Figure 1. The number of published studies per years that used tracking technology (GPS, radio transmitters or resource tracking) on frugivorous species (a) and the number of published studies per years that either calculated seed dispersal distances or focussed on other themes (b) between 1978 – 2022.

The number of studies that estimate seed dispersal distances from tracking data also increased since the late 1970s to the present (Fig.1); the earliest study was published in 1988 (see Murray, 1988), but not until 2007 were more than two studies published annually (Fig 1). Eight studies were published 1988 - 2006, whilst 59 were published 2007 - 2022 (Fig 1); a 738% increase in the last 16 years compared to the previous 19 years.