Did you know that there is a species of martin in Portugal that digs its nests instead of building them?
The Sand Martin (Riparia riparia) is the smallest martin that occurs in Portugal and the one that stands out most for its nesting habits. Unlike its counterparts, which build their nests in mud, the Sand Martin digs tunnels in the sandy slopes of river banks or sand pits. This martin can also use holes in retaining walls for nesting.
This is a gregarious species that forms colonies of several hundred individuals. The largest colony recorded in the andorin campaign has more than 150 nests. If you too know of one of these colonies, register it on our website!