Precipitation and timing of flowering in ghost orchids (Epipogium aphyllum Sw.)

The rare, fully mycoheterotrophic Ghost Orchid, Epipogium aphyllum is only visible during its short flowering and fruiting season, which lasts for a few weeks between May and October. Due to the apparent unpredictability of its flowering, decades may pass between subsequent observations at the same locality. The factors affecting timing of flowering in this enigmatic species remain largely unexplored. In Hungary, it is an extremely rare species: between 1924 and 2014 only 25 dated observations from 15 locations are known. Hungary is located on the edge of the species’ distribution area where higher precipitation may occur only in higher regions of mountains. Hence, the spatial and temporal pattern of precipitation might limit the emergence of generative shoots. In this paper we compared rainfall patterns in relation with the Ghost Orchids’ observations to multiannual precipitation averages. The year of flowering and the month preceding flowering (but not the year before flowering and the month of flowering) were characterised by significantly more rainfall than the multi-annual average precipitation. These results suggest that the appearance of the species in Hungary is precipitation-dependent

Seasonal Changes in Colour: A Comparison of Structural, Melanin- and Carotenoid-Based Plumage Colours

Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult, although whether this affects signalling has not been sufficiently assessed.) displaying various coloration types (melanin-, carotenoid-based and structural). Birds were caught regularly during three years to measure plumage reflectance. We used models of avian colour vision to derive two variables, one describing chromatic and the other achromatic variation over the year that can be compared in magnitude among different colour types. All studied plumage patches but one (yellow breast of the blue tit) showed significant chromatic changes over the year, although these were smaller than for a typical dynamic trait (bill colour). Overall, structural colours showed a reduction in relative reflectance at shorter wavelengths, carotenoid-based colours the opposite pattern, while no general pattern was found for melanin-based colours. Achromatic changes were also common, but there were no consistent patterns of change for the different types of colours.Changes of plumage coloration independent of moult are probably widespread; they should be perceivable by birds and have the potential to affect colour signalling

Predictors of conservation value of Turkish cemeteries: A case study using orchids

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