Threats & Mitigation
Threats to nest sites may be temporary or permanent.
Temporary threats usually take the form of scaffolding or disturbance during the nesting season. While swifts can negotiate open scaffolding if it is constructed with them in mind, netting prevents all access.
Permanent threats range from the complete destruction of the building where they nested to minor repair work like repointing stonework or repairing loose tiles. Although complete destruction is usually non-negotiable, demolition can at least be timed to avoid loss of active nest sites. The swift species action plan requires that demolition should not take place between May and August where swifts are known to be or suspected to be nesting.
Other threats can be either designed out altogether or mitigated by replacing lost nest sites as close as possible to those lost.
The scale of the threat in any one instance varies depending on whether the buildings are in public, corporate or private ownership. Huge areas of redevelopment pose a greater single threat but are easier to identify and to mitigate by dealing with one or two key people. Piecemeal repair and development by individual house-owners offer a less serious immediate threat but may be harder to identify and mitigate unless the owner is sympathetic.
The success of mitigation measures depends largely on the ability to retain existing nest sites or to recreate nest sites in exactly the same position as those lost. Recreating nest sites even six inches away from the originals, fails to keep the swifts.
Here's a selection of common threats with mitigation measures: