In the last blog it was mentioned that Tit species had struggled to raise broods and that Pied Flycatchers were just hatching with a heatwave forecast later in the week. Well we got a mini heatwave but night temperatures were still getting close to freezing during clear nights. Also, before the heatwave, we had an absolute deluge of rain and strong winds generally over the night of the 1st June and into the 2nd. A camera trap set near the Centenary Hide showed the dramatic rise in water levels (take note of time in bottom right corner of video).
Time-lapse using Camera Trap outside Centenary Hide
Our volunteer and local ringer, Mike Haigh, has the job of checking all the boxes spread across the reserve along with a small team of helpers. He has provided a summary of the box checks so far this year:
“Box occupancy very good with 66% boxes used, with 298 nests found of 6 species (Blue, Great & Coal Tit, Pied Flycatcher, Redstart and Nuthatch). Blue Tit and Great Tit nest attempts has increased on previous years following the high breeding success in 2014 and a warm winter and Pied Flycatchers nest attempts are also slightly up by approximately 10%.
However…
All birds in small nest boxes require caterpillars to feed the young and the cold nights of 2015 have caused a severe shortage of moths and therefore, chick food. Consequently nesting failure is already worse than last year (and we haven’t yet completed final checks).
33% of Pied Flycatchers have already failed and this total will increase as we discover more dead broods during further box checks (last year approximately 1 in 4 nests failed which is a more typical failure rate). In addition the number of chicks in surviving broods are reduced with siblings either dying through lack of food or eggs not hatching due to poorly conditioned adults.
2 days of high wind and torrential downpours from 31 May made things even more of a struggle as caterpillars were washed from trees parents found it hard to forage.
Fledgling Pied Flycatcher from Lake Vyrnwy in 2014 (Photo by Gavin Chambers)
It's not all bad news though - healthy fledged Pied Flycatcher chicks being fed by adults have been seen this week. Our Pied Flycatchers are ringed as part of a long term scientific study and this always produces interesting information. Pied Flycatcher winter in Sub-Saharan Africa and complete a round trip of 13,000km to return to Lake Vyrnwy, quite often to the same wood in which they previously nested and in one case this year, the very same box. We also have 2 Pied Flycatcher sisters who fledged last year, flew to Africa and returned to nest in adjacent boxes at Lake Vyrnwy!”
One wet misty morning we spotted a female Goosander sitting on the shores of the lake and she appeared to be sheltering a family, though it wasn’t until a couple of days later that we found her with 6 healthy looking ducklings. Could this be the family from one of our boxes mentioned in a previous blog? Other fledglings have included Pied Wagtail, Long-tailed Tit, Dipper, Willow Warbler and a couple of Mallard ducklings in front of the Centenary Hide. An Otter was seen below the dam on the 11th and was enjoying by several staff members during their lunch break during an RSPB Mid-Wales meeting.
Fledged Pied Wagtail (Photo by Gavin Chambers)
Plant of the Week
Common Butterwort / Tafod y Gors, (Pinguicula vulgaris) (Photo by Gethin Elias). This is an insectivorous plant. Each leaf is curled at the edges and, when an insect lands, the sticky surface of the leaf holds it fast. The victims struggle to free itself and activates a curling mechanism on the leaf margin. The leaf then secretes digestive enzymes to break down the still-living body, and absorbs the nutrients through its surface. When it gradually opens again, the undigested bits are blown or washed away. Its flowers vaguely resemble a violet in a kind of old-lady mauve - hence its other common name of Bog Violet.
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