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Purple Martin Foundation mission statement

-restore and conserve Western Purple Martin populations along W Coast of NA
-return BC Purple Martins to natural nesting sites in open forest and near freshwater habitats
-eliminate need for human intervention for survival in BC


What do Purple Martins eat

Insects! fly up to high altitudes to catch large flying insects such as dragonflies, moths, beetles, & smaller insects. Dragonflies especially good for hungry nestlings


nootropic migration

A bird that spends the summer in its breeding range in Canada or the United States (the nearctic) but migrates to Mexico, Central America, South America or the Caribbean (the New World or neo-tropics) for its nonbreeding range in winter


Western Purple Martin northern limit of breeding range

north end of Georgia Basin, near Campbell River, VI


PM timing of migration

Adults arrive in BC early-mid April
Younger subadult birds arrive later in May and June


largest BC PM colony

Ladysmith Maritime Society marina in Ladysmith Harbour (67 nests, 2008)


PM colonies

mostly 5-30 nesting pairs in artificial housing and less than 10 pairs where they still occur in the wild in the western USA.


Where do PM's build colonies

cavities, traditionally woodpecker holes close to water
now, mainly human provided nest boxes- clustered together on marine pilings near/on water


Eastern vs. Western PM nesting

Eastern prefer condo-style or hanging gourds
W prefer individual boxes in loose clusters


How PM's are being tracked ("new")

miniature light-level geolocator data loggers recently developed by the British Antarctic Survey (www.birdtracker.co.uk)


how do miniature light-level geolocator data loggers work

record time and light intensity every 10 minutes, allows determination of bird’s position from day length and sunrise/ sunset times


precision of miniature light-level geolocator data loggers

(+/- ~300 km)
battery expectancy >1.5yrs


the PM study

put locators on 20 adults on Central VI, July-Aug 2009
worn until they returned in spring 2010


how are geolocators attached

attached with a tiny “backpack” harness around the legs, a design which neither harms the bird nor interferes with its movements


PM study, year 2

only recovered 1 locator
find migration = ~22,000 km long
applied 10 more locators


PM study, year 3

retrieved 4 locators
added 20 more locators


PM conservation goals

-sustain current highly successful volunteer nest-box-based recovery program
-increase abundance to min 800 nesting pairs by 2012
-re-introduce sig. proportion of population to original/equivalent nesting cavity situations in wild
-redevelop a sustainable wild-nesting population (as far as practical)


BC PM nest box program

1985- installation of nest boxes at Cowichan Bay, probably rescued from extirpation
increased slowly, nest boxes installed at more suitable marine locations
1989- 14 nesting pairs located at 3 nest box sites and 1 piling location on S VI
-2000 ~200 pairs at 16 colonies.


BC PM nest box program, 2000's

2002- Georgia Basin Ecological Assessment and Restoration Society (GBEARS) takes over and renames "BC Purple Martin Stewardship and Recovery Program"
2005-06, freshwater sites added


PM volunteers

now 145+ volunteers
First Nations, individuals, naturalist/conservation groups, corporations, federal, provincial, regional/municipal government departments, and universities


PM recovery and weather

warm = insects = success-- 2006, population tripled
cold wet = less insects = population slows or declines
2008- worst conditions, long cold spring, week of rain at end of July, lack of food = loss of ~100 adults and ~40% of nestlings, subsequent decline in breeding pairs the next year


moving PM's back to natural sites

Two freshwater sites were occupied in the Fraser Valley area for the first time in almost 40 years – one each in 2006 and 2007. There are currently 1500 nest boxes distributed among 70 marine and 20 freshwater locations.


reasons for bird surveys

simply wanting to know # of species
baseline information for poorly known species/area
land development assessment designation (legal protection)
set priorities to focus conservation efforts
determine habitat associations


why monitor

estimate population trends over time
set conservation priorities
research tool
early pointers for underlying causes of trends
underlying demographic mechanisms
determining success of conservation actions


conservation actions

acquisition of land to protect species
adoption of new management practices
species recovery programs
government environment policies


very important for monitoring

consistency of method is crucial


most common deforestation causes

agriculture, unsustainable forest management, mining, infrastructure projects, increased fire incidence/intensity


indirect effects on deforestation

road building, opening up passages, 'death by a thousand cuts'


deforestation, Conversion of forests

removing natural forests to meet other land needs, such as pulp/palm/soy plantations, agriculture, pasture for cattle settlements and mining, settlements, roads and infrastructure


deforestation, Forest fires

millions of ha/yr
worse where fires have been suppressed for years (unnatural accumulation makes fire burn more intensely)