Tuesday, 20 July 2010

Alamootie update

Out of about 140 study sites, eggs have been laid in 56 storm-petrel nests. While high levels of daytime occupancy of nests earlier in the season suggested that foraging conditions might be good, we have witnessed a fair amount of egg neglect in the last 2 weeks. Petrel eggs are specially adapted to survive chilling and interrupted incubation is common. However, previous research in the early 1990s revealed egg neglect in approximately 4% of nests, whereas current frequency of egg neglect is over 10%. We have also found a fair few dead eggs seemingly kicked out of nest sites. This suggests birds are neglecting their eggs (i.e. leaving them alone) and, in the meantime, another bird is coming in to prospect for a potential nest site and kicking out an egg. This may in fact mean that foraging conditions are not so good as we might have hoped.

A neglected egg which when removed and inspected was seen to have a couple of small dinks in the shell (slightly right of middle), making it unviable (Hannah Watson)

Out of about 45 nest-boxes on the island that we are monitoring, so far 7 boxes are occupied by incubating birds. The nest-boxes provide a great means of studying stormies, allowing visual inspection of nests with minimal disturbance. Here’s a sneaky peak of a stormie incubating an egg inside a nest-box...

Incubating stormie in a nest-box (Hannah Watson)