miércoles, 17 de diciembre de 2014

New Publications !!

Rivas, M., Santidrián Tomillo, P., Diéguez Uribeondo, J. and Marco, A. Leatherback hatchling sea-finding in response to artificial lighting: Interaction between wavelength and moonlight.

© Dawn Witherington | DrawnbyDawn.com
Over the last decades, growing human populations have led to the rising occupation of coastal areas over the globe causing light pollution. For this reason, it is important to assess how this impact threatens endangered wildlife. Leatherback turtles (Dermochelys coriacea) face many threats of anthropogenic origin including light pollution on nesting beaches. However, little is known about the specific effects. In this study we studied the effect of different light wavelengths (orange, red, blue, green, yellow and white lights) on hatchling orientation under the presence and absence of moonlight by analyzing: (i) the mean angle of orientation, (ii) crawling duration, and (iii) track patterns. Hatchling orientation towards the sea was always better under controlled conditions. In the absence of moonlight, leatherback hatchlings were phototaxically attracted to the experimental focus of light (misoriented) for the colours blue, green, yellow and white lights. Orange and red lights caused a lower misorientation than other colors, and orange lights produced the lowest disrupted orientation (disorientation). On nights when moonlight was present, hatchlings were misorientated under blue and white artificial lights. Crawling duration was low for misoriented hatchlings and high for the disoriented individuals. Our conclusion to this is that hatchlings can detect and be impacted by a wide range of the light spectrum and we recommend avoiding the presence of artificial lights on nesting beaches. Additionally, actions to control and mitigate artificial lighting are especially important during dark nights when moonlight is absent

Journal of Experimental Marine Biology and Ecology 463 (2015) 143–149

Dornfeld, T, Robinson, N. J, Santidrián Tomillo, P., Paladino,  · Frank V. Ecology of solitary nesting olive ridley sea turtles at Playa Grande, Costa Rica

© Dawn Witherington | DrawnbyDawn.com
Olive ridley turtles (Lepidochelys olivacea) have two distinct mating systems: independent (solitary) and synchronized and mass assemblages (arribadas). Arribada nesting beaches have been the focus of most research, even though solitary nesting is the most common behavior. The purpose of this study was to assess the contribution of solitary nesting turtles to the olive ridley turtle population. We studied the nesting ecology of solitary nesting olive ridley turtles within the national park Parque Nacional Marino Las Baulas (PNMB) in Playa Grande, Costa Rica (10°20′N, 85°51′W) and compared these turtles to nearby arribada turtles. Between 2009/2010 and 2013/2014, an estimated 933 nesting activities occurred within PNMB. This number of turtles has not changed significantly since 1995. During this study, 285 females were tagged; of these, 30 females were encountered nesting on more than one occasion. Significantly, more females emerged (31.1 % of tracks) during the third-quarter moon, often a predictor. of arribada events, than any other moon phase. However, there was no significant change in nesting activity at PNMB during nearby arribada events. Mean hatching success (78.5 ± 23.4 % SD) was higher, and incubation temperatures were lower (ranging from 28.3 to 33.4 °C) than at nearby arribada beaches. Thus, clutches are relatively successful and may produce males. These data suggest that solitary olive ridley turtles are important. Currently, PNMB protects turtles from October to March; however, hatching success was highest and 40 % of nesting activity occurred during the rainy season (August–November). More turtles could be protected by increasing the temporal scope of park protection.

Marine Biology: DOI 10.1007/s00227-014-2583-7

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