<p>Human disturbances can have large impacts on wildlife and their behaviour. The extent of the effects of different kind of disturbances during different seasons is, however, less well known. Here, we assessed the impact of three different human disturbance types (a sole walker, two walkers talking, and a jogger) on the flight initiation distance (FID) and flight duration (FD) of a bird species that frequently breeds on coasts, the Little Tern (<i>Sternula albifrons</i>) during the breeding season. Our study was conducted in an area heavily utilised by tourists, the Alvor dunes in the Algarve in Portugal. We further assessed the effects of weather conditions and nest age on behavioural responses to disturbances. Although the sample size was limited (experiments were performed on 30 nests), we found that the jogger caused the largest FID, followed by the walker, and two walkers talking. The adult terns tended to return sooner to the nest when they were further along the incubation. The weather did not have any significant effect on the FID and FD in our study. These findings, along with other studies, emphasise the need for careful consideration of disturbance-free zones for coastal breeding birds. Furthermore, the FIDs and FDs cannot be generalised across bird species, time, space, and disturbance type.</p>