Saturday 15 July 2023

Breeding bird studies....

During ongoing Linnet and House Sparrow RAS (retrapping Adults for Survival) studies we are seeing returning adults amongst the many juveniles. This early in the season it is difficult to analyse as most adults are on second broods. Chris and Andy will summarise later in the season.

Coastal habitat at the North Pembs Linnet RAS site

A juvenile (3JP) Reed Warbler  ringed on the 6th June was the earliest date for us by 12 days. By the 14th of July we have ringed 56 juvenile birds presume most fledged on the Teifi Marshes, our RAS study site now in its 9th year. We have fewer returning ringed adults at this stage of the season but we are still encountering new ringed adults for RAS and a surprising number of unringed adults. 

Our first juvenile Sedge Warblers were caught on the 28th June.

The Teifi Marshes Reed Bunting RAS and colour ringing is continuing into its 12th year, and our RAS season for this species continues until 30th September. As with all our RAS studies, a small summary in a forthcoming post.

New photographers on the reserve are coming on board with looking for colour rings and reporting them to us. This one that was ringed in 2017 and  sent to us recently.

Pied Flycatchers

In Pengelli Forest North Pembs, out of fifty boxes, five were used by Pied Flycatchers. Five adult females and thirty pulli were ringed and all fledged. All figures from this year's work are very high by recent years. Occupancy, eggs laid, v low infertility and high fledging rate.

Pied Flycatchers in Ffynone

Pied Flycatchers were first proved to breed in Pembs in 1979 in Ffynone where they still breed. In Ffynone wood, only four boxes put up by a local school several years ago remain. One near the waterfall was used this year by Pied Flycatchers and 5 young fledged.

Pengelli is owned by the Wildlife Trust of South and West Wales and has a nest box scheme primarily for Pied Flycathers which started in the early 1980's.

In the years 1984-1987 average box occupancy by Pied Flys was  11.5 pairs p a  (range 8 -14 pairs).  This level was not maintained for long.

When the TRG took over monitoring on behalf of WTSWW in 2011 occupancy was 3/4 pairs and from 0 to 21 pulli ringed in each year until this year (30  pulli ringed and fledged). 

Reasons for a more successful 2023 breeding season may be easier to understand next year. Return rate of  "Pengelli' adults and weather / food availabilty.  Historical Pengelli data from Nathan Walton (WTSWW)

Of boxes in the Gwaun Valley (PCNP) only two box were used and 11 fledged.

Rheidol Valley woods (WTSWW) 
No change in Pied Flycatcher box uptake at Coed Simdde Llwyd, but attempts were down at Pant Da (10 attempts compared to 15 in 2022).
Unusual loss of young during chick stage, with some broods only fledging 3, 4, or 5 chicks when the average is 6/7.  Luckily, only two nests were totally lost and this was due to predation; one unknown predator, and one woodpecker (judging by the size of the hole!) One adult male found dead in the same box a great tit was found dead in the week before – but no sign of nesting!
Across the two woodlands all broods were ringed, (91 young), 6 new males, 9 new females, and one female control from Lake Vyrnwy!
Coed Simdde; 35 fledged from 53 eggs laid. Pant Da; 56 fledged from 61 eggs laid. (Naomi Davis)

(Rich D and Wendy J)

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