Despite the growth of interest in nature based leisure pursuits, including ecotourism, there is little understanding of the environmental orientation of those who are more interested in nature based leisure experiences when compared with those who are not. This research sought to gain deeper insights into the psychological profile of the person who prefers nature based leisure activities, such as ecotourism, over other types of leisure activities by extending existing models of pro-environmental altruism (conceptualised as an ecological worldview) and incorporating a new and explicitly emotional construct of love and care for nature. This construct, variously termed ‘biophilia’ or a ‘land ethic’, has not been previously measured in spite of its apparent importance in the development of an environmental ethic. In order to achieve the aims of this research a psychometrically sound scale that measured the construct of love and caring for nature was developed. The development process, involving 568 respondents, led to a final scale that exhibited good psychometric properties, including high reliability and good content, criterion-related, and construct validity. The findings of this research show that an ecological worldview, comprising deep love for nature and pro-environmental biospheric values, does significantly influence people’s pro-environmental interests, attitudes, and choices, including preferences for nature based leisure experiences. More specifically, love and caring for nature was the most important influence (more than values or beliefs) on pro-environmental choices and behaviours, which were indicative of a stronger environmental ethic. Such behaviours and choices involved more effort and commitment on the part of the individual, including willingness to make personal sacrifices to protect the environment. The new 15-item measure of the construct of love for nature, the Love and Care for Nature (LCN) scale (Perkins, 2010), is easily administered and has potential application across a wide variety of contexts for predicting a pro-environmental orientation and pro-environmental behaviour, as well as interest in nature based leisure experiences.