Chiffchaffs Phylloscopus collybita feeding in a small group on a local concentration of emerging moth flies (Insecta ; Diptera ; Psychodidae)

Abstract

In the Maltese islands, Chiffchaffs wintering in suburban areas usually forage singly during the day and then gather in the late afternoon in small groups consisting of from six to ten individuals to roost in one of the more sheltered gardens. This is what happens at San Anton Gardens where Chiffchaffs are usually seen foraging singly. At times however, small groups of Chiffchaffs are seen, usually feeding at a large and plentiful source of food. This happened at San Anton Gardens this year, where between mid-january and late February 1991, a small group of C11iffchaffs could be seen feeding close to a stone irrigation canal in the centre of the gardens. Moth flies were emerging in large numbers from the sludge at the bottom of the stone canal and as many as 10 per 100cm2 of canal could be counted. The Chiffchaffs spent most of their time about 2 to 5 metres from the canal, visiting the canal periodically to take one or more moth flies. The table shown below gives the number of Chiffchaffs seen in an area of about 10 x 10m near the canal on days when observations were made.