Vocalisations and seasonal variation in singing and aerial displays of the Short-clawed Lark Certhilauda chuana

Abstract

The southern African endemic Short-clawed Lark Certhilauda chuana is listed as 'Least Concern' globally. As a result of its highly localised distribution in South Africa, it is regarded as a species of conservation concern, and it is afforded legal protection in all three provinces in which it is found. Its calls are distinctive and a valuable aid to correctly identify the species for monitoring purposes. However, descriptions of the various calls are ambiguous in some publications, and the existence of local dialects further complicates the correct identification of the species. Here we report on the vocal repertoire and annual variation in vocalisations and displays of Short-clawed Larks from the species eastern population. Short-clawed Lark vocalisations can be divided into four categories: territorial calls (males only), contact calls (both sexes), song (mostly males only) and nestling distress calls. Each male has a limited territorial call repertoire of only 3–6 'signature' phrases. The limited number of phrases facilitates recognition of neighbours and strangers for a resident, territorial species such as Short-clawed Lark. Vocalizations and aerial display frequency peaked 1–3 hours after sunrise in the peak (December) and late (March) breeding seasons. Knowledge about the vocal repertoire and seasonal variation in the frequency of the different vocalisations and aerial display flights will be valuable from an atlasing point of view and for designing a monitoring protocol for the species.