Tuesday, 10 May 2016

Collared Dove exhibition flight

Collared Doves have a extraordinary behaviour, their display flight. As males incubate during the day - between 10 am and 4 pm -, and females by night, males are most vocal and active advertising their territory in the early morning and in the evening. Males call their repeated three-note phrase from a prominent perch an aerial or a tree top in the vicinity of their nest. At the end of their call they pause and then launch themselves into a display of pure flight power: climbing almost vertically up to 10 m into the sky, and then gliding down in a broad, long spiral, with wings kept spread pointing downwards, and tail fanned, to finish in the same or nearby spot, sometimes calling a mute trumpet-like landing call. The wing flaps make a soft whistling noise. This sequence can be repeated several times in the early morning and evening. This morning I watched this male sitting on a church top calling, and managed to get the initial jump of the perch into his display flight.
You can watch a slow motion clip of the display flight by redjered here

Monday, 2 May 2016

Greylag nursery

 Many Greylag geese pairs in our large local park have now young goslings. Although geese can be quite intolerant of each other at the start of the breeding season, now the families join together in an area of grass by the lake forming a large nursery. These behaviour might allow them to better detect and defend young from predators. Goslings are precocial and once dry after hatching they can feed by themselves straight away. In the few hours that the goslings spend on their own with their parents they imprint on them and will follow them everywhere. Both parents tend their young by fiercely protecting them from potential predators, hissing or chasing them away, while the goslings feed or rest quite oblivious to their parent's nervousness.
Goslings seek warmth under their mother's wing. Only females are in charge of brooding the goslings in their first few weeks, when they are still unable to regulate their body temperature.
 Despite geese being quite accustomed to people in the park, they still fiercely hiss even as they are being fed. We noticed that pairs differed on how nervous they were. In one of the pairs, the female, instead of hissing, uttered contented calls while she fed and the male didn't hiss at all, despite their goslings being very close to us.
Two families with females brooding young (on the left) and males stand guard.
A group of five goslings follows parents.
Two very nervous parents defending their only young.