated to their body size. Neville Fletcher, who has written text-books in the field of acoustics and bioacoustics, calls it a rule that holds from insects to elephants. And he is right; it does, by and large. There are simple physical reasons for this behaviour. They relate mainly to the efficiency of sound production at frequencies appropriate to the organisms size and to the mechanisms of sound production. For instance, insects use resonators as an important element in their sound production mechanism. A large resonator, therefore, leads pretty much deterministically to a lower frequency.

Now, many bioacousticians take this a step further and suggest that size relates to frequency not just across species but also within species. This is not really a large logical step. The reasons why this relationship would hold are the same as for the across species relationship.

The next step that researchers in the field have argued for is somewhat more problematic. They assume (and also test, sometimes) that because this relationship exists, information about size exists and can be percieved in the sounds an animal makes. There is some tentative evidence and a strong belief that size is important to mate choice and choosy females prefer larger males who are somehow 'better' in evolutionary terms. Taking the step, however, it turns out is more complicated; there are a few assumptions that have to hold to make this 'information transfer' and consequent 'choice' possible.

The first assumption is about reciever psychology. There is a presumption that a reciever can make frequency discriminations that are as fine as the spectrum analysis techniques used to study the sounds in the first place. If the change in size associated change in frequency within a species is smaller than the frequency resolution of the listening party, the question of telling the size of a caller is moot.

The second assumption, which we are concerned with, relates to the next level of variation, the within individual variation. The first level of variation is across species, then within species and finally within individual variation. If within individual variation in frequency is higher than within species variation, then information about size is obliterated and no meaningful 'choice' is possible.

 Here's where the crickets come in. The way crickets sing is quite special. Not only do they use resonance to produce song, they also use the resonance to tightly control the song frequency using something called an escapement mechanism*. The idea runs: therefore, within individual variation will always be lower than within species variation and the information must exist in the song. And not just for crickets; this relation is often thought to hold for insects in general since many of them use resonance as a sound production mechanism.

Not so, say the tree crickets, whose frequency changes with ambient temperature. As a direct result of this property, an individual tree cricket's frequency variation is as large as that of the whole species and the train of logic crumbles because an assumption is not met. Remember the law has not been violated, not strictly, the range of frequencies each individual insect will produce will still depend on his size. But since he can call from anywhere within that range, you can't figure out his size from hearing him at any given time. The information that falls out of the 'law' is gone.

We found that these insects, tree crickets, use resonance for song production as well, and have the same singing mechanisms as other crickets. But these mechanisms fail to control song frequency. So we asked, well, how do they do it? What does it take to break this link down and remove 'information' about body size from song frequency? How hard a transition is this? It turns out, its really simple. All you have to do is sing with longer wings. No fancy non-linear mechanics, no stochasticity in the relation between body size and resonator size, no super temperature sensitive materials, nothing special. Just longer wings. Geometry trumps everything.

And that is why its an interesting result. It doesn't take a lot to break down a train of logic which everyone thought derived from a profound biological 'law'. It takes a relatively small change in geometry to undo a laws effect. That is how easy it is to tweak biological systems. And that ease is one of the sources of the huge diversity you see out there.

Paper: Mhatre, Montealegre-Z, Balakrishnan, Robert (2012) Changing resonator geometry to boost sound power decouples size and song frequency in a small insect. PNAS http://dx.doi.org/10.1073/pnas.1200192109 

*  Its the same mechanism that clocks use to keep time. There's a starter image to explain it on this page if you want to know more.

Poetry and Utamaro woodcuts

I've been writing a story about a Japanese soldier in Guam, and while doing some research I stumbled on these beautiful books. Some of the beauty of the poetry will obviously escape non-Japanese speakers like me. But the detailed nature of the drawings will not. I thought some of you would really enjoy them. Do have a look!

http://www.fitzmuseum.cam.ac.uk/gallery/utamaro/

Word beast bats: Or this one?

Gotta love how I think I can do my editing online!

Word beasts: an arms race

 

About 65 million years ago, is the accepted estimate for when bat echolocation first appeared on the scene. This was the beginning of a long and protracted arms race between the bat hunters, and the hunted, the insects. For a bat, the nocturnal insects of choice are the moths. Plentiful, and with large fat bodies which make them quite attractive. It helps that they are also easy to find; their wings are great reflectors of the ultrasonic frequencies that bats use to find them, flagging them up against the clutter in a bats sonic world.

Way back in evolutionary time, the moths responded to their new predators. In the beginning simply, by evading the bat attacks with crazy evasive diving maneuvers. Then, with more sophisticated methods; ears that were tuned with great precision and sensitivity to the bats very high pitched cries. The very echolocation cries that the bats used to find moths now immediately alerted their prospective prey to their presence.The moths could now dive and circle away well in advance of the swooping bat.

In response, the bats called more softly, they started whispering, and changing the pitch signatures of their calls. They tried their very best to make echolocation calls that the moths could not easily detect or discriminate the direction of. The moths kept up their part of the race too, the pressure not to become supper being quite high. They changed the shape of their wings so their main body would not be attacked and just the edges of their wings would be taken. Some even started making sounds of their own! Sounds that either jammed bat sonar or made them sound unappetising, the acoustic equivalent of very red berries. And in return, its seems that some bats have responded by finding prey by the sounds of the prey alone and silencing their echolocation calls. And so, on it goes. 

And on goes the research, starting with the work of Brock Fenton, way back in the late 70's, right up to today with many different groups still working on different aspects of the same behaviour and ecology! Including the work of fellow post-doc Holger Goerlitz, who helped me do this beast. If you want to know still more about this cool co-evolutionary arms race, you could do worse than read this lovely review (if you can get behind the paywall).

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

Word beasts: Bat and moth coevolution teaser

Running interference

I'm on the familiar shore of a familiar sea just now. But I miss my river. The sullen muddy river with its tides and drowned shopping trolleys and bikes. It doesn't freeze, but the harbour does. Then the graceful and scornful swans waddle on frozen bits of water which cave under their weight. But its by the rivers banks that the cormorants swallow eels and the apples grow and I run, sometimes.

I missed the sea once, and still do but not this sea. Some mythical sea, where there is only the sound of the sea but none of traffic or people. Some mythical seashore on which there is a little girl who still waits for the gulls that are rare and come only in the winters.

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

A leg up

I occasionally get emails I really don't believe I ought to deserve. Sometimes I refuse the offer made, there were a few advertising offers and a few requests for reviews. I don't really have the visitor stats on the blog that make me feel that I can honorably accept that sort of offer. But occasionally a photographer writes in, asking for a mention. I don't really know what to do then. I'll decide on a case by case basis, but everyone can use a leg up, no matter how small...So here's my small nod to Gabriele Basilico, because he was nice.

(c) Gabriele Basilico

Gabriele's a young Italian photographer from Saronno, who likes to shoot film, even in the age of digital photography. With a Rolliflex. Brave man! He says he enjoys the process of visualisation and the challenge of waiting to see what you imagined emerge in a darkroom. And he has a couple/few of photographs up for auction for the first time! Which is cool and exciting for someone starting out....