Cool autumn temps affect birds & bugs
The autumnal temperatures of the past week have knocked back the butterfly population at Arundel Wetland Centre. The September sun must warm up the dragonflies a bit quicker – sightings remain steady. Last Thursday I even saw a migrant hawker dragonfly feeding in the early evening.
We had some great views of soprano pipistrelles and Daubeton’s bats feeding over the World Wetland ponds during our final bat walk of the 2013 season last week. Our group picked up the sounds of a large noctule bat on the bat detectors. We counted nine soprano pipistrelles sleeping in the large woodcrete bat box on the back of the Wetlands Secrets building. The group lined the ramp access of the nearby Reedbed Hide to watch these tiny bats emerge at dusk.
In 2013 bat numbers have been down at Arundel Wetland Centre, most notably among the soprano pipistrelles. The population may have suffered a die-off when the cold spring delayed the emergence of the insect population. Bats coming out of hibernation on time would have found little food. If the bats remained in hibernation, the fat they put on to sustain them through hibernation might not have been enough.
The weather has forced migrating sand and house martins, and the insects they hunt, closer to the ground. Last Sunday our visitors had amazing views of thousands of house martins hawking insects all around the reserve. Sand martins have been visiting the Sand Martin Hide in the hundreds, generally after the sun has warmed up the insects up a bit. The birds come in very close to investigate the sand martin calls we are playing over the speakers to interest them in our artificial nesting bank.
Kingfishers are still very active around the reserve. Grounds warden Alan and I were chatting by the Pondskater Play Area when a pair of electric blue streaks came up the path towards us, split around our heads then rejoined and continued around to the front pond!
Volunteers from HSBC and our own WWT volunteers have started the autumn cut, gathering reeds and grasses from the islands on our Wetland Discovery area. This has thrown up many interesting discoveries. I found and photographed a huge toad. An elephant hawk moth caterpillar was found and unfortunately a large wasps nest was discovered on one of the Islands!
Sept 19 Wildlife Sightings column appears in the Chichester Observer, the Littlehampton Gazette, the Bognor Regis Observer, the Shoreham Herald and the Worthing Herald.
