Each of us has a ‘personalised ecology’, a set of direct interactions with nature that is unique in its composition and varies daily, weekly and annually. These interactions are important for our wellbeing, and may also influence our emotions, attitudes and behaviour towards nature. This paper concerns detection functions, which describe the relationship between the probability that a person observes or hears (or possibly senses in some other way) an individual of another species and the number of individuals of that species that are present. These functions have previously been used by ecologists to estimate the abundances of species, but can be reorganised to express the determinants of the nature interactions that someone has in a given place and time. This exercise illustrates how people’s personalised ecologies are shaped both by clearly ‘nature’ associated variables, such as the number of organisms present, but also by variables that are strongly influenced by characteristics of the person, such as how they use or explore an area and their personal nature detection abilities. Many of the issues that have previously been explored in the context of human-nature interactions are then seen to concern these component variables of detection functions, and approaches to improving the frequency of interactions are seen, in effect, to be targeted at affecting change in different ones of these variables.