FOR444 Lecture Notes

May 9, 2000

Dr. Sue Haig: Conservation of endemic birds in the South Pacific

Avian extinctions on islands

• 93% of avian species that went extinct between 1600 – 1980 were island endemics
• main threats are habitat destruction and exotic species

Guam – of 12 native bird species, 6 are already extinct, and 6 are seriously threatened with extinction

Guam Rail – flightless; habitat and diet generalist; high fecundity; at one time was so numerous that native people kept them for pets.

Currently, there are 0 Guam rails in the wild; mainly the result of Brown Tree Snake.

Rails experienced a severe population bottleneck when a captive breeding program began in US: only 7 genetically distinct founders.

Ideas for snake control:

• Snake-proofing trees to reduce predation of nests by snakes
• Building fences that are snake barriers to exclude snakes from area where rails can be reintroduced.

Micronesian Kingfisher (MKF)

Guam “subspecies” – extinct in wild; US status = Endangered.

• Extremely precipitous population decline: from 3,000 to extinction in 40 years (less genetic diversity than in Guam rails, because rail population was about 40,000 40 years prior to extinction).

• Lack of life-history information is problematic for recovery effort
• Captive-breeding program has not been too successful
• Re-introduction is planned, but snake-free areas for release are extremely scarce!

MKF on Pohnpei may or may not be same species as on Guam. If not a different subspecies, could use healthier Pohnpei population to repopulate Guam.

Pohnpei is relatively pristine, has not yet been invaded by golf courses or BT snakes.

Project to study wild populations of MKF on Pohnpei to obtain basic life history information.

Project goals:

• Describe mating system and annual cycle
• Territoriality and dispersal – how are territories formed and maintained, and when does dispersal occur?
• Habitat Resource characteristics – what resources are required?

MKF Project Results

• Breeding behavior – findings used to improve husbandry at zoos, in captive breeding programs
• Socially monogamous
• Cooperative breeders
• Long-term pair bonds
• Nest only in arboreal termitaria in old-growth or well developed 2^nd growth forests
• Courtship ritual involving excavation of termitaria necessary for breeding

• Territoriality and dispersal – implications for captive breeding programs and potential re-introductions
• Clan/family group on exclusive territories
• Juvenile males disperse prior to breeding season, start new territories
• Space is saturated

Mariana Moorhens

Wetlands connectivity is important in population dynamics

Inter-island movement likely occurs

More known about moorhens than MKFs:

Breed year round; average of 3 chicks/brood; cooperative, polyandrous breeders (females mate with more than 1 male, males and helpers tend eggs and young).

Habit of nesting over water may have saved them from extinction by BT snake, because snakes won’t cross water to depredate nests. However, BT snake is still the major threat because of predation on chicks after they leave the nest.

Other threats:

• Navy practice of dropping torpedos in lakes where moorhens are nesting destroys many nests
• Competition and predation by introduced fish
• Introduced vegetation changes habitat
• Predation by Komodo dragons

Water Buffalo dilemna: culturally important but destroy native vegetation and habitat with their wallows. However, they are actually good for moorhens (but not for native habitats in general) because moorhens nest in the algal flats created by buffalos.

Nesting platforms have been successful in providing safe nesting habitat for moorhens