Recording birds in real time: a convenient method for frequent bird recording

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. A method is presented here that has been employed by the author since 2003 to frequently record a predefined subset of bird species along standard routes and locations. The approach is a hybrid of the five-minute bird count and slow-walk transect methods, designed for high frequency use while the observer is stationary and moving respectively. Predetermined subsets of bird species are recorded in 20-min intervals, often consecutively, each with one nested 5-min interval. N-mixture models now allow for abundance and detection probability to be statistically separated from such simple high frequency, pseudo-replicated count data. Nearly 100 000 bird counts have been collected using this method, plus many more ‘sought but not found’ records. The value of this simple, high frequency monitoring approach is demonstrated by summarising data from one location, one weekly route, and one daily route for three widespread native forest birds. These show striking patterns of seasonality and biotope use in urban and rural Christchurch. Hence this approach, if widely adopted, could provide a valuable resource for bird monitoring.