Perches placed nearby enabled exhausted migrants to rest in safety. This scheme was very successful and many birds were able to continue their journey when the weather improved. Many have been killed in this way, but many others find a safe perch on the brightly illuminated platforms. Weather in the British Isles frequently makes migration difficult. Overcast skies, headwinds and driving rain slow movement almost to a halt.
Many birds go off course and perhaps never reach our shores.
Others arrive exhausted and seek shelter in coastal fields, woods and gardens before continuing their journey. Sometimes unusual birds, intending to fly somewhere completely different, are blown onto out shores. There are examples of birds migrating successfully and of racing pigeons returning home in conditions when they could not see the sun or stars. They may have other means of navigation. There is a real possibility that birds such as homing pigeons have a magnetic sense.