The first day of Spring (well, maybe) and a bit about Female Birdsong

On Sunday I cycled out to Guisborough Forest - a Forestry England site about 8 and a half kilometres south-east of my house as the Crow (or indeed the Jackdaw, Rook or Raven) flies. This involved riding up the vicious hill called Ormesby Bank (erm, well to be honest I pushed the bike up at least half of it) and then going along the fairly busy A171 Whitby Road which was a bit hairy in places  (although there is now an off-road cycle track for about half of the stretch I was on). 

The distinctive shape of Roseberry Topping, a sandstone outcrop
south of Middlesbrough, was visible for most of my journey

However, despite these hardships, I really enjoyed the journey. It felt like the first day of spring - warm and sunny with lots of birds singing. Almost as soon as I left the house I started hearing Robins, Dunnocks and Blue Tits warbling and chattering away. Then, while having a rest halfway up Ormesby Bank, I heard the descending wheeeze  that is Greenfinch song, followed by the "fast bowler's run-up and delivery" of a male Chaffinch and the repetitive teacher, teacher, teacher of a Great Tit. Just past the Cross Keys Inn on the A171 the ethereal song of a Skylark drifted down from the heavens - amazingly still audible over the pretty constant traffic noise. I didn't hear my first Blackbirds and Wrens of the day until turning off the main road just  before I arrived at the car park and visitor centre, where I locked up my bike.

The area around the visitor centre was very crowded with people, and quite noisy, so at the earliest opportunity I got on to the little footpaths going uphill and once again I was surrounded by singing birds. As well as more Robins, Chaffinches, and Dunnocks there were a couple of Song Thrushes (each lovely flutey phrase repeated two or three times before moving onto the next one) and lots of Coal Tits, particularly in the areas dominated by coniferous trees. Coal Tit song sounds (to me anyway) very like a Great Tit but more slurred and not as ringing. 

Although some of the bird noises described above might not seem very musical to you, they all qualify as birdsong and are used by the singers to attract mates, establish territories and ward off rivals. Like many birdwatchers I grew up thinking that singing birds were always, or nearly always, males of the species. In recent years however, work by ornithologists from across the world, (aided by a larger group of citizen-scientists sending in recordings) has shown that, far from being a rare event, it is actually quite common for female birds to sing, particularly in the tropics. This might be one of the reasons why it has taken us so long to notice female birdsong. 

Until the early 21st Century, most research into birdsong had been done in temperate regions of the northern hemisphere. In these places the harsh winters mean that songbirds breed only in the spring and summer, and so have to set up breeding territories every year. In addition many species are migrants that race north in the spring to their breeding areas, having spent the winter in the tropics. The males often arrive first and compete with each other to set up territories - which they do by singing their hearts out. The females then arrive and choose the male with the most elaborate song (which, presumably, indicates that he has been able to find a good territory, fend off other males while still having time and energy to waste on singing). This leads, over successive generations, to male song becoming more and more elaborate.

In the tropics it's a different story. Many species breed year round, with no discernible breeding season, and may keep the same mate and territory for several years. In these circumstances it is possible that birds sing for different reasons than in temperate or arctic zones, and that this might explain why the ladies, in some cases at least, sing much as the chaps. To find out more about this fascinating aspect of bird behaviour, or if you are just confused by my explanation, visit the Female Birdsong Project's website (The Female Birdsong Project) to find out more. You can even contribute to the project, if you see a female bird singing.

Although I didn't notice any females singing at Guisborough on Sunday, I did have an experience with this in August last year when I saw two Linnets, a male and a female, singing together for several minutes near my home - I wrote about this in my blog at the time (Linnet pair singing together). That blog post includes a bit of video in which you can hear the song, although the birds are just dots in the film. I do remember that when I was watching them through my binoculars I could definitely see that both birds were singing and not just the male.

Anyway, back to Sunday's trip. As well as all the birdsong, plus a Great-spotted Woodpecker drumming (its equivalent of a song), I saw and heard two or three small twittering flocks of Siskins at the tops of some tall alders. I searched in vain for Redpolls (another small finch about the same size as a Siskin) but did add three species to my NMT list for the year - Rook, Treecreeper and Goldcrest (nos. 80, 81 & 82) - all common species that I was surprised not to have seen yet. 

I also saw several flocks of Common Gulls in the fields next to the road - a sure sign that spring isn't quite here yet, as this species is only a winter visitor in these parts. In the next few weeks they will be dispersing to their nesting areas, mostly north of here.  

Common Gull often goes unnoticed among flocks of its noisier, better known,
cousins, Black-headed and Herring Gulls. It is midway in size between the
two and, unlike either of those species has greeny-yellow legs, feet and bill.