RE: while the females go off cavorting in the sea.


egg productions is a major effort for most birds.. (kiwi's produce the biggest egg, relative to body size) but even small eggs are packed full of fat (the yolk) and protein, as well as having a hard shell.. the resourses for egg production are what the mother contributes. Not to mention laying the egg!

female hummingbirds get a really bad deal.. male penguins are don't suffer that much.. and once the chick is hatch, both parents feed.. so really all the female is doing while waiting for egg to hatch is replenishing her reserves.. all the male is doing is fasting for a short while. (living off the built up reserves-- not fiving the reserves to a egg!)