We’ve had a lovely display of water irises in our pond this year, the bright yellow contrasting beautifully with the verdant surrounds.

Despite the mild weather and lack of winds, the flower heads have been disappearing soon after opening.

While enjoying a morning coffee in the back room last weekend, we found out why.

The Superb Blue wrens, while being socially monogamous, are apparently the least faithful birds in the world. Although they mate for life and will share the feeding and upbringing of their young, they are remarkably promiscuous. The females have a particular weakness for males bearing a yellow petal.

She may be courted by up to 13 males in half an hour and, for the right one, will leave the nest, mate with him and return as though nothing happened. Consequently, the offspring in any one brood will have different parentage. Maybe it’s because the male never presents a petal to his mate?

And why a yellow petal?