Blythe Valley Ringing Report 2018

BLYTHE VALLEY RINGING REPORT 2018

Welcome to the 7th year of bird ringing at Blythe Valley, organised by Redditch Ringing Group (RRG), on behalf of the West Midlands Bird Club (WMBC)and British Trust for Ornithology (BTO). All ringing is undertaken by trained volunteers, usually at weekends and weather permitting. Birds are caught throughout the year using mist nets and, during the breeding season, by monitoring a number of nestboxes on site.

Mute Swans

Ringing sites 2018

Figure 1. Map of Blythe Valley ringing sites

Ringing during 2018 was limited by the ongoing works on site, and of access to certain areas, and no ringing was undertaken in Hawkeshaw area. Weekday ringing was almost impossible during the second half of the year. Most areas endured a great deal of disturbance, making it very difficult to ring. Notwithstanding this, combined with usual limitations of the weather, we still managed a total of 22 visits during the year (including nestboxes), many of which were with a smaller team, due to aforementioned issues.

Humphrey, and his team from WMBC, once again ably monitored and recorded all nestbox activity during the Spring, and almost all pulli were ringed prior to fledging.

Figure 2. All birds captured by calendar month

Ringing data was gathered by RRG over a total of 22 visits and 182 volunteer hours during 2018 (not including WMBC efforts), and saw 28 species caught - 769 birds (see Fig 3), 346 new, 141 pulli and 282 re-traps (birds previously ringed by RRG).

One Bullfinch, previously ringed at Blythe on 24th August 2016, was reported, found dead locally (see below) by a member of the public.

Bullfinch

Figure 3. All birds captured 2018

Jackdaw

Figure 4. All birds captured 2018 by age

Age codes 1 Pulli ringed in nest 2 Fully grown, year of hatching unknown (including current year) 3 Definitely hatched during current calendar year (e.g. first-years in autumn) 3J* Passerines only - definitely hatched this calendar year and still partly or completely in juvenile body plumage* 4 Hatched before current calendar year - exact year unknown (e.g. many adults in autumn) 5 Definitely hatched during previous calendar year 6 Hatched before last calendar year - exact year unknown (e.g. many adults in spring)

From Fig 4, we can be fairly confident any bird ringed as a 3J has likely fledged from a nest on site. In addition, we can also identify evidence of breeding either by presence of a brood patch (generally females only) or cloacae protuberance (CP) for males - (Fig 5 below), giving a probable breeding total of 15 species from all ringing data.

Figure 5. Probable breeding birds recorded, 2018

Whitethroat

Chiffchaff

Nestboxes For the first time, Blue Tit occupied 100% of nestboxes (Fig 6), and had a good breeding season, as can be seen from Fig 7. We're now starting to accumulate a reasonable amount of data, and whilst Fig 7 generally reflects a good level of overall nestbox success, productivity of both pulli from eggs and fledged from eggs has declined over this period (Fig 8.) Breaking this down further in Figs 9 & 10, we can see this trend is true for both Blue and Great Tit, but the latter has better success of fledged young from pulli (Fig 10.)

All 2013 2014 2015 2016 2017 2018 Blue Tit 13 16 15 12 13 17 Great Tit 3 4 4 7 6 0 Nuthatch 1 Total 16 21 19 19 19 17 Fig 6. No of Nestbox records, 2013-2018

Nest success summary 2018 Outcome First Nest Number Species Subsite Box Outcome Egg Eggs Pulli Fledged type Blythe Valley 487 BLUTI MARL A10 NE S 23/04/2018 10 10 10 488 BLUTI MARL A11 NE S 18/04/2018 9 9 9 489 BLUTI MARL A12 NE S 23/04/2018 11 10 10 490 BLUTI ILLSHA A14 NE S 26/04/2018 10 10 10 491 BLUTI ILLSHA A15 NE S 03/05/2018 8 8 8 492 BLUTI BLYTHG A16 NE S 28/04/2018 8 7 7 493 BLUTI BLYTHG A17 NE S 21/04/2018 6 6 5 494 BLUTI ILLSHA A19 EO F 10 0 0 482 BLUTI MARL A2 NE S 06/05/2018 11 11 11 495 BLUTI ILLSHA A20 NE S 24/04/2018 14 10 10 496 BLUTI BLYTHE A23 NE S 26/04/2018 10 10 9 497 BLUTI BLYTHE A24 NE S 06/05/2018 9 9 9 498 BLUTI MARL A27 NE S 26/04/2018 9 8 8 483 BLUTI BLYTHE A3 NE S 20/04/2018 10 10 10 484 BLUTI MARL A4 NE S 23/04/2018 9 6 6 485 BLUTI BLYTHE A5 NE S 04/05/2018 8 8 8 486 BLUTI BLYTHE A8 SY S 26/04/2018 10 10 7

Place totals: Nests: 17 162 142 137

Year totals: 162 142 137 Year averages: 9.53 8.35 8.06 % of eggs: 87.65 84.57 % of pulli: 96.48 Total nest records: 17

Fig 7. Nest-box records, 2018

Nestbox productivity all 2013-18 100%

95%

90%

85%

80%

75%

70% 2013 2014 2015 2016 2017 2018

pulli from eggs fledged from eggs fledged from pulli

Fig 8. Nest-box records, 2018

Blue Tit Nestbox productivity 2013-18 100%

95%

90%

85%

80%

75%

70% 2013 2014 2015 2016 2017 2018

pulli from eggs fledged from eggs fledged from pulli

Fig 9. Nest-box records, 2018

Great Tit Nestbox productivity 2013-18 100% 95% 90% 85% 80% 75% 70% 65% 60% 2013 2014 2015 2016 2017

pulli from eggs fledged from eggs fledged from pulli

Fig 10. Nestbox productivity trends 2013 - 2018 Blue Tit pulli

The aim of our group is to ring regularly at a number of local sites throughout the year, and over a number of years build up a database of records, observing trends over a period of time. During 2018 it was difficult to achieve this, particularly through the summer months, and we missed the opportunities to ring many of the usual summer migrants in any great numbers. Much of the habitat normally suitable was either destroyed or inaccessible. Notwithstanding this, we were still able to ring a similar number of birds to previous years (see Fig 11).

For those commoner species we catch a good number of, we can now start to build up a picture of how they have fared over this period. Blue and Great Tit are obviously the commoner species caught, and we have nestbox data to add to this analysis.

Figs 12 & 13 give a breakdown of both species by age over the period. At a glance, this information gives an indication of how successful a breeding season has been, and an indication of survival. these species are used because they can be aged throughout the year, unlike say, Long-tailed Tits. Fig 14 shows same for Robin, another bird which can be aged throughout the year.

Fig 11. Number of new birds ringed 2013 - 2018

Fig 12. Great Tit captures by age 2012 -2018

Fig 12. reflects nestbox monitoring, with no pulli (age 1) and very few juvenile (age 3J) and first year (age 3) birds caught in 2018, which suggests it was a poor breeding year for Great Tit. This is also reflected in number of Great Tit ringed in 2018 (Fig 15). The one positive from 2018 is that a good number of birds hatched in 2017 (age 5) survived into the following year.

Fig 13. Blue Tit captures by age 2012 -2018

The domination of Blue Tit in nestboxes is also reflected in the record number of pulli (age 1) ringed in 2018. Fig 13 also shows a reasonable number of adults (age 6) ringed in 2018 and a second best ever year of birds surviving their first year (age 5), probably explained by the highest ever number of juveniles (age 3) ringed in 2017, many of which have survived over winter.

Fig 14. Robin captures by age 2012 -2018

Fig 14 shows a big fall of both juvenile (age 3J) and birds hatched before current calendar year (age 4) in 2018, but in a good number of juveniles (age 3) caught. This may be as a result of us being unable to ring in suitable breeding habitat for Robins. Much of the areas lost to development were scrubby areas with good cover of brambles and other dense foliage, so it may be that we were unable to catch these birds soon after they had fledged, but once dispersed, caught them in other parts of the business park.

Fig 15. New birds ringed 2012-18

We have now ringed over 4,000 new birds of 40 species (Fig 11) since 2012, adding our first Jackdaw and Brambling to the total in 2018.

Brambling

Fig 16. Re-traps by year 2012-18

Great Spotted Woodpecker Juv

Species % Retrap Fig 17 shows % of retraps from new birds ringed over Blackbird 5.71% the period 2012-18. Whilst this is a fairly basic Blackcap 9.09% analysis, the higher numbers demonstrate those Blue Tit 47.36% species we are likely to retrap, and are usually year Bullfinch 23.08% Chaffinch 7.84% round residents or, where the number of birds ringed Chiffchaff 10.20% is very small, confined to a particular area or habitat Coal Tit 18.18% e.g. pond, such as Reed Warbler. Dunnock 32.91% Goldcrest 11.11% Some birds, such as Long-tailed Tit, spend much of Goldfinch 1.34% their life-cycle in flocks so, if we catch one, we Great Spotted Woodpecker 97.56% generally tend to get a group of them in one go. Great Tit 74.64% Greenfinch 2.26% Many of the commoner species, such as Blue & Great Lesser Redpoll 1.24% Long-tailed Tit 100.00% Tit, don't travel far throughout the year, so some Nuthatch 37.50% individuals are caught lots of times (Great Tit Reed Bunting 32.00% NY63779 has been retrapped 7 times during 2017- Reed Warbler 56.90% 18). Robin 24.48% Sedge Warbler 35.71% Goldfinch is very interesting in that we have only had Song Thrush 8.33% 2 retraps from 149 birds during this period, and one Treecreeper 18.18% of those was a bird initially ringed in 2015 (see Fig Whitethroat 17.86% 18). Perhaps they are birds which continually roam? Willow Warbler 20.51% We have observed this at other sites too. Wren 13.75%

Fig 17. % of Re-trap to new birds ringed 2012 - 18

RING Fig 18 shows some of the more Date NO SPNAME RTYPE AGE SEX noteable retraps in 2018. 05/04/2014 LC80917 Great Spotted Woodpecker New 5 M Great Spotted Woodpeckers 22/01/2015 LC80917 Great Spotted Woodpecker Retrap 4 M have a good recapture rate, 10/05/2017 LC80917 Great Spotted Woodpecker Retrap 6 M and all 5 new birds ringed in 14/04/2018 LC80917 Great Spotted Woodpecker Retrap 6 M 2018 were juveniles, which No of days 1470 suggests all adults in our catching area are now ringed. 25/10/2014 Z109891 Great Tit New 3 F 01/11/2014 Z109891 Great Tit Retrap 3 F It is also interesting that whilst 25/01/2015 Z109891 Great Tit Retrap 5 F some birds are caught on a 28/12/2016 Z109891 Great Tit Retrap 4 F regular basis, Great Tit Z109891 14/04/2017 Z109891 Great Tit Retrap 6 F has only been caught once each year, and Blue Tit 08/04/2018 Z109891 Great Tit Retrap 6 F Z279448 escaped recapture for No of days 1261 nearly 3 years (both Fig 18).

11/08/2015 Z279448 Blue Tit New 3J 16/08/2015 Z279448 Blue Tit Retrap 3J 24/11/2018 Z279448 Blue Tit Retrap 4 No of days 1201

31/10/2015 Z898378 Goldfinch New 3 F 08/04/2018 Z898378 Goldfinch Retrap 6 F No of days 890

Fig 18. Detail of selected Re-traps 2018

In addition to the above data, we also observe many species which are difficult to catch, such as Buzzard, Kestrel, Grey Heron and Common Snipe. The latter is a good example of a species which can be present in good numbers over the winter months - indeed in December 2018, 70+ birds were counted near the Arup building. They were observed on some rough ground, and up to 30 were observed on other occasions.

Even with the moderate number of nestboxes monitored at Blythe, it is still possible to see developing trends, as previously described. Whilst it may be difficult to establish local trends for those species where a limited number of birds are caught, all data collected locally is electronically submitted to the BTO, who then collate similar data from ringers all over the UK, making this available for further research and investigation. This data is vital to conservation, as it forms the backbone to many of the studies/reports on populations and trends released by Government and other bodies, and is also widely available for use in further research.

The BTO is an independent charitable research institute combining professional and citizen science, aimed at using evidence of change in wildlife populations, particularly birds, to inform the public, opinion-formers and environmental policy and decision makers.

Despite the obvious importance of collecting this data, the majority of effort is dependent on volunteers, whether through ringing, Garden Birdwatch, Breeding or Waterway Bird Surveys or via apps, such as Birdtrack. A total of 182 hours of ringing was undertaken by the ringing team in 2018.

Nuthatch

I would like to thank all the ringers who give up many hours of their time, Humphrey and his nest-box team, Jon Saddler (for graphics), everyone on Security, and Blythe Valley Management for providing the funding for rings, equipment and bird food throughout the year.