Siren believes that the diversity of plant and animal life on Earth is necessary for our physical and spiritual well-being. Meeting the material needs of people is undermined through loss of wildlife. People will, when all their material needs are met, still want, and indeed need, to be able to experience nature.

Siren believes that it is our moral duty to prevent human-driven extinctions of other creatures on this planet.

Siren believes that the conservation of species diversity is critical to maintaining natural life-support systems, and essential for our economic and social development.

Siren believes in the welfare of animals. Protecting the lives of individual animals is important, except where this conflicts with the preservation of another wild species' existence

Siren believes that protecting nature needs to accommodate human rights to adequate food, water and shelter, and to basic care and protection. We aim to facilitate and at the very least not inhibit the work of humanitarian organizations such as Oxfam for whom we have the greatest respect. Often, the goals of such organizations are served through nature conservation.

Siren believes that acting to protect nature will entail compromise, since the material needs of over six billion humans are often in conflict with those of perhaps 100 million plant and animal species. It is not possible, under current circumstances, to meet all human needs and aspirations and to save all species from extinction. Choices are breathtakingly hard to make. Yet, the world's great anguish is no excuse for apathy: indeed as the situation worsens, we must strive harder and more openly in making it right.

Siren believes that the existence of cultures and local traditions is important and that this diversity also requires protection. We aim to be supportive of these except where they interfere with our first principles of preventing extinctions and looking after the welfare of human and other living creatures. Indeed, we believe that nature conservation for intellectual, aesthetic and spiritual purposes is necessary for maintenance of cultural diversity.

Siren believes that it can make a difference, notably in a world where too much is said and not enough is done. Siren therefore works within the guidelines of the Charity Commission to generate as much output as possible with as little institutional bureaucracy as possible.

Siren believes in partnership and not in the promotion of one organization over another, and in particular not in the promotion of individuals over action.

Siren places a high value on individual commitment, co-operation, compassion, openness, respect, fairness, integrity and humour both in our working practices and in life in general