This double CD contains vocalisation of two bird groups, treecreepers and kinglets (genera Certhia and Regulus). For both genera, all species and many of the subspecies are represented. Of the wide-spread Goldcrest, most of the subspecies are included, from the Azores and Canaries to Siberia, China and Japan. This holds true also for the treecreepers wherever possible. Treecreepers are represented by 43 tracks, the kinglets by 46 tracks.