Bird nerd part 13: Big Garden Birdwatch 2016: where were they all?

Last weekend was the RSPB’s annual Big Garden Birdwatch, where hundreds of thousands of people around the country spend an hour recording the birds that visit their garden or park. Bird nerd that I am, of course I took part. But my sightings this year were far from impressive.

I didn’t get off to a good start. Sunday was a damp, blustery day. The sort of day when I see far fewer birds than normal. And Jazz, our neighbour’s cat, spent the first 20 minutes sitting under the buddleia, getting into the birdwatching spirit. Not helpful. Dr C offered to chase him off, but I demured – the count is not a competition, it’s trying to get reasonably representative snapshot. As Jazz spends quite a bit of time lurking in our garden, I figured his presence was fairly typical.

Still, I was relieved when he disappeared under the fence. No birds were foolish enough to visit the garden with him around (the pigeon feathers on our lawn hint at what happens to foolish birds). And it would just be embarrassing not to see any birds.

The timer sped on, and my concern increased. Finally, I heard a robin. Heard him, but couldn’t see him. Then eventually he showed himself. I could put something down on my list. Sadly he remained the sole avian visitor to our garden that hour – a big contrast with my results in 2014.

We have been seeing far fewer birds than usual for this time of year. I think that might be because of the mild weather we’ve had so far. Those that do visit the garden seem uninterested in the seeds, suet pellets and mealworms we put out, preferring the ivy berries. In recent weeks I’ve been recording around 5 species a day – about half what I usually expect in January.

Hopefully this means that the birds are finding plentiful food elsewhere, rather than a dramatic decline in the bird population. Data from the BTO’s Garden Birdwatch survey (collected every week, rather than once a year) will give us a better idea of the impact of our weird winter weather beyond the boundaries of my garden.

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Barn owl numbers plummet

Battle to save barn owls after freak weather kills thousands

A few weeks ago I wrote about the plight of barn owls in the UK. This article in the Guardian sums up the situation well.  Apparently it is not just in the UK that barn owls are struggling. The figures are deeply disturbing. Let’s hope that this winter is kinder to barn owls.

The Barn Owl Trust have come up with a list of 10 ways to encourage barn owls, some of which even town dwellers like me can do. Do have a look and think about how you can help these iconic birds.

Related articles

• Battle to save barn owl after freak weather kills thousands (theguardian.com)
• Barn owls vanishing
• One of our barn owls is missing (naturegirl)

Barn Owls vanishing

Last month I was staggered to learn how bad things are for barn owls. According to the Barn Owl Trust, this year there are fewer barn owls in Britain than there have ever been. On top of this, the poor spring has meant that there have been fewer young successfully reared than usual.

Barn owls are instantly recognisable, iconic birds. When flying they are large, ghost-like white shapes in the gloom. Perched on a fence post they are neat, heart-faced birds. Their shriek is startling (no polite hoot for them).

Until I went to a talk by the Barn Owl Trust, I’d always assumed that barn owls were doing ok. I’ve had many encounters with them, both in Devon and Hampshire. But thinking about it, I don’t remember seeing any ever in Surrey, nor anywhere else in the last 2-3 years. This is very sad.

There has been a long-term decline in the numbers of barn owls in Britain since the 1930s. Barn owls are farmland birds. While, back in the 1930s, pretty much every farm had a barn owl, now only one farm in 75 is home to a barn owl. This long-term decline is probably largely due to changes in farming practices, with more grassland being intensively grazed, and silage cut twice a year, rather than grass being left to dry into hay. This has reduced the habitat for the small mammals (voles and mice) that make up the barn owl’s diet.

The number of suitable nesting sites (barns, as the name suggests) has also declined dramatically, with many barn conversions not leaving room for barn owls, and new farm buildings often not providing suitable space and access.

Poisons used to kill rodents may also be a threat to barn owls, although the evidence on this is still sketchy. What is known is that more than 90% of dead barn owls studied in 2012 contained rodent poison. What effect this has on the owls is unclear, but with exposure being so common, any problems these poisons do cause would be a large-scale threat.

On top of this long-term decline, the weather in Britain in the last few years has not been good for barn owls. Heavy snows mean the owls can’t hunt so well, meaning more die of starvation. And the poor spring this year has meant breeding has been less successful than usual.

The Barn Owl Trust is working to preserve these beautiful birds. If you would like more information about barn owl boxes, rodenticides or anything else barn owl related, I suggest you look at their website.

Kingfisher glimpses

I’ve just got back from a lovely week staying on the banks of the River Otter, in my homeland of Devon. While I’m secretly a little disappointed not to see any of the river’s namesake (not that I expected to), I’m delighted that I got some glimpses of that jewel among British birds, the kingfisher.

I’ve always found British kingfishers very elusive. While I’ve had good views of kingfishers in Africa and India, until a couple of years ago I’d never seen one in this country. Last week I was able to see a kingfisher several times. There’s something magical about seeing a flash of electric blue dart past. In my view they are the most beautiful birds this country is home to.

It’s been my ambition to get a good photo of a kingfisher for years. Sadly the kingfishers were not very cooperative, preferring to perch in trees that still had plenty of leaves to obscure them. I didn’t have the patience (nor the thermal layers) to wait in the near freezing temperatures for the perfect shot. But I would love to return in spring, when they will be busy fishing to feed their young, and the weather might be slightly kinder to a keen but warmth-loving photographer.

So, in the absence of a decent photo of a kingfisher by me, I can only suggest you have a look at these beautiful watercolour images of kingfishers by the wonderfully talented painter Jean Haines. Details of where you can see her work can be found on her website.

Related articles

• A miracle at the Kingfisher nest. (parrotletsuk.typepad.com)
• Kingfishers nesting on a nearby river. (parrotletsuk.typepad.com)

Fascinating wildlife fact #1: House sparrow’s beaks

Male house sparrow’s beaks are black during the breeding season, but turn yellow by the end of the breeding season.

Related articles

• House sparrow explosion (wildsouthuk.wordpress.com)

Bird Nerd part 3: feeding habits

As I mentioned in my last bird nerd post, I have quite a lot of data on the birds that visit my garden, and am keen to hear ideas for questions I could look at with it. Someone suggested that it might be worth looking at whether birds with similar feeding habits have similar patterns of visits over the year. So I gave it a go.

First I tried to work out how I could group my avian visitors, and settled on the following categories:

• those that feed from the seed feeder (house sparrows, great tits, chaffinches)
• those that feed from the suet pellet feeder (blue tits, coal tits, black caps, long-tailed tits)
• those that eat seed from the table (wood pigeons, collared doves, feral pigeons)
• those that eat suet pellets or mealworms from the table (starlings, magpies, jackdaws, crows)
• those that feed from the ground / other sources (blackbirds, song thrushes, pied wagtails, wren, dunnock, robin)

Of course there is a certain amount of overlap. For example, sparrows and bluetits will feed from both the seed feeder and suet pellet feeder, but do seem to have preferences.

I then created some simple line charts, using the average number of each species seen per observation day for each month of the year, based on data from June 2012 – May 2013. Here are the charts.

 

For most of them it looks like the average number seen per observation day is independent of feeding habits. But there may be some relationship for those that feed from the ground or suet pellets or mealworms from the table.

The patterns are unlikely to be driven by changes in the availability of food in my garden, as this is broadly steady throughout the year. However it could be linked to the availability of other food sources beyond my garden. It may be that birds in this category are more influenced by the weather than the other categories, so fluctuations are more in line with each other.

It’s not conclusive evidence, but it’s an interesting hypothesis. When I have time I will use data from the whole 3 years to draw up scatter plots for pairs of birds whose average numbers seem correlated. Can you think of other ways I should test for a relationship? Are there any other questions you think I should look at?

Related articles

• To Feed or Not to Feed? (theecotoneexchange.com)
• Bird nerd part 1
• Bird nerd part 2

Bird nerd part 2: summary stats

So, having collected all this lovely data, what do I know about the birds that visit my garden? Here are some summary stats from the last three years of data collection.

• In 2010-11 I saw on average 7 different species per observation day. In 2011-12 this went down to 6, and in 2012-13 it went up to 8.
• In 2010-11 I saw on average 14 individual birds per observation day. In 2011-12 that went down to 12, and in 2012-13 it went up to 15.
• These averages hide quite a bit of seasonal variation: September is generally pretty quiet, while the bird table is unsurprisingly busy in December and January.
• The most regular avian visitors to the garden were: bluetits in 2010-11, being seen on 55 out of 64 observation days, starlings in 2011-12, being seen on 35 out of 43 observation days, and woodpigeons in 2012-13, with only one observation day out of 44 when they didn’t make an appearance.
• The most numerous visitors to the garden were starlings by far (which won’t surprise anyone who has seen hoardes of them descend on a bird table), although in the last year house sparrows have almost managed to catch them up.

  

  Bluetit gathering nesting material

Changes in which species visit over time

As I mentioned in the first ‘Bird nerd’ post, altogether I’ve seen 26 different species of bird in the garden, although never all in the same year. In 2010-11 I saw blackcaps on 15 observation days (in the winter), but only once in 2011-12 and once in August 2012-13 (which is a shame, as they are pretty birds).

There have been no records of jays since 2010-11, but even then they were not frequent visitors. Other birds missing in 2012-13 that I have seen (infrequently) in other years include crows, greenfinches and siskins.

On the bright side, in 2012-13 I saw chaffinches and some kind of warbler for the first time. It’s quite encouraging that 4 years after moving here we’re still spotting new species.

Future analysis to be done

The few stats I’ve presented here are only the tip of the iceberg in terms of what I could examine from my data. One question I would like to look at is how the weather affects bird numbers. I’ve got very basic data on weather for most observation days, but only as far as whether it was sunny, snowy, rainy or overcast. Since we had solar panels installed last June I now have data on sunlight. My theory is we get more bird visits on sunny days than rainy or overcast (controlling for the month of the year), but we’ll see if the data supports that…

Let me know if there are any other questions you would like me to look at – for example, if you’re interested in a particular species or comparison over time…

Related articles

• Bird nerd part one: a confession (wildsouthuk.wordpress.com)

Amateur ecology

Over the last few years I’ve been doing quite a lot of reading about wildlife, as well as going on courses. One of the biggest surprises I’ve had is there’s so much we don’t know, even about some of our most familiar species. For example, we don’t really know what water voles do all winter, or where basking sharks go. Linked to the realisation of how much we don’t know about our wildlife, is the discovery that normal people, like you and me, can make a meaningful contribution to scientific research about wildlife.

The other day I read, in Hugh Warwick’s book The Beauty in the Beast, about Denis Summers-Smith. It was inspirational. Denis is a mechanical engineer and an amateur birdwatcher, who has written five books and over forty scientific papers on the house sparrow. He has discovered many things about house sparrows, including that they mate for life. And all this has been done in his spare time…

For those of us not quite ready to write a book based on our own discoveries, there are many citizen science projects that rely on the contributions of hundreds (or thousands) of volunteers to gather data from across the country. The commitment and expertise involved varies considerably.

For example, each year in January the RSPB run the Big Garden Birdwatch. Almost 590,000 people took part in it in 2013. This involves spending an hour counting the different types of birds that come into your garden on a specific weekend. From this, they can analyse the data from across the country, and spot any significant changes in the bird population. This is important to inform conservation work.

Many other organisations run similar surveys. This BBC Nature article contains a good list.

At the other end of the spectrum, the National Dormouse Monitoring Programme is rather more indepth, requiring trained and licensed volunteers to carry out box checks each month (except over winter). The data collected from this programme is providing new insights into these lovely creatures. At a dormouse conference I attended a couple of years ago, it was very exciting to hear scientific presentations based on data that I helped (in a very small way) to collect. We now know much more about this species than we did before the programme started.

Like many girls of my generation, I gave up studying science after I finished my GCSEs, despite getting my best grades in science and maths. I didn’t think science was for me. I didn’t realise how exciting science could be, and the range of things it could involve. It has been thrilling to learn, somewhat belatedly, that science is for me, and I can contribute to finding answers to questions about our native wildlife. These answers may help us better protect our beautiful and vulnerable creatures, for this generation and those to come.

Related articles

• House sparrow decline stabilises, figures show (theguardian.com)
• Profile: dormice (the cutest creatures in existence?) (wildsouthuk.wordpress.com)
• No PhD Required: Science Goes Grassroots (techonomy.com)

House sparrow explosion

House sparrows have been fairly regular visitors to our garden. We see them all year round, with an average number of 3 per observation day. But in the last few weeks the sparrow population in our garden seems to have exploded. Before September this year, the most we’ve seen at one time was 9. Now there are more than I can count (they keep moving!).

They’ve been hanging around our garden quite a bit, and getting through the bird seed faster than I’ve ever seen before. I’ve no idea why we have had the sudden increase. In previous years there hasn’t been a large increase in numbers around this time of year.  Perhaps they’ve had a particularly good breeding year?

They’re not the most spectacular of birds, but it’s great to see so many of them, as their numbers have plummeted in recent years. In the 1970s there were around 12 million pairs in the UK. Now there are between 6-7 million pairs. The good news is, data from the British Trust for Ornithology suggests that the decline has stabilised. Now we just need to work out how to help them recover.

Earlier this year we installed a sparrow terrace (to try and tempt them away from our gutters as a nest site). The boxes weren’t used this year, but hopefully some of our new visitors will decide they’re a good nest spot for next year. I’ll let you know!

Have you noticed anything similar in your garden?

Related articles

• House sparrow decline stabilises, figures show (theguardian.com)

Bird nerd part one: a confession

I have a confession to make. I am the garden bird equivalent of a trainspotter. For the last three years I have not only been watching birds in my garden, but recording details of the numbers of individuals of each species I see.

Each day that I work from home I keep an eye (and ear) out for birds in the garden, and record the maximum number of individuals seen at the same time from each species. Over the last 3 years I have clocked up 153 days worth of observations, and lots of completed forms.

Some of the completed forms…

While I appreciate that this makes me seem slightly obsessive and sad, it also means I have lots of lovely data to play with. This allows me to monitor trends over time, and see how changes in the garden, weather and seasons affect my feathered visitors.

This behaviour came as a surprise to me. I’ve always considered myself more of a mammal person than a bird fan. I saw birds as nice, but a bit dull (unless they were spectacular kingfishers or powerful birds of prey).

Then we moved house and got a garden. I don’t know when I changed my mind, but soon after moving we installed the bird feeding station, and waited for our first feathered visitors. And waited. And waited.

We had to wait almost a month before we saw the first bird in our garden. Our first visitors were a pair of collared doves. Then more and more types of birds started visiting. Something clicked, and I realised that the garden birds were wild creatures I could watch from the comfort of my own home. And they had their own characteristics. And I could watch real life mini dramas being played out in front of me.

I’m still not sure where the urge to obsessively keep records comes from. I think it must be from working with statisticians for too long. And the transformation is not complete – real twitchers wouldn’t consider me as one of their own. I don’t travel the country in the hope of seeing a rare small brown bird. I’d still choose a glimpse of otter or badger over the rarest of feathered migrants any day.

But I do enjoy watching the birds in the garden. Observing a species we’ve never seen in the garden before makes my day.

Having got that confession out of the way, I’ll try and share some of my observations with you in future posts…