This week marks two anniversaries of global green campaigning groups that could scarcely be more different, while holding almost identical aims.

On Thursday, Greenpeace turns 40 – an unlikely candidate for middle age, given its activists' reputation for eye-catching and sometimes dangerous stunts. Last Sunday, WWF celebrated 50 years since the opening of its first office in Switzerland – a much more staid affair, as befits an organisation that boasts the support of the Prince of Wales and the Duke of Edinburgh.

WWF – it stands both for the Worldwide Fund for Nature and the World Wildlife Fund, its original name, though these days the organisation prefers to be known only by its initials and its famous panda logo – was born out of a realisation that some of the wild places and wild species of the world were under serious threat.

The catalyst for its foundation was a series of articles in the Observer by Sir Julian Huxley – a biologist and grandson of Thomas Huxley, the Victorian champion of evolution nickhamed "Darwin's bulldog" – warning of the spoliation of wildlife habitats in Africa.

He was joined by a small group of conservationists including Godfrey Rockefeller, of the US oil dynasty, and Peter Scott, son of Scott of the Antarctic, and the World Wildlife Fund quickly gathered an aristocratic backing.

Its first president was the playboy Dutch prince Bernhard of Lippe-Biesterfeld – said to be one of the models for James Bond – who also founded the secretive Bilderberg Group, and he was soon to be followed by Prince Philip. Ironically for a group focused on saving endangered species, several of its early high-profile backers were the same hunters who a few years earlier had enjoyed killing "big game".

As the fund grew – last year, WWF's global income was more than half a billion euros – the organisation gradually took a broader approach to conservation, with the concentration on "charismatic mega fauna" replaced by campaigns on climate change, pollution and public policy.

WWF also started to work closely with big companies – some of them the same alleged polluters or high-emitting business that other NGOs were criticising, such as cement company Lafarge and The Coca-Cola Company, which has been accused of damaging water courses in some of its operations.

A colourful history and new direction have earned WWF its share of detractors. "Sell-out" and "too cosy with business" are common criticisms when activists from other green organisations are asked their views. "Some of the people who work for WWF are probably quite similar to those in other NGOs like Greenpeace, but the people who support them are very different," says one campaigner.

Solitaire Townsend, an environmental consultant whose own company Futerra celebrates its 10th birthday this week, characterises the organisations as "an angry teenager and an elegant, silvery 50-year-old" and says they serve very different purposes.

"The types of people who are attracted to them are totally different. If environmental problems make you really pissed off and you want to get out there and stick it to the man, you go to Greenpeace. If they make you sad, and you want to sit in your room with a cuddly toy and look at pictures of cute animals, you would go to WWF," she says. "There is room for both, of course, but I don't think there's a lot of overlap in the personality types."

David Nussbaum, chief executive of WWF-UK, does not quite see it that way, but he acknowledges the distinction between his organisation's approach and some of its noisier fellows. "That more combative, aggressive approach of Greenpeace can be effective," he says, "but we have a contrasting method. We see a need to engage constructively with the commercial world. We use our influence with businesses."

While Greenpeace is likely to be found outside a corporate headquarters protesting, its counterparts in WWF might be inside meeting the chief executive. To critics who say this could lead to companies using WWF to greenwash their message, Nussbaum is unapologetic.

"If you take a company like Marks & Spencer, which we work with, they are very principled and ethical, but you can say there is room for improvement – having a target implies that you haven't got all the way yet to where you need to be."

The broadened focus of WWF has taken it from campaigns on tigers and whales in its early days to working on the minutiae of the UK's energy efficiency legislation – a stretch, perhaps, for some long term supporters?

Nussbaum is eager to stress that the new political campaigns have their roots in the vision of WWF's founders – he quotes Max Nicholson, the ornithologist: "WWF is not just about saving whales and tigers and rainforests, and preventing pollution and waste, but is inescapably concerned with the future conduct, welfare and happiness and indeed survival of mankind on this planet."

Whether the nature of WWF's support has changed over 50 years is difficult to assess – the crowned heads are still there, among the 5 million less aristocratic supporters around the world.

In the UK, about 40% of these are long-serving regular donors, typically retired couples. About a third have adopted a species for themselves, mostly well-educated young, single people but also include lower paid people with families. About 28% are people who have been bought a species adoption as a gift, and many are children.

Comparisons cannot be made as no such data was collated in the first decades of the group's life, but the share of individual donors has changed – they still make up more than half of the group's income, but governments and other public bodies account for about 17% and business donations are more than 10% of income.

That both WWF and Greenpeace have become instantly recognisable global brands is a testament to their success in the last decades, and to the enduring importance of the issues on which they campaign, says Townsend.

But, she argues, the real challenge for both in the next 50 years is not the differing approaches taken by the pair – it is the question of how to spread their support from their western bases to be equally effective in other parts of the world. "Can these sorts of NGO model work outside the west? That is not clear yet," she says. "Concern for the environmental and degradation are universal, but what works in Norway might not work at all in China."

(By Fiona Harvey, Guardian.co.uk, 14/09/2011)