A GOOD, MEATY OVERVIEW article by regular contributor Bill Naylor is one I always look forward to, and so I eagerly tucked in to Bill’s latest, which you’ll find on page 14-15. Here, Bill is discussing some of the most attractive species from the family Corvidae: the crows. These are species that I find not only beautiful but fascinating, so Bill’s article has already prompted further reading. Take, for example, the azure-winged magpie, which is nowadays divided into two species.
The eastern one is a popular cage bird in the Far East, and is found widely in Japan and China. (Look out for it if you ever visit the very birdy gardens of the Summer Palace in Beijing.)
It is also (I read) popular with cuckoos, as a host species on which those pesky parasites can palm off their eggs.
It is now, anyway – yet, in Japan, parasitism by cuckoos was first reported only about 35 years ago, not before. The habit, once established, has spread like lightning, and in some parts of Japan more than half the magpie nests now have cuckoo eggs laid in them. Several times recently in Cage & Aviary Birds we’ve reported on research findings in the field of cuckoo parasitism, where constant competitive adaptation favours now the host, now the parasite. What’s interesting is how swiftly the advantage can change: recent Japanese studies report that magpies have suddenly begun to recognise and turf out cuckoo eggs.
Initiative regained. Meanwhile, in Europe, the closely related Iberian magpie (Cyanopica cooki) has, traditionally, been a martyr to parasitism by the great spotted cuckoo (Clamator glandarius). Older studies in Spain and Portugal, and magpie clutches held at our own Natural History Museum, prove it.
Yet recent studies can find no evidence that great spotted cuckoos are parasitising Iberian magpies today. They have been rumbled. The two species live happily side by side, with no interference.
Researchers have tried smuggling cuckoo eggs into magpie nests; it’s no good, the canny corvids spot the difference and smash or chuck out the wrong ’uns. That was all news to me when I did a bit of digging around after reading Bill’s article this week, and I’ve no doubt there’s lots more interesting stuff out there. I hope you find this issue feeds your own interests just as much.
Enjoy your birds this week.