The Botanic Garden is a habitat actively managed for wildlife and the Bioblitz results have been published into a Species List that gives the clearest picture we have of the diversity of species present in the Garden at mid-summer. You can download the Bioblitz 2011 Species List from the link left.
The Bioblitz uncovered many highlights. As the sky turned inky blue on the night of Friday 22 July, Soprano Pippisrelle bats began to swoop, identifiable by the rate and pitch of the ticking noises amplified by the handheld bat detectors loaned by the Cambridgeshire Bat Group. The night turned gloomy for the midnight moth-trapping and then the heavens opened. The incandescent bulb used to attract the moths had to be moved to under a canopy for protection and was placed before a suspended white sheet on which the moths congregate.
Thankfully as the team re-gathered early on the Saturday the sky was blue and the sun shining. With the help of members from the Young Zoologist Club, based at the Museum of Zoology, the pitfall traps were emptied and the bank voles and woodmice weighed and released. Evidence and sightings of muntjac, badger and fox were also added to the mammal record. With public bioblitzers queuing to join in at 10am when the gates opened, the day passed in a whirl of wildflower walks, bumblebee surveys, lichen records, identification of moths as they were released from the overnight traps (they are dozy in daylight, slow to fly off, and thus easier to identify).
Alien land snails were discovered in the Glasshouse Range from such far flung places as Hawaii - gastropods with an itchy foot! One exotic snail that bioblitz recorded, Gulella io, was originally discovered in RBG Kew, no doubt having hitched a ride on a plant accession, long before it was found in its native Liberia. Richard Preece from the Department of Zoology led the mollusc surveys and was really pleased to have re-discovered Testacella haliotidea, describing it as ‘a rather rare slug, not slimy like most but with a drier skin rather like that of a caterpillar. Again, unlike most slugs, it has a tiny external shell that sits on its posterior. We found four of these characteristic shells but no living animals. These slugs are largely subterranean, so we would have needed to dig into the flowerbeds, which may not have been popular with the gardeners!’
The bird-spotters both professional and amateur put together an impressive list from the camouflaged tree creeper to the larger, more obvious species such as the resident sparrowhawks and a heron that came in to roost on the Friday evening. Rob Pople who led one of the forays, reckons he found evidence of several families of Goldcrests. Unfortunately, between his recce on Friday morning and the walks on Saturday, the very last chicks had flown the nest. No bigger than a tennis ball, Rob estimates it held perhaps 6–8 eggs, which demonstrates just how tiny the species is - at circa 9 cm long and 5–7g in weight, it's the UK's smallest breeding bird!
Pond dipping on the Fen Display boardwalk proved a real hit with younger visitors, as voracious predators such as Water Boatmen, dragonfly larvae, gorily-named leeches, young newts and much more were fished out into shallow tanks to allow closer inspection. Later in the day this was a good location for spotting several species of dragonfly and butterfly.
Nearly one thousand visitors came through the gates in the 24 hour Bioblitz and many became really enthused and involved. One bioblitzer summed up just some of the revelations: ‘Some slugs have shells! A goldcrest weighs just 6 grams! The variety of pond life is startling! Butterflies take part in intercontinental travel!’ Bioblitzers also really responded to the easy access to expert knowledge, with one visitor commenting that the staff were very helpful and informative and that they had ‘loved the one hour wildflower walk, which had really engaged the children’.
The experts enjoyed their own personal firsts too. Dr Lynn Dicks from the Department of Zoology, led the bumblebee surveys: ‘We set out to try and record the tree bumblebee Bombus hypnorum in the Botanic Gardens for the first time. This species arrived on the south coast of the UK in 2001, and has been rapidly spreading northwards ever since. We did not manage to catch a specimen, but a magnificent queen of the species was spotted resting on a leaf by a little girl during one of our workshops. This was a highlight for me, as I've not seen a queen tree bumblebee before. I hope it was a highlight for the keen-eyed observer too, because she saw it long before all the adults did.’
The date for next year's Bioblitz will be announced shortly.