Friday, 26 October 2012

Redwing Migration

I have been following the growing interest in monitoring birds migrating at night by making long running sound recordings and analysing the resulting sound files to see what species called while flying overhead. "Vis-mig" is fascinating and this has been a great week for it with ideal weather setting up perfect "fall" conditions on the east coast.  Huge numbers of thrushes and finches have been on the move with over 21,100 Redwing, 9345 Fieldfare and 2675 Brambling recorded at Spurn on Monday 22nd alone!  I had heard some Redwings flying over the house earlier in the week and thought it would be a good time to experiment to see what I could record.

I left a portable recorder with a built in microphone and a 4gb memory card outside in the garden for the evening.  The batteries went flat after about 4 hours but not before a 2gb sound file had been recorded. The file covered the period between 17:20 - 21:00 and using a freely available software program called Audacity I reviewed the file.  Audacity can display the spectrogram of the file which shows a picture of the sound by graphing sound frequency against time.

The picture below shows the call of a migrating Redwing flying over the house.  The red pattern at the bottom is low frequency background noise.  The Redwing call is the down-sloping red line between 8 and 6 khz. (I used another freely available program called Raven Lite available from Cornell Labs to print the spectorgram)
Redwing spectrogram recorded 25th October, Mellor, Lancashire
There were 25 Redwing calls recorded in the file over a three hour period as well as a Tawny Owl and some as yet unidentified sounds, some of which I think are high-pitched mammal sounds - such as mice and shrews - but some are other birds.

This is my first ever attempt at recording night migrating birds and my equipment and techniques will need some tweaking to improve the quality of the recordings, but i am more than happy with the first night's results.  Ultimately I'd like some way of automatically processing the large files to pinpoint the high-frequency sounds for further investigation.  Some programs have been developed to automatically identify certain American birds, so it would be interesting to see what's available for European migrants.

Thursday, 25 October 2012


It's been a good week in the garden bird-wise.  On Sunday I heard and then briefly saw a Brambling.  Unfortunately, I didn't get great views as it flew up into the tall Ash tree and was in silhouette against the setting Sun.  Nonetheless, it was the first Brambling of the year and a new bird for the garden.  Then on Tuesday, while sat at my desk, staring out of the window for inspiration I saw a Redwing fly into the beech tree at the bottom of the garden where it stayed for few seconds before flying off.  This caused me to pay at bit more attention to the activity around the feeders where there was the usual assemblage of common birds as well as...another Brambling! This one (if it was a different one) stayed around for a while and I took some respectable record shots of it.
Male Brambling, Mellor, Lancashire, 23 October 2012
Other interesting stuff in the garden this week included Tawny Owl, Sparrowhawk and Woodmouse.

Friday, 19 October 2012

Letter to Nigel Evans MP re: The Badger Cull

Letter to my MP Nigel Evans regarding the Badger Cull and upcoming debate in parliament on October 25th 2012.

Dear Mr Evans,

Over 100,000 people, myself included, have signed a petition that has resulted in the proposed pilot Badger Cull being given a parliamentary debate on 25th October 2012.  This is the first time the Badger Cull has been debated in parliament and is an opportunity for the government to by held to account for what is evidently a mistaken policy.

I am strongly opposed to the cull for the reasons below, however I must first state that my view is based on the science and economics and not in sentiment or emotion.

1. The scientific evidence does not support a badger cull. The final report of the independent scientific group on Cattle TB which conducted the Randomised Badger Culling Trials made the following conclusions and recommendations in 2007:

1. On the basis of our careful review of all currently available evidence, we conclude 
that badger culling is unlikely to contribute positively, or cost effectively, to the control of 
cattle TB in Britain (10.48 and 10.92).
2. We  conclude that there is substantial scope for improvement of control of the 
disease through the application of heightened control measures directly targeting cattle. 
Therefore, we recommend that priority should be given to developing policies based on 
more rigorous application of control measures to cattle, in the absence of badger culling 
(10.57 and 10.93).

2. Indeed there is strong belief in the scientific community that badger culling may make TB in cattle worse

3. The cull will not provide value for money for the taxpayer either and the costs of the cull will exceed the benefits to the farmers:

4. The government is on the wrong side of public opinion as shown by this recent poll and risks losing credibility in its wider environmental policy (remember this is supposed to be the greenest government ever).

5. Vaccination is the only long term solution to control Bovine TB in Badgers and thus reduce transmission to cattle and is being successfully trialled in several locations including Wales and Cheshire, although it is too early yet to observe any results.

Bovine TB is a serious issue and is devastating to the farmers whose cattle are affected by it.  Both they and the public deserve that government takes the issue seriously and gets the policy right.  Unfortunately, the government has chosen a policy that will fail to make any long term impact on TB rates in cattle, waste tax-payers money, give farmers false hope of a solution, divide communities in the areas where culling will take place, and cause unnecessary destruction of, and distress to, badgers.

The cull is a mistake. The debate in parliament on Thursday, which has cross-party as well as public support, is a opportunity for the government to reassess the evidence, stop the cull, and consider the more appropriate alternative of vaccination.


Steve Flynn