Spring has sprung and with it a focus on renewal among political parties. National MPs are obediently acting like deciduous trees - those deemed in the autumn of their political lives (and some who aren't such as Chris Tremain) - have watched their leaves drop to the ground and duly issued a press release that they would shuffle off to make room for some thrusting green sprouts.
Over in Labour, however, its MPs have stubbornly decided they can be evergreen. So far only one - Ross Robertson - has announced he will not be returning.
This is partly because National has more room to prune - it has 59 MPs while Labour has just 34. The way things are going, National will have fewer or the same after 2014, so the only way to get new people in is to trim out the old. On the other hand, Labour is likely to have more MPs, reducing the need to prune.
Nonetheless, the apparent ease with which National is managing to open up spaces for new people has prompted questions in Labour about why it can't do the same.
"Rejuvenation" is as much for perception reasons as for practical reasons. It is all well and good to say a party has a new energy. It is another thing to show it and the bluntest way to do that is through some change in personnel.
Adding to this is the need to hit the target of women decreed by the party. That goal of reaching 45 per cent of women by 2014 and 50 per cent after the 2017 election means pressure will go on men in the seats.
That will be a short-lived pain somewhat like pulling off a sticking plaster. Once they reach that target, in theory the selection chances of men and women should be about equal. But when plasters are ripped off, they pull out hairs. So poor old Phil Goff and Trevor Mallard have found themselves stuck to the tape, albeit hanging on hard. This is purely because of perception rather than any comment of effectiveness. Of late, Phil Goff has proved he is one of the most effective MPs Labour has.
Goff and Mallard have both said they intend to stand again - and given the strong support in their electorate organisations, it is a stand-off they are likely to win. That will leave the party able only to dump them down the list in a futile show of objection.
That passes the problem on to the males who do rely on the list to make it into Parliament.
There are signs some MPs are looking at an exit in the next term by standing as list-only candidates. That has become a stepping stone to retirement, allowing an MP to leave during the term without the resultant hassle and cost of a by-election.
Annette King is understood to be one of those, opening up her very safe Labour Rongotai seat. One obvious replacement in Rongotai is Andrew Little, at present a list MP. But another possibility is Helen Kelly, the head of the Council of Trade Unions, who has been rather coy about her intentions in 2014. A dead-cert ticket to Parliament will be hard to resist.
In many recent selections, Labour has chosen female over male candidates - a bit of pre-emptive action before the targets kick in. In 2011, George Hawkins was replaced by Louisa Wall in Manurewa. Meka Whaitiri replaced Parekura Horomia in Ikaroa-Rawhiti. In Christchurch East, despite strong groundwork, the well-regarded James Caygill was beaten by the relatively unknown Poto Williams, who moved to Christchurch from Auckland in January.
Little will not be holding his breath that Labour will replace a female electorate MP with a male.
As well as King, Shane Jones opted against running in Tamaki Makaurau again. That is possibly because of the likelihood he would actually win it in 2014 given Pita Sharples' retirement and Jones' own rising star. Sticking to the list gives him the flexibility to leave rather than sit through another term in Opposition.
The trouble for other men of Labour who exist on the list is many of the slots held by other males high up on the list, such as Raymond Huo and Rajen Prasad, are there for other 'equity' reasons, such as ethnicity. That makes it harder to budge them. So it will be a tricky juggling match for the list ranking committee to try to ensure men such as Kelvin Davis and Stuart Nash get surety. Davis and Nash were both defeated at the end of their first terms by the results of 2011. Both are standing again and are likely to need the list to get back in. Nash's chances in Napier are negligible. Davis is hoping to stand in Te Tai Tokerau again, against Mana leader Hone Harawira. Even if he did have a chance of unseating Harawira, Labour will quietly ask him not to try too hard.
Harawira is is very much Labour's John Banks - a one-vote buffer if things are close after the election. Thus it would work in Labour's favour for Harawira to hold the seat as a potential support partner in 2014. This may work in Davis' favour when it comes to the list: if Labour ranks him highly, it will send a signal to voters that he does not need to win the electorate to get in. Another thing in Davis' favour is that the Maori caucus within Labour has already exceeded its female quota. There are now two men, Shane Jones and Rino Tirikatene, to four women: Nanaia Mahuta, Meka Whaitiri, Moana Mackey and Louisa Wall. That's a 33-66 split. To the women the spoils.