Stephen Moss: Father’s Day

This weekend sees dads all over the world celebrate Father’s Day – but what role do male birds play in the lives of their families? As I discovered, this varies from sharing the duties equally with their mate, to abandoning the female and their offspring altogether.

The Role of the Male in Songbirds

As with the vast majority of living creatures, in birds the male and female have very clearly distinct roles. The male fertilises the female, who then lays the egg or eggs.

However, that’s about as far as things go when it comes to universal behaviours. There are now considered to be over 11,300 different species of bird in the world, and while there aren’t anything like that many breeding strategies, there are certainly an awful lot.

Let’s start with a fairly typical approach, which applies to the majority of the world’s 6,000-plus species in the order Passeriformes – usually known as perching birds or, for the majority, songbirds.

With a typical songbird – let’s take European and American Robins as examples – the male takes the lead in courtship, and defends his breeding territory against intruding males while also trying to attract, and mate with, one or more females. He does so by using his song: singing the same (or varieties of the same) tune throughout the day, from dawn to dusk (and sometimes before and after), during the breeding season, which can extend for three or more months in the spring and summer.

Because he spends so much time singing,  notable exception is the wren family: male Winter and House Wrens in North America, and the Eurasian Wren in Britain and Europe, all build a number of ‘cock’s nests’, which they then proudly show the female, until she selects the one where they will raise their family.

No male bird can lay eggs, but once the female has done so, and the clutch is complete, the male and female will often share the incubation duties – though again, wrens often leave this entirely to the female. During incubation, males will often reduce their intensity and regularity of song, as they have these other duties to do.

Once the chicks hatch, again most songbirds share the feeding duties, with Dad doing just as much fetching and carrying of food as Mum. (Again, wrens are the exception to this – the female does all the feeding of the chicks).

Cheating and Dishonesty

Unfortunately, some males are also rather devious. While the female Wren is doing all the hard work incubating the eggs and feeding the chicks, her mate will be away starting a second family, which again he does very little to help. Another common British garden bird, the Dunnock (once known as the Hedge Sparrow, even though it is in the accentor family), has the most complicated sex life of any songbird, with epic cheating on both sides – hardly a moral lesson for us!

However, by mating with other females the male Dunnock, maximises his chances of raising more young; while the female Dunnock mates with other males to ‘hedge her bets’ and ensure that her offspring have a wide range of genetic variation. So biologically it all makes sense – and warns us against trying to draw parallels with human behaviour.

Monogamy

Many larger birds are far more faithful to their mates – swans, for example, especially the Tundra (Bewick’s) and Mute Swans, are generally monogamous and mate for life. For long-lived species this makes sense, as by strengthening the bond between the pair they tend to be more successful; and by sharing the parental duties between Dad and Mum they have a greater chance of raising more chicks. Even so, the males tend to do more defending while the females do more caring, in what appears a more traditional sharing of the roles.

Desertion

For some species, the males take no part at all in the raising of their family. These are often ‘lekking species’, where the males perform to attract the females, sometimes in an ‘all-or-nothing’ scenario where the successful male gets to mate with all or most of the females. Having done so, male Black Grouse and Capercaillie then never meet their mate – or their offspring – again; the female does all the hard work. Again, what might seem morally reprehensible to us works for the birds themselves.

So perhaps the lesson we can learn from fathers in the bird world is that we shouldn’t compare ourselves with them, and if we do, it’s best to take as much part in the raising of your family as your mate does.

Happy Father’s Day everyone!