Sea turtle migration Studies of loggerhead and leatherback hatchlings have shown that moonlight reflected from the sea is an important visual cue in guiding movement from the beach to the sea. This navigational mechanism becomes a handicap if nesting sites are affected by artificial lighting since this can mean that hatchlings head towards the artificial lights rather than offshore towards the moonlit sea. Hence, the use of moonlight by turtle hatchings as a navigational cue can be considered an 'evolutionary trap'. Loggerhead and green turtles can detect the orbital movement of waves and use this information to swim perpendicular to the waves crests.
Loggerhead shrike length, tail length, and colour. "L. l. migrans" have a paler forehead than the top of the head. According to Mundy et al.’s 1997 study, there is a substantial genetic difference between the island subspecies "L. l. mearnsi" and the mainland subspecies "L. l. gambeli" due to a gene flow barrier between the two species. The loggerhead shrike is a medium-sized passerine. "Loggerhead" refers to the relatively large size of the head as compared to the rest of the body. It measures approximately 9 inches from bill to tail. The wing and tail length is about 3.82 and 3.87 inches