Update from Latvia

Posted on Jun 8, 2014

A normal year for Rollers

We now have 14 pairs of Rollers on eggs across the three sub-sites of the relict Latvian population. Below is a graph (a graph!) of my preliminary estimates of first egg dates for these 14 clutches, showing what looks like a bell-shaped curve, with some points missing from the right-hand side.

A Graph!

A Graph!

According to some basic territory mappings, there are still at least 7 pairs for whom I don’t yet have a nest. Some of these may already be breeding in black woodpecker holes, and some will certainly make up the tail-end of the above distribution. By the looks of things then, it seems to be a fairly good season for the northern-most European Rollers (certainly not a bad one, anyway – maybe just normal. And by ‘European’ I mean living in Europe. I think the species gets a bit further north in Russia, but that doesn’t count).

Roller enablers

Roller enablers

Trail cams

The camera trap study I mentioned in an earlier blog (aimed at testing whether we can prevent Pine Martens from climbing tree trunks by using plastic sheets or turpentine) has so far failed to deliver. Apparently the Martens are not interested in our bait (some tasty chicken spines accompanied with strawberry jam). If anyone has any better ideas for bait, I’d be interested to hear from you. Although, the camera traps have now been appropriated for deployment on Roller nest boxes (either occupied boxes, or ones which Rollers are showing an interest in). Edmunds has already got some good results from an earlier deployment.

Setting a camera trap

Setting a camera trap

Caught on camera

Pied Flycatcher checking out a trail cam

Pied Flycatcher checking out a trail cam

He also got a photo of the above pair copulating, which I can’t wait to see (a bit pervy, I know). We hope to record prospecting, incubation & provisioning behaviour, as well as any predation events (not that I wish any ills to befall the Rollers). 

Insect surveys

I’ve finished the first of 6 rounds of 60 fortnightly insect transects. The density of beetles still seems to be quite low, so I’m getting quite a few 0s. Things will pick up soon, I hope. The vegetation measurements I’m taking will allow me to quantitati…titatively compare the structure of various habitat. For a visual, sit-and-wait predator like the Roller, vegetation structure has a strong influence on prey accessibility, which together with prey abundance determines prey availability.

Dung beetle - Geotrupes sp. I think

Dung beetle – Geotrupes sp. I think

Other bits

Most weekends I get out with Edmunds and his 4×4 & ladder. This gives us a chance to get a good look inside the nestboxes – we’ve ringed several Hoopoe, picked up some Swifts (1 live, on eggs, and 2 dead), found several dead Hoopoe chicks from last year, seen some rather cute Redstart chicks, inspected lots of Roller prey remains, and even found some Owl pellets (identification pending). We’ve also been protecting occupied boxes with plastic sheeting – hopefully to stop Martens.

Fixing plastic

Fixing plastic

Disgusting, smelly bird

Disgusting, smelly bird

Wildlife

Some more wildlife sightings for the field site include: Adder, Slow Worm, Red Fox, Red Squirrel, Bull Moose, Osprey, River Warbler, Black Redstart, Garden Warbler & Marsh Tit. I’ve also found nests of Crested Tit (x2), Pied Flycatcher & Great Spotted Woodpecker

GRSWO chick

GRSWO chick

That’s all folks.