Friday, 12 January 2007

Early Breeding

Dr Johnson famously noted that “when two Englishmen meet, their first talk is of the weather”, a pattern of behaviour that is as relevant today as when it was written. The social anthropologist Kate Fox believes that this “weatherspeak” is not a genuine discussion about the weather at all but a social facilitator, enabling relative strangers to overcome their social reserve and to actually talk to each other. I was pondering on this the other day whilst watching a pair of collared doves establishing their pair bond prior to mating. Our “weatherspeak” is akin to many of the ritualised behaviours exhibited by animals during periods of social interaction. The more questioning among you may be wondering why two collared doves were indulging in such bonding in the middle of winter; well, it’s all to do with the weather.

As I am sure you will have noticed (and, indeed, commented upon to friends and acquaintances) it has been unseasonably mild of late and this has prompted a degree of premature breeding activity amongst some of our bird species. Over the last few days I have received reports of active nests of song thrush and blackbird (both with young chicks), and of other birds seen carrying nesting material. Such reports are not unique and most years there are at least some early nesting attempts taking place in January or even December. The onset of breeding in our garden birds is under the control of hormones, which are themselves triggered by a range of factors, the most important of which appears to be the change in day-length. The hormones set loose changes within the individual bird, including the development of the reproductive organs. Perhaps uniquely among the “higher animals” the reproductive organs of birds shrivel to almost nothing outside of the breeding season but, come spring, they may enlarge by several hundred times. The controlling influence of change in day-length means that, for most species, it is still too early to be preparing to breed. However, there are some species which always seem to feature in early nesting attempts. Along with the odd blackbird, robin, wood pigeon and thrush, there are the tawny owl, which normally starts laying eggs during February, and the collared dove, which seems to keep going all year round, so long as the weather holds.

Over the coming weeks you may start to hear other birds proclaim ownership of breeding territories. A warm day in February or early March might well prompt a great tit to send forth its “teacher teacher” call or a mistle thrush might sing from the tallest of trees. Certainly, if you come across nests with eggs or young I would love to hear of them.

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