Monday, December 17, 2007

Macaques: expressive, intelligent and social? Or the other way around?

PS: I'm at home in Bombay. To call my internet access here bad is to compliment it. Posting will be a bit slow for a while.

Have you ever watched a Bonnet Macaque and felt that it was extremely expressive? It indeed is. Macaques use a huge range of facial gestures to communicate within and between their social groups. Each gesture has a subtle meaning that indicates different degrees of submissive to aggressive behaviour, to simple greeting and play behaviour. Simple things like lip-smacks (submission) and eye-flashes (greeting) lubricate everyday living. Presenting, a display of the bottom, unlike in humans, is almost a gesture of humility, at any rate, submission. And yet, even high ranked males will occasionally present to lower ranked monkeys, perhaps to keep their loyalty, to keep everyone happy. Adult males, females and younger members will groom others (allogrooming) to ingratiate themselves to the groomee. When members of another troop come too close, a strategic yawn will display the majestic canines of the alpha male, providing an oh-so-subtle indicator of discomfort.

Behaviours are also used to indicate heirarchy, each animal's knowledge of its position within that ladder and subtle shifts that occur. A young male will present often to an older, higher ranked male, until one day it begins an alliance with another and reaches upward on the social ladder. Females are born into their positions on this ladder in Bonnet macaque societies, and cannot climb or descend. Almost tailor made for these trapped females, Bonnets have a separate ranking system one that measures social attractiveness. Females may have a low social rank, but be quite comely in other ways. Socially attractive females in certain interactions actually precede higher ranked females.

If you think about it that's a lot to keep in mind. Social heirarchies and networks will jostle for brain-space with food and water maps, spatial maps, cultural memories, and off course all the other hard-wired stuff. The boundaries and details of these social interactions will shift continuously, new players may emerge, old ones disappear. The representations of this complex system in the brain must constantly be rewired. It must remain flexible and capable of learning through an entire macaque life.

Anindya Sinha from NIAS, among others, has argued that this may be the route through which we humans, primates as well, have reached our extravagantly complex and conscious brains. He argues in yet another paper, that many complex mental states such as deception, intentionality and attribution may be seen in even 'primitive' primates like the Bonnet. The idea I suppose is that somewhere along the primate lineage the two process ran away with each other, complex and intelligent brains fueled the growth of more elaborate social and communication structures and vice versa.

An elegant idea, and testable! The more social an animal is the more likely it is to be intelligent. Even now, if one thinks about all the animals that are attributed with intelligence whether merely through folklore or through actual research, many are indeed social. Dolphins, apes, elephants, corvids are the first to come to mind, each with complex sometimes unexplored social systems.

Tuesday, December 11, 2007

Lighting for macro

A paper wasp (Vespa sp) taking off from the nest
One of the things that I find annoying about macro work, mine mostly, work that has been done with flash is the bland, black, unlit backgrounds. These give you darn little feel for the environment the animal is in. They happen largely because all macro work is this fine compromise between magnification, depth of field (DOF), available light and flash light.

When you increase magnfication, DOF falls, it's the law. If you want high DOF, which you usually do, that means you've got to nuke the subject with light. When you're adding huge amounts of light using a flash and meter for the flash, it usually is over-powers ambient light. Its so much brighter than ambient light that ambient makes very little contribution to the final image. Hence the black backgrounds. (Strobist on balancing ambient light.)

A hornet leaves the nest to forage
There are off course many ways to deal with this. You can compromise on DOF, use selective focus instead of trying to keep everything in. That allows you to lower your aperture, pour in less light and be closer to the metering you would get from ambient light.

The second is simply to find areas of high ambient light. Not necessarily on your subject but on the background. On some distant object, for instance, which then becomes this nice bright source of buttery background bokeh as in the hornet images in the post. The bright patches in the background come from a tree which the evening light was hitting. It was at least 4 feet away from the nest, completely out of focus and created this lovely warm coloured bokeh. You can also use the sky in this manner, it's almost always a very bright source.

Inbound and outbound traffic

The third is to actually light the background yourself! I personally have gotten so stuck with the idea of lighting my subject that I never think of backgrounds at all. Off course, in my defense most of my earlier images used a single flash which could only be pointed in one direction. So, it was a bit hard to light two things at the same time, now with two I can do more if I want to.

The other good reason for lighting the background, is to be able to separate the subject from the background. When the main subject is lit directionally, it may have parts of it in shadow. This part will be the same near black shade as the background. It's a good idea not to have this so you can tell the shape and form of the subject itself, to separate it so to speak.

Two ways that immediately come to mind to do this, brighten the background as before or rim /back light the subject. The hornet pictures actually have both tricks in them. The back light is provided by a fully zoomed flash, you can even snoot it to prevent spill, the trick is to get the light behind the subject just lighting the edges.

A few more technical details on the hornets in my flickr photostream.

Saturday, December 08, 2007

Clean up 3: or the story of keep trying

Some of the folks at clean-up 3
You must remember the first two clean-ups (1, 2)? It didn't end with those. The green-gang had yet another clean up and this one unlike the previous one was attended predominantly by students and a fair number. I can't say exactly how many, people kept drifting in and out of the effort depending on their schedules, but lets say at least 15 in all. I was thrilled!

We picked an area around one of the messes, the C mess. The garbage here is largely the responsibility of mant of the very lazy students IISc breeds. Folks won't walk 2 meters to a garbage can, they'll leave things right where they are. It doesn't help that the place is surrounded by residential areas. Much the same thing happens and occasionally domestic waste also ends up in this place. Its a thorough-fare as well, so you can imagine the state. Anyway, we had a long session of picking up after the .... and then we had a discussion about what next.

Mahua recruiting for Green-gang
Many were understandably not happy about the idea of clean ups alone, and wanted to do more to ensure that places we cleaned would remain that way. We initiated a few things, one of these has so far generated a positive response. We decided to ask IISc admin for more dustbins, to begin with in this area. We got much more than that, we were told that the area was ear-marked for 'development' and they asked us to plan what we wanted there. After some back and forth, it was decided we didn't trees and bush hacked away, since the areas actually quite rich in bird life, and we presented a plan for a few extra dustbins, lights and cleared paths. And voila! Work seems to be already underway!

This is the most positive and immediate response I've seen IISc make about just about anything. Good to know it can be done!

The other clean-up efforts had also spawned several initiatives, many of them have gotten quite far in themselves. A post about them in a short while, or maybe Arati who has put in a great deal of effort into many of those endeavors, will pick on this and oblige us with a post on what's been going on?

PS: For those of you wondering why the blog silence for a while, I made the last push needed to finish and submit my thesis. It's done and we'll be back to regular schedule shortly.

Wednesday, December 05, 2007

Johnathon Jones in the Gaurdian

I couldn't agree more. And this is NOT a bad thing.

"Critics and museums lie when they claim serious art is accessible. It is obscure and demanding."
Johnathon Jones

Bat harems

These are short nosed fruit bats (Cynopterus sphinx). I like this picture and a lot of folks do as well. One of the reasons is I guess the nice geometric formation. But the other almost certainly is our human preference for large-eyed infantile creatures. These are nocturnal bats and cant echolocate so they use their eyes to find food and hence must have large eyes. Unlike the eyes of the next guy who is an insectivorus bat, which echolocates and creates a world view using that sense instead. Thats most probably one of the leaf nosed bat species (probably Hipposideros ater), and was shot in Lepakshi, AP. (Not pipistrel like I'd said before).

The other interesting thing about this group is that its a group. Most bats actually live in some kind of group. But this one is special, because its a harem. A male bat creates a resource, in this case its a roost. Actually under more natural conditions these bats build what are called tents. However this group lives in the eaves of the physics dept. And the females basically live in his resource and he gets the first go at reproducing with them. The groups remain stable over quite some time apparently, with some dynamic fusion fission going on. So I guess a female could truly 'evaluate' a male over a period. According to one study, harem keeping males though sire abt 65% of the offspring of harem females, not all interestingly!

A bat guy who came to the lab recently speculated that the guy outside the group is the male, he says that the male is probably the bat on the outside cause they dont usually stay within the group and are the first to leave at disturbance. Which are both interesting actually. Cause if you look closely at the image (click for a larger version) you'll notice ticks on some of the animals. All animals in groups face some costs, here females are sole parental care providers so there is no 'division' of the males efforts. But they will almost definitely get parasites from their roost mates. Also a big group is also always more attractive to a predator! (If you look carefully one of the bats has an eye missing, put out by a predator?)

Its interesting that males show behaviours that suggest avoidance of both these costs but the females don't! I wonder if and why the costs are assymetric between the sexes?

Sunday, December 02, 2007

Vultures in the main building

This image to me is iconic IISc. The Faculty building has been the face of IISc for donkeys years, its on every brochure, every handbook, every calender. No one notices the details.

Like the two Scavenger vultures that have been on its ledges for the many years (don't ask a lady her age, and a PhD student how long they've been) that I have been here. I'm told they've been there well over thirty years. They're reputed to mate for life and I think larger birds are relatively long lived (but 30 years? maybe they've turned over...) I wonder if Tsundue had a word with them when he was up there?

Anyway, a few years ago Nature news had a feature to which the title was "Faeces brings colour to birds' faces: endangered vulture eats shit to impress females". Now see thats just a brilliant feature to read with your breakfast chai. Its also the sort of thing that adds to the perception that theres not much 'substance' to biology just these silly 'observations', particularly the more classical branches like mine.

But lets put this whole observation in perspective. These birds eat feces in order to accumulate carotenoids which give their heads that characteristic yellow colour. This colour is a signal they can't fake as far as we know, they must eat shit to be yellow, hence its an 'honest signal'. The birds when they eat the shit are obviously taking a risk with endoparasites, enteric infection and so on. And a female could judge from the colour just how much of a risk a particular male took. She could also asses his present condition and tell whether he got away with the risk. Now then, the male bird is in essence signaling to her saying in a sense 'I can do well despite my handicap, hence I must have good genes!'.

Amotz Zahavi sometime ago came up with a brilliant theory called the handicap principle which he says explains many many examples of exuberant sexual display in organisms, which are hard to explain in terms of plain old natural selection. And this behavioral observation seems to fit quite well with his theory. And off course there is an opposing theory, which is Fisher's runaway selection hypothesis.

Here's the paper for the work I referred to. Here's the theoretical work that proved that the handicap principle can work as model. The history of the theory itself is full of some nice internecine evolutionary biology warfare, but I'll leave that to you to find out.