In an effort to curb to some extent this spoliation of the landscape, the Scenery Preservation Act was passed in 1903, by which three islands were set apart for the preservation of birds and plants: Little Barrier in the north, Resolution in the south, and Kapiti to cover the central districts. Since then, however, much greater destruction has been caused by deer, goats, opossums – animals introduced for sport and other reasons. To offset this there has been agitation from a persistent few to preserve more of our native forests, as, for instance, in the fencing off of a large area by Guthrie Smith at Tutira.

Leonard Cockayne was an ardent advocate of the setting aside of further areas for the preservation of plants and birds, and in his detailed reports on plants in many areas he constantly urged the adoption of preventive measures. He advocated the growing of native plants in public and private gardens and showed what could be done in his large garden of 4 acres at New Brighton, Christchurch, and, later, in the area at Wilton, Wellington, which has since become well known as the Otari Plant Museum, a living monument to the memory of this great man. Though there are now 28 sanctuaries supervised by the Department of Lands and Survey, as well as many municipal and private parks and areas set aside where the public are asked not to destroy flora or fauna, there is still much destruction occurring outside these areas, either as a sacrifice to the cause of progress, or as the result of depredations of deer and opossums and other feral animals.