Sparrowhawks male vs female

[Guinnessman1974]

Why are female Sparrowhawks larger than males?

There are quite a number of birding 'anomalies' I've come to think of recently, for example in the birding world, the males tends to have the brightest coloured feathers.

However, both male and female Robins have red breasts! Why?

Are there bird books with these sort of Q and A's?

[aeshna5]

One reason often given is to reduce competition for food between the sexes- the larger female usually taking bigger prey than the male, though there will be an overlap in prey items.

It's also not unknown for a female Sparrowhawk to take a male!