Kiore colonised Lizard Island, Mokohinau Group (outer Hauraki Gulf) in the mid 1970s, and were subsequently removed by poisoning in 1978. Studies of lizard and bird populations before, during and after the kiore occupancy provide direct evidence of the effects of kiore on an offshore island's fauna.
The kiore or Polynesian rat (Rattus exulans) has been suggested as the probable cause for reduced reptile, seabird and invertebrate faunas on many of the northern offshore islands of New Zealand, but the evidence is largely circumstantial and it is based on comparisons between islands with and without kiore.In 1977, kiore colonised a small island in the Mokohinau Group (Hauraki Gulf), where they caused a dramatic drop in lizard numbers.
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