Another Egyptian goose

When I hear about Egyptian geese I think of the species Alopochen aegyptiaca, native of the Nile and sub-Saharan Africa, and considered sacred by the ancient Egyptians. I saw them for the first time when we visited Kenya a couple of years ago. The featured photo was taken on the banks of the Mara river. The coloured patch around its eye makes it instantly recognizable, although the rest of the colouring varies a little. But now, in a paper which will appear in April in the paywalled Journal of Archaeological Science, Anthony Romilio of U Queensland has identified another extinct goose from ancient Egyptian paintings.

The panel in the picture above is part of a larger painting which was originally on the north wall of the chapel tomb of Itet, wife to King Sneferu’s vizier, Nefermaat, and likely to have been the king’s daughter-in-law. The original is now in Cairo Museum, and a fascimile can be seen in the Metropolitan Museum in NYC. A description in the website of the Met says ” The artist took great care in rendering the colors and textures of the birds’ feathers and even included serrated bills on the two geese bending to graze.” It is this level of detail in the paintings from the tomb which set Romilio thinking about the species. A series of measurements convinced him that it is not a living species. The red breasted goose, Branta ruficollis, seems to be the closest in appearance, but it has not been spotted south of the Mediterranean, nor have remains ever been identified in ancient Egyptian archaeological sites.

“Artistic licence could account for the differences with modern geese, but artworks from this site have extremely realistic depictions of other birds and mammals,” Romilio is quoted as saying in a press release from UQ. It is interesting that the Sahara was a lush landscape about 10,000 years ago when Nile-dwelling humans began to move into this landscape. The process of desertification began at about the time of the unification of the upper and lower kingdoms, in around 3100 BCE. Romilio has worked on reconstructing taxa of extinct animals of ancient Egypt from ancient Egyptian artwork, and is an author of a book on this subject.

No middle

Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. Arthur Conan Doyle put these words into the mouth of his creature, Sherlock Holmes. This principle is very hard to use in the real world. Take the example of the caterpillar in the featured photo (black and white version below). Which butterfly does it develop into? I suppose it does not grow into a moth, but maybe it could. It is estimated that there could be about 10,000 species of moths in India, and about 1,500 species of butterflies. So a caterpillar is 6 times more likely to grow into a moth. Butterfly or moth, from this picture, and the internet, it would take half a lifetime to eliminate all the lepidopterans that this caterpillar would not grow into, and so figure out which is the only it could be. The problem of how to eliminate a very large number of hypotheses seems to have inflamed the imagination of several philosophers of science. In the book Zen and the Art of Motorcycle Maintenance, Robert Pirsig gave one answer to this problem: use aesthetic judgement to narrow the field. That way lies danger. I don’t have to explain how difficult it would be to apply this method to the question of the caterpillar.

Conan Doyle’s conceit was to transpose logic from the realm of simple problems into the “real” world. It usually doesn’t work, of course. That’s why great detectives are found in works of fiction, and not in the evening news on TV. Much better to reduce the problem: from colour to black and white. In the realm of formal logic, Leibniz had a simpler formulation: a statement must be either true or false. This led in various ways to the ferment in mathematics at the beginning of the last century. Famous names enter into the debate: David Hilbert, Leopold Kronecker, Hermann Weyl, Ernst Zermelo, Bertrand Russel, Kurt Gödel. In this exploration of black and white I don’t intend to go there. I just wanted to point out the spikes on the back of the butterfly; so much more eye-catching in the B&W version, don’t you think?

We don’t see the world as it is …

Someone said something like “We don’t see things as they are, we see them as we are.” Who? A search, filtered through my web bubble, ascribed it to Stephen R. Covey, Anais Nin, Albert Einstein… The trail is complex enough that the Quote Investigator has an article on it. When you start thinking about the path from the the eye to the perception of the world around us, you realize that the world is so complex that the brain’s computations can only create an approximation. A frog sees a world of moving objects in exquisite detail. A butterfly sees the bright patterns in ultraviolet light that flowers have evolved to attract them. We do not. And the camera, that instrument that we carry around in our pockets, does not see what we see. So it takes a little work to tweak a camera’s output to get the impression of dark water, its surface reflecting the clouds above, its transparency letting you see a rotting leaf slowly sinking, its beading on the fresh leaf to reflect the sun, into what you think you see.

The cold war led to the development of CCDs to act as eyes on spy satellites. In the same year, 1976 CE, that they were first used for this purpose, they were also used for astronomical observations. The very next year they were put into the Voyager satellites, our first eyes to travel to other planets. Kodak labs had developed the first CCD camera in 1975, but it wasn’t till 1988 that the first commercial digital camera became available. There is enough information in the output that what looks like a perfectly black image at first can be used to tease out details. Even without using raw data, I could recover an image of a gaur (Bos gaurus) that I saw on a dark night in a forest. You see that imposing creature in the photo above. This was an old camera, so there is a lot of noise, but I like it that way. After all even our eye/brain does not see too well in the dark.

Colour perception is another whole kettle of fish. The simple RGB colour space model which cameras use is a very crude approximation of what our eye sees. Actual human colour perception is still an active research area. So the images that come out of a camera require colour correction. And the interaction of attention and colour; let’s not even go there. When I looked at this lotus pond inside a forest my first reaction was to the bright red of the flowers. Only later did I realize that the number of insects on it was enormous. And was the water strider (Gerridae) there for the flower, or its shade? I forgot all about the red. To reproduce a semblance of this attention I had to tweak the photo.

Lens artists will want to see the” originals” too. The step from raw to jpeg is all digital magic, so nothing is really original. For that matter, our eyes are not particularly great instruments, so the brain’s chemical-electronic magic is really needed to build up, see, the world around us.

Mudskipper

Two branches of life grabbed the Devonian opportunity to colonize a new environment: the land. The fastest evolving were the tracheophytes, a group of plants which developed internal plumbing to transport water and nutrients, and rapidly spread across the continents, growing into new ecosystems of massive forests which captured atmospheric carbon and buried them deep underground. Once a land ecosystem developed, the second group, our remote ancestors crawled out into it to eventually find the buried carbon and release it back into the air. But this is not the story that fascinates me today. It is the story of the remainers, our cousins in nerve and bone, the fish, that I find gripping. Over the eons that passed, they evolved more exquisitely into new opportunities in the main element of our planet: the water.

I have seen mudskippers now and then, mostly in the muddy mangrove forests of the east coast, a littoral of the world’s center of biodiversity, namely the Indo-Australian seas. A year ago, when I visited Jamnagar I realized that I was in an unique place. The special shape of the Gulf of Cambay causes enormous tides, and creates an unique ecosystem: a huge expanse of tidal mud flats, and a second hot spot for mudskipper diversity. I watched one flopping in the exposed mud at low tide. Its fins were placed far ahead on its body, very close to the head. As I watched it walked on its fins from one shallow pool of water to another. Which species was it? I am not an expert on identification. But from its shape and the stripes on its body, my guess is that it was the Boleophthalmus dussumieri, common across east and west coasts of India all the way to the Arabian gulf.

The bulge behind its head came from a bubble of water it holds to keep its gills moist, as it breathes through its skin and the mucous membrane that lines its mouth. The one I concentrated on had its mouth closed, but the others kept opening their mouths to breathe. The males create burrows in the mud where females lays eggs. In high tide the burrows fill with bubbles of trapped air where they retreat to hide from aquatic predators. One mystery which has received a lot of scientific attention is how they survive in such low oxygen content. The other mystery dawned on me slowly as my companions left me to go watch the numerous birds which stalked the flats. Why do they not feed on these exposed mudskipper? They are eaten by the fishermen of Gujarat. Are they toxic to birds?

Why do I find the story of mudskippers so gripping? Its because I was wrong about them; they are not remnants of the ancient group of fish which flopped on to land and gave rise to tetrapods. They are part of most recently evolved group of fishes: the percomorpha (coloured in the evolutionary tree shown above), and are more recent arrivals on earth than the mammals. Mudskippers are close cousins to seahorses and mackerel and eels, and the many other percomorphs in modern seas. Mudskippers (Gobioidei) began to evolve along the western coasts of the giant ocean called the Tethys, just as the first mangroves were beginning to colonize tidal mud flats, and Gondwanaland was breaking up into Africa, Australia and India. That is a remarkably elegant and parsimonious explanation of the present global distribution of mudskippers. What a wonderful solution to that mystery.

Green thoughts

Newspapers have written a lot about tremendous drops in insect populations and their imminent extinction. With the climate changing before our eyes, mountain ecosystems moving to higher altitudes, the Arctic losing its ice cover, this was very clearly part of a vast and immediate problem. Or so I thought until I saw a headline which said: Insects are declining in India and we don’t even have data. Umm, if we don’t have data, how do we know? It was time to do a web search. The results were not exactly reassuring, but not harbingers of doom either.

Insect populations are definitely declining worldwide, and extremely rapidly in some places. But, as an article in The Atlantic said “The claim that insects will all be annihilated within the century is absurd … Indeed, insects of some sort are likely to be the last ones standing.” Last year the journal Insect Conservation and Diversity put together a special issue on the topic of rapid decline of insects, where many of the articles pointed out that declines have been seen in several insect species, but increase was clear in others. Climate change and direct human intervention upsets all kinds of balances in nature. An article (pay walled, unfortunately) set out a further program for study, opening with the sentences “Many insect species are under threat from the anthropogenic drivers of global change. There have been numerous well‐documented examples of insect population declines and extinctions in the scientific literature, but recent weaker studies making extreme claims of a global crisis have drawn widespread media coverage and brought unprecedented public attention. This spotlight might be a double‐edged sword if the veracity of alarmist insect decline statements do not stand up to close scrutiny.

So I am reassured that I can continue to worry about the numbers of green jewel bugs (Chrysocorix stolii) as I photograph them.

On a clearer day

A couple of warmer days cleared the haze a little. I can now see a smudge above the trees which is the horizon. With the relatively mild amount of pollution the sunrises and sunsets are glorious. I sipped my second cup of tea and looked at the enchanting yellow morning light on the mango tree. The tree is still in bloom, but if you look at the inflorescence carefully, you can already see the green spheres which are the new fruit. A year has rolled around. Last year this time everyone was busy not paying attention to dark clouds. This year everyone is looking at that little bright patch in the clouds, the vaccine, and telling each other that the storm is over.

But one can still make the best of the day. The Family breezed in and announced excitedly “Grey hornbills.” As I searched for my spectacles, she impatiently handed me my camera, knowing that it would be the next thing I would look for. There they were, on a gulmohar tree far away. Indian grey hornbill (Ocycoros birostris). Two of them. Probably juveniles, judging by the orange coloured bare skin around the eyes, and the incompletely developed horn above the bill, the casque. So the nesting pair which had lost its usual nesting hole when last year’s storm blew down the tree did manage to find another tree in the garden.

This pair afforded us a good view of what hornbills do when they are not building nests or looking for food. One sat and preened its chest feathers, the other scratched behind its ears with one claw. They looked content. I watched for a while, clicked off a couple of dozen action photos of birds doing self-care, and wandered off. Half an hour later, when I came back, they had gone. I guess the young eventually leave the vicinity, find a mate and a nesting site, and settle down to produce brood year after year. Our garden has had a single breeding pair for year. The young do not seem to come back here to nest. Perhaps that is for the best. Since they can survive in trees that humans grow in gardens and cities, they will keep finding new nesting spots. At least one of this group of magnificent large birds has thrived in an urbanized world.

Egrets, regrets

When a cattle egret (Bubulcus ibis) flew up to sat on a tree at dawn, I had to take out my camera to take some photos. After having spent some time in my initial years of watching birds, I’ve given up looking at these white egrets. They are very common, and since the four species are not terribly easy to tell apart, I don’t usually bother to either record them or to look hard. Cattle egrets are the easiest to tell apart from the others; they always have some yellow on them. In the breeding season it covers their head, neck, and back. In winter, the yellow recedes to a small patch on its forehead, as you see in the photo above.

To identify the other white egrets you have to look at the feet and beaks. Since the birds are usually seen in extremely muddy places, this is not easy. The little egret (Egretta garzetta) has a dark beak, dark legs, and yellow feet. In breeding season it has two long plumes hanging behind its nape. The large egret (Casmerodius alba, formerly Ardea alba) has dark legs and feet. Its beak is dark in the breeding season, and yellow otherwise. In both seasons it has a dark line extending from the beak under its eyes and beyond. This is called the gape line. If you see it flex its somewhat longer neck, you might see a kink in the neck. In the photo above (taken last February near Jamnagar), the gape line clearly extends beyond the eye, and there is a definite S-shaped kink in the neck, both telling us that this is a large egret. The intermediate egret (Mesophoyx intermedia, formerly Ardea intermedia) is the most confusing. Its legs, feet, and beak are very similar to that of the large egret, but the gape line stops below the eye. Also, its neck is a little shorter, and does not kink into an S-shape. Distinguishing them is always a puzzle, and I’m never sure that it worth taking the time to solve.

Against the light

The warm mid-morning sunlight and the cool air of the garden made me lazy. There were butterflies fluttering around the edges of the lawn, but I did not want to get up to photograph them. “I have a monster zoom,” I told myself, “let me use it.” Easier said than done. These marvelously bright and colourful creatures can disappear into the background when they want to. I saw a common pierrot (Castalius rosimon) flying around a tree, but every time it sat down I would lose sight of it. Eventually I managed to figure out where it was going back to sit each time, and focused on those leaves. After I got the photos (one is featured) I realized that it was disappearing into the bright light reflected from the surface of the leaf. The bright patterns on its wing broke up its outline very effectively, exactly like the camouflaging stripes on a tiger’s skin. You cannot imagine a tiger being unspottable when you see it in photos, but when you are trying to spot one in the dappled sunlight of the jungle it is very hard to see. The common pierrot is similar.

I’ve usually been extremely lucky with the lemon pansy (Junonia lemonias). I’ve often caught this butterfly with its beautiful black and white spots on tan forewings, the four eye spots bright, sitting with its wings stretched out on a sunny leaf. This time it was fluttering around a hedge, coming down in the open and suddenly vanishing. I followed it with my eyes for a while, and then looked through the camera. The camouflage was incredible. It would disappear on the open lawn. As it came to rest on blades of grass, the pattern would fool the eye into seeing it as little bits and pieces of brown earth. The eye spots serve a different purpose: distraction. When a predator, such as a bird pounces on it, it can be fooled into thinking that these spots are eyes, and bite at that part of the wing. You may have seen butterflies without part of their wings. That’s often due to birds misjudging where to strike. Losing a portion of the hind-wing does slow down a butterfly, but it can still manage a slightly slower flight. Laziness taught me something that morning!

A musical garden

You don’t need to look up from your work to know that there are purple sunbirds (Cinnyris asiaticus) around you. Their sound fills a garden. The Family spent a while trying to look for them, but it was useless. The males are small, dark, and have a handsome song. The females are drab and brown, but easier to photograph. Waiting pays off. After a day I saw two of them screaming songs at each other from the open. The dark plumage makes them one of the hardest of birds to take a good photo of, but I think the silhouettes you see here are reasonably interesting.

I’ve written about them before, and given you their songs, so I won’t do that again. I will just leave you to imagine the sunlit patch of garden, surrounded by tall trees, where these birds flit from branch to branch. Through the trees you can see the distant Kalsubai hills, and below that the enormous lake behind the Bhandardara dam. A restful place to work from.

A champion

My only sighting of a Himalayan Birdwing (Troides aeacus) came one evening in the Mizo hills area of Tripura. A very large black and yellow butterfly flew past overhead, headed straight for flowers at the top of a nearby tree. I took a couple of photos, but it was sitting edge on to me, and in silhouette I could no longer see the attractive colours. We talked about the then record-holder amongst Indian butterflies, the Southern Birdwing (Troides Minos), of which one specimen collected in 1932 had a wingspan of 190 mm (7.5 inches). I’d not seen one then, and I still haven’t. The butterfly we had just seen was easily as large as a sparrow, perhaps larger. But the photo was not very good, and I put it away.

This March a new champion emerged. One specimen of the Himalayan Birdwing turned out have a wingspan of 194 mm, beating its southern cousin by a whisker! When I read that paper, by Shristee Panthee and Peter Smetacek in Bionotes (Bhimtal), I had to dig out the featured photo. It is not a good photo at all, but if you look carefully, you can see that the hindwing is yellow and the forewing is black, with some streaks of white or yellow. When you have only one photo of a champ you are proud of it, even if he is not seen at his best.