A FEW weeks ago, a new generation of dippers fledged along the river Wharfe near Ilkley. I have been concerned about how this species is faring (Nature Notes, 4th Nov. 2021). As I have mentioned before, in this location, these are challenging times for wildlife. Loss of riverbank vegetation and the emergence of large ‘beaches’ when water levels are low mean that nesting and feeding locations are, at best, less secure and, at worst, no longer viable. However, despite this adversity, Dippers seem to be hanging on, at least in places.

Nesting locations, for Dippers, are almost always along a river bank, often taking advantage of natural features of the watercourse, but frequently using human structures, such as bridges or culverts. Where the existing features allow, nests take the form of a ball of vegetation, with an entrance hole. This provides important thermal insulation. However, in some circumstances it is necessary for the birds to be less elaborate. (This YouTube video shows an example of a dipper nest: www.youtube.com/watch?v=iU7BZmPb0Is .) Into this, the female will typically lay a clutch of 4 or 5 eggs, one per day. She will incubate these for approximately 16 further days before synchronous (all at once) hatching occurs. Both parents are then involved in feeding their young, who will remain in the nest for approximately three weeks, before emerging to face the challenges of their aquatic lifestyle.

When they do so, fledglings are most easily differentiated from adult birds by their rather ‘dowdy’ appearance. The white breast, that is such a distinguishing feature of the adult, is heavily flecked with brown, and the chestnut band along the lower breast/belly is absent.

Post-fledging, the young birds will stay in their natal area for another week or two, before dispersing to find their own territories. During this time, they receive support from their parents, who initially continue to provide food and demonstrate foraging activity, but slowly encourage independence.

It was possible to watch these recent fledglings, at an important early stage in this process, as they began to feed away from the nest site. Perhaps with some luring by an adult (for the more cautious youngsters), a fledgling would locate itself on a fairly prominent rock in the stream. Once there, it signalled its eagerness to be fed by elevating its tail, flapping its wings energetically (using very short, quick wingbeats), and opening its beak to expose its bright yellow-orange gape. The adult would forage nearby and returned very regularly, generally with an offering of food that was placed deep into the fledglings open mouth.