After a lengthy absence from the blogosphere I’m rushing to squeeze a last post in in 2013. It won’t be topical so I’m harping back to a visit to the Lime Kiln in Cherry Hinton, on the southern edge of Cambridge, from back in July. I posted from here earlier in the year about the resident peregrine falcons.
The main reason for this visit to the Lime Kiln was to see if the peregrines were still in residence. One of them appeared overhead and gave chase to a pigeon, but it was in level flight not in a stoop so the pigeon made good its escape. It was more like a juvenile practice run than a serious attempt to make a kill. It seemed that the family group had dissipated and were no longer spending the whole day at the Lime Kiln.
The peregrine is the worlds fastest bird, but only in a stoop, which is gravity assisted and more a controlled fall than real flying. In level flight it is comparatively cumbersome and not the fastest, that accolade goes to a species of swift called the ‘white throated needletail‘ (Hirundapus caudacutus) with recorded level flight speeds of around 70mph (112km/h).
The black tailed skimmer dragonfly was perched on the chalky ground and this is characteristic behaviour of the species. As the temperature rises above the mid 20′s Celsius he will perch on low vegetation instead. This one is an adult male, his blue abdomen is diagnostic and can only be confused with the male scarce chaser, but he lacks the dark patches at the proximal end of the wings which distinguish the scarce chaser.
The female and the immature skimmer have yellow bodies instead of the blue of the male:
I’m not entirely certain whether this skimmer is a female or a juvenile, the juvenile has pale green eyes and the female has darker grey/brown eyes so I think this one is a female. Interestingly, this species is associated with water and males will fiercely defend a bankside territory against other competing males. But as far as I know there is no water in the Lime Kiln so the male above may be a non-territory holding male, and females do spend time away fom water. The black tailed skimmer feeds on a variety of prey and can show a preference for bigger prey species such as butterflies and grasshoppers. They’re ferocious, albeit short lived, predators!
There were very few birds to be seen on this trip, it was at lunchtime on a very hot day (mid to high 20′s Celsius) so I think they may have been hunkering down in the shade, but I could hear a male whitethroat singing and a family of jackdaws were playing around on the white chalk cliff face.
Because of the relatively young age of the Lime Kiln, and possibly as a result of the unusual nature of the terrain, large areas of the floor are bare chalk and there are less plant species than there may be in a more conventional habitat.
One of the wild flowers growing there is self heal (Prunella vulgaris). This skipper butterfly was perched on a self heal flower head but I’m not sure if it’s an Essex skipper or a small skipper, they are very similar in size, shape and colour, and alas I’m not sufficiently expert to unambiguously identify them.
I didn’t manage to publish this post in 2013 so it’s now my first post of 2014. So Happy New Year to everyone, may the next 12 months bring you health and happiness!