I agree with Durhamjen, that is the way it works in most refugee situations. The men leave in an attempt to find a better life and if they succeed they send for their families. When you consider the journey they have to make, it makes sense for the young, fit men to be the ones to go. Obviously it is no fun for the women left behind to look after children and old people but then neither is a trip across the Med on a leaky boat. The point about 'why don't they stay and fight for their country' which someone makes above is not valid because many of these men have already served their time in the army, particularly in Eritrea.
I do think we have to differentiate between refugees and economic migrants. Lindsay Hillson (I think that's right) on channel 4 news tonight said she had found that most of the migrants are economic ones, not refugees. She may have been speaking of a specific route because obviously many of the poor souls we see on our screens certainly are refugees escaping from tyranny in their own countries. She went on to say that the whole thing is total chaos and no-one is really taking responsibility for anything.
I don't know what the answer is but someone has to come up with something soon. Going after the traffickers makes the most sense but that line of action does not improve the actual situation in these countries. My personal view is that the west should never have interfered in the first place, upsetting the status quo that had existed for centuries, albeit an undemocratic status quo. Democracy is not a 'one size fits all'.