Life and Death

Posted on Jul 12, 2014

A lot has happened since I last posted an update, and unfortunately there’s not much good news.

Here's a pretty bird, before I break the bad news

Here’s a pretty bird, before I break the bad news

And here's a moody tree

And here’s a moody tree

Not good weather for Rollers

The cool wet weather which coincided with hatching – when the chicks are bald and at their most ‘vulnerable’, (Springwatch parlance) – has taken a heavy toll. Out of 20 original nests, 14 have failed, leaving just 6 known nests in all Latvia. It’s likely that we missed a few nests in Black Woodpecker holes, but there’s little activity around them any more, suggesting that these have failed too. The surviving 6 broods have been reduced to a measly average of 2.5 chicks (the long term average is between 3 and 4), and there are several malnourished runts which may not make it. Most losses have occurred (unusually) at the chick stage, but there has also been a high incidence of hatching failure (perhaps due to the bad weather impairing incubation), and a few entire clutches have been lost through predation and some curious cases of ejected / damaged but uneaten eggs. 

Nursing a chilly chick - poignant

Nursing a chilly chick – poignant

The northernmost remaining Roller site

The northernmost remaining Roller site

All told, it’s been the worst breeding season in 17-years of detailed Roller monitoring in Latvia. 

Radio tracking

As well as being tragic and sometimes heartbreaking, these losses have scuppered several of my plans. Of the 6 nests at which have so far deployed radio tags, 4 have failed. So rather than studying home range and habitat selection during chick provisioning we have taken to studying the equally interesting question of where failed breeders end up. They’re not easy to track down, but we’ve recorded movements of up to 12km. All 4 birds seem to have stayed in Latvia, for now at least. 

Jamie modelling a Yagi antenna

Jamie modelling a Yagi antenna

More weather

And instead of wondering what determines the productivity of a nest, I am now forced to ask what determines weather (/whether) a nest survives at all following a spell of bad weather – is it something about the surrounding habitat, the quality of the parents, or just the luck of timing? And speaking of weather, it’s now back to normal – lovely and warm (a bit too warm really) with regular thunderstorms – and the insects are getting bigger and more abundant.

Chick ringing

The remaining chicks have grown up crazily fast (I feel like a proud parent), with the exception of the aforementioned runts – poor souls. Most have now been ringed, which is a memorably messy business. Feather samples have been taken for isotopes and genetics (not just in Latvia, but across pretty much the entire Western Palearctic), and they’ve all been fitted with coded colour ringed, which allows future identification without recapture. These ring resightings build up an incredible dataset, particularly given the closed nature of the Latvian population: most breeding birds were ringed as chicks here, so we know the exact time and place of hatching, plus details of preceding breeding attempts. We can then say, for example, that 68% of  breeders identified so far this year are 2-4 years old, with a steep drop off in older age classes.

Cutie pie

Cutie pie

Wildlife

I’ve seen a couple of new species for the site (for me) in the last few weeks, including Smooth SnakeHoney Buzzard & White-backed Woodpecker.  

IMG_9691 edit

A stunning Smooth Snake

In Ādaži Military Area we came across an amazing patch of riverside which had been maimed by Beavers. I was awestruck by their power as ecosystem engineers. They’d felled some massive birch trees, only to strip off the smaller branches. The resulting dead wood must be great for beetles and other such creatures.

Castor fiber-ed

Castor fiber-ed

I suppose this is also a good place to share some images of the other birds which make use of the ~130 Roller boxes:

Swiftlets!

Swiftlets!

Common Redstart chicks

Common Redstart nestlings

Hoopoe chick

Hoopoe nestling, exploring the big wide world