Tuesday, 31 December 2013

End of Year Round Up

Well as another year draws to a close its only fitting that we say thank you and Happy New Year to those who have been helping with catching and re-sighting birds, publicising the project, or just reading the blog!

Our highlight of 2013 was reaching the 50 bird milestone! For a while it didn't seem like we'd make it! Although the birds haven't exactly been rolling in since then and we finish 2013 on a project total  of 56 birds; 29 of these being caught in 2013.

We had 99 re-captures/re-sightings of 22 individual birds in 2013 compared to a mere nine in 2012! A big thank you to Hattie Fuller, Ellie Brown and everyone who has contributed to these. We'll be looking to beat this number in 2014 so keep your eyes peeled and don't forget to tell us!
As you can see from the graph below there is a lot of variation in the number of times different individuals have been re-sighted. This will be in part down to the individual behaviour - its no surprise that A4 tops the chart as he is the most approachable bird we've ringed. Other highly visible birds were often on the avenue (e.g BX and BK) or easily recognised such as B6.

During 2014 we'll keep you up to date with the project's progress and news. 2014 will be on us in a matter of hours and the start of the breeding season hot on its heals. What will 2014 hold? Hopefully lots of blackbirds!

Happy New Year from the Cardiff Blackbird Project team!

We couldn't have a post without a picture of a blackbird could we?! Here is one
from the archives - our most approachable blackbird, A4

Sunday, 8 December 2013

Ringing in the changes

The number of blackbirds is building up nicely in the study site, particularly around the paddocks. So this is where we headed on Friday for the third catch of the winter. We were hoping for at least one new blackbird as the last two outings have drawn blanks.
We caught three males in quick succession while putting up the nets and while these were being processed we caught a further two birds! Our project total now stands at 55 and we'll hopefully increase this total over the coming weeks. The session's "by catch" was a surprise too, containing as it did two young magpies. Despite being a common bird, only 30 magpies were ring in Wales in 2012 and only 6 of these were caught in Glamorgan.

Three in a row! These males were the first of five new birds added to the
project. These three were in at least their second calendar year while the fourth
was one of this year's young. Our fifth bird was a female.
Friday's session was also the start of a new colour ringing scheme. We have been having some trouble with obtaining field sightings of the coded rings and so have begun using a conventional plain colour rings. Over the coming months we will be comparing which of the two techniques is most effective. Should you see blackbirds with either ring type then please let us know!

One of Friday's blackbirds ringed with conventional plain colour rings.
Hopefully these rings will increase the ease with which birds are resighted in
the field. We will keep you posted on the comparison.
A big thank you to Hattie, Ellie, Laura and Chrissie for helping with the session.

Thursday, 28 November 2013

The Tales of Four Travelling Blackbirds

During the winter, the UK's resident birds are joined by migrant birds arriving from the continent. You might notice the influx in your garden or where there are berry laden bushes. In fact the blackbird visiting your garden could well be a bird from the continent.

This is well illustrated by four birds from Pentrych, a small village on the outskirts of Cardiff. All four birds were ringed and later found dead by members of the public - usually having hit a window. All four show how well connected Europe's blackbirds are and it is interesting to see that they moved from urban area to urban area.

Our first bird is K994348, a first year female ringed in Zandvoort, The
Netherlands on 15th November 1998. 17 days late she was found dead in
Pentyrch on 2nd December.

RP48651 was ringed in March 1999 as a first year male. He didn't live long,
being found dead having hit a window in May of the same year. He had however
made all the way to the Swedish town of  Borlange.

CW34666 was ringed as first year male in February 2006. Just over eight months later
in November of the same year he was found dead in the Norwegian town of Egersund.  

LB34416 was an adult female ringed in Pentyrch just before Christmas in 2010.
She was found dead two years later having hit a window in the Dutch town
of Naaldwijk in November 2012

Robinson, R.A. & Clark, J.A.(2013) The Online Ringing Report: Bird ringing in Britain & Ireland in 2012 BTO, Thetford (http://www.bto.org/ringing-report, created on 15-August-2013)

Sunday, 10 November 2013

Winter Walk

This morning saw us out on one of our regular walks of the study site which are being done in line with the BTO's Winter Thrushes Survey to further increase the value of these sessions. We were joined by Hattie, a second year zoology student at Cardiff University, who will be volunteering on the project over the next few months to help with surveys and resightings.

Today's walked picked up several blackbirds but we were only able to read the ring code on one bird, BX (see map below). He was ringed on 5th December 2012 as an adult making him at least three years old. Where BX was seen today is his usual spot and its likely it is close to where he bred this year. The vast majority of the other blackbirds seen were unringed - we need to get out more!

The results of our mornings survey. B = blackbird (the yellow B is BX),
R = redwing (we saw 8), and MT = mistle thrush

Sunday, 3 November 2013

BK - the first retrap for the Autumn!

We headed out this week with the intention of adding some more birds to the project total. It was rather a dank morning and although there were plenty of "chooks" and "chucks" from our resident birds as the sun rose, sightings and movement were virtually non-existent. In two hours we managed to catch two birds; a robin and a blackbird. Both retraps!

Our retrap blackbird was BK - a female originally caught in mid October 2012. She was at in at least her second calendar year of life when caught, making her a minimum of three years old when caught this week.

 The green triangles (you might have to enlarge the image!) so the locations of where BK has been sighted since her original capture. She was caught within this area this week. Earlier in the year she was seen feeding a fledgling so it is like she nested somewhere close to the boundary between the allotments and the riding school

Sunday, 27 October 2013

Autumn restart

With summer well and truly over, blackbirds have finished their post breeding moult and are becoming more obvious in the study site. This time of year is a good for spotting first year males - they will have brown outer wings, unlike adults which are a uniform black. 

At this time of the year our resident blackbirds are also joined by birds from mainland Europe. These visitors are the same race (T. m. merula) as our resident birds. There is often great debate over whether male blackbirds with dark bills and eye rings are migrants from the continent or not. All first year male blackbirds will have these characteristics so they can not be relied on to determine the origins of these birds. However, at this time of year we do catch bird that differ in general size and feel different in the hand than "normal" and these could be migrant birds.
A winter visitor form the continent or a bird born locally late in the season? This
particular individual was noticeably smaller than would be expected compared to
birds we usually catch.
An easy to spot winter arrival whose numbers will be on the up in the next few weeks is the redwing. The BTO is looking for volunteers for its Winter Thrushes Survey which aims to map the distribution and work out the habitat needs of visiting fieldfares, redwings, mistle and song thrush and blackbirds. Were conducting the survey during our regular walks of the study site, although at the last visit we only recorded one redwing! We will keep you posted on our results but why not take part the survey yourself?

Saturday, 3 August 2013

Blackbirds Thin on the Ground

Despite AB and A4 putting in regular appearances recently, its becoming more difficult to re-sight our blackbirds simply because there are fewer blackbirds about! Only two blackbirds (including A4!) were seen during a walk around most of the study area yesterday.
The detectability of blackbirds (as can be seen from the BirdTrack graph below) declines as the summer progresses. At this time of year the birds begin to go through their annual moult; a time when they renew their plumage an the birds tend to skulk in the undergrowth, keeping themselves to themselves. Although this behaviour reduces their vulnerability to predation it of course makes them harder to see! 
Reporting rates of blackbirds reported to BirdTrack show the seasonal change in the 'detectability' of the species. 
The blue line shows the reporting rate for 2013 and the red line shows the average reporting rate for all previous years.

Thursday, 18 July 2013

Relaxing in the sun

It appears it isn't just us humans that are taking advantage of this current spell of fine weather. On Tuesday a ringed male (sadly we didn't see his code) was seen foraging along the avenue that runs down the centre of study site. Having consumed a worm he walked quickly to a bare spot, turned around before fattening himself on the ground with his wings outspread.

Blackbirds are known to "ant" where by they lie near an ants nest, allowing the ants to clean parasites off them. However, after the bird had flown off the area was check for ants but none were found. This male might have just been taking time out to relax in the sun; and who could blame him!
This male was either 'anting' or sunbathing, either way he appeared to be
enjoying  himself in the midday sun.

BK was also spotted, in fact she was the only bird who's code we were able to read despite there being several others! She seems to have had some success in the breeding stakes as she was seen feeding a rather large, and noisy, fledgling.
BK looking watchful as her youngster was not too far away.

Monday, 15 July 2013

50 at last!

The project finally reached the milestone of 50 Blackbirds! The latest addition, an adult female ringed HP, was caught this evening while we working on another project. Hopefully the next 50 won't take so long!

Judging by the size of here brood patch she is likely breeding
close by to where she was caught.

Sunday, 14 July 2013

Catch Up

We must apologise for the lack of updates of late; with a delayed spring and blustery  (and sometimes wet!) start to the summer fieldwork for the project has been sporadic.

Much of our time of late has been re-sighting birds we’ve ringed over the last year for the RAS element of the project. This is also allowing us to build a picture of how the birds use the park. Some birds seem to hold very distinct territories (or are at least seen in discrete areas) while others wander a little more. So far we’ve re-sighted over 25% of the birds ringed in the last year, several of which have been collecting worms or feeding very plump fledglings. If you see any colour-ringed blackbirds then please let us know!

While some birds, such as A4 seem to stick to a discrete area, others like AB
apparently like to wander about more. However, the picture is far from complete
and we would welcome more records from the allotments!

Ringing sessions ceased for a couple of months while the birds began to breed during a very cold and delayed spring. These sessions started up again recently and we have managed to add two more birds, both this year’s young, bringing the project total to 49 (47 of which are colour ringed). These sessions not only allowed us to catch up with birds we have not encountered so far during the breeding season but also provided some interesting “by-catch” in the form of a kingfisher and a lesser whitethroat.

A3 was the 10th bird ringed for the project and was recently
re-caught less than 100m from where he was originally ringed
last May.

Sunday, 14 April 2013

Signs of Spring

Despite the weather we've been out and about in the study area re-sighting birds. In the paddocks near the weir (the very east of the study site) we caught up with CH and a colour ringed male but we could not read his ring combination.  He is likely to be AS, who was ringed and seen there in the past. CH was ringed in January of this year at the allotment feeding station, making her a long distance mover in terms of this project!The metal ringed only male was seen again. However, he seems to have lost his tail since the last time we saw him. Perhaps he has had a narrow escape from a sparrowhawk, cat or been in a brawl? Or perhaps its an entirely different bird?!

A ringing session in the paddocks failed to catch the metal ringed male. Although we were unsuccessful on that front we did manage to add two new birds to the project, bringing our total of colour ringed birds to 45 (project total 47). We also managed to catch a  Mistle Thrush, only the second one we've caught, and two chiffchaffs which is a sure sign that spring has finally arrived.

Above: The projects latest recruits; HB and CD. Sadly we didn't catch the
metal ringed male. Below: Chiffchaffs, and their close relative the Willow
Warbler, are migrating through the study site at the moment. Some
individuals will breed there too.
Casual re-sightings of birds along the main avenue has also revealed another sign of spring when C3, an adult female, was seen adding to an already full beak of worms. She was seen flying off over a hedge into the Pontcanna Permanent Allotments where she is obviously feeding a hungry brood; a timely reminder that spring has sprung and that we should start nest recording pretty sharpish!

Monday, 1 April 2013

Have we met before?

On the whole the recent weather has not be conducive to catching birds but we have managed the odd session. The last resulted in four new birds for the project bring our total to 43 colour ringed birds and 45 birds ringed since the project started. Among the four new birds was a male with a white chin spot. Hopefully this will be as a useful aid to identifying this bird as B6's white spot.

The white chin patch of one of our new males.
We have of course been continuing with re-sighting already ringed birds. One surprise while trying to re-sight birds in the east of the study site was coming across the male pictured below. Although several blackbirds have been ringed in other parts of Cardiff, prior to the start of the project only a handful of blackbirds had been ringed on our site; and only one of these was male. If this is LB09234, he is doing well as he will be in his fifth calender year!
Is this LB09234?

Thursday, 14 March 2013

A Trio of Thrushes

We were out catching more blackbirds for the project this morning. There were plenty of un-ringed birds about and we managed to add another three to the project - two males and a female. We could only colour ring one (due to the rings breaking!) so we are now on 39 colour ringed birds and a project total of 41- niether is far from our target of 50 for the first year! We also re-caught AH and re-sighted A4.

Left to right: one of the new Blacbirds (DH), a Song Thrush and a Redwing
Among the other birds we caught were two other thrush species - a song thrush and a redwing. The latter is a winter visitor to the UK. They are famed for their night time migration and on  clear autumn and early winter nights you can often hear their faint "tseep" call as they pass overhead. Redwing are commonly seen in our study area during the winter and occassionally the odd fieldfare, anther winter thrush.

Tuesday, 12 March 2013

Spot the Difference

Catching new birds for the project has been put on hold recently due to the cold and windy weather of recent weeks. Instead we've been out re-sighting previously ringed birds. All our birds carry colour rings providing us with an essential way of identifying seemingly identical looking individuals.
Occasionally however, a bird will give you a helping hand by having a trait that tells them apart from the masses. For example A4, a male, is very tame and allows close approach which provides a clue to his identity. Some traits, such as plumage variations, are far more useful. Although male blackbirds live up to their name, every now and again one will have plumage that deviates from the norm of plain black. One such male is B6 who has a small white spot at the top of his left breast.
B6's white spot makes him easy to recognise in the field.
Plumage abnormalities can be caused by a number of reasons; genetics diet, injury, disease or even age. Where the cause is genetic the abnormal colouring will be consistent from one moult to the next. Abnormal colouring caused by environmental factors, such as diet, can often be reversible. Sometimes you will hear partially white birds referred to as a "partial albino" however this is incorrect - albinism is absolute, there being half way house. A bird is an albino or not.
Blackbirds are among the species most reported with abnormal feather growth. Whether this is because they are abundant and closely associated with humans or because they are just more prone to colour abnormalities is unknown. But research is under way on to the prevalence of abnormal plumaged birds in urban environments. The British Trust for Ornithology run an Abnormal Plumage Surveyand are asking people to report abnormally coloured birds they see in their garden.
Compared to some blackbirds, B6's plumage aberration is very slight but it is still very useful identifying mark, especially when he is feeding in long grass!

Sunday, 24 February 2013

Are you looking at me?!

A large part of the Blackbird project involves re-sighting birds we have previously caught. On our most recent visit we noticed that the birds' behaviour to our attentions can be different to that compared to their behaviour toward other park users.

Even though a walker, cyclist, jogger or even dog walker would pass by a few metres from them, the birds would move away calmly with a few hops towards cover, re-emerging only a few seconds later. However,  on a few occassions when we focussed scopes or binoculars on them, despite being 10m or so away, the birds would move towards cover with much more urgency sometimes flying to the nearest hedge or up into a tree. Surely, being further away, we represent far less of a threat?
The answer may lay in the results of a recent study published in the journal Ethology. Clucas and colleagues looked at how American Crows (Corvus brachyrhynchos) varied the urgency of escape and flight intitiation distance to approaches by humans with varying degrees of eye contact and facial expression.

Although the facial expression (smiling or scowling, sadly they didn't test frustration) of an approaching human had no affect on the crows behaviour, the amount of eye contact did. Crows moved away sooner and with more urgency when the human was gazing directly at them compared to when they averted their gaze. Such a response may represent an adaptation to living in urban areas with the crows using this visual cue to gauge the intention of onlookers.

While other park users may pay little attention to the blackbirds, we are directly gazing at them when trying to read their ring numbers. Perhaps some of them perceive the lenses of our binoculars or scopes as eyes, exaggerating the "gaze affect"?

With a little fieldcraft and patience we did manage to re-sight A4, B6, B4, AB,  BK and BD, not to mention several unringed birds! A4 in particular seems completely oblivious to our attentions and at one point stopped in front of us before resuming feeding a few metres away.

Here's looking at you: Intially some blackbirds are wary when the binoculars
 are focused on them, while others carry on feeding as normal.

Clucas, B., Marzluff, J. M., Mackovjak, D., Palmquist, I. (2013), Do American Crows Pay Attention to Human Gaze and Facial Expressions?. Ethology. doi: 10.1111/eth.12064

Sunday, 17 February 2013

Five new birds!

Two early morning visits to the park on Friday and Saturday resulted in the addition of five new birds to the project; three males and two female. This brings our project total to 37 marked birds. Our target of 50 before April 30th should be achievable!

Friday's catch very much exemplifies our data set as a whole, with males out numbering females 2:1. Watching the birds may have provided part of the answer; the males seem to blunder and bluster about the park, showing off to rivals and generally being boisterous towards the each other, whereas the females keep very much to themselves.
The three birds from Friday's catch with their new colour rings.
After each catching session we took sometime to catch up with already ringed birds, managing to re-sight A4, AB, AH BC, BB, BD, BX and BK. The latter two seem to have established a territory together on the border of the Llandaff Allotments and the muddy paddock to the south. Although she was not seen carrying any away, BK was seen picking up potential nest material so nest building in the park is imminent if not already in progress. If you see colour-ringed blackbirds in (or out!) of the park then please do let us know. You can find out how to submit sightings here.
BX (above) seems to have set up territory with the similarly coded female BK

Sunday, 10 February 2013

The Cardiff Blackbird Project

The Cardiff Blackbird Project was established in April 2012 to examine the ecology, behaviour and demography of urban birds using the blackbird as a model. The blackbird has many traits that make it ideal as a model species. It is a common species, making for large data sets. It is a relatively large species, meaning it is easy to observe. Blackbirds also wide spread which allows comparison between populations in different habitats and geographical scales.  Currently the study site for the project is the northern part of Pontcanna Fields in the area which includes the allotments and Cardiff Riding School.

View Larger Map
The project is based around developing a long-term monitoring programme, contributing to the British Trust for Ornithology’s (BTO) ‘Retrapping Adults for Survival’ scheme, on which a number of more detailed research projects examining blackbird ecology in a suburban environment will be based. The success of these projects relies on having a large population of individually marked birds that can be followed throughout the year. Unique plastic colour rings are fitted so that individuals can be recognised through binoculars/telescope, avoiding the need to capture birds multiple times.
Close up of a female blackbird showing the metal BTO ring and her Cardiff Blackbird
Project colour ring. CJ was ringed in January 2013
If you see a colour ringed blackbird we'd love to hear about it. You find out how to you can submit sightings here.