
Robin singing
Dear Readers, there is a very interesting article in my British Birds magazine this week, about the prevalence of song in female birds, and how understudied it is. I often use Xeno Canto for examples of bird song, but Mark Constantine and Lucy McRobert, the authors of the piece, point out that only 0.01% of the bird songs were labelled as ‘female’ back in 2016. However, Constantine and McRobert’s project, The Sound Approach, has recordings of female sounds for 41% of Western Palaearctic species. There seems to be an assumption that any bird that sings is a male, but this is increasingly being shown to be untrue.
Why do birds sing? It can be done to attract a mate, but it can also involve territorial defence (we know that when a territory-holding male blackbird ceases to sing for more than three days, another male is likely to move in), warning off rivals (the volume and complexity of song can give an indication of the aggression and size of the bird) and pair-bonding (many birds sing ‘duets’).
In Robins, for example, both male and female birds sing, with no difference in vocal performance between the male and female outside the breeding season – females are as adept at the complicated parts of the song as males are. Robins are intensely territorial throughout the year (though it reaches a peak in breeding season) – often a female and a male will hold adjoining territories that are combined when the time to pair off and nest arrives. The Sound Approach team are trying to gather more examples of female song, to see if there are differences in the sounds that can be used to identify the sex of the singer. As male and female Robins look identical, this could be useful in the field.
One interesting case is that of the Alpine Accentor (Prunella collaris), a close relative of our Dunnock (Prunella modularis). In the Alpine Accentor, females sing to attract males, and often solicit copulation as soon as the male arrives, often mating with multiple males. Older females who lay the largest clutches of eggs have the most elaborate songs; having several males who think they may be the father of the nestlings means several sources of food provision and defence.

Alpine Accentor (Photo By Paco Gómez from Castellón, Spain – Acentor alpino (Prunella collaris)-2, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=10653904)
In the Greater Painted-snipe (Rostratula benghalensis) not only is the female the principal singer, but she is also the more brightly coloured sex – the male is more cryptically-coloured, and takes care of the eggs and young.

Greater Painted-snipe (female) Photo By Afsarnayakkan – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=81947019

Greater Painted-snipe (male) Photo By Bernard DUPONT from FRANCE – Day 20 : Greater Painted-Snipe (Rostratula benghalensis) male …, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=138683408
In the UK, it wasn’t until 2020 that female song was identified in the Barn Swallow (Hirundo rustica). Wilkins et al discovered that females sing at the beginning of the breeding season, and, furthermore, they sing over the top of their mate’s song, preventing him from advertising his availability to other females.

Barn Swallow (Photo By Andreas Trepte – Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=40877458)
And finally, male and female Common Swifts (Apus apus) duet with distinctly different calls, usually at dusk. It was described by scientist Erich Kaiser back in 1997. Usually, the call consists of a series of short screams, given alternately by each sex. The higher ‘swee’ sound is made by the female, the lower ‘ree’ sound is given by the male. Amazing! And something to listen out for over the next few weeks in the UK before the Swifts leave to head south. I wish I’d paid more attention when they were zooming up and down the road yesterday.
So, paying more attention to female birds is opening up all kinds of questions, and is starting to help us understand the complexities of the lives of different species, some of them very close to home. I wonder what else we’ll discover, when we put aside our assumptions and come to look at birds with an open mind?

Common Swift (Photo By Alexis Lours – Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=170916976)








































