Natural exposure to ultraviolet‐B radiation in two species of chameleons from Madagascar

Abstract

Many reptiles require ultraviolet-B radiation between 290 and 315 nm (UV-B) to synthesize vitamin D3 and process dietary calcium. In captivity, exposure to too little or too much UV-B can result in health problems such as metabolic bone disease. While it is recognized that UV-B is necessary to successfully maintain many reptiles in captivity, the actual levels of UV-B that species are exposed to in nature is poorly known. We measured the UV-B exposure of two species of chameleon (Calumma brevicorne and C. nasutum) in the field in Madagascar over a period of four months. We found that both species were exposed to less UV radiation than that which was available in full sun.Only on rare occasions were chameleons observed in areas with a UV Index (UVI) greater than 3.0, and the median UVI for both species was only 0.3. There was no daily temporal pattern in UV exposure for C. nasutum, but C. brevicorne was found in areas with lower UV levels in the late afternoon when compared to late morning.Additionally, C. nasutum males showed higher UV exposure than females in late morning. Our results suggest that both C. brevicorne and C. nasutum can be classified as Ferguson Zone 1 species, and should be provided with a UV-B gradient in captivity that offers access to UV-B radiation as well as adequate shaded refuge. K E Y W O R D S Calumma, captive husbandry, Ferguson Zone, reptile lighting, UV-Index wileyonlinelibrary.com/journal/zoo Zoo Biology. 2018;37:452-457. SUPPORTING INFORMATIONAdditional Supporting Information may be found online in the supporting information tab for this article.

Is the natural UV zone important for successful captive propagation of the Panther Chameleon (Furcifer pardalis); are different UVB irradiance exposures that generate a similar dose equally successful?

“…We have limited knowledge of reptiles' UVB requirements (Baines et al, 2016; Schmidt et al, 2010). A few studies document a species' natural UVB irradiance exposure in the field (Baines et al, 2016; Edmonds et al, 2018; Ferguson et al, 2010). However, daily dose exposures are unknown for most of these (Ferguson et al, 2014, 2015).…”