January 19th   Leave a comment

Normally when I write Wild Crail I try to stick to the basic idea: it’s about Crail and its wildlife. But as I spend the second day of this weekend looking out at the driving rain coming in on a south-easterly and the dusk sky at midday, with no hope of getting out there to see anything, I need cheering up. So I will write about sunnier places. Last weekend I was in mid-California on a short road trip looking for birds after a conference. California as you will know has a classic Mediterranean climate. Rainfall occasionally only during the winter, but mostly dry, warm and very sunny. At this time of year it’s a perfect climate. Probably far too hot in the summer and in fact probably too dry if you want to grow anything sustainably. Birdwise it’s a great place. I have been to the north in Canada and Alaska but never to California. Despite this it’s eerily familiar from a lifetime of West Coast TV programs and Hollywood films. And many of the birds, despite me not having been there, were old friends from Crail: whimbrels, turnstones, grey plover, sanderling, common starlings, collared doves, and even the occasional osprey. But of course most were not and I had one of my greatest pleasures, of finding new birds and not knowing instantly what they were, having then to check the book, work out their identification and learning a whole range of species. It’s like going back to when I was a teenager each time I go to a new place in the world. I have to start again. True it gets a lot easier and many of the birds I know from photos and looking at books in hope that one or two of them might make it to Crail and I might then know what they are from perhaps only the two second opportunity you might get onto a vagrant. Still, laying eyes on any new bird is one of the highlights of my birding, as is seeing a whole range of different species. And California provided both.

Whimbrel - on beaches from California to Crail to Australia

Whimbrel – on beaches from California to Crail to Australia

I won’t bore you with lists of species that will mean little to you unless you too have been birding in California, although some of the names are great: California thrasher and California towhee, Say’s phoebe and mountain bluebird. The last really is special. One of my less-birdy companions described it as being better than the real thing – meaning the bluebirds from the Disney films. Male mountain bluebirds are ridiculously, gorgeously blue, indeed like an idealised cartoon version of themselves. And added to the blue, they occur in huge flocks flycatching above the dry vineyards making sweet chirruping flight calls that perfectly match their lovely plumage. Anyway there were many such highlights for me, and I will tell you about just one in detail.

An acorn woodpecker storage tree (coincidentally at the entrance to a famous Californian winery)

An acorn woodpecker storage tree (coincidentally at the entrance to a famous Californian winery)

I first heard about acorn woodpeckers when I was at University doing a course on behavioural ecology – which is now what I research as an academic. Here you try to work out why animals behave as they do in light of the ultimate function of their behaviours. Put more simply, this is finding out why it is better for a bird, for example, to lay 12 eggs for two years of its life compared to two eggs for 12 years of its life. Perhaps the first species lives in a tough, unpredictable environment and so it is better to live fast and die young, whereas the second lives in a gentler place and so can afford to invest more in its fewer offspring and conserve its resources to breed over a much longer life. Essentially its understanding how evolution results in the diversity of species and their behaviours and so how whole ecosystems function. My granny would never get this as a legitimate field of study and used to ask me when I would get a proper job. It wasn’t until I asked her how she thought that nice man on the telly, David Attenborough, actually knew all that stuff about animals that she was convinced I did something worthwhile. But back to acorn woodpeckers and their behavioural ecology. Acorn woodpeckers are famous in my field because they have very interesting social and cooperative lives and explaining why these woodpeckers do what they do, rather than shuffling around trees in a solitary way like most other woodpeckers is a challenge.

Acorn woodpeckers do two really special things. First, although acorn woodpeckers can breed as a typical pair, in parts of their range they have all sorts of arrangements. Several males, one female; several females, one male; several males and several females: all helping to raise each other’s chicks. The extra helpers at the nest are sometimes related individuals – perhaps the young of last year helping their parents – sometimes unrelated individuals perhaps hoping to inherit the territory when one of the dominant breeding birds dies. It’s always better to raise your own chicks rather than help someone else even if you are related in some way to them, but ecological circumstances such as shortage of territories or high population densities (the same thing really) might mean you have to do the best you can, and it’s the same with the acorn woodpeckers.

Acorns in storage and room for more

Acorns in storage and room for more

Second, they store food cooperatively and manage their food stores as a group in a highly conspicuous way. All during my trip I would stop by the lovely oak trees that occur on the edges of the fields, vineyards and sides of the road and notice that each was pockmarked with hundreds of little pits, and in most of these pits were acorns. The result in some trees was if they had grown there, such is the number and regularity of their placement. Instead the resident acorn woodpeckers have drilled each pit carefully and then stuffed an acorn in each one. These trees with their many carefully constructed food stores then obviously become a huge resource. Acorn availability and so food supply can then be controlled through the winter, as long as the resident woodpeckers keep an eye on the trees – which with their large cooperative groups they can do so more easily. The acorns can be eaten and removed as and when needed, and the pits can be used again and again for storage, making the trees and their pits themselves a very valuable resource worth defending.

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An acorn woodpecker – shot through my telescope with my phone – John’s in the Falklands chasing penguins so it’s my sorry efforts I’m afraid

Knowing something from reading it and seeing it yourself is a completely different thing. Acorn woodpeckers and their interesting lives as an example of how ecology shapes the behaviour of an animal are now very real to me. And thinking about watching them pushing acorns into old cork oak trees and flycatching (another story there – American woodpeckers seem to be big flycatchers, but why them and not European woodpeckers..?) against the clear blue Californian sky is a definite antidote to a very miserable winter’s day in Crail.

I’ll be back on the case in Crail this week and will find some things despite the weather. The evenings are getting lighter and with the more typical warm springs of late (apart from last year) we may only be 2 months away from the first blackbird nest.

Posted January 19, 2014 by wildcrail in Sightings

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