North Cornwall Barn Owl Ringing 2020

As a licenced bird ringer it is imperative that I take a scientific approach and ensure that my activities are done with some validity and structure to ensure that the data that I obtain is of significant substance, either locally or nationally and in the ideal situation, both. I feel that in most instances I tick all the boxes; carrying out constant effort ringing in the summer months to monitor some of Cornwall’s breeding birds and also by helping out at the monumental site that is Nanjizal, where a large volume of migrating birds pass through each autumn. However, there is a particular species that I cannot help but get all doughy eyed over and feel immense privilege and joy when surveying.

The Barn Owl has to be one of the most iconic and loved birds of the British Isles and indeed further afield. Its ethereal presence has captivated the hearts and souls of so many Britons for centuries. Yet for such a captivating species it has undergone some worrying strife. In 1932 the British population of Barn Owls was estimated to be around 12,000 and even this was a substantial drop in numbers from what was once Britain's commonest owl. A further survey was undertaken between 1982-1985 and concluded that there were approximately 4500 pairs breeding in Britain. Seeing a further decline of 67%! This prompted it to be amber rated in the list of Birds of Conservation Concern having had a moderate (25-49%) decline in the UK breeding population or range over the previous 25 years. In addition, it was assigned a Schedule 1 status and special protection. Under the Wildlife and Countryside Act 1981 as amended by the Environmental Protection Act 1990, it is an offence, liable to special penalty, to intentionally disturb any wild bird included in the Schedule while it is building a nest or is in, on, or near a nest containing eggs or young or to disturb dependent young of such a bird. As with so many British birds, the main reason for decline seemed to be the decimation of natural nesting locations and the ever-changing countryside and suitable hunting habitat. Traditional sites in old farm buildings have also been lost as barns have been converted to other use including residential occupation or have simply been allowed to deteriorate until they collapsed or were demolished. 

It is important to monitor this species in order that the current population levels can be assessed to determine whether any further declines have occurred. West Cornwall Ringing Group participate in a national project that is coordinated by the British Trust for Ornithology to provide ongoing assessments of the UK Barn Owl population. Monitoring consists of a visit to the nest site by specially trained and licensed bird ringers in the breeding season, where details of occupancy rates, breeding performance and survival are recorded, and any young are ringed with uniquely numbered leg rings. To find out more about ringing in general please visit: BTO Ringing Scheme

2020 Monitoring Results 

Monitoring a north Cornwall Barn Owl Box.

Over 100 nest boxes are currently surveyed across Cornwall and I have slowly started to assist in growing the number of sites monitored in the north of the county. In 2020 a further 7 boxes were added to the North Cornwall monitoring list. Sadly due to the Covid-19 lock down I was unable to do any early monitoring, so egg clutch sizes were not recorded during this period. However, early brood sizes were obtained so I was still able to produce some important nest record data nonetheless. I was interested to compare this years data with last seasons and noted that the average brood size was very similar to that of 2019.     

Adults Ringed

             

A distinct lack of adults were processed during 2020 by me! This was partially down to the late initial checking dates but also some alteration was needed in the catching technique. However, I was pleased to add 2 adult females and an adult male to the scheme. I am hopeful that I might encounter these again in the future. 

Chicks Ringed

         

 

I had heard from other Owl ringers across the UK that it was going to be a pretty dire year for the productivity of the species as they were finding many nests unoccupied. However, Cornwall seemed to have bucked the trend and it appears we had a bumper crop of juvenile Barn Owls! Of the 10 boxes occupied 32 chicks were ringed. The largest clutch being 5, but the majority having clutches of 3 and 4 birds and all looking very health and likely to fledge. Interestingly, birds that chose to lay eggs later did not appear to be as successful; only producing 1 or 2 fledglings. This was most likely due to the atrocious weather we had here in Cornwall that was almost consistent through the whole of June!

I am looking forward to seeing how the Barn Owls fared across the rest of the county and indeed the rest of the UK during 2020. I know there are a couple of boxes with some breeding activity still occurring within Cornwall, but will be checking the ringing groups web page with regularity for the final outcome. If you wish to do the same then please keep an eye on here: West Cornwall Ringing Group

Over the past couple of seasons I have also had the upmost pleasure of attending many boxes with legendary photographer and naturalist Adrian Langdon. His photographic works speak volumes on his commitment and passion. Your eyes will be in for a real treat if you visit his blog spot found here: Images Naturally   

Lastly, it is always a real pleasure to witness the enthusiasm of those persons that grant permission for us to monitor boxes. There is none more so than those with cameras fitted to their boxes who get a real intimate showing of the trials and tribulations that the owls face. One of the nests that I monitor has such a device and it makes for some pretty addictive viewing. To watch how this family group has fared this year then please grab a hot beverage, put your feet up and take a look here: Mike and Molly the North Cornwall Barn Owls    

Sylvia's: Warbler Sound Quiz Answers

The answers to our Sylvia Warbler Quiz are now finally ready! Each species has a brief account on what makes it's song unique and there are also some handy tips if you would like to see and hear one of these stunning Sylvia Warblers for yourself. The rarer species in this quiz are all very possible finds for the intrepid birder in spring. Listening out for unfamiliar Sylvia song once your knowledge of the common species builds up will hopefully pay off one day with the birding find we all hope for. If you do ever find a rare Sylvia recording it's song and or calls is now an important part of the process of ID. Many portable recorders are now available from companies such as Tascam but it's surprising how good smart phones can be for this job. 

1) Eurasian Blackcap. The full song of Blackcap can be confusingly similar to Garden Warbler and it's varied subsong typically heard in short bursts early in the breeding season or on migration can include mimicry of other species. However there are always clues to it's identity. The main song is rather loud and has a rich fluty quality to the tune. It is delivered at a fast pace and the most distinctive part of the song is the ending which speeds up into a trilled whistle. Pretty much every Blackcap I've heard singing repeats this phrase eventually, even as part of it's sub-song. Blackcap is a common (seemingly increasing) summer migrant to the UK and can be heard singing from woodland, parkland and even large gardens. Winter visitors from the continent can also be heard singing on sunny late winter days in urban areas and from sheltered spots around the coast near to Ivy or Blackthorn. Try Goss Moor Nature reserve to test yourself with Blackcap and Garden Warbler in the summer months as they sing alongside each other. During winter Padstow, Pentewan and Gannel Estuary hold good numbers of birds that will sing their sub-song on milder sunny days.

2) Garden Warbler. The song of the Garden Warbler is one of my favourites of all bird song. At first it is difficult to separate from Blackcap in particular but once you familiarise yourself with it there are distinctive differences. The song has an even tempo and a richness which is very different to the more erratic song of Blackcap. The ending doesn't speed up and it doesn't have the fluty ending . For me it has the qualities of a Blackbird and a Skylark mixed together! Garden Warbler has a rather patchy distribution in Cornwall and is much scarcer than Blackcap, found close to moorland and in some sheltered valleys. It seems to prefer more open areas with scattered tree's than Blackcap. In conifer plantations it is usually found in young conifers alongside Tree Pipit and Willow Warbler whilst Blackcap tends to sing from the mature conifers alongside Chiffchaff. The top site in Cornwall is Goss Moor National Nature Reserve whilst it is also patchily distributed throughout Bodmin Moor.

3) Common Whitethroat. The typical song of Common Whitethroat is a series of four or five scratchy notes which is often repeated note for note whilst it sits on a prominent perch. It is a familiar summer sound in our countryside. However it's subsong can be confusing as it often sounds richer ,  more warbling in quality and noticeably varied with some mimicry. If you are patient and continue to listen a bird in sub song will eventually utter the more well known song phrase, usually at the end of the subsong. A male Common Whitethroat on territory will also burst into song flight which sounds like a fast paced, ramped up version of it's typical song, although lasting considerably longer before intervals as the bird hovers in the sky in a Pipit like fashion. It can be found throughout Cornwall in coastal locations and inland in mature hedgerows and road verges. My number one spot in Cornwall for this species would be Lands End were if you walk along the cycle track in early May there will be 20-30 birds singing from almost every thicket!

4) Lesser Whitethroat. The rattle of Lesser Whitethroat is one of my favourite summer sounds and it is surprising how far the noise can carry, several hundred yards from my experience. It sounds a bit like the beginning of a Chaffinch's song but is dryer and harsher in tone. If you get close enough to a singing male you will also be able to hear the much quieter start to the song which is a short, sweet and rather melodic warble. Males often set up territory in coastal valleys amongst Blackthorn scrub , moorland edges and mature hedgerows but it is a relatively scarce summer migrant and is always a nice find. Top sites in Cornwall include Porth Joke valley in mid to late May and Windmill Farm Nature Reserve on the Lizard Peninsular.

5) Spectacled Warbler. The song of Spectacled Warbler is perhaps a little softer in tone to my ear than it's Mediterranean counterparts (such as the Subalpine Warbler complex and Dartford Warbler). A rather whistley and sweet warble with a mournful quality (sounding a bit like Crested Lark) that is sang in short bursts at staggered intervals every 2-3 seconds. Spectacled Warbler is a rare vagrant to Britain with just nine accepted records by BBRC. However seven of these have been in spring and at least six of these have been singing males (including one on Dartmoor 3rd-6th June 1999). The likelihood of one eventually turning up in Cornwall is quite high in my opinion. They seem to like low gorse and saltmarsh habitat so one could turn up in any number of places in Spring but if I had to predict one site in Cornwall it would be along the Kynance road on the Lizard Peninsular or perhaps the cycle track at Lands End.

6) Dartford Warbler. This spritely Sylvia 's song is a rather monotonous dry sounding warble lasting around two seconds and usually repeated at regular intervals when it is delivering full song. The song isn't particularly complex and the rather low toned, harsh sounding notes lack the tuneful and melodic qualities of Spectacled and Subalpine and are closer to Sardinian Warbler in many ways. The male will often sing under cover but will briefly pop up onto the tops of Gorse in response to threats whilst a bird on territory will often sing from a prominent perch during the breeding season (typically March to June). It is a specialist of heathland and is our only sedentary Sylvia Warbler in the UK (meaning it doesn't tend to migrate and can be found throughout the year). In Cornwall it is rarer now than it was five years ago mainly due to the "beast from the east" of February 2018 and a succession of wet winters. It could possibly be found on coastal heath or inland on many of our moorland areas so long as there is an adequate amount of Gorse, it is a schedule 1 breeding bird so specific sites around the county cannot be disclosed but a trip to RSPB Arne in Dorset at almost any time of year would be productive.

7) Sardinian Warbler.  This rare vagrant is a particularly vocal Sylvia that utters distinctive dry (machine gun like!) calls seemingly whenever it moves and if you travel to the Mediterranean coast of Spain you will hear them almost constantly. The song however surprised me when I first heard it as it was much more musical than I was expecting. The harsh rattle like call notes are interspersed with a fairly basic loud yet sweet and melodic warble which lasts for around 3-5 seconds (typically longer in duration than other small Sylvia's) before being repeated. In a habit that reminds me a little of Common Whitethroat the warble gets even more melodic and tuneful when it alights into a song flight. When in song the male tends to sing from a conspicuous perch but it will also sing from deep cover and can be fairly skulky on migration. Cornwall has a good track record for this species with the last two records involving singing males from

The last three bird songs are from the recently split Subalpine Warbler complex. I have some field experience of all three species but it has been interesting for me to research and refresh my knowledge on how Eastern Subalpine, Western Subalpine and Moltonis Warbler can be identified and seperated by sound. Whilst my conclusions might be a bit amateurish compared to some of the birding sound guru's out there but I do believe that songs and particularly calls can help to identify a vagrant in the UK. Around 80% of Subalpine Warbler records relate to males so knowledge of songs and calls plus having a device to record them for later analysis is important.

8) Western Subalpine Warbler. 

Western Subalpine Warbler occurs within a large area encompassing North Africa (Tunisia to Morocco) and Western Europe (Iberia, southern France, and north-west Italy). It is a rare but annual vagrant to Britain in the Spring. This is potentially the most likely Subalpine Warbler to be found in Cornwall and they are generally annual in their occurrence. Any coastal site could turn up a Western Subalpine with Porthgwarra and Lands End in West Penwith and the Kynance area of the Lizard peninsular being good areas to search in April/May in Blackthorn. In comparison to Eastern and Moltoni's the song sounds slightly richer in quality and tends to have more variance and more complex warbling. The call is also a distinctive hard 'tack tack' which sounds rather dry (a bit like Lesser Whitethroat). 

9) Eastern Subalpine Warbler.

As the name suggests Eastern Subalpine breeds in Eastern Europe (north-east Italy, the Balkans & Greece) plus part of western Turkey. A further subspecies (Sylvia cantillans cantillans) breeds in parts of southern Italy and Sicily. It is rare vagrant to Britain typically in April and May. It is a rarer occurence in Cornwall than Western Subalpine but shares the same habitat niche and pattern of arrival so there will be more records to come in the future hopefully. The song of Eastern Subalpine reminds me a little of a Sardinian Warbler, the rapid song sounds harsher and dryer in tone and there is less variance and more repetition of notes. The call is very similar to Western but is slightly softer in quality: 'Trrrett' 'Trrett'.

10) Moltoni's Warbler.

The range of Moltoni's Warbler is much more restricted compared to it's two sister species; occuring in parts of central Italy, Corsica, Sandinia and the Balearic Islands. This is the rarest form of Subalpine Warbler to occur in Britain with eight accepted records, all have been in spring and seven have been males. Cornwall has yet to record an accepted record by BBRC but I believe a male which turned up at Porthgwarra in October 2014 was this species on plumage but sadly no sound recordings were obtained. However a male in spring 2016 on nearby Isles of Scilly was accepted so there is a good chance another will occur perhaps in west Cornwall. The song has a Common Whitethroat quality but has the speedy delivery of a Subalpine. It has a buzzy tone to the song, lacking perhaps the rich notes of a Western Subalpine but not sounding as harsh or dry as an Eastern, The call (which can be heard in the recording) however is the clincher for this species and is diagnostic; a buzzy Wren like trill which is completely different to the calls of Eastern and Western Subalpine.

A big thankyou to Gary Thoburn for allowing me to use his excellent photographs for this post

Warbler Sound Quiz Part 2: Sylvia Warblers

Eastern Subalpine Warbler - Gary Thoburn

For the second instalment of our sound quizzes we will be looking at the Sylvia Warbler family. In a UK context this familiar group of warblers are a mixture of long distance migrants, rare vagrants and a single resident. As we all know they can be skulky and difficult to view in their favoured habitat of dense vegetation and having the knowledge of their songs is a great time saver when counting breeding pairs on a local patch. Being aware of some of the rarer species songs will also one day hopefully pay off as rare Sylvia Warblers that turn up in spring have a tendency to be singing males.

Spectacled Warbler by Gary Thoburn

Some of the Sylvia's in this sound quiz have only recently been given full species status and it's been a learning curve for me producing this! As always I will post the answers shortly which will include a write up on each species song and explain what for me makes them distinctive and unique. I will also be including some sonograms in the answers for the more difficult species as recording bird song and analysing them on a computer has become a key part of sound recognition in birding and on a scientific level and has been something I'm getting to grips with myself since lockdown and I am not an expert but I feel it's part of the future of birding so hopefully you can learn with me along the way!

Common Whitethroat Paul Ash

We hope you enjoy the quiz! Click below on the ten questions to have a go.