Contrasted influences of moon phases on the reproduction and movement patterns of four amphibian species inhabiting different habitats in central Italy

Abstract

Many studies have provided evidence that prey adjust their behaviour to adaptively balance the fitness effects of reproduction and prédation risk. Nocturnal terrestrial animals should deal with a range of environmental conditions during the reproductive season at the breeding sites, including a variable amount of natural ambient light. High degrees of illumination are expected to minimize those behaviours that might increase the animal detection by predators. Therefore, under habitat variable brightness conditions and in different ecosystems, the above mentioned hehaviours are expected to depend on the variation in prédation risk. Although moon effects on amphibian biology have been recognized, the direction of this infiuence is rather controversial with evidences of both increased and depressed activity under full moon. We tested in four noctumal amphibian species {Hyla intermedia. Rana dalmatina. Rana itálica. Salamandrina perspicillata) the effects of different (i) light conditions and (ii) habitats (open land vs. dense forest) on the reproductive phenology. Our results showed that the effeets of the lunar cycle on the study species are associated with the change in luminosity, and there is no evidenee of an endogenous rhythm controlled by biological clocks. The habitat type conditioned the amphibian reproductive strategy in relation to moon phases. Open habitat breeders (e.g., ponds with no canopy cover) strongly avoided conditions with high brightness, whereas forest habitat breeders were apparently unaffected by the different moon phases. Indeed, for all the studied species no effects of the moon phase itself on the considered metrics were found. Rather, the considered amphibian species seem to be conditioned mainly by moonlight irrespective of the moon phase. The two anurans spawning in open habitat apparently adjust their oviposition timing hy balancing the fitness effeets of the risk to be detected by predators and the reproduction.

Winter habitat associations of eastern spotted skunks in Virginia

“…Therefore, overcast skies from inclement weather or shade from canopy cover may not be affecting the response of spotted skunks to moon illumination. In areas of variable percent canopy or forest type, activity patterns and detectability of nocturnal animals may be influenced by light intensity irrespective of moon phase (Vignoli et al ); however, our study was unable to distinguish between the effects of light intensity and moon phase. We found no strong effect of survey effort on detectability, which suggests the variation in survey length among sites likely did not bias spotted skunk detection probability.…”

Sexual dichromatism and throat display in spectacled salamanders: a role in visual communication?

“…0.1–0.001 lux; Roth, 1976, 2012), comparable to those occurring during the active hours of Salamandrina in nature (i.e. <0.001 lux under forest canopy; Vignoli et al., 2014). Moreover, amphibians are well known to detect and rapidly respond to changes in visual scenery, and to lose interest in static objects, due to the lack of foveae (Ewert, 2004).…”

“…Salamandrina are typical forest‐dwelling salamanders, and their terrestrial activity, as for many other salamanders (Wells, 2007), is mainly influenced by soil moisture. Consequently, terrestrial activity is positively associated with higher canopy cover, precipitation, nocturnality and cloud cover (Angelini et al., 2007; Romano et al., 2017; Utzeri et al., 2005; Vignoli et al., 2014), all being conditions that imply low light intensity levels. There are currently no studies assessing the visual capabilities of Salamandrina spp., yet other salamanders are capable of visually locating inconspicuous objects at very low light intensity levels (e.g.…”

Assessment of habitat and survey criteria for the great crested newt (Triturus cristatus) in Scotland: a case study on a translocated population

“…For example, newts may be less disturbed by torchlight when there is a natural source of bright light. However, several species of amphibian have been observed to synchronise breeding behaviour in response to the lunar cycle (Vignolli & Luiselli, 2013;Vignoli et al, 2014;Kusano et al, 2015). Great crested newt activity is reported to increase around the new moon of the lunar cycle, linked to geomagnetism and higher gravitational pull (Grant et al, 2009).…”