LIFE, Dr Alison Cronin insists more than once, marches on.

She means it of course, but it's obvious from her eloquent words that it is likely be a long, slow and painful process.

Something else is clear. While the 160 primates whose home is Monkey World need her, she needs them just as much.

"Coming back to Monkey World without Jim was one of the most difficult things I have ever done in my life," she says, her voice cracking with emotion.

"But the animals need us and they always will. It was one of the strangest things when people asked me, with everything that's happened, if I would carry on the work.

"Of course. It never crossed my mind that Jeremy (Keeling) and I wouldn't be here, probably working even harder to try to make up for the incredible energy and passion that was Jim."

Jim Cronin died in his native New York in March at the age of 55, the victim of liver cancer. It was a shocking bolt from the blue, which Alison describes as an incomprehensible tragedy.

She has also drawn huge comfort from the staff at Monkey World and the thousands upon thousands of letters which poured into the centre in the wake of Jim's death. They are still arriving daily and she reads every single one.

But her biggest source of strength has been the animals, all of them.

"Quite frankly, if I didn't have the park and the animals things would have been bad," she says.

Being responsible for 160- plus primates is like having a large extended family, a bigger and needier one that gets larger all the time. Each family member develops and they don't fly the nest.

Alison insists she has no favourites but when she came back to the park after Jim's death she first visited little Julio, the grey woolly monkey who was hand reared.

"Every time I look at him my heart melts," she admits.

We are talking in the big log cabin which serves as her office and the administrative HQ of Monkey World. In one of those little twists of irony - there are many - the environmentally friendly Swedish building was something that Jim organised.

"I had been telling him for ages that the little shed we used for years was in danger of falling down on top of us and I felt the wind and rain on my back every winter," laughs Alison. "Now we've got this great place and Jim isn't here to see it."

It is not difficult to see and understand how Jim's death has affected Alison. But what about the animals?

"It's hard to say whether all of the monkeys and apes are aware that Jim is not here, but I think some of them are, especially the chimpanzees and orang-utans because their cognitive abilities and their minds are much more like ours.

"Does Sally for instance sit and think: I haven't seen Jim around recently?' I don't know but I do know they were always used to seeing Jim and I together."

Jim remains her guiding light. "Not a minute goes by that I don't think, what would Jim have thought about this or that?

"But you don't want to belabour it too much by telling people that he would have done this or that because in the end we have to get on with it and make a go of things."

There are two big projects abroad well along the pipeline.

The first is a rescue centre for small primates, including the golden cheeked gibbon in Vietnam, being established in conjunction with the Vietnamese government. Alison will shortly be breaking the ground on the centre.

The second is bringing back dozens of capuchin monkeys from a laboratory overseas, the biggest rescue undertaken in the history of the park.

The details are under wraps for the moment but it is, she admits, "a little bit daunting". The laboratory approached Monkey World and requested help, as so often happens.

Almost always the answer is yes.

"We jokingly say we are here to put ourselves out of business but I don't believe that's ever going to happen," says Alison, who thinks much more needs to done in our schools to educate children about the natural world and where we're going wrong.

She has established the Jim Cronin Memorial Fund to set up a state-of-the-art education centre at the park, especially but not exclusively for children.

Given the way we're currently destroying rainforest and adding more and more animals to the endangered species, she is almost certainly right about Monkey World being needed.

There will always be primates needing a refuge from exploitation, experimentation or the destruction of their natural habitat in pursuit of industrialisation and growing of lucrative oil palms plantations.

The orang-utans of Borneo are currently facing an unprecedented threat as jungle is being rapidly wiped out to satisfy global demands for bio-fuel.

So Jim's pioneering work will go on with the same founding principles that he launched Monkey World with 20 years ago.

"It's really important to me, to Jeremy and to everyone here that the park continues with the same ethos. You've got to make sure that the heart is still right and that will never change.

"People must continue to walk away from this place knowing what matters and that the animals matter for what they are, not what we would like them to be.

"So that ethos, passion and focus that Jim set up back in 1987 will go on forever and I will stake my life on that fact."