bird ecology

To make sense of how nature is responding to an increasingly rapidly changing world, a lot of species distribution and abundance data are needed. To infer population trends, these data ideally need to be collected in a standardised, repeatable manner that includes ‘absence’ data on species sought for but not found. If many people, even just professional ecologists and postgraduate students, are to record biodiversity frequently in their daily lives, a convenient method that meets these requirements is needed.