Download Climate Change and Biodiversity

Climate Change
and
Biodiversity
Dr. Jerry Skinner
KCeeI, July 23, 2008
Golden Toad
Bufo periglenes
Once abundant in the cloud-shrouded rainforests of Monteverde in
Costa Rica, no one has seen one since 1989.
Harlequin Frogs
About two-thirds of
Central and South
America's 110 harlequin
frog species are
believed to have
vanished during the
1980s and 1990s. The
primary culprit is the
pathogenic chytrid
fungus
Batrachochytrium
dendrobatidis, which
has been favored by
global warming.
Ivory Gull
Birds and Climate Change
• More is known about them
– not too many ‘fish-watchers’
– ‘canaries in the coal mine’
• 9787 known living species
– 21% (2,055 species) are extinction prone
(for a variety of reasons)
• habitat destruction/fragmentation impacts ~85%
• climate change is quickly emerging as a leading
factor
• growing season-increased 10 to14 days in
temperate latitudes in past 19 years
• phenology
• primary production
• species distributions and diversity
Impacts on Individual Birds
• are homoeothermic
(warm-blooded)
• have a energy budgets
• must thermoregulate
• Q-10 effect
Case Study: American Robin, Turdus migratorius
• Why are they
distributed as they
are?
• What determines
northern/southern
limits?
• What determines
migration routes?
Nesting
•where to build
•how many eggs
•how many clutches/yr
Ability to find food
What do they eat?
Being out of ecological synchrony
• tied to seasonal events: flowering, seeds, insect
emergence, etc.
• phenology:
– egg laying-UK-20 of 65 species studied were laying
8.8 days earlier
– migration timing-Canada-1st spring sightings-63 yr
data set, 25 of 96 species had altered arrival dates
significantly, most (but not all) arriving earlier
• some individuals are no longer migrating-nonmigratory
populations?
Being out of ecological synchrony
• being out of step with food supplies may mean the early
bird doesn’t get the worm
• species may be driven by different cues:
– birds by photoperiod
– insects by temperature
• examples
– Spain: leaf out 6 days earlier, flower 6 days earlier than 1952;
fruiting 9 days earlier; but spring migrants arriving 15 days later.
– France: Blue Tits almost double normal metabolic rate while
foraging. They must search harder for food because breeding
cycle is behind the peak of insects-food is scarcer.
– Long-distance migrants from neotropics can’t predict the onset of
favorable conditions on breeding grounds 1000s of miles to the
north
Can’t they just move?
• many species rich areas are already
protected, e.g., national parks, nature
preserves, etc.
– if vegetation changes, habitats are lost
Case Study: Prairie Potholes
• provide breeding habitat for 50-80% of
N.A. ducks, the most productive area in
the world—a ‘duck factory’
• model based on
– doubling of CO2 by 2060
– 2.5 ºC increase in temperature
– no increase in precipitation
• results
– number of ponds decreases by 67%
– duck numbers reduced by 72%
What makes a species extinction prone?
• specialists (vs generalist)
– habitat
– food
– nesting requirements
– restricted range
• important to humans
• predators, diseases, etc.
Will ‘southern’ species replace those
that are being squeezed north?
Ecological communities will be reshuffled
As species move they may have to deal
with changes in
– prey
– predators
– competitors
– parasites
– diseases
– habitats that are less than ideal
Case Study: Hawaiian Honeycreepers
Honeycreepers
• once 29 species, now 19 due to habitat
loss, disease, predators
• avian malaria, one agent, pushed their
distribution to altitudes where the mosquito
was rare
• 2ºC increase will reduce habitat by 50%,
96%, and 100% in their three established
refuges
Reverberations through the food chain
Two hundred years from now, people will not remember Iraq.
They will laugh at our distress over $4.00 gas prices.
What they will remember is that
•this President
•this Congress
•this Generation…
…was in charge when something needed to be done.
when something could have been done.
Will they be proud of us?