Transcript Endangered Species - M. Lang Standring

Q&A
 What
does it mean for an organism
to be endangered ? Do you know of
any animals who are endangered?
Endangered Species
Classifying Species at Risk
 Extinct
– a species that is no longer
found anywhere (i.e. Blue walleye)
 http://www.brainpop.com/
(extinction)
Another One Bites the Dust …

Passenger Pigeon
– Let’s meet Martha
– Last passenger pigeon– Died in 1914 in Cincinnati
Western Black
Rhino
Became
extinct in 2006 due
to over poaching
and habitat
distruction
 Endangered
– A species that is close
to extinction in all parts of Canada
(giraffes, polar bears etc. )
Eastern
Cougar
Extinct
2015
 Extirpated
– any species that no
longer exists in one part of Canada,
but can be found in others (i.e.
grizzly bear)
Classifying Species at Risk
Threatened – any species that is likely to
become endangered if conditions are not
reversed (i.e. wood bison)
 Did you know ?

– Almost 200 000 once roamed the north but by the
early 1900s their numbers had plummeted to fewer
than 300.
– ･Since 1980 has brought their numbers up to
approximately 4500 but bovine diseases, brucellosis
and tuberculosis remains a major obstacle to further
recovery
Wood Bison
 Vulnerable
– any species that is at
risk because of low numbers (i.e.
grey fox)
Classwork
 Page
14-15, #2
 Read pages 16-19 #1 - #3
3
Activity- Food Chains
groups:
– 18 Grasshoppers
– 6 Shrews
– 2 Hawks
 Grasshoppers
hunt for food first
 Put as much food (plants and
flowers) in their stomachs
 You have 30 seconds to eat without
the threat of predators (shrews)
 You can continue eating once the
shrews are hunting
 Shrews-
Watch the grasshoppers
feed like good predators
 Try to catch the grasshoppers by
tagging them
 Once you tag a grasshopper, you
take their bag of food and the
grasshoppers goes to the side.
 You can tag more than one
grasshopper but watch out for
hawks!
 Hawks- Go and hunt some shrews!
– Don’t forget to take all their bags of
food !
Food Chain Activity- Back in the
Class
 Uneaten
players – Count your total
food tickets
 How many green did you have ?
 How many pink?
SURPRISE
 All
the green plants were actually
sprayed with a pesticide
 This pesticide accumulates in food
chains
 All surviving grasshoppers with green
tickets = dead
 All surviving shrews with more than
half green tickets= dead
 Hawks- you don’t die…. But….
Hawks
 You
have so much pesticide in your
body that the egg shells produced
during your next mating season will
be so thin that they eggs will not
hatch successfully.
 Eggs are also so thin that they break
easily.
 This does not get better as time goes
on.
 Result- ??
The Bald Eagle
In the early 1900’s biologists noticed a
decline in their numbers
 A pesticide, DDT was harming them

 DDT
is insoluble in water
 It is soluble in fats and oils
 DDT was sprayed to kill mosquitoes –
which carry the disease malaria
 Bald eagles would eat small rodents
(mice) that had been exposed to
DDT
This caused them to lay thin shelled eggs
 As a result the baby eagles would not
survive
 Population numbers dropped
 DDT has been banned in Canada since the
70’s

 Bioamplification:
the movement of a
toxin up the food chain (i.e. from
plants – carnivores)
Endangered Species Video
 Can
you list the endangered species
from the video?
 What was causing them to become
endangered?
 What was being done to help them?
 Was it working?
Scallops and Sharks
 What
is happening to the sharks?
 How is this affecting the scallops?
 Why is this happening?
 What can be done to prevent it?