Hmmm. Personally I think there are two points to make.
Firstly, in absolute terms, I'd say that there is a reasonably equal balance between male and female leads overall. If you disagree, look through a typical day?s schedule (like today). Look at the bedtime hour (their most popular hour I imagine) ? 2 out of the 4 programs have lead females (Mama Mirabelle and 64 Zoo Lane), one arguably has a lead female (Charlie & Lola ? well Lola always seems to be the main one to me anyway!) and the other is non-specific (Rubber-Dubbers).
The second point, however, is critical. Whilst women/ girls seem to take the lead on live-action programming (e.g. Me Too, Balamory, Nina & Neurons, Green Balloon club) and to be fair in many non-traditional female roles (e.g. bus driver, scientist, taxi driver) the majority of lead cartoon characters, on the other hand, are invariably male (e.g. Postman Pat, Lunar Jim, Bob the Builder) in traditional male roles which appeal to children (e.g. fireman, astronaut, builder).
Why is this? Well, if you've ever looked at the economics of children?s TV, program makers make nothing (and in fact generally lose money) on the programmes themselves - they make their money in DVDs, merchandising and licensing. Any economically motivated children?s TV producer has to develop programming and characters which therefore will sell DVDs and particularly merchandise - invariably these are cartoon characters because (a) they consistently appeal to children across both sexes and ages and (b) the adaptability of the franchise (i.e. how many types of merchandise you can get out of it) enables more spin-off products. All the major children?s TV companies (e.g. HIT, Chorion, Entertainment Rights) center their portfolio on cartoon characters which sell well to a mass audience. Only a non-economically motivated program maker (e.g. the BBC) can afford to make loss-making live-action children?s television.
What this tells me, at least, is a few things. Firstly, children (in general) prefer cartoon characters in stereotypical roles ? if they didn?t, then the children?s TV companies wouldn?t make the merchandise for them. They only produce these programs because they were profitable. If live-action female-led programming was more profitable, they?d do that instead but it?s not. We can debate the rights and wrongs, but that is the case at the moment. Secondly, this is not a sexist decision but an economic decision. If they thought a female zookeeper character would outsell Fireman Sam they would produce a program featuring one ? these companies are all about profits. Thirdly, cartoons are likely to be the dominant/ most popular form of kid?s programming for the moment ? they appeal to children and offer the most flexible and attractive merchandising opportunities. Finally, the BBC is clearly flying the flag for women and (relatively) egalitarian programming ? look at the BBC produced programs and it?s clear that they have far more women in major roles than other kids? TV producers (although this is because they?re publicly funded and can afford the losses on the programs).