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Demographics and adult activity of Hemiphlebia mirabilis : a short‐lived species with a huge population size (Odonata: Hemiphlebiidae)
Author(s) -
CorderoRivera Adolfo
Publication year - 2016
Publication title -
insect conservation and diversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.061
H-Index - 39
eISSN - 1752-4598
pISSN - 1752-458X
DOI - 10.1111/icad.12147
Subject(s) - damselfly , odonata , ecology , biology , population , extinction (optical mineralogy) , habitat , endangered species , threatened species , population size , local extinction , zoology , biological dispersal , demography , paleontology , sociology
Rare species are expected to be more susceptible to extinction, particularly if rarity can be used to describe several characteristics for a particular species. Hemiphlebia mirabilis , an endemic damselfly known from a few sites in the South of Australia and Tasmania, has been considered at risk of imminent global extinction, given its small population size, its localised distribution, and the fact that it is a ‘living fossil’, described as the oldest extant damselfly. One population found in a protected wetland in Victoria, was studied by behavioural observations of marked animals, during Nov‐Dec 2013. Results indicate that H. mirabilis is a short‐lived species, with a mature lifespan of about 1 week in males and 4 days in females. Population size estimates and field observations indicate that this population is huge, likely over one million individuals per generation. Adults show little mobility and fly for short distances, being inactive most of the time, particularly at temperatures below 17 °C or over 35 °C. The low mobility and cryptic coloration, and the inaccessibility of its preferred habitat might explain why huge populations like the one studied here have remained unnoticed until recently. Nevertheless, both sexes show frequent abdominal flicking displays, and fast rotations over the perching support, both behaviours apparently unique to this species, making them highly conspicuous to human observers. It is concluded that H. mirabilis should not be regarded as critically endangered.