Bioacoustics of Altihoratosphaga montivaga

In the acoustic repertoire of A. montivaga, the combination AB is also the most distinctive verse type. However, in our recordings it was never found to be isolated, but was always preceded by several (mostly two) A elements, with increasing amplitude (Fig. 3). This complete final verse (A + A + AB) is usually preceded by a series of often three, rarely up to 15, softer verses, consisting of A elements only or additionally with an abbreviated B element (one or two impulses only), separated from each other and from the final verse by intervals of around 10–20 s. Rarely, other final structures such as A + AB or A + A + AB + AB were observed (N= 81 final verses in 90-min recording time). The structure of both elements was the same as in A. hanangensis sp. nov., with between six and eight single impulses or impulse groups in element B. Differences in the duration of both parts may be at least partly related to temperature differences.

Diet : Seen feeding on the herb Isoglossa laxa . Habitat. Plantation belt, montane forest (Sjöstedt 1909); clearings with Isoglossa laxa in Olea africana forests of West Kilimanjaro, in extensively used coffee-plantations at West Kilimanjaro and forest edge with dense bushes and herbs. On Mt Meru at 1400 m on the eastern slopes on clearings within disturbed forest. Song. All Altihoratosphaga species produce songs containing two types of elements, A and B with A. montivaga showing the most distinctive verse type (Hemp et al . 2010c). The song is mainly heard in the night hours. Molecular phylogeny: Vo j e et al . 2009. Hemp et al . 2010c. Altitudinal range at Mt Kilimanjaro : 1000–1200 m (Ragge 1960); 1300–1800 m On Mt Meru up to 3000 m (Sjöstedt 1909). Records : 9