Transcript Photo: Alastair Rae

Animals of the Poles
Presented by Kate Devlin
Antarctic krill, Euphausia superba; Actual Size: 58 mm long
(Photo by Uwe Kils) http://www.ecoscope.com/krill/index.htm
Arctic Tern, Sterna paradisaea
Photo: Alastair Rae
Arctic Tern and the midnight sun….Greenland
Photo: Carsten Egevang and Iain Stenhouse
Arctic Tern Breeding Range in Red, Non-Breeding
locations in blue, Migration routes in green
Notice anything curious about this map?
Map by
A.Trepte
Long distance trip between ~late-July and
October by an Arctic Tern banded as chick
Direct flight = ~6165 miles
Map by
A.Trepte
50 data
loggers in
2007, to be
recaptured
in 2008
Photos: Carsten Egevang and Iain Stenhouse
New
Brunswick
Collaborative
Project
Maine
Nova
Scotia
Gulf of Maine
100 km
www.ngdc.noaa.gov/mgg/shorelines
Devlin
Machias Seal Island
Petit Manan Island
USFWS
Seal Island
USFWS
© 2001 P. W. Hirtle
Matinicus Rock
Nesting Pairs of Terns between southern Maine and Grand Manan
10000
Number of Nesting Pairs of Terns
9000
Arctic Tern
Common Tern
Roseate Tern
8000
7000
6000
5000
4000
3000
2000
1000
0
1900
1910
1920
1930
1940
1950
Year
1960
1970
1980
1990
2000
Nesting Pairs of Terns between southern Maine and Grand Manan
10000
Arctic Tern
Common Tern
Arctic Terns on 4 Islands
Number of Nesting Pairs of Terns
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
1984
1986
1988
1990
1992
1994
Year
1996
1998
2000
2002
2004
Diamond
Field work – small
islands, many
hours in bird blinds
spent watching
what happens –
eggs hatching,
chicks growing,
adults bringing in
food, etc.
Allard
Photos: Carsten Egevang, Iain Stenhouse, Karel Allard, Antony Diamond
Puffins
and
Terns
Cranford
USFWS
Cranford
USFWS
USFWS
Photos: USFWS and Paul Cranford
Devlin
“Relative” tameness of study species….yes, it did fly away…
Polar Bear, Ursus maritimus
www.free-picture-graphic.org.uk
For Text interview: http://thirdcoastfestival.org/behind_scenes_bryant.asp
For Audio: http://audio.wbez.org/thirdcoast/player/3player_new.asp?fileId=prey
Seabird Research
A color-marked and banded Sabine’s Gull, Larus sabini
Photo: Carsten Egevang, and Iain Stenhouse
Photo by Alastair Rae
Sabine’s Gull: trapping,
calling and one day old chick
Photos: Carsten Egevang and Iain Stenhouse
Sunlight over drifting Canadian
ice floes
Photo by Paul Nicklen
Polar Bear on ice…
http://science.nationalgeographic.com/science/photos/tundra-wildlife-plants.html
http://www.huntingsociety.org/PolarBearpics.html
http://www.arcticartsales.com/polarbear_skull.html
http://www.arcticartsales.com/polarbear_skull.html
http://www.arcticartsales.com/polarbear_skull.html
Photo: Alastair Rae
Photo by: Captain Budd Christman, NOAA Corps
http://www.getfreephotos.com
Foraging caribou herd
Photograph by Joel Sartore
Caribou herd on Arctic tundra
Photograph by Norbert Rosing
http://science.nationalgeographic.com/science/photos/tundra-wildlife-plants.html
http://www.getfreephotos.com
http://www.getfreephotos.com
http://www.getfreephotos.com
http://www.getfreephotos.com
Photos: Carsten Egevang, and Iain Stenhouse
http://www.polarbearsinternational.org/lessonsfor-your-classroom/polar-bears-and-ecotourism/
http://www.huntingsociety.org/PolarBearpics.html
Polar bear crossing pack ice
Photo by Ralph Lee Hopkins
http://science.nationalgeographic.com/science/photos/tundra-wildlife-plants.html
Allard
Jamieson
Allard
Satellite Tracking of Eider Ducks is a joint venture by
researchers in Greenland and Canada
Nuuk
East Bay
Nanortalik
http://eastbay_eiders.trackit.cubitech.dk/main
Dovekie, Alle alle
Photo: Alastair Rae
“A number of bird species,
including several globally
endangered seabird species,
are projected to lose more
than 50% of their breeding
area during this century.”
“Many species from around
the world depend on summer
breeding and feeding grounds
in the Arctic, and climate
change will alter some of
these habitats significantly.”
Source: Arctic Climate Impact Assessment (ACIA) 2004
Photo: Alastair Rae
http://www.atanarjuat.com/media/press.php
Photo by: Giuseppe Zibordi
Credit: Michael Van Woert, NOAA NESDIS, ORA
http://sciencebulletins.amnh.org/?sid=b.s.antarctica_life.20071210&src=e
Food Webs and Species Interactions
• Community Webs
– A food web summarizes the feeding relations in a
community.
– Complexity and Structure
• Keystone Species
– The feeding activities of a few keystone species may
control the structure of communities
– Effects on Diversity
Winemiller
1990 in Molles
2007; Fig 17.3
Winemiller
1990 in Molles
2007; Fig 17.3
Strong Interactions and Food Web Structure
Robert Paine (1966, 1969)
– Suggested criterion for strong interaction is degree of
influence on community structure.
– Not based on quantity of energy flow, but on degree
of influence
Paine suggested feeding activities of a few species may
have a dominant influence on community structure.
– He predicted that some predators may increase
diversity
• Keep prey populations below carrying capacity
– Number of individuals that environment can
sustain long term
• Reduces potential for competitive exclusion
between prey species
– Depends upon niche overlap; lower pop. size
means less intense overlap
• Reduced competitive exclusion means more
species can coexist
Keystone Species
From Molles
2007, Fig.
17.6
Pisaster ochraceus
PREDATORS
Nucella lamellosa or Thais lamellosa
Mytilus californianus
Balanus glandula
PREY
SPECIES
Lepidochiton flectens
Patella vulgata
Keystone Species
From Molles
2007, Fig.
17.6
© Paul Foretic http://baja.divebums.com/FieldID/Pages/sun_star_gulf.html
Food Web Structure and Species Diversity
• Paine found as number of species in intertidal food webs
increased, proportion of the web represented by
predators also increased.
– According to his hypothesis, higher proportion of
predators produces higher predation pressure on prey
populations, in turn promoting higher diversity.
• Removal of starfish (top predator) caused decline in
diversity from 15 to 8 species
• After 3 months
– Barnacle (Balanus glandula) took over 60-80 % of space
• After 1 year, 2 species dominate – this lasted for 5 years
– Mussels and goose-neck barnacles
– Other species – no attachment points
• Space was a limiting resource
• Pisaster = keystone species
Consumers’ Effects on Local Diversity
• Jane Lubchenko (1978) proposed to resolve the effect
herbivores have on plant diversity,
– Herbivore food preference.
– Competitive relationships between plant species in
the local community.
– Variance in feeding preferences and competitive
relationships across environments.
Consumers’ Effects on Local Diversity
• Lubchenko studied influence of intertidal snail (Littorina
littorea) on structure of an algal community.
– Snails fed on green (Enteromorpha spp.) and red
(Chondrus crispus) algae.
• Under normal conditions, Enteromorpha outcompetes Chondrus in tide pools, and Littornia
prefers Enteromorpha.
– In the absence of snails, Chondrus is
competitively displaced.
Enteromorpha spp.
Littorina littorea
Chondrus crispus
Consumers’ Effects on Local Diversity
Molles 2007, Fig. 17.8
Consumers’ Effects on Local Diversity
• When snails are present in high densities, Littorina
grazes down Enteromorpha, releasing Chondrus from
competition.
– Green crabs (Carcinus maenus) prey on young
snails, preventing juveniles from colonizing tide pools.
– Populations of Carcinus are controlled by seagulls.
J. Anderson
Consumers’ Effects on Local Diversity
– Low snail density - Enteromorpha dominates tide
pool.
– Medium snail density - Competitive exclusion
eliminated, and algal diversity increased.
– High snail density - Feeding requirements are high
enough that snails eat preferred algae and lesspreferred algae.
• Algal diversity decreased.
Keystone Species: Summation
• Mary Power (1996) : Keystone species exert strong
effects on their community structure, despite low
biomass.
In Molles 2007;
Fig 17.14
Molles, 2007: Fig. 17.2
Websites for animal information:
Penguins:
http://www.windows.ucar.edu/tour/link=/people/postcards/penguin_post.html
Polar Bears:
http://www.amnh.org/sciencebulletins/?sid=b.s.polar_bears.20070108&src=/eart
h/polar/b
http://www.usgs.gov/newsroom/special/polar_bears
Caribou
Walrus
Seals – Ringed Seals, Fur Seals
http://www.windows.ucar.edu/tour/link=/earth/polar/arctic_marine_life.html
Adaptations…hands on lab exercises…..
Bergman's rule
In zoology, Bergmann's Rule is a principle that
correlates environmental temperature with body
mass in warm-blooded animals. It asserts that
within a species, the body mass increases with
latitude and colder climate.
Allen's rule
is a biological ‘rule’ proposed by J. A. Allen in 1877. It
states that endotherms from colder climates usually
have shorter limbs than the equivalent animals from
warmer climates.