Missing out on Mullion Cormorants

The bank holiday weekend plan was to see if we could ring some of the Cormorant chicks on Mullion Island, so a group of five of us paddled out on Saturday to have a look. We'd had to leave it this late as there were several nests 'behind the curve' this year, so ringing the larger chicks would have exposed the smaller chicks to predation from the many Great Black-backed Gulls also nesting on the island. However, because of the delayed visit the larger chicks were now too large to risk going onto the island, so we just satisfied ourselves with a paddle round the island counting breeding auks instead.

All was not lost over the weekend though, as a check on one of our Dipper boxes found not eggs but chicks, which were the perfect age for ringing. This was a bit unexpected, but perhaps my timings were a bit off! Sadly the second box on this stretch of river was unoccupied for the first time since we started monitoring in 2013.

Ringing demo and the first chicks to ring

This weekend saw the annual Cornwall Wildlife Trust wildlife celebration at Trebah Gardens, where the ringing demonstration is one of the highlights (allegedly). Over 2,500 people came along last year so it's a great event to get the word out about what amazing wildlife we have in the county. This year was a bit quiet bird-wise, but we did still manage to show people a range of birds, including Nuthatch, Chiffchaff and Coal Tits.

We also run a couple of walks checking what's happening in the nestboxes, but with the event being much earlier than previous years that was a bit quiet as well! Instead we taught people how to find open-nesting species and even show them Robin and Song Thrush feeding chicks and the Robin nest below on five eggs. Everyone seemed keen to get home and look in their own nestboxes, so hopefully there will be a rush of Nestbox Challenge registrations soon...

Away from Trebah, the weekend saw us ringing the first chicks of the year, but in quite different places! Saturday saw us ringing the first of our Dipper broods in Idless Woods, with five chicks being a pretty good start!

Sunday was an all-together more adventurous evening, as we paddled over to Mullion Island to ring a few Cormorant chicks. We timed it perfectly, with the biggest birds not so big that they were all running around, with seven broods with chicks big enough to ring. Cormorants are very asynchronous and some birds were still incubating eggs, and there were also many chicks that were still too small to ring. But we did manage to ring and colour-ring 15 birds, which compares pretty well to previous years (11, 19 and 7 in 2013-15).

The timing of the trips over is also variable, with this visit being earlier than the last couple of years: previous ringing trips were on 6th April 2013, 17th May 2014 and 7th May 2015. It did mean that we weren't able to count the Great Black-backed Gull nests, as most were just at the building stage. In fact, we only found two nests with eggs in, with two in each, so may have to plan another trip over to count these.

Reedbeds, Dippers and an interesting Barn Owl movement

With summer vaguely arriving in Cornwall, this week saw us dusting off the mist nets to start the 2015 CES (Constant Effort Site) season at Gunwalloe. This is now the fifth year we've run the scheme, adding to the BTO's national dataset monitoring the breeding performance of a range of species.

The so-called 'dry ride' at Gunwalloe

The first few visits of the season are always a bit quiet, as we are mostly targeting reedbed migrants here, yet to arrive in big numbers. Those that have arrived are busy setting up territory and not flying round the reedbed, so the catch of just 16 birds was expected. This was mostly Reed and Sedge Warblers though, including two of the former ringed in 2013. We also retrapped Reed Warbler Y101100, originally ringed as an adult at Gunwalloe in June 2011 and retrapped seven times since on site. This is even more impressive when you consider this bird has now crossed the Sahara desert at least 10 times!

We are now also just starting the main nestbox checks of the year, with the first chicks ringed this week in the form of our usual Dippers in Idless Woods. We probably missed one brood that fledged quite early, but the second box had two fat chicks (from four eggs) at the perfect size for ringing.

Two Dipper chicks tucked up in their not-so-cosy-looking nest

Last but far from least was another morning spent doing Barn Owl box checks, this time in the west of the county with National Trust ranger Shaun Boyns. Once again birds seemed to be doing pretty well down here, with two pairs already with chicks hatched! One interesting National Trust story was the male in the box at Trevean (an NT farm), which the nestbox camera had shown was ringed. We presumed it was a bird from one of our sites locally, but was in fact a bird that we'd ringed as a chick at Treveal (an NT farm) in 2014. At 8km, this isn't the longest movement we've seen, but it's great to see a bird breeding in its first year, and one we know very well indeed.

GR80993 in his new home at Trevean

GR80993 and two siblings when ringed at Treveal in 2014 (we're not sure who's who though!)

Next stop are Cormorant chicks on Mullion Island tomorrow and hopefully retrieving the remaining GPS data-loggers from our Herring Gulls in St Ives...

Easter eggs

It only seems right that over Easter weekend we should post about all things egg... Whilst the season has only really just begun, we already have a few species sitting on eggs. The first to lay were Mullion Island Cormorants, closely followed by a few early Shag nests at Rinsey Cliffs, the latter site now having 12 birds sitting. Shags being Shags, some of these won't be sitting on eggs, but at least seven birds are sitting on full clutches of three eggs.

Our first nestbox birds are also on eggs as well: not surprisingly Dippers in Idless Woods. One box just contained a lined nest but the second box had a presumably as yet incomplete clutch of three eggs, nicely covered with beech leaves (I think!). This is a little later than last year, when they had a full clutch by 27th March, but earlier than 2013 when the same date say just two eggs laid.

Idless Woods Dipper nest

Truro Dipper chicks

Summer is really getting going now and we've recently been out ringing our first pulli (nestlings) of the year. Whilst most of our other nestbox birds (tits) are still building, our Dippers are already feeding rapidly-growing chicks. We only monitor a couple of boxes near Truro, but both of these had chicks to ring last week.

Dipper nestbox-checking

The three chicks in this first box (from four eggs) were just sprouting flight feathers, but those in the second box (only two chicks out of five eggs...) were a few days behind, still being pretty naked. Two chicks from five eggs is a bit disappointing, but Dippers normally produce 2-3 fledglings per breeding attempt (per BTO BirdTrends page), so this isn't too bad.

Mullion Cormorants

Yesterday a small boatload of us made our first visit of the year to Mullion Island. With our outboard not quite in a usable condition yet, so thanks to Luke for rowing us out! Whilst it might seem a bit early in the season, Cormorants have a very long and extended breeding season so an early visit is essential to make an accurate count of nests.

Once on the island, we were greeted by well over 80 Cormorants around the main 'colony', which seemed to have shifted slightly along the top of the island (or was that just my imagination?). In total we counted 52 active nests, which compares well to the 24 counted last year.

Most of these nests appeared to have complete clutches of three or four eggs, with one even having five eggs which is pretty unusual. The earliest nest was also in the process of hatching, with three naked chicks hatched and the final chick just breaking out of the egg. But the timing is much later this year, as our first visit last year (on the earlier date of 6th April) saw 14 out of the 24 nests already with chicks, with several big enough for ringing. So with incubation of around a month (thanks BTO BirdFacts), watch this space to see how the later season progresses...

  

Downscaling a bit, we also had chance to check two of our Dipper boxes near Truro. Both were on eggs last time we visited and nothing had changed, with clutches of four and five eggs. With incubation of just 17 days it won't be long until these clutches both hatch.

Dipper nestboxes are simple but effective!

'Almost Easter' eggs

OK, so it's not quite Easter yet, but April always seems very spring-like, so what better time to recheck a couple of Dipper boxes we inherited from a decades-old project. A couple of weeks ago both were built, lined and ready to go, and this afternoon both were occupied. A judicious bit of chatting ensured one female slipped away on approach, revealing four eggs, whilst the other female sat tight (in the box you can just about see under the bridge below), so one to visit another time...

So with incubation of 17 days, it hopefully won't be long before we'll be ringing our first nestlings of the year!