It was a slow start to the day for our peregrines this sunny saturday. Although things kicked off quite well with a feed at 7am this morning, it was not until mid afternoon that the next prey item came in. The tiercel had a very productive day yesterday, which he often seems to follow with a quieter morning
The strong wind in the open areas may have affected hunting today. A tail wind can help a peregrine but the conditions in general may have made the accuracy of hunting more difficult. Peregrines do not always hunt by flying high into the sky and stooping. They can often sit on a vantage point and just fly down onto an unaware bird.
Some peregrines have become famous for using this method, sitting on a skyscraper or cathedral and flying down to a flock of pigeons below. Shorter distance hunting techniques can often be used in less favourable conditions. This may have contributed to the tiercel catching the unusual prey item of a juvenile Dipper. Out hunting for just 20 minutes, it is likely he caught this just upriver from the site.
The heat late morning and early afternoon could have led to the peregrines avian prey being less active. For the hottest part of the day both adults spent much of it keeping cool in the oak tree (on separate perches of course!)
Both adults (particularly the female) seemed to be struggling with the heat, panting and spreading their wings. Birds cannot sweat like us, so they need to rely on other ways of keeping cool. Spreading their wings and bodies out increases airflow, but also creates a larger surface area to volume ratio (this is the same reason that elephants have big ears!). A larger animal has a smaller surface area to volume ratio (hence why the female is more susceptible to the heat).
Eventually the chicks were fed well today. The slightly larger and more active of the two, started to tear of it’s own meat from the carcass held in the falcons mouth. Although it just did this action a couple of times during feeding, it is a promising development. By next weekend I would expect both chicks to be able to tear up their own meet from the prey items brought in.
Tom Wells – Peregrine Protection Officer