Harry Britton's report - 2009
Survey of the animal life in the Orchard
During the summer and autumn of 2009, a survey of the animal life was carried out at the newly founded Orchard to the rear of St Mary’s Church, South Street. The survey would ascertain the variety and distribution of fauna present and the impact of human activity upon it (i.e. the mowing of the “lawn” areas in rotation, the main path being used as a cut through and general usage of the Orchard.
As the area was developed and new fruit trees planted, along with the allotment site formation, there could be an impact on the animal communities on the site. Several methods were used to sample the site so that as comprehensive as possible result could be obtained. Also, different phyla needed to be sampled in different ways.
Sample methods used were:
- Netting (flying insects)
- Pooters (for small plant dwelling insects)
- Pitfall traps (ground and leaf litter dwelling invertebrates)
- Sweeping (on the herb layer for plant visiting invertebrates)
- Soil sampling (for fossorial and leaf litter invertebrates)
- Catch and Release live trapping (small mammals)
- Ultrasonic Heterodyne Detection (bats)
By far the most prolific pollinators are the insects and also the most abundant in numbers. Of these, the order Diptera – True Flies – were by far the most numerous and several orders of these were evident. The order Syrphidae or Hover flies were encountered most often and it is understood that all the fly orders are the main protagonists in fruit tree fertilisation.
Bluebottles, Greenbottles, Stableflies, Craneflies and Houseflies were often evident along with three or four species of Midges where the clouds of male insects would “hover” under the shade of the trees, possibly affording some protection against predation, waiting for a passing female.
Honeybees (Apis melifera) were seen, but rarely (they seem to be in decline nationally).
Bumblebees like the Buff Tailed and Red Tailed were often spotted, usually on the low-lying blossoms of clover, etc., and were found to be resident in the orchard, as they “nest” underground. The entrances to the nests were always in long grass or near hedgerows and away from well worn paths.
Butterflies were seen flying on most (sunny) days and these include: Small Tortoiseshell, Red Admiral, Painted Lady, Comma, Large and Small Whites (male and female), Silver Spotted Skipper, Gatekeeper, Meadow Brown, Speckled Wood, Small Heath, Common Blue and Small Blue. All of these will help in pollinating plants and are a wonderful splash of colour on a summer day. Several moth species were noted but to get a fuller overview, a specific light trap would be needed, therefore moths were only casually observed. Day flying Five- and Six-Spot Burnet moths and the Jersey Tiger were numerous, as the tall grassed areas afforded some cover. Several species of the Pyralid moths fed as caterpillars on the tall grass and, probably due to their size and predation possibility, stayed within the grassed areas for their entire lives.
Several species of the order Odonata (Dragon and Damsel flies) frequently used the Orchard as they are all predators and fed heavily on the available abundance of insect life. The Southern Hawker was seen most often, patrolling and squaring the Orchard, looking for prey. Occasionally, the Beautiful Demoiselle and Banded Demoiselle damselflies were seen (probably due to the abundance of prey) although they seldom, if ever, stray far from water.
Pooters were used to obtain small (less than 10mm) leaf and grass dwelling insects, as handling could damage them. Among the vast numbers of specimens were mainly small beetles and flies. The beetles were mainly ladybirds (which fed on aphids that can cause quite severe damage to fruit crops) and are always a welcome sight. The small flies were most numerous both in species and specimens. Among these are Mosquitoes, Black Flies, Cluster Flies, Midges, Fungus Gnats and Fruit Flies. The last family are the most important as they feed on rotting vegetable matter, especially windfall fruit.
These are set in the ground to determine the invertebrate life living in the ground and in the leaf litter layer. A steep-sided pot is dug into the soil and covered to prevent predators and rain entering. The most abundant finds include Ground Beetles, Rove Beetles, Earwigs, Springtails, Harvestmen, Mites, Wolf Spiders, Bristletails, Woodlice and Centipedes. All species help in decomposition of leaf litter and many are a food source for larger invertebrates, therefore extremely important.
Several species of Orthoptera (Crickets and Grasshoppers) were noted during sweeping the grassed areas, including: Bog Bush Cricket, Green Grasshopper, Meadow and Field Grasshoppers. Lacewings were also found in the sweeps, as were several species of beetles, moths and flies.
Soil sampling was undertaken at various places around the Orchard in order to see if different types of cover (long grass, mowed grass, pathways etc.) affected the soil inhabitants. As was expected, there was (generally) no difference in the type and range of soil dwelling invertebrates. The most found were Collembola (Springtails) and Thysanura (Bristletails). These very small primitive insects are the main detritovores in the grassy, meadow, garden type environment. Earth worms are also very abundant and found everywhere. The samples were examined in laboratory conditions.
Catch and Release
Due to the high metabolic rate of small mammals, live trapping can be fraught with problems, e.g. the prey dying before it can be examined, so great care was taken to examine the traps, leaving them no longer than an hour and providing food and bedding for the specimen. Traps were set in and along the two hedgerows (to the south and west of the Orchard). Traps were set in various central locations, with no success.
During the survey, 7 different individual woodmice were caught, marked and released (one particular mouse was trapped 5 times, so after clipping the hair on his back he had a unique and becoming hairstyle).
1 Dormouse was caught – unusual but exciting, since they shun humans and human habitation.
A Field Vole was also trapped. A Water Vole was observed (not trapped) presumably up from the River Brit to feed.
As mammals are (mainly) crepuscular or noctural, the optimum time to set traps was just before last light and nightfall, so whilst waiting to examine the traps, keeping still and quiet, other activities were observed. Foxes regularly patrolled the Orchard to feed on the small mammal life present; also one evening two Badgers galumphed across the central path and disappeared into the Churchyard. There were also several Hedgehogs (a mother and offspring) regularly seen.
Bats can be detected using an ultrasonic converter to make their calls audible to humans. As the bats swoop catching moths and lacewings, their calls can identify them as they (generally) call at different frequencies. The Pipistrelle was the most numerous with as many as fifteen or so evident at one time (maybe roosting in nearby St Mary’s.) Daubentons and Brown Long-Eared bats were also identified.
The animal life in the Orchard is many and varied, and although no rare or endangered species were identified, it was so exciting to find the vast range and extent of organisms found living in, or casually using, the Orchard.
With the advent of a permanent pond on the site, and the maturing fruit trees and maturing allotments, the prospect for wildlife watching and study is even greater.