Crows in Japan

The main motivations for our recent Japanese holiday were cultural and historical but naturally I kept a look out for birds and beasts, as I do here. We spent time in Osaka, Kyoto, Nara, Takayama and Koyasan, listed from largest to smallest, and from each of them except Osaka we ventured into the edges of the surrounding forested hills.

We didn’t see many birds, however, either in variety or in absolute numbers. Crows outnumbered all the rest, even in urban areas. Beyond them, I can only recall sparrows, a couple of hawks soaring over the rivers in Kyoto, and a couple of waterbirds on a pond at the historic village on the outskirts of Takayama. The weather must bear some of the blame, since we had more wet days than dry and sensible birds stayed out of the rain as much as they could (although we tourists just carried on regardless, as we did in the Italian heatwave last year).

crow
Crow beside the path to the forest shrine in Nara

The (wet) crow above is perching on the pedestal of one of the hundreds of stone lanterns lining the path to a major Shinto shrine on the outskirts of Nara, a beautifully mysterious/haunted/sacred walk through misty forest.

stone lanterns
The path to the shrine

Crows and their close relatives are difficult to tell apart, all of them being much the same size and colour. Japan has four, according to wikipedia: the Jungle Crow, Corvus macrorhynchos; Carrion Crow, Corvus corone; Rook, Corvus frugilegus; and Common Raven, Corvus corax. I think mine is a Jungle Crow, and there’s a blog post about the species here which I just have to mention for the extraordinary ‘tool use’ of urban crows it documents. It’s worth reading for more general info, too; the photos are good but exaggerate the blueness on the crows’ feathers.

Australia has five species, three of which live in North Queensland: the Torresian Crow and Australian Raven, both of which have large ranges including the coast, and the Little Crow, which doesn’t live on the coastal strip but occupies all the drier part of the continent.

Amazing bird behaviour

We don’t habitually think of birds as being very intelligent but sometimes we see behaviour that makes us re-assess them. Video cameras are ubiquitous these days and social media shares anything noteworthy with amazing speed, so more of us see more examples now than ever before. Whether that will lead to a cultural shift in our perception of bird intelligence remains to be seen … let’s hope it does, because we only protect what we value.

These three video clips all appeared in my Facebook feed in the last few months. The first two show swans and a crow indulging in sports we consider specifically human, surfing and tobogganing, and there is no doubt at all that they are doing so for our own reason – it’s fun!

The swan footage was filmed by a local on the Gold Coast, shown on Channel 9 News and quickly went viral, according to the Gold Coast Bulletin. By the time I saw it, Channel 9 had been edited out and the information about location lost, but I tracked down the original:

The crow is using a ‘tool’ for entertainment and that’s pretty impressive but we always knew that crows were among the smarter birds. What about herons?

As one commenter on the YouTube page noted, this goes beyond using a tool for purely mechanical advantage (e.g. a monkey using a stick to increase the reach of his arm) to exploiting predictions about the behaviour of another animal. It’s not unique to this individual bird, either, as I found when looking for the original video: typing “heron fishing bread” into the YouTube search box got me over 100 results and, even allowing for duplications and irrelevancies amongst them, at least a dozen birds of several related species showing similar skill.

“Bird-brain” may take some time to become a compliment, but I do think we need to stop using it as an insult.

Crow butterfly – caterpillar and chrysalis

A little while ago I posted pictures of a full-grown Crow butterfly caterpillar and an egg just laid by an adult of the same species. I was lucky enough to follow the development of both of them

The egg was laid on a bud on March 19 and I was concerned about what would happen to it if the bud opened before the egg hatched. I needn’t have worried: mother obviously knew best.

On the 22nd I saw a very tiny caterpillar munching on the soft juicy petals, and I photographed it each day for four days, at which time the remains of the bud fell off the plant and I lost track of the caterpillar. The developmental sequence is very clear: the creamy infant darkens and grows spines although it doesn’t achieve the full orange-black-white colour scheme in those first few days.

cream caterpillar on pink bud
Crow caterpillar day 1 (click for larger image, as usual)
darker caterpillar
Crow caterpillar day 2
caterpillar on damaged bud
Crow caterpillar day 3 – the bud looking the worse for wear

 

caterpillar with spines
Crow caterpillar day 4

Meanwhile, the fullgrown caterpillar was ready to pupate. I only have two photos of the chrysalis because it did not change much. When very new – in the first two or three days after it was made – it was a milky white with faint brownish markings but it soon turned bright silver,  the coloration all the reference books mention.

white chrysalis under leaf
Crow chrysalis soon after forming
Crow chrysalis in sliver
Crow chrysalis in sliver

Caterpillar season

Our Wet season is the ideal time for caterpillars since that is when their food plants are growing best, so it makes sense that the Wet is also peak butterfly mating and egg-laying time. In the last week or so I have seen lots of Migrants, Eggflies and Crows and observed both mating and egg-laying; I have also seen a few Hawk-moths and know they have been similarly busy. Here are two caterpillar stories from the last few days.

The Common Crow

orange caterpillar with black and white stripes
The very colourful caterpillar of the Common Crow, Euploea core, on a Desert Rose

Don Herbison-Evans says this caterpillar is usually found on Oleander but is also known to feed on Frangipani. The Desert Rose, Adenium obesum, is a member of the family Apocynaceae, as are both of these, so the Desert Rose is a logical addition to the list. The adult butterfly is a rather plain black and white creature, as the name suggests:

Common Crow 7733
Common Crow, Euploea core, on snakeweed (an exotic pest species, but the butterflies love it) on Cape Pallarenda.

I saw one of them alight on the Desert Rose, curl its abdomen around and lay an egg … then went and got my camera:

Egg of Common Crow 8382
Egg of Common Crow on Desert Rose

The egg is about 1.5 x 1 mm and a close-up of it is here. What will happen to it when the flower opens, I wonder?

The Hawk-moth

green caterpillar
Young Hawk-moth caterpillar on what’s left of a pentas leaf, one of their favourite foods – in our garden, at least

Hawk-moths are quite large and heavily built and so are their caterpillars but this is a very young one, about as thick as a toothpick and two-thirds as long. The tail-spine and the eye-spots are characteristic. A gallery of older individuals, both caterpillars and adult moths, may be seen here.

 

Two species of Crow butterfly on the Common

Two dark butterflies on a treetrunk
Two species of Crow with not a feather between them

At least four species of Crow butterfly (Euploea) are found in the Townsville region, three in the immediate vicinity and the other at least as close as Jourama Falls to the north.

Here are two of them together: E. sylvester, the Two-brand Crow, is perched above E. core, the Common Crow. It is not too hard to tell them apart when they are seen together like this (the large white spots follow the edge of the wing in E. sylvester but cut straight across in E. core) and the third local species, E. tulliolus, (photo here) is even more distinctive. But they are all much the same size and coloration and in isolation are easily mis-identified.

I found them in a large mixed aggregation* on the edge of Townsville’s Town Common on my visit a fortnight ago. Peter Valentine tells us that this behaviour is normal in the Dry season but you have to be in the right location to see it – in this case, a patch of cool, dark, damp woodland at the foot of Bald Rock, just near the bird hide. Dozens of them, perhaps hundreds, were in constant motion, restless but never flying far. All they are doing, really, is passing the time until the Wet, their breeding season, arrives.

There were Blue Tigers, Tirumala hamata, in the same little spot but the Marsh Tigers, Danaus affinis, and Plain TigersDanaus chrysippus, preferred sunnier areas nearby.

Marsh Tiger, Danaus affinis, camouflaged in long grass
Marsh Tiger, Danaus affinis, amazingly well camouflaged in the light and shade of long grass

* Flock? Swarm? Wikipedia tells me that the correct collective nouns for butterflies are ‘flight’, which sounds okay, or ‘rabble’, which doesn’t and isn’t even dramatic like the collective noun for feathered crows, ‘murder’. None of them seem quite right.