Hawaiian Hoary bat

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Hawaiian Hoary bat
Conservation status
Image:Status iucn2.3 EN.svg
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Chiroptera
Family: Vespertilionidae
Genus: Lasiurus
Species: L. cinereus
Subspecies: L. cinereus semotus
Binomial name
Lasiurus cinereus semotus

The Hawaiian Hoary bat (Lasiurus cinereus semotus) is an endemic land mammal in the Hawaiian islands. The bat is a member of the family vespertilionidae or common vesper bat.[1] The Hawaiian Hoary bat is considered a subspecies of the North American Hoary bat which is considered the most widespread bat in the continental U.S.[2] The Hoary bat is named after the animal's appearance: "Hoary" describes the fur of the bat, which is brown and grey, tinged with white, so that the bat looks "frosty."

When the bat was first discovered by the native Hawaiian inhabitants it was named "Opeapea" which refers to the bats half taro leaf, canoe sail body outline.[1] The Hawaiian Hoary bat weighs between 5-8 ounces. The Hoary bat is solitary, nocturnal and it feeds on insects. In a single night the Hoary bat can eat up to its own weight in insects.[1] The female bats are larger than the males with a wing span of approximately 10.5-13.5 inches.[3] It has been documented by the fossil record that the Hawaiian Hoary Bat was once present on the islands of Hawaii, Molokai, Maui, Oahu, and Kauai, but now they have only been documented as breeding on the islands of Hawaii, and Kauai. A complete extinction of Hawaiian Hoary Bats on the island of Oahu was hypothesized to be due to a loss of habitat brought upon by the land change to accommodate humanity in the 19th century.[4] Much of the forest was cut down to make room for houses and buildings. On top of habitat change the Hawaiian Hoary Bats populations appear to be indirectly effected by the use of pesticides, the mechanisms are as of yet, unknown.[5]

Contents

[edit] Endangered species status

In 1970, the Hawaiian hoary bat was listed as endangered under the Endangered Species Conservation Act of 1969[6] which was later replaced by the Endangered Species Act of 1973.[7] Under section 3 of the endangered species act, an "endangered species" is any species or subspecies that is "in danger of extinction throughout all or a significant portion of its range." The exact number of Hawaiian Hoary bats is unclear and remains unknown. The decision to add the Hawaiian Hoary bat to the endangered list seems to have been precautionary[8] and motivated by the rapid extinction on the island of Oahu, and the loss of forest habitat in the bat’s range.[9] Till this day there exists conflict on the decision to list to Hawaiian Hoary bat as endangered. According to Fuller, 1989 who surveyed the island of Kauai for Hawaiian Hoary bats, "the Hawaiian Hoary Bat is deserving of its endangered status" while others such as the article written in Plants and animals of Hawaii by S. Scott (1991) claim that "although the Hawaiian Hoary bat is on the federal endangered list, it may not truly be endangered." Until exact numbers of the Hawaiian Hoary bats are found, uncertainty over whether or not the bat should be listed as endangered is a matter of opinion. However, since the Hawaiian Hoary bat was listed in the 1970's conservation has been underway by the Nature Conservancy, the US Fish and Wildlife Service, and independent researchers.

[edit] Recovery plan and conservation methods

The US Fish and Wildlife Service has appropriated a recovery plan for the Hawaiian hoary Bat.[10] The goal of the recovery plan is to de-list the Hawaiian Hoary Bat from endangered status to threatened status[11] however, due to the lack of understanding of the life history of the bats, more information is needed to conclude effective numbers for de-listing the bat. According to the recovery plan, all islands that have Hawaiian Hoary bats must have increasing populations for at least 5 consecutive years to be considered for down listing to threatened status.[12] New methods are being infiltrated to try and get a good estimate of the population numbers of Hawaiian Hoary Bats. One method that looks promising is monitoring the bats echolocation calls. Unlike most parts of the world where there are other species of bats whose calls would interfere with the hoary bat's echolocation transmissions, the Hawaiian hoary bat is the only species of bat found in Hawaii so any echolocation tranmission[13] that is heard and recorded is from the Hawaiian Hoary bat.[14] So far, echolocation monitoring has worked well because it is non-obtrusive to the bats, which is important when working with an endangered species.[15] Another approach that is being looked into is that of putting GPSsatellite receivers on the bats to try and gain a better understanding of their life histories and strategies. However, since the bats are small it is hard to outfit them with trackers without potential side effects of the already endangered bat.[16]

[edit] Outlook

Although not much reliable information is known about the Hawaiian Hoary Bat, its prognosis for survival seems high due to the facts that it is found on multiple islands, there have been frequent individual sightings, and it can be found in both native and non-native plant habitats; which shows diversity in livable habitats.[17][18]. For these reasons the conservation of the Hawaiian Hoary Bat seems probable, and possible. By the year 2010, the US Fish and Wildlife Service hopes to have the Hawaiian Hoary Bat listed as threatened and not endangered.[19]

[edit] Notes

  1. ^ a b c Honolulu Zoo, 2007 [1]
  2. ^ Shump and Shump, 1982
  3. ^ USFWS 2007
  4. ^ Tomich, 1986
  5. ^ USFWS. 1998
  6. ^ USFWS, 1970
  7. ^ Species Profile
  8. ^ Fuller, 1989a
  9. ^ USFWS 1998
  10. ^ http://ecos.fws.gov/docs/recovery_plans/1998/980511b.pdf
  11. ^ USFWS: Recovery Plan 1998
  12. ^ USFWS: Recovery Plan 1998
  13. ^ [2]
  14. ^ Fenton et al. 1994
  15. ^ Fuller. 1989b
  16. ^ USFWS 2007
  17. ^ Nature Conservancy Website, 2007
  18. ^ Microsoft Word - HHBats_20070405final.doc
  19. ^ USFWS: Recovery Plan 1998

[edit] References

  1. Fenton, MB, Rautenbauch, IL, Smith, SM, Grossel, J and van Jaarsveld, J. 1994 Bats and Raptors: Threats and Opportunities. Animal Behaviour Vol: 48. Pg 9-18.
  2. Fullard, JH 1989a Opeapea: Hawaii’s elusive native bat. Bats Vol: 17(3) Pg 10-13.
  3. Fullard, JH 1989b Echolocation survey of the distribution of the Hawaiian Hoary Bat (Lasiurus cinereus semotus) on the island of Kauai. Journal of Mammalogy. Vol:70 Pg. 424-426.
  4. The Nature Conservancy in Hawaii: http://www.nature.org/wherewework/northamerica/states/hawaii/science/art2417.html
  5. Scott, S. 1991 Plants and Animals of Hawaii. Bess Press, Honolulu, Hawaii.
  6. Shump, KA Jr. Shump, AU. 1982 Lasiurus cinereus. Mammalian Species. No:185 Pg 1-5.
  7. Tomich, PQ. 1986 Mammals in Hawaii (2nd edition). Bishop Museum Press, Honolulu, Hawaii.
  8. US Fish and Wildlife Service 1970. Appendix D-United States list of endangered native fish and wildlife. Federal register, 35: 16047-16048.
  9. US Fish and Wildlife Service 1998. Recovery Plan for the Hawaiian Hoary bat. US Fish and Wildlife Service. Portland, OR.
  10. US Fish and Wildlife Service Website 2007. http://www.fws.gov/pacificislands/wesa/hrybatindex.html
  11. The Honolulu Zoo: http://www.honoluluzoo.org/hawaiian_bat.htm. 2007.
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