birds – Don't hold your breath

Canada goose + Birds of the Week Invitation CLXXIV

Canada geese (Branta canadensis) are native to north America. Migrating birds were once spotted rarely in Iceland and the extreme west of Ireland, as well as in eastern Siberia. This large goose is unmistakable due to its black head and neck with a white “chin strap”. As in many long-lived birds, the pairs stay together over many breeding seasons. Chicks remain with the parents for a full year, and form a family group which migrates together, until the young find mates in their second spring. I first saw a flock almost thirty years ago in Long Island, USA, but I don’t seem to have a photo from that encounter. There are several subspecies, which differ from each other both genetically and in morphology.

They were introduced into France and UK in the 17th century CE, and soon established feral breeding colonies, which expanded into the rest of Europe by the early 20th century. I saw a breeding pair in the small village of Kirchlengern in northern Germany. The photo here shows one of the pair. They are considered to be pests in Europe, because they drive away native species and overgraze on aquatic grass and sedge.

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Birds of the Week CLXXIII

Egyptian goose + Birds of the Week Invitation CLXXIII

Spotting a gaggle of Egyptian geese (Alopochen aegyptiaca) in a park in Darmstadt surprised me. I was sure of the identification: the brown mask is a giveaway, and is supported by the colour of the beak, the pink legs, and a brown patch on the breast. I’d previously only seen them in Kenya, and I’d put them down as a species from sub-Saharan Africa. I found later that my memory was not wrong. It was introduced into UK in the 17th century, but in the Netherlands only in the 1980s, and expanded from there into the rest of Europe. The expansion had just begun when I lived in Germany, so I’d missed them earlier. Breeding populations are now also found in the US. The featured photo is evidence of it breeding in Germany. The two below show it in its native habitats in Africa.

The chicks made me curious about its breeding and mating behaviour. Like most birds, there is pair bonding. Since the young develop in eggs, nests have to be defended, and brooding adults have to be nourished. This is the evolutionary pressure behind pair bonding in birds, at least for a season. But pairs of Egyptian geese bond over several seasons, often for life. In the past behaviour such as this was taken to be a moral example. But behaviour is driven by biology and its imperatives. So it is interesting to try to figure out driver behind such long-term pair-bonding.

The question has exercised several generations of evolutionary biologists. Field studies with several species show that long-term pair bonding improves fertility in long-lived species of birds. The reasons are not yet totally clear. In some species birds begin to play mating games for a year or two before they are mature enough to breed, and it is believed that long-term pairs are formed in this process. If so, it would seem to require effort and time to form new pairs, so reducing the time in each spring during which successful breeding can occur. With our very detailed knowledge of the complexity of long-term pair-bonding in one species, we can imagine that there is much more to this story. There is also interesting speculation about how long-term pair-bonding may lead to the evolution of cooperation.

Birds of the Week CLXXII

Eurasian Coot + Birds of the Week Invitation CLXXII

On my first ever trip specially for bird-watching I saw an enormous number of small water birds which were very distinctive. They were completely black (head and shoulders glossy but sooty body) and had a standout white bill and frontal shield. These were Eurasian coots (Fulica atra, also called common coots). They were unforgettable, especially since, for years, I would spot flocks every time I passed near water. They seem to be less common now, but I’ve not really kept count and cannot dispute the general agreement that it is of least concern for conservation efforts. But I’d never seen the chicks before: in India the breeding season is during the monsoon, and I do almost no bird-watching at that time.

In mid-May, when I was out for a walk with a friend, next to a fast-flowing stream in Germany, I saw the chicks that you can see in the featured photo. They were beginning to lose their down and the emerging plumage was very dark. They were not the young of ducks or geese. I don’t know most of the birds of Europe, but I had a feeling that these could be the chicks of Eurasian coots. Nothing else I knew was so dark. Soon enough, a parent came paddling by, and my guess was verified. Later I read that the young will retain the white on their neck and face for some time. The beak will change colour, and the frontal shield will develop at about the time the plumage turns darker.

Eurasian coot, Fulica atra, adult with nest

The chicks were too young to have wandered too far from their nest. I looked around, and on the riverbank nearby I saw another parent near a nest. A nest very close to water, emerging from vegetation, and resting on it, is said to be common. Sometimes, though, they have been seen floating on water. In no sense can this be called a lifer, but I was very excited to see the hatchlings of coots, and a nest, for the first time. For me, watching birds is not only about keeping a score of the species that I have seen. It is also about watching the behaviour of birds. Nesting and rearing of the young, hunting and feeding, mating rituals, are all interesting things to observe.

Birds of the Week CLXXI

Little cormorant + Birds of the Week Invitation CLXX

Never before have I looked down at a Little cormorant (Microcarbo niger) swimming. Standing on a bridge above this stream in Pilibhit Tiger Reserve, I could see how it uses it normally rigid tail as a rudder. The stream was shallow, but must have had small fish. It dived a few times, but came up without anything in its mouth. Cormorants feed by throwing its catch in the air and swallowing it head first, so I should have seen it if it had caught something. They do eat frogs and tadpoles, but in this flowing water I didn’t think there were tadpoles. I wonder what fraction of its dives result in a catch (I got AI generated answers, but since they did not hit on a field study, I can’t trust the result). When you have a new perspective on a bird, new questions come to your mind.

Birds of the Week CLXIX

Indian Grey hornbill + Birds of the Week Invitation CLXIX

Light of this kind is not easy to come by, so I didn’t hesitate to click a photo of this male Indian grey hornbill (Ocyceros birostris) sitting on top of a tree. I’ve written about them many times before so let me just remark on one behaviour that I’ve seen. For years we saw a pair nesting in a tree hole visible from our balcony. Now and then I would see two birds locking bills as if wrestling. When I saw this behaviour, it would usually be the chicks which were doing this. I put it down to play. But once I’d seen the adult couple bill-wrestling. I recently came across a paper which claimed it was a courtship ritual. Pairs of these birds apparently bond for life, so this behaviour could be more plastic than courtship. I wonder.

Birds of the Week CLXVIII

Chestnut-headed Bee-eater + Birds of the Week Invitation CLXVIII

Solitary or gregarious? When I posted about Chestnut-headed bee-eaters (Merops leschenaulti) before, I’d written that they are gregarious. But after seeing some again in Pilibhit Tiger Reserve I wondered. I could see one most of the time, and a pair now and then. I went back and looked at the photos that I have, and found that I’ve only ever photographed solitary birds. I’ve seen many green bee-eaters all huddled up together in mornings, but never a crowd of these. Apparently they are known to nest either individually or in small colonies. So I’ll keep the answer as a provisional “mostly solitary”, and keep open other options for now.

Birds of the Week CLXVII

Bank Myna + Birds of the Week Invitation CLXVII

Bank myna (Acridotheres ginginianus) are a common sight in the streets and bazaars of small towns in the north of India as well as around cultivated fields. It is easily differentiated from the Common myna (A. tristis) by its dustier colour, and the reddish-orange wattle behind its eyes. It’s a bird of the south Asian plains, from Pakistan to Nepal, Bhutan, Bangladesh and all of northern India. Its range is slowly expanding southwards, with reports of its sighting in Andhra Pradesh and further into peninsular India. This omnivore gets its name from the fact that its preferred nesting sites are in the banks of rivers, where it excavates tunnels reaching deep into the mud.

Birds of the Week CLXVI

Common myna + Birds of the Week Invitation CLXVI

Are bird populations increasing? For most species the answer is no. But for the Common myna (Acridotheres tristis) the answer is yes. Its original range was an arc around the Tibetan plateau, from Kazakhstan to China, and as far west as Iran and south as the Malay peninsula. Then it was introduced across the world, into the islands of the Indian Ocean, Australia, Africa and North America, and have become dangerous invasives in many of these places. It is very easily identified by the yellow beak and wattle behind its eyes, and the flash of white rimmed dark feathers in flight.

From February to April I have noticed high activity and frequent calls, as pairs of these omnivores scout for nesting sites, aggressively evicting competing species and conspecific pairs, and laying claim to sites by dint of the noise they make as well as unlimited physical aggression. The incubation period is about two weeks, and hatchlings leave the next in about three weeks. As a result, pairs can often raise two broods in a season. The lack of sexual dimosphism does mean that the sexes participate almost equally in nesting, brooding and feeding. Asian koels are known to parasitize the nests of mynas.

Birds of the Week CLXV

Streak-throated woodpecker + Birds of the Week Invitation CLXV

Bad light can mean many things when you are birding. When I spotted the Streak-throated woodpecker (Picus xanthopygaeus) that you see in the featured photo, I realized that the lighting was not very good for photographing it. There was too much contrast. I could rescue it with some work, so now I have a decent photo from the sighting in Pilibhit TR las month. I can’t quite say the same for the photo I got three years ago in a resort near Dehra Dun, as you can see below. Still, you can see the moustachial stripe on the face of the bird. I had to go eleven years back to my first sighting of this species in Valparai to get a better photo, and this time from the front, so that you can see the streaks on its breast.

Streak-throated woodpecker, Picus xanthopygaeus, Dehra Dun

You can see this bird in many parts of India, and east to Nepal, Bhutan and Bangladesh, southern China and Myanmar and south to Sri Lanka, Thailand, Cambodia, Laos and Vietnam. It is rare outside of India. The bright green back, the head (red for males, black for females), the chequered flight feathers and the scaly underparts are usually enough to allow me to identify this species. The scaly-bellied, which is found in the Himalayas, has denser streaking on the belly and a green colour on its throat. There are other confounding species in other parts of its range, but I haven’t birded in the south-east Asia yet.

Streak-throated woodpecker, Picus xanthopygaeus, Valparai

It is a non-migratory species which is seen foraging in open forest (hence in dappled light where it is hard to photograph) and on the ground. Although it breeds from January to May, which is prime birding time, I’ve yet to see a nesting pair. As in many woodpeckers, sexual dimorphism is essentially restricted to head colour. I wonder what this means for sex-based division of labour in nesting. I see reports that both sexes drill nest holes in trees, but there seem to be no detailed studies of their further roles in nesting and rearing of chicks.

Birds of the Week CLXIV

Black-rumped flameback + Birds of the Week Invitation CLXIV

Black-rumped flamebacks (Dinopium benghalense, also Lesser Goldenbacked woodpecker) are a common south Asian species, being widely seen in Pakistan, India, Sri Lanka, Nepal, Bhutan and Bangladesh, anywhere which is not a desert or a dense forest. If you have seen a woodpecker in an urban area, it is very likely to be this. The bright yellow back identifies all flamebacks. The red head, black rump and throat single out the Black-rumped flameback. The male has a fully red head, whereas the front of a female’s head is chequered black and white.

Bird of the Week CLXIII