Durham Wildlife Services use a number of specialised local sub-contractors to survey for terrestrial and aquatic invertebrates, identify scarce species and key habitat areas and provided mitigation measures for sites under development.
A number of invertebrates are afforded full protection under the Wildlife & Countryside Act, 1981 (as amended) This legislation makes it illegal to:
- intentional kill, injure, or take a scheduled animal;
- damage, destroy, or obstruct access to any structure or place used by a scheduled animal for shelter or protection; and
- disturb of any scheduled animal occupying such a structure or place
Invertebrate surveys
There are a number of techniques for surveying invertebrates:
Sweep Netting Surveys
Sweep netting involves the use of a strong net for ‘sweeping’ through low herbage, bushes and tree foliage, in order to dislodge any invertebrates within the vegetation. The invertebrates are then caught within the net bag. The surveyor can then record and release the catch.
Pitfall Trap Surveys
The pitfall trapping technique involves the use of a ground pit into which invertebrates fall and cannot escape. The trap is filled with an aqueous solution designed to trap, kill and preserve invertebrates. This technique is useful for sampling ground dwelling species. As this method results in the death of invertebrates this techniques should only be employed at a site for one season and not more than once every three years.
Light Trap Surveys
This method is effective way of surveying moths. Light traps emit high levels of ultra violet light which attracts moths. Moths attracted to the trap are caught alive within the main body of the trap. The surveyor can then record and release the catch.
Grubbing Surveys
Grubbing involves direct searching techniques, whereby the surveyor will search, sieve, beat and dig to record invertebrate species.
Survey Timing
In order to cover all the activity periods for all the species, survey work ideally needs to extend from April until September. However, basic assessments of the potential of the on site habitat to support important communities of invertebrates can be carried out throughout the year.
Contact DWS to discuss your requirements –
01388 488 885