animal behaviour – Don't hold your breath

Oriental Magpie-robin + Bird of the Week Invitation XIV

Among the backyard birds of India oriental magpie-robins (Copsychus saularis) must be the most common. You see them most commonly foraging among fallen leaves or hopping along branches looking for insects. I’ve seen them around Shanghai, which is about as far north as they range. On the west their range ends between Islamabad and Kabul. Their geography is constrained by mountains, deserts, and seas (you can see them in Borneo, but not in the Philippines). In the female the glossy black of the male is replaced by a dull brown. As always, sexual dimorphism indicates a difference in behaviour: although both sexes are involved in raising hatchlings, only the female incubates the eggs. During this time she needs the camouflage.

The photo you see above was among my first close ups of a bird, and I fortunately caught it with its tail characteristically erect. With the short lenses I had then, I would have to creep up close to a bird in order to take a photo like this. I’ve lost that craft now.

There aren’t many places on WordPress where bird watchers can share posts. If you post any photos of birds this week (starting today and up to next Monday), it would be great if you could leave a link in the comments, or a pingback, for others to follow. You don’t have to post a recent photo, nor do you have to post a photo of the same bird as mine. It would helpful to give as much information as you can: which bird it is, where and when you saw the bird, any behaviour you found interesting, for example. You might consider using the tag “Bird of the Week” to help other search for old posts. I hope you’ve had the time to look at what others have added this week and in the previous weeks.

Somber Saturday

When you visit a national park you expect to see nature in all its aspects. We stopped to look at the remnants of a chital. I suppose it must have been prey to a tiger, and then smaller predators and scavengers would have had their share. The antlers are not of much use to animals. They lay in the open meadow, slowly being bleached in the sun.

Saturday’s slinky

Leopards are notoriously hard to spot: they’ll observe you from hiding and duck when they think they can be seen. That’s why I was really fascinated by the relaxed posture of this juvenile, even though I had to take the photo at extreme range. After looking at this in monochrome, I recalled that most ungulates have dichromatic vision, with no ability to distinguish red from green. Now I wonder whether leopards are easier for us to see than their usual herbivorous prey. Since monkey vision is similar to ours, they spot leopards rather quickly. The difference in vision may be a reason why alarm calls of deer are less reliable than those of monkeys.

A flower and a bird

Coneflowers, genus Strobilanthes, are common across India. The most well known among them are the Karvi (Strobilanthes callosa), which mass flowers once in seven years in the Sahyadris, and the Neelakurinji (Strobilanthes kunthiana), which mass flowers once in twelve years in the Western Ghats of Kerala. But most species of coneflowers are annuals. I hadn’t expected to find one flowering in October throughout the lower heights of Kumaon. I shouldn’t have been surprised. There are many species found across the Himalayas. This one seems to be sticky ruella (Strobilanthes glutinosus).

From the leaves, I think this specimen, the first coneflower I saw on this trip, must be the same. The slightly different shape of the flower is an earlier stage in its opening. It was standing in the shade by the shore on the paired lakes called Ram and Sita Tal in Sattal. That was at an altitude of about 1300 m. After that I saw it again and again, up to a height of about 1900 m around Dotiyal and Maanila in Kumaon. Like many of the plants in this genus, it seems to have uses in folk medicine. In Pakistan there has been a first go at screening it for useful phytochemicals.

It was interesting to find a lone male Koklass pheasant (Pucrasia macrolopha) strut about a meadow full of these flowers, munching on the leaves and flowers now and then. These birds are known to feed on seeds and nuts, but this behaviour was not something I’d read of before. Leaves and flowers are not likely to be a major source of energy. I wonder whether the bird eats these coneflowers for trace nutrients.

Eats shoots and leaves

Ramayana has a story which defines Hanuman (Semnopithecus entellus, Northern plains gray langur). When Lakshman is wounded in battle, Ram sends Hanuman off to fetch a rare herb from a distant mountain. The person was well-chosen. These langurs are herbivores who know the forests well. In the myth Hanuman is unable to locate the herb, but knowing that time is short brings the whole mountain back with him.

After breakfast I stood near a grove of bamboos and watched a small troop of the langurs quietly feeding. Herbivores need to eat a lot, and, left to themselves, will spend most of their time foraging and feeding. The larger they are, the more time they spend on food. I suppose that is why these langurs seem to be more even tempered than macaques; their larger body size forces them to spend one third of their waking time in feeding.

An odd nest for a lapwing?

While driving along a track in the grassland of the Dhikala range in Corbett NP, we spotted a pair of Red-wattled lapwings (Vanellus indicus) at a nest. They usually nest in scrapes on the ground, but I’d never seen one before. Still, the location in the middle of a track seemed oddly exposed (featured photo). The pair had chosen the grassy part where the wheels of jeeps would seldom reach, so that the danger of accidental crushing of the eggs by passing vehicles was minimized. Lapwings are known to keep guard around the nest and mob larger animals to protect their nests. I supposed that this is the way they ensure that deer or elephants do not crush their eggs (I would dearly 🙂 love to watch two lapwings trying to budge an elephant from its intended path). The very next day I saw a lapwing determinedly stand its ground in front of our jeep, forcing us to skirt it (photo below). We looked for its nest, but it must have been hidden in the grass nearby. So at least with us this behaviour succeeded.

Ground-nesting birds lose eggs to predators, and this is no exception. A count in the grounds of the Delhi zoo showed that over 40% of their eggs are taken by predators, mainly mongoose, crows and kites. It is now known that crows can discover nests by watching humans, so the extreme hands-on process of counting, as described in the article, may have caused more loss of eggs than is normal. Still, even inside Corbett NP there must be a significant number of predators on the watch for eggs. One response from the bird is camouflage: the eggs are the colour of the dust you see here, with splotches of black, which make them hard to spot among leaf litter and grass.

Like many others, I make it a principle not to go to a nest and take photos of the eggs, so that we don’t lead predators like corvids to one. But I kept worrying about the selection of such an exposed site. I later found a report of a pair nesting on the open roof of a bungalow. There was an even older report of a pair nesting between the tracks of a frequently used railroad. I wonder whether V. indicus protects its eggs by active deterrence rather than subterfuge. The very presence of two adults would alert egg-stealers of the location of a nest, even if it is hidden. So it is possible that these sightings of relatively visible nesting sites is no accident. Clearly there is much still to be understood about even such a common species of bird.

Clever little mynas

One morning in Corbett NP I was watching a herd of elephants walk through tall grass and noticed that a flock of common mynas (Acridotheres tristis) followed them. Sometimes they sat on the elephants, hitching rides on their back, ears, tusks, and even, once, on a trunk. At other times they swooped and swerved between the bulky herbivores. I’d seen them in association with other large herbivores before: gaur (Bos gaurus, the Indian bison), Indian one-horned rhinoceros (Rhinoceros unicornis), nilgai (Boselaphus tragocamelus), and even sambar (Rusa unicolor). I knew something about what they were doing: rendering a service to the host by picking ticks off them, and also keeping an eye on the many insects thrown up from vegetation by the passing of these large animals. This mutually advantageous behaviour is unlikely to be genetically programmed, partly because the birds seem to be able to generalize from one large herbivore to another. In every jungle, the mynas find more than one large herbivore which provides the same opportunity for mutual benefit. If humans did something like that, we would call it cultural learning.

Later that day when I saw a sambar (Rusa unicolor) in the distance with a myna on its back, I didn’t think much more about it. But now, looking at the photo I realize that it was a jungle myna (Acridotheres fuscus), easily told from the common by the tuft of feathers that it has over its beak. So this mutualism between herbivores and birds is deeper. In Africa I’d seen oxpeckers (genus Buphagus) riding on herbivores; it is still an open question whether there is an element of parasitism in this relationship. Oxpeckers are not in the same family as mynas, but may be closely related. So this mutualistic behaviour between some mammals and dinosaurs could have evolved earlier, and the culture could have passed on even though the species evolved into new ones. This may seem weird, but then humans may have inherited the culture of using hearth fires from ancient ancestors called Homo erectus. I wonder whether there are other examples of cultures being preserved for times long enough for biological evolution to disperse it across multiple species. For example, was the use of tools a discovery made so far back in our ancestry that both chimpanzees and humans took the idea from a common ancestor?

Which hawk-eagle?

One species that I find most confusing in the field is the Changeable hawk-eagle (Nisaetus cirrhatus). The least confusing aspect is that there are two morphs. The one you see in these photos is called the light morph. The dark morph does not have the streaked white chest, and is much darker uniformly. But more than that, the field identification is rendered more confusing because of controversies about subspecies and cryptic species. This has left a legacy of birders looking at multiple characteristics and distinguishing between features which could perhaps be widely variable without distinguishing species or subspecies. I will not enter that controversy (you can read a condensed version in its Wikipedia article) but will go with the Linnaean wisdom: if two things have the same binomial, they are one species.

It’s a common enough bird, easily spotted across India, south of Jammu, below the Tibetan plateau, and eastward across Asia right up to Banda Sea, in central and South Vietnam and the Philippines. What was uncommon about this sighting in Kanha NP was that I found it in a little muddy pool drinking water in great gulps. It looked up as we stopped, but after that it didn’t pay us much attention. It is the apex predator in its own niche, after all. I’d never seen it drinking water before, so I didn’t know whether it was extra thirsty because of the heat or what looked like an orgy of drinking was normal. But then, just a week before, I’d seen a small but feisty Jungle owlet (Glaucidium radiatum) drive one away by flying directly at it. I wouldn’t have thought that was normal either, except that a much more experienced birder said that he’d seen smaller raptors shooing away bigger ones before. The longer you watch birds, the more interesting behaviour you see. I suppose all that it means is that, within their physical limits, creatures have more autonomy and adaptability than they were once supposed to have. Hawk-eagle, thy name is change.

The invisible Florican

Bengal Floricans (Houbaropsis bengalensis) are said to be critically endangered. What does that mean, you ask? IUCN will give you one answer. There are less than 1000 individuals left of this species, the only one of its genus. When the last of these grassland bustards dies, not just the species, but the whole genus will disappear. I look at it in another way. Cornell’s ebird application is used by many birders to record their observations. Take a common Indo-Malayan bird like the white-throated Kingfisher (Halcyon smyrnensis). It has been reported on ebird 520,415 times when I wrote this. The Indian nightjar (Caprimulgus asiaticus) is perhaps as common, but has been reported only 10,852 times because it is a nocturnal bird; harder to see and identify. The Bengal Florican has been reported 1,037 times, twice by me. There were seven people with me in Manas NP when we saw this bird, so the same sightings may have been reported about ten times more. It is truly rare.

We’d planned our trip for March, which is the breeding season of the bird. Our visit to the eastern range of Manas, the grassland, started early in the morning because the birds are active in the mornings and evenings. The grass was tall, as you can see from the featured photo of the peacock (Pavo cristatus). Floricans would have been entirely hidden. We scanned the grassland fruitlessly for a long time. Then we heard the harsh but faint clicking of the Florican. One came flying low over the grass at a distance. Immediately, another one jumped out of the grass, clucking. The males are territorial. There was a long aerial chase around the horizon. Neither bird came near us. I got a few distant shots of the birds in flight. You can see the white primaries, splayed out like fingers contrasting with a dark lower surface of the wings. The upper surface is completely white, and the body is jet black. As a photographer I was disappointed, but as a birder I was very happy to see this long display of territorial aggression.

The next morning we started much earlier. Perhaps the birds would be more active in the morning. We were either correct or lucky. As soon as we got into the open grassland we spotted a peacock and a Bengal Florican on the road in the distance. The grass was clearly so high that the Florican would be lost in it if it moved away. So we stopped at a distance to get a first shot. The scene was dreamy in the morning fog, and I could not believe in my continuing run of luck: good as a birder, bad as a photographer.

We couldn’t approach too close without spooking the birds. But as long as we kept our distance, we had ample opportunity to take photos. The light was bad because of the fog. But I had a wonderful view of the male: black head and neck, long like any other bustard, dusty speckled brown body and wing coverts, with the white primaries of the wings showing. I’ve consciously traded a long zoom, 2000 mm, for a large sensor, and I’m usually happy with it. But in this light I wished I had a camera with a better sensor. Still, I must count myself satisfied with my first sighting of this rare bird, one in five hundred of all reported sightings. As our grasslands disappear, places like Manas and Kaziranga are the last redoubts of the once common species that abounded through most of India.

The rites of spring

In the Spring the wanton lapwing gets himself another crest;
Locksley Hall by Alfred, Lord Tennyson

When we stopped to watch a yellow-wattled lapwing (Vanellus malabaricus), The Precious protested, “Such a common bird.” She’d started birding before us but had stopped for some years now. She didn’t know how rare a sighting this is now. It was almost three years since our last view of these birds. Their homes, the arid grasslands which once covered the country are becoming rarer as humans begin to build on what the forestry department calls “wastelands”. And as the habitat disappears, this species, still classified by IUCN as being of least concern for conservation, has become a rarer sight. The Mayureshwar Wildlife Sanctuary that we were in may be the best place to see this lapwing around Pune.

This bird was quite uncharacteristically silent as it stood still and looked around. It looked around as if it was confused. Then strode off into a nearby acacia bush. This behaviour is common with the lapwing: sudden stops and starts, as if it is an absent-minded professor who suddenly recalls an urgent appointment. I gave it no special heed. From the other side of the bush another lapwing popped out, and then crouched. “Hmm. Unusual,” I thought. The first bird came out behind it, looked around as it approached and jumped on to the croucher. They were mating I realized, as soon as the eight-year old with us said “They are fighting.” Coitus last for ten seconds or so in this species, as I can confidently say from the time stamp on these photos.

We’d completely missed the long courtship display that precedes it. Descriptions that I’ve read (see an easy to reach account here) call to my mind the many elaborate ensemble courtship dances that you see in Bollywood movies: with the hero and his male friends displaying in front of the heroine. Except that for the dancing lapwing cohort there is no designated hero; the female chooses. This was the peak of the mating season. If the grassland refuge were larger then we could have just wandered around till we saw another dance. But the refuge is small and closely bordered by agricultural fields.

I can’t spot studies of the behaviour of the Indian lapwings, so to understand whether they do indeed mate for life, I have to fall back on a study of an European species, the Northern Lapwing (Vanellus vanellus). This is the very same one that was described by Tennyson in a passing line in a long and closely observed poem on spring. It turns out that lapwings, long thought of as monogamous (except by Tennyson), are actually both polygamous and polyandrous. One male lapwing reportedly defended two nesting territories! I wonder if that is also true of these. Maybe when I retire I’ll supplement winter and spring travels by spending the long summer days reading old Sanskrit nature poetry. Maybe I’ll learn something new.