“I have watched this particular behaviour many times with my wife, usually when out cycling in the early morning. When not breeding, a group of Chestnut-headed Bee-eaters (Merops leschenaulti leschenaultia) roost over night at a dead Rain Tree (Albizia saman) in my area.
“In the past (2-3 years ago) numbers were 40-45. Now numbers have increased to more than 300 and nearby rain trees have been commandeered. My comments below are based on many years of casual observation of this site when we cycle past.
“The above image shows an overview of the main dead Rain Tree. I counted 305 Chestnut-headed Bee-eaters in this tree alone. Note that other birds are also hidden by branches and also occupy nearby trees. The image below tries to show the density of the birds in a few branches.
“Usually by 6.30-6.45 am they begin calling and it is quite delightful to hear hundreds of them voicing their opinion in the early morning light. There is quite a bit of movement with birds changing branches.
“Progressively as the sky lightens (around 7.10-7.15 am in November) attempts are made to leave for the feeding grounds. The process of leaving is interesting to watch. A single bee-eater or a small group flies off trying to lead but if there is no response, it or they return. At times a firm decision is made and the group does not return or only a few do so with the rest flying off to feed. This could be groups of 2, 5-7 or even 15-20 birds. At times the entire flock makes an attempt to leave (above) with a loud din, then returning to roost. Until finally a flock decision is made and they all head out (perhaps there is a recognised senior member of the flock who decides?). Then the air is filled with bee-eaters (below). By this time a sizable proportion of the group would have already left in smaller flocks.
“Another image showing the spiral upwards in the dawn as one group pulls away (below).
“A small audio recording of the event HERE. Not possible to edit the background.”
“Disclosure: It is not possible to adequately capture the experience and intensity of this large experience and the tree in question is not very accessible. Images were taken in the early morning in low light.”
Dato’ Dr Amar-Singh HSS & Datin, Dr Swee-Im Lim
Ipoh City, Perak, Malaysia
10th November 2013
Location: Ipoh City, Perak, Malaysia
Habitat: Urban housing environment