Some people may ask "why bother with conservation?" We now realise that it is important to maintain the planet's biodiversity, that it is the richness (variety) of animal and plant life, its abundance and wild habitats that keeps us all healthy and happy. The more species disappear, the more entire eco-systems become vulnerable and would eventually fall apart as the links in the food chains become broken. For example certain animals only eat certain plants and those plants may need that animal to pollinate it or spread its seed. Without one, the other is also likely to die out.
From a selfish point of view, we humans never know how valuable a species of animal or plant may be for us in the future, perhaps as food, medicines (particularly plants) or for specific information such as for biomimicry.