78). Males were found vocalizing throughout the year, while females were less common and gravid females were only found in November, March and June. Recapture probability was relatively constant at 25% for males, 24% for females and, overall, 29% of males were recaptured at least once. Young individuals were encountered
in all months but one and, being extremely small, were impossible to quantify. Thus, the Striped Frog is active and breeding year-round as indicated by the constant singing of adult males, the few gravid females found at different times and the frequent encounters of young frogs at all times of year. While survival and captures varied throughout the year, the only seasonality was in the number of captures that increased during longer nights. Nonetheless, click here recapture probability was constant. These dynamics contrast strongly with most anuran species and especially subtropical selleck and temperate species
in other places. This first detailed study of population parameters of a subtropical species with its unusual dynamics may suggest that once studied, other species of anurans may also have surprising population dynamics. “
“About 300 species of mammals have adapted to the dark underground ecotope. Despite a long history of underground existence, many strictly subterranean species have retained structurally normal eyes possessing the capability of image-forming vision. Moreover, their retinae often feature high cone proportions, an indication of conserved photopic (daylight) vision. Although it has been suggested that low acuity vision plays an important role in predator avoidance, not a single attempt to measure light conditions in burrows has been made so far. Here, we report the first measurements of light propagation in an illuminated artificial tunnel and DOK2 in experimentally opened burrows
of Ansell’s mole-rat, Fukomys anselli in its natural habitat. Only about 0.2–2.5% of the ambient visible light entered the opened burrow. Light intensity attenuated quickly and reached mesopic light levels (at which both cones and rods contribute to vision) within a few centimetres from the burrow opening; scotopic light levels (at which only rods operate) were estimated to be reached at one to a few metres from the opening. Thus, although cones may hypothetically contribute to vision for up to a few metres, they play an indispensable role only in the immediate vicinity of a breach, where rods are fully saturated. Rod-mediated light sensation in straight tunnels seems to be possible over distances much longer than 100 m, implying that it is the burrow architecture (tortuosity and branching) what limits light sensation under natural conditions. These findings clearly show that light propagating within a breached burrow may serve as a reliable cue providing information about the site of potential predation risk.