Abstract We studied the natural history knowledge (NHK) of students (18–19 years), considering the salience of nature expressed through the knowledge of names of organisms, routes for knowledge transmission and acquisition and the potential of specific taxa to represent a student's overall knowledge. We report a 2‐year study of the NHK of 149 UK‐resident first‐year biology students surveyed by means of a free‐listing exercise, facilitating the assessment of salience, prior to participation in a residential field course run by the University of Oxford. Each year, students anonymously completed a questionnaire asking them to name any five species in each of five taxonomic groups (birds, trees, mammals, butterflies and wildflowers) found wild in the British Isles, also stating if those named were native or introduced. Metadata were collected on the students' background and sources of knowledge (e.g. family, teachers, etc.). Of the five taxonomic groups, birds were the best known by the students, while butterflies were the most poorly known group. However, although asked for names at species level, while 94% of students could name five British bird taxa, only 55.7% named them at species level, many giving folk generics such as ‘duck’ or ‘seagull’ instead. For butterflies, only 12.8% of students correctly named five British species, and 47% named none. Family influences, self‐motivation and knowledge of birds, rather than formal education, best predicted students’ overall NHK. While urban/rural residency had a small effect on NHK, it strongly influenced the relative importance of other factors. Factor analysis showed that NHK was best represented by knowledge of birds. Furthermore, the bird species named predicted students’ total NHK as well as the students’ knowledge of birds. Asked to name their favourite bird, students with family influence were significantly more likely to name native species. We describe the complex interplay between context, family and formal education in developing nature salience; roles which we define as nature ‘advocacy’. In the urban context, the advocacy of family and teachers was essential to engage young people with nature, while this was not so in a rural context. We briefly consider the implications of our study for natural history education going forward. A free Plain Language Summary can be found within the Supporting Information of this article.