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Conservation Conservation
Background and theory Avian
Perspective - how
many bird species extant? how
many thought to have existed calculate
extinction rate 90,000/130,000,000 yrs = .00069 why
bother worrying about a few more?
Conservation biology - Class-define
biodiversity species
level 30-100 x 106 species - can cons. bio. be species based? population
level - sources sinks metapopulations system
level species
interactions fragmentation
roots of Conservation Biology Romantic-transendental
Conservation Ethic of preservation Throreau,
Emerson, Muir 1800s Resource
Conservation Ethic - Gifford Pinchot 1900
- US Forest Service Evolutionary-Ecological
Land Ethic 1930s
- Aldo Leopold Aldo
Leopold (1887-1948) is considered the father of wildlife ecology and a true
Wisconsin hero. He was a renowned scientist and scholar, exceptional teacher,
philosopher, and gifted writer. The Land Ethic Passenger Pigeon, extinct Men still live who, in their youth, remember pigeons. Trees still live who, in their youth, were shaken by a living wind. But a decade hence only the oldest oaks will remember, and at long last only the hills will know. ... The pigeon was a biological storm. He was the lightening that played between
two opposing potentials of intolerable intensity: the fat of the land and the
oxygen of the air. Food and Fuel To avoid the first danger, one should plant a garden, preferably where there is no grocer to confuse the issue. To avoid the second, he should lay a split of good oak on the andirons,
preferably where there is no furnace, and let it warm his shins while a February
blizzard tosses the trees outside. Conservation
Biology is:
crisis discipline
manage endangered species
define critical population sizes
define habitat requirements
manage corridors?
wrestle with economics - how
much does it cost to save a species? can
species or habitat be accurately priced?
What make species vulnerable?
large size = low
population size slow
reproductive rate
top order predators - accumulate toxins
restricted range = low
numbers susceptible habitat
destruction disease/predation natural introduced hunting/trapping
physical attributes
good looks -
Snowy Egrets
parrots in general, etc. good
taste flightlessness
low numbers alone doesn’t guarantee threatened status
Passenger Pigeon numbered 2 billion
Eskimo Curlew
since 1600 = 92 extinctions 91%
partly due to introduced spp 32%
partly due to habitat change (Bachman’s Warbler in 1960s) 25%
partly due to human hunting
Modern threats
habitat loss scrubland
urban
sprawl grazing rainforest 14->7%
land area
>>50% of species coffee
plantations - Neotropical Migrants. Shade-Grown Coffee •Migratory birds and many resident birds find sanctuary in the forest canopy of traditional coffee plantations. •Shade trees protect the plants from rain and sun, help maintain soil quality, and aid in natural pest control, thanks to the birds. •Traditional coffee plantations help to conserve watersheds, leading to higher water quality and quantity for local populations. •Shade-grown coffee is cultivated in specific ways that help protect biodiversity. •Shade coffee plants can produce crops of beans for up to 50 years. Sun-Grown Coffee •90% fewer bird species are found in sun-grown coffee areas compared with shade-grown coffee areas. •Requires chemical fertilizers and pesticides and year-round labor, placing financial demands on the growers. •Leads to greater soil erosion and higher amounts of toxic runoff endangering both wildlife and people. •Sun coffee plants produce crops of
beans for only 10 to 15 years. More
threats to modern birds non-rainforest
US
wiped out all eastern forests 90%
of Pacific Northwest Northern
Spotted Owl also
Marbled Murrelet
nest only discovered 1988 wetlands development affects breeding
of waterfowl migratory
stopovers other
species - ecosystem
function Habitat
fragmentation restricts
available habitat edge
effects Direct
mortality
270*106 out of estimated 20*109 in continental US cats
- 1,000,000,000 birds/yr! underestimate feral
cats cat-scratch
fever hunters
(120,000,000) market
hunters cannons 1863
on Nantucket - killed birds till they
ran out of ammo
Plume hunters 5x106
birds/yr for fashion Chapman
counted 700 hats, 542
had birds parts 20
species
T. Gilbert Pearson – NC and the start of Audubon windows,
towers roadkills other
Pesticides & “xenobiotics” usually
affect fecundity xenobiotics
affects during embryonic development, effects show up later in life
Live bird trade 2-5
x 106 birds taken from wild/year >50%
African finches but
77 families 2x106
legally imported into US, many others smuggled Parrots
- Spix’
(Little Blue) Macaw now
two in wild, 40 in captivity $10-50K/bird
birds of prey Gyrs,
etc. - story
overblown captive
breeding
Extinct (?), Endangered, and Threatened Species
California Condor (more below)
Ivory-billed Woodpecker ?
Eskimo Curlew ? Extinctions of Birds of the Eastern US – 160 nested, 4 have gone extinct (or is it 3?) since European settlement: Carolina Parakeet Once numerous throughout forests, serious
agricultural pest. Shot by farmers, gregarious nature made it
extremely vulnerable 1831 Audubon commented on declining numbers Frank Chapman recorded the last wild flock in
Lake Okachobee FL in 1904 Captive flock survived until 1918 Passenger pigeon Once the most abundant bird on earth, with
flocks that darkened the midday sky… Gone by the turn of the 20th cent. Why? Hunting and deforestation – curiously, it
was really the railroad and telegraph that drove the final nails in the coffin Key is understanding the ecology Mast fruiting of oak, beech, hickory forests
to swamp predators Passenger pigeons responded by becoming nomads Formed huge nesting colonies in the spring
where there was an abundance of fruit from previous year Effectively used same strategy as
trees—overwhelm nest predators--One colony in Wisconsin 136,000,000 birds over
750 square miles This was good protection against hawks, foxes,
coons, but not against humans From one colony in MI 100,000 lbs of pigeon
meat shipped to market By late 1600s people noted declines Last major nesting in New England was in MA in
1851 By 1860s big flocks gone from NY and PA Fecundity low (1/pair/yr) and most nested in a
few colonies. By late 1800s last strongholds were the great
lakes region. By 1878 estimates of 50,000,000 By 1890 only scattered individuals could be
found Railroad permitted market hunters access to
even most distant colonies and ship meat back to markets and telegraph spread
the word when a new colony established itself. Last wild pigeon killed in Pike Co., Ohio in
1900. Martha, the last individual of the species died in the Cincinnati Zoo in
1914 How did they go so fast? Hunters disturbed every breeding colony for
several pigeon generations so entire cohorts died off without replacing
themselves. Few stragglers nesting in small groups
didn’t have the benefit of large numbers and fell prey to natural predators. Ivory-billed woodpecker Specialist on beetle grubs excavated from
recently deceased trees in old-growth bottomland forests of the southeast. Densities low—1 pr/6.25 miles Disappeared below radar screens in US in last
40 yrs, but credible sighting this year (2000)? Still persisting in Cuba, perhaps, but
critically threatened there as well. Clearly a case of low-density habitat
specialist succumbing to habitat loss Bachman’s Warbler A curious extinction Another bottomland specialist of the SE Wintered exclusively in Cuba Described by Audubon in 1833, not seen again
for 50 yrs (except a sighting in Cuba). Then a flurry of sightings, but by the
30s it was already declining. Last sightings in 60s – Terborgh
thinks it had a very sparse population, limited by wintering grounds (Cuba)
which spread out over a vast area. Population size got so low that birds
couldn’t find mates. Kirtland’s
Warbler - Jackpines in Mich. and Bahamas Golden-cheeked
Warbler - Edwards Plateau of central TX Austin
residents approved large bond to purchase critical habitat
Bachman’s Warbler - rarest
warbler last
sightings in SC breeds
in canebreaks & wet woodlands winters
in Cuba and Isle of Pines.
Red-cockaded WP
Neotropical Migrants
Puzzling trends
Migrants decline while non-migrants don’t
fragment size matters
data difficult to interpret
Where could problem lie?
breeding territories
wintering grounds
stopovers
Progress - Case studies what
do we need for conservation to happen an
ethic/public awareness democracy
or an environmentally benign dictatorship
laws incentives penalties
knowledge inventories natural
history captive
breeding & reintroduction legislation
- 1708/1710
closed seasons/no camouflaged or sailboats for hunting ducks 1800s
misc. restrictions on hunting 1886
AOU model law for states 1916
1st international convention - protects
migratory birds
1934 Duck stamps
1973 ESA
1985 West Hem. Res. Syst. Network
1989 CITES
successfull programs
California Condor? 1987
last Gymnogyps californianus taken out of
wild - joined 26 already in captivity
now >100 release
sites?
Whooping Cranes http://whoopers.usgs.gov/ 18
in 1939
now over 140
captive populations built with “insurance eggs” of wild birds
problems disease cross
fostering with Sandhill Cranes not
very successfull
Peregrine Falcons great
success expensive hard
to pull the plug
Aplomado Falcons - limit of range In 1977 The Peregrine Fund decided to develop a captive breeding and reintroduction program for the Aplomado Falcon because suitable habitat appeared still to exist and because their habitat requirements were consistent with certain forms of current land use, notably cattle ranching. Twenty-five nestlings were collected over a period of several years from populations in Mexico, from which a total of 578 captive-bred falcons have been released into the wild. The Aplomado Falcon recovery effort received its first hint of success when a pair of adult falcons, bred and released by The Peregrine Fund, successfully fledged young in Cameron County, Texas, in 1995. This first successful nest heralded the return of a species that had been absent from the United States for some 43 years. Mauritius
Kestrel
behavioral manipulation (as w/ Peregrines. The Mauritius Kestrel only exists in the wild on the island of Mauritius, the former home of the extinct Dodo Bird. As a result of habitat loss and pesticide contamination this small falcon was reduced to only four known wild birds in 1974.
Through captive breeding and release, and management of wild pairs, the population increased to about 100 pairs in 1996 with an estimate of 400 kestrels in the overall population. With the help of the Mauritian Wildlife Appeal Fund, The Peregrine Fund, Ruth Andres, and other cooperators a fantastic recovery has occurred.
Hawk Mountain - Rosalie
Edge / Maurice Broun logged
1,000,000th raptor in 1992 public
education Amateurs—How
can you help? xmas
counts Breeding
Bird Surveys Cornell’s
Project Feederwatch, and many other “citizen science” projects Support
conservation groups with your time and money.
Conservation Review Vocabulary: Biodiversity Questions: Who were: John Muir, Gifford Pinchot, Aldo Leopold What characteristics make a species vulnerable to extinction? Are there exceptions? Cite examples. How many extinctions of bird species have been recorded since 1600? What factors have been identified most often with these extinctions? Why should you drink shade-grown coffee? Where do Marbled Murrelets nest? (What family are they in?) What biotic and abiotic changes accompany habitat fragmentation? List 5 sources of direct mortality that threaten bird populations. How can these affects be lessened? If so much forest has been cleared in the eastern US, why have only 4 of 160 species gone extinct? How did the telegraph and railroad contribute to the extinction of the Passenger Pigeon? What are the key elements of managing habitat for Red-cockaded Woodpeckers? What species have responded successfully (or apparently successfully) to conservation efforts? What have been the keys to success in each case? What species have proven problematical? What have the problems been with these species?
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