Nature Diary

Birdwatching on the Rio Luján

This is the final article in our series about the Rio de la Plata. Check out the first article, the second article, and the third article.

The River Luján, with sailing yachts and fishermen, but very few fish
The River Luján, with sailing yachts and fishermen, but very few fish

One thing which doesn’t interrupt my thoughts, as I stand in meditation on the foredeck, is the quacking and whistling of waterbirds – and that’s because there are surprisingly few in this vicinity.

Toxic waterway

The Rio Luján and our quiet little creek are very polluted. Having passed through hundreds of miles of farmland and through cities with every form of industry from leather tanning to nuclear power generation, the river is choked with heavy metals and poly-poisons and also with an abundance of fertilisers and pesticides. Argentina is one of the biggest producers of Monsanto GMO soya-beans, and I suppose that the water running past our boat is probably washing gallons of Round Up, the company’s highly toxic, glyphosphate weed-killer, out into the ocean.

Smelt (pejerreyes) gasping for air in polluted waters at La Plata
Smelt (pejerreyes) gasping for air in polluted waters at La Plata

While we’re moored here, the marine growth on the bottom of our boat dies and withers away. And nothing takes its place. That’s good news, from one point of view; a clean hull means a faster boat. But micro-organisms and algaes form the base of the aquatic food pyramid, and if they’ve been wiped out…

White heron seeking his supper
White heron seeking his supper

We don’t see a lot of fish jumping in the creek, and although people do sometimes dangle a line in the water, we’ve yet to see anybody catch anything. In all the time that we’ve been here we’ve only seen one coypu – but, then again, perhaps those secretive little animals sneak past while we aren’t watching!

A magnificent grey heron with a good catch
A magnificent grey heron with a good catch

We do occasionally see a magnificent grey heron fishing amongst the reeds, and we’ve also seen a white heron and a couple of unidentified smaller herons, or garlins. We’ve seen one, lone moorhen, and we often see a water rail. The rail creeps along on the mud, when the tide is very low, poking about and looking for freshwater worms and crustaceans.

There’s also a cormorant with emerald green eyes – and he wouldn’t be here if the river was completely dead. We’ve seen him struggling to swallow a decent-sized catfish.
Out on the Rio Luján one sometimes sees a row of ten or fifteen cormorants waiting patiently, as if for a bus, on a low wall in front of one of the marinas; and I regularly see a whole skein flying high in the sky. But only our lone, green-eyed friend looks for his supper here.

A lone cormorant fishing near the boat
A lone cormorant fishing near the boat

Also to be seen, out there on the river, are a couple of pairs of red-necked grebes. They evidently manage to sustain themselves.
Still, it’s a rather low head-count compared to the abundance of life in the trees. One does wonder how much toxic waste the river and the mud and the animals can bear before the system collapses altogether.

Peckers and creepers

Standing on the foredeck, failing to watch my breath, I hear a gentle tap-tapping. It’s been going on for at least half an hour but it’s nearer now. I open my eyes to see a little black and white woodpecker, the size of an English starling. (His Spanish name is Carpintero Bataraz Chico.) Because I’ve been standing as still as a tree the bird doesn’t mind my presence, and so I am privileged to be able to watch him earnestly foraging on the bark of the willow to which we are moored. He scurries about, like a mouse sniffing for seeds, systematically exploring the underside of a branch which hangs low over the river.
A moment later my eyes catch another movement, nearer to the trunk, and I discover a tree creeper – much larger than the English sort – who is circling and shuffling about the branch in the same manner. He has a wonderful hooked bill and a smart eye-stripe, and his local name is Chincherro Chico. (His American name is the narrow-billed woodcreeper.)

Are we no better than the birds?

Mollymawk, seen from the riverbank
Mollymawk, seen from the riverbank

The two birds have hardly been cohabiting on the tree for more than three seconds before Chincherro Chico makes an angry dash at Woodie and chases him off, and up the river. Evidently he perceives the tree to be his territory – but by what right, I ask myself? “Isn’t it rather greedy of such a small bird to claim a whole tree? Why can’t he be nice to the other fellow? Why can’t they share?”
Then I realise: if mankind can’t even share with others of his own species – if the Israelis harass the people of Palestine, and if the American army harasses people in Afghanistan and Iraq – how can one expect a tree creeper to feel empathy with a woodpecker?
Turning the matter on its head – since we can instinctively intuit that the little bird has no right to claim a whole tree all to itself; since the mere idea of a bird owning a tree seems ridiculous – why can’t we also see that for richer, more powerful nations to try to grab all of the goodies in this world is also totally outrageous? Just who do we think we are, trying to get our hands on the minerals buried under the soil of a land where other people live?

Come to that, does it make any sense for anyone to own anything that is not his own creation, made by his own labours from materials which he…
“Which he owns…? Is that what you wanted to say? But how can anyone own any kind of materials when everything in the world is simply here; when everything simply is?
How can we even own our labours, or own our selves, when everything in creation is simply matter and energy being recycled over and over again?
We don’t own anything here. Even our bodies are just borrowed.”
And our thoughts… What are our thoughts?
Ah… the million-dollar question.

The tree creeper and the woodpecker come darting down the river again, with their wings whirring. They are so alike – the same size; the same flight pattern in this hard sprint; the same diet, evidently. Presumably the long curved rapier is more dangerous than the heavy but somewhat shorter weapon belonging to Woody. And here on the riverbank, as amongst humankind, might gives the megalomaniac his right.

The sap is flowing again…

16th August
16th August

When we arrived in our creek, a couple of months ago, the trees were still clad in a few shoddy tatters of brown leaves. Within a week they had all been blown away, leaving the landscape naked and shivering. For a while, the willows looked so grey and brittle that one might easily have mistaken them for dead trees. However, winter, at this latitude, is just a short nap. The wildlife is already awakening from its slumbers.

20th August
20th August

On August 11th a martin went flitting along the creek, and it was at about this same time that I noticed a yellow-green fuzz rimming the trees which border the creek. The curtain of twigs which hangs down by the boat was seen to have sprouted tiny leaf buds; and over the course of the next week those buds became leaflets, and the leaflets are growing and greening the riverbank.
It’s happening so fast that I’m sure those trees are greener, after my hour long meditation, than they were before!

The world awakens…

So far as the birds are concerned, Spring means an ample supply of grub, for with the warmth and the fresh vegetation come the flies, the bugs, the beetles, and – yes – the grubs. The cardinals no longer spend so much time begging for cheese – they can find more nutritious fare amongst the bushes – and, as we have seen, other folk are finding food on the bark of the trees.
Besides the little barred woodpecker we have spotted three other species. There’s a bigger barred woodpecker, with a churring call; there are yellow-throated woodpeckers which sit on the ground and poke about; and there are also white woodpeckers.

… And love is in the air

Of course, Spring is also the time of year when a bird’s thoughts turn to love – or, at any rate, to procreation – and when all is said and done, their lives have no other purpose than to perform, again and again, the frantic cycle of reproducing themselves.
Last week I saw two white woodpeckers chatting to each other as they foraged in separate trees beside the boat, and yesterday I saw three together. Hearts are being stirred… but if two is company then three is surely a crowd, and one of those white woodpeckers must have been unwelcome.

Kiskadee couple on Mollymawk's bow
Kiskadee couple on Mollymawk‘s bow

So far as one can gather, birds are less particular than people. If the other fellow is of the same species and the opposite gender, she’s welcome to stick around. Even the mocking bird has been seen flirting with his opposite number instead of seeing her off; and the kiskadee who used to sit alone and sing now has a girlfriend to chase.

Mocking bird
Mocking bird

Then again, birds are just as intolerant of infidelity or of the prospect of such complications. The male wants to be certain that it’s his own young that he’s working so hard to rear, and not those of some cuckholding interloper. Thus, even the friendly little Kiskadee has been heard swearing blue murder at another bloke as he shooes him away, and the mocking bird spends an hour or two each morning spitting his anger at three others.
Of course, I’m only assuming that these unwelcome extras are rival males. It could be that, like the hawks, Mr and Mrs Mocking Bird are a well-established couple and are simply having trouble persuading last year’s brood to pack their bags.


Spur-winged plovers are aggressive but also very intelligent. Cursed with the instinct to nest on open ground, they need both of these talents in order to breed successfully.
Many plover couples nest on the lawns belonging to the various yacht clubs, but this bird and her partner have chosen a very public place, on the grass verge beside a marina. On one side the territory is bordered by water, and on the other three sides it’s fringed by a low fence. The birds have evidently noticed that although there is a constant commotion of people and dogs, these dangerous beings have no access to this strip of grass. Just to be on the safe side, they have placed their nest in the exact centre of the long thin oblong.
When we spotted the nest, on August 24th, there were already four eggs but the birds were not yet incubating them.

Others, unknown

While the leading actors perform at centre stage, a whole cast of others twitter in the wings and act out walk-on parts; parts so very brief that I generally fail to find out who they are.
They go flitting through the bushes with their prospective partners, chasing flies and flirting loudly at the same time; like farm workers calling out to one another while they dig potatoes, perhaps.
“Sccrrrrr! Twiddley-twiddley-tweet-tweet-tweet-schrrrrr…” With that sort of song being shouted, with a grasshopper’s shrill intensity, in the bushes close by, I find it impossible to stay with my breath; impossible not to peek. However, although our floating hide is very close to the bank I have never yet managed to get a good look at these twitchy flit-about things.
One sighting was of a pair of long-tailed black birds, one of whom sang like a warbler, positively yelling for attention. They were identified as a masked gnat-catchers.
Then there’s the “tchui-tchui” bird, as I used to call him. Eventually I found the culprit: an uninspiring green and brown bird, not much bigger than a finch. “Always more heard than seen,” says my bird book. Yes, that’s got to be him: Juan Chiviro.

Nesting habits

Almost as furtive but less able to hide away are the red-bummed thrushes, known locally as zorzal. When the tide is very low they like to poke about on the mud, but when it’s high we seldom see them. They don’t seem to have a lot to say for themselves either, and they remind me of female blackbirds.

Oven bird's nest
Oven bird’s nest

There are also some slightly smaller birds, with plumage roughly similar to the zorzal. They look rather uninteresting, but – like the plain, balding fellow in an anorak, who turns out to be accomplished at marquetry – this second species has a trick up its feathered sleeve. Whereas most songbirds weave their nests from twigs, this one makes a home from mud and earth. The adobe structure is more like a swallow’s nest than anything else, but it is built to a much higher standard. And unlike the swallow’s nest it’s spherical, and it’s glued on top of a branch or a man-made post rather than under the eaves of a house. This nest being reminiscent of a primitive oven, the bird is known by that name – it is a hornero, or oven-bird.

Beware the jabberwocky bird

The screamer is armed.
The screamer is armed.

One bird which we know from La Plata and which occurs here also is the screamer, or chaja in Spanish. The first time we saw one of these we hopped into the dinghy and rowed towards it very quietly. How close would it let us get, I wondered, before it flew off?
Well, we reached the reed bed under the bird’s perch, and it still didn’t go. After I’d taken a succession of photos I decided that I wanted some of the creature in flight, so I stood up and clapped my hands. No result. The bird merely gave me a disapproving look and shook its wings. Eventually we were throwing flotsam at the perch – and it still wouldn’t go!
Looking at the photos, later in the day, I understood why the bird was so unafraid. Like the plover, it has a mean set of spurs on its wings – two sets, in fact; and they are very long and sharp! Bearing in mind that it is the size of a turkey, one would not want to mess with them.

This one is driving me crazy

One bird said to be common here and which we would very much like to spot is the bittern, or Mira-sol (which means sun-gazer). However, the bird which I would most like to see is one which has haunted me all the way down the coast from Ilha Grande, in Brazil, and which I have also heard in this creek – albeit only in the summer. This bird makes a noise which conjures up ideas of an over-excited chicken laying an ostrich’s egg. I’ve never even caught a glimpse of the perpetrator, but I call him the Crazy Chicken Cuckoo. (I’ve an idea that he might be a carau, or limpkin, simply because that bird looks so daft…)

Loony Limpkin perched in a flimsy tree, last summer. Is he my Crazy Chicken Cuckoo?
Loony Limpkin perched in a flimsy tree, last summer. Is he my Crazy Chicken Cuckoo?

On the evening of August 16th, after a delightfully warm day, the riverbank suddenly came alive with the sound of frogs – little frogs, who had evidently just awoken from their slumbers. Already they had just one thing on their minds: finding a mate and proliferating; adding to the food chain from which they must also take; throwing themselves with frantic eagerness into the mad and mysterious web of life.

I stood in the gathering dusk and listened to ten thousand shrill whistles… And suddenly, there it was again – that crazy clucking and chortling; that Chicken Cuckoo!
If anyone can identify him from this description they will put an end to more than a year of fruitless, frustrating investigation. If I knew what he looked like I might even be able to keep my eyes closed and keep my mind on my breath.

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