17 January 2016

Too Early For Some

My street showing the favourite perch of our resident blackbird

I thought I had finished with the school run. Both children have fledged the nest. However, the eldest hasn't quite developed her flight feathers, so I drive her to work in the morning. The school run has become the work run.

It is not too much of a bother. At least I have the satisfaction of being useful to someone. The other bonus is being outside as the sun rises. I had forgotten, or maybe hadn't fully acknowledged, that the Dawn Chorus also happens in the winter. While I'm de-frosting the car, and the eldest is applying her make-up in the front seat, blackbirds and robins are shouting their little hearts out. It's a magical start to the day. Well, I think so, the eldest disagrees.

Let's give some thought to this. Why are the birds singing in the cold, when presumably food sources are still scarce, and the joys of spring are yet a couple of months away?

At this time of year territories are being established. The year old males are eagerly looking forward to their first breeding season, and are the first to claim a territory. So the earliest singers of the year are the youngest males. They may even start in October/November. All the posturing and shouting then sets off the older males. However, since most birds live two or three years, the older males may only be in their second season themselves.

Once they've got their place, which for urban birds can be as small as a few metres up to an acre or two, courtship and pair bonding happens. That's not to say though that the little guys are mating yet. It only takes a day for an egg to develop after fertilisation. Mating and egg-laying happens all at once in the warmer weather of spring. So what is really happening now is all quite heart-warming. The pairs are simply enjoying each other's company (I may be anthromorphising).

Here is a table showing the months when the first clutch of eggs are likely to be laid. I've listed the birds I'm familiar with in my suburban street, and some I'm guessing might be around. The numbers are the median date of the first laying. For example, blackbirds may start laying eggs in March if the weather is favourable. During a normal year this is most likely to happen around 22 April, but if it's rainy and wet then the first clutch could be delayed until early summer.

As you can see there isn't much we can learn from this table, other than there are a couple more months of singing yet to go before it gets really busy, and Woodpigeon are as promiscuous as their feral cousins.

International Dawn Chorus Day this year is on 1st May. Which, looking at the above table, now makes sense. This is when you are encouraged to get up before dawn, and go into your garden, or on an organised event, and make a note of the birds you can hear. I have done this a couple of times, with mixed results - here and here

But we are getting ahead of ourselves.

I'll leave you with something to ponder over in an idle moment. This is a table of the same birds showing their preferred diet, and the habitats they are mostly likely to be seen in. I thought there might be a correlation between diet, natural habitat, and the date the first eggs are laid.

Information source British Trust for Ornithology