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Street lighting on coastal roadways is often visible at sea turtle nesting beaches, and disrupts the nocturnal orientation
of hatchlings as they crawl toward the sea. Our objective was to determine whether an alternative lighting system (light-emitting
diodes, embedded in the roadway pavement) prevented orientation disruption. Hatchlings at the beach oriented normally when
only the embedded lights were on, or when all lighting was switched off. However, turtles showed poor orientation when street
lighting was on. Measurements confirmed that street lighting was scattered to the beach, whereas embedded lighting was not.
We conclude that embedded lighting keeps the beach dark and thus protects sea turtles. However, on two overcast evenings,
lighting (“skyglow”) from nearby development, reflected by cloud cover to the beach, weakened hatchling orientation. Thus,
both indirect (reflected) and direct sources of lighting negatively impact the turtles. 相似文献
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Claudia Borgioli Giovanni Maria Marchetti Felicitas Scapini 《Behavioral ecology and sociobiology》1999,45(2):79-85
Under stressful conditions (e.g. finding themselves on dry or moisture-saturated substrates) littoral talitrids (Crustacea,
Amphipoda) demonstrate zonal orientation, in which they must promptly reach the optimal zone of the beach, the wet fringe
near the shoreline. A relationship might therefore exist between the use of orientation and the frequency of such stressful
conditions in the natural environment. Moreover, the efficiency of orientation toward the sea could be related to the possibility
of using strategies other than zonal orientation in order to avoid stress. This study analysed the actual use and efficiency
of orientation under natural conditions of four Talitrus saltator (Montagu, 1808) populations from Mediterranean and northern European Atlantic coasts with different ecological features.
Orientation tests were carried out on the beach with all natural cues available. Then the same individuals underwent control
experiments to study their sun orientation far from the sea in an experimental arena. The following results emerge from the
comparison of the circular distributions: (1) marked differences among populations in the precision of zonal recovery under
natural conditions; (2) a common solar orientation capacity in the control tests far from the sea; (3) different orientation
choices of the same individuals according to the test conditions, natural or controlled. The habitat diversity of the four
populations (amount, distribution and kind of detritus and wrack on the beach, degree of coastal erosion, orientation of the
shoreline, human use of the beach) provides an ecological interpretation for the differences in orientation observed among
populations.
Received: 13 October 1997 / Accepted after revision: 26 April 1998 相似文献
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