Transcript MAMMALOGY AS A SCIENCE

Mammalogy
(Fall 2013 Althoff - reference FDVM Chapter 5)
Zoogeography
LEC
15
ZOOGEOGRAPHY--the study of
the distribution of animals
Nearly every region of the world
contains fauna that reached the
How,atwhen,
and fromtimes,
wherefrom
“region”
___________
did
animals reach
the areas
____________
regions,
by
they now occupy?
__________means.
Mammal basics:
• Mammals occupy all continents
(only Antarctia has no land
mammals)
• ______ occupy all continents except
Arctic & Antarctia
• Leporidae, Cricetidae, Sciuridae,
Canidae, Felidae, & Mustelidae--all
continents _______________ (exception to
this is human-aided dispersal…introduction of
exotics)
Mammal basics...con’t
• All oceans (and seas connected
to oceans) are inhabited by
cetaceans
• Some cetaceans live in large
lakes and rivers
Dispersal
• DEFINITION when individual or a
popn moves from place of origin
to a new area
• ___________ disperse is nearly as
important as ability to reproduce
“The more __________ a species, the
less likely it is to be forced into extinction
by local mortality, and as a result natural
selection has usually _______ those
species that have broad distributions.”
T.A. Vaughn 1972
Mammalogy
W.B. Saunders Co.
Philadelphia, PA
“A high __________ premium is placed
on dispersal ability”
T.A. Vaughn 1972
Mammalogy
W.B. Saunders Co.
Philadelphia, PA
“...without ____________________ most
animal populations would have
succumbed, over a period of time, to the
vicissitudes of the environment.”
M.D. F. Uvardy 1969
Dynamic Zoogeography
Van Nostrand Reinhold Co.
New York, NY
Ability to expand distribution...
• Innate ability to disperse (flyers
like bats have greater ability to
disperse than burrowers like moles)
• _________ of environmental conditions
tolerated
• Presence of _________
Migration & Faunal Interchange
Certain regions have apparently been
major centers of origin of mammalian
groups:
a) Eurasian area
b) North American area
George Gaylord Simpson’s
Avenues of Faunal
Interchange
• Corridors
• Filter Routes
• Sweepstakes Route
Simpson, G.G. 1940. Mammals and Land Bridges.
Journal of the Washington Academy of Sciences
30 : 137-163.
Corridors
• DEFINITION:= pathway that offers
relatively _____________ to
mammalian migration
• Example: continuous corridor
between ______________
Filter Routes
• DEFINITION: the effect of allowing
passage of certain animals but
stopping others
• Example: Siberia - Alaska land bridge
...certain species
not adapted to cold
conditions,
therefore those
can’t pass
Filter routes...continued
• other examples:
a) mountain ranges
b) deserts
c) tropical areas
• See FDVMK Fig. 5.13, p83 for
example of Central America
“filter” influence on “southern”
and “northern” mammals
Southern
mammals
Northern
mammals
Sweepstakes Route
• DEFINITION: pathway _____
traveled/attemped by many of a
given species; likelihood that
individuals make it are _____
• Example: travel by flying, swimming,
rafting to another continent or
island...California to Hawaii
Sweepstakes Routes...con’t
• Unusual faunas of
Madagascar (from Africa)
New Zealand (from Australia)
…..provide evidence for this
to have happened
occasionally
Zoogeographic ____________
•
•
•
•
•
•
•
Palearctic (Europe/Asia)
Nearctic (Canada/USA/Mexico)
Neotropical (Central & South America)
Ehtiopian (central & southern Africa)
Oriental (India, Indonesia, Philippines)
Austrialian
Oceanic
latitude
EQUATOR
longitude
Evidence for “Origin”
...fossil records
This has, is, and will continue to be a field
of study with many “______” in the data
sets and dependent on considerable
_________________.
Definition:
ENDEMIC--a species that lives
_______________; lives in no other
area in the world
Families & No. Endemic
Region
Families
Endemic
Nearctic
37
2
Palearctic
42
0
Neotropical
50
19
Ethiopian
52
18
Oriental
50
4
Australian
28
17
Nearctic
• ________ climate regimes
• Many biomes represented
• Two endemic families (2 species):
Aplodontidae (mt. beaver)
Antilocapridae (pronghorn)
• Diverse mammalian fauna,
resembles ____________
Mountain Beaver
Washington, Oregon, California,
& small part of British Columbia
Palearctic
•
•
•
•
___________ region
Broad climate regimes
Many biomes represented
___________:
a) desert from Ethopian
b) mountains from Oriental
c) sea from Neartic
Neotropical
• Great ____________ variation
• Diversity of biomes
• ________ Ethiopian Region has more
diversity of mammals
• Has the ______ endemic families (19)
Ethiopian
• ________ variation in climate
• 2nd in number of endemic
families (18)
• Most species of ___________ in
the world (including most
__________ which are endemic)
Oriental
• Dominated by __________
climates
• Most resembles Ethiopian Region
• All tropical “affinities”
a) four families of primates
b) all endemic families are
tropical (4)
• Lacks diversity of antelope…why?
Australian
• Mostly ______, some tropical
forest
• Australia alone has greatest
diversity of ______________
• Nearly _____ (17 of 28) of families
are endemic--all are __________ or
____________…no placental species
Palearctic - Nearctic
“The Land Bridge...sometimes”
• Movements of mammals across the
_____________...the land bridge
• Evidence for several “peaks”of
migration (see next slide)
• Helps explain some Ethiopian
& Oriental families in Nearctic
Bering Strait “Land Bridge”
• Filter route: during certain eras it was
_________ for passage by mammals from
_________ climates to survive
• Examples of Europe  North America
dispersal:
Talpidae (moles)
Soricidae (shrews)
Cervidae (deer, elk)
Australian Mammals
• Vaughn (1972)suggest that establishment
of _______________ on this continent
result of “sweepstakes route”
....single pregnant female base
for entire marsupial fauna
• Monotremes from therapsid reptiles ??
Australian Mammals...con’t
• Marsupials very diverse...most terrestrial
niches filled:
a) kangaroos & wallabies
take place of _________
b) Petauridae (gliders) take
place of __________________
• Dingo--only __________...probably
brought to region by aborigines
COO
Center of
Origin
concept—
where taxon
arose…
Criteria are:
1) Earliest known fossil evidence
2) Fossil history of earlier progenitors
of group in question in same area
3) The region with the highest diversity
of a particular group may indicate
the place of origin
Pt. of
entry
Refugia,
species
dispersal,
molecular
techniques
Ex.
American Pika
Fig. 26.9 from FDVM
(2nd edition only)
Hafner and Sullivan (1995)
J. Mammalogy 76:302-321
Duplication of Functionality
• Concept of Continential Drift - Plate
Tectonics (Fig 5.3, Fig. 5.4, p72-73)
• Evolution on several land masses under
isolation or semi-isolation
• “Convergent evolution”
examples: orders eating ants
and termites (Fig. 5.6 pg 76)
Convergence - myrmecophagy
“habit of eating ants”
________________________
_________________________
___________________________
• Anteater (Xenarthra: Myrmecoophagidae)
• Scaly anteater (Pholidota: Mandiae)
[pangolins]
• Aardwolf (Carnivora: Hyaenidae)
• Numbat (Dasyuromorphia: Myrmecobiidae)
• Echidna (Monotremata: Tachyglossidae)
Woodlots As Islands:
Influence on Small Mammals
• Gottfried’s (1979) study
American Midland Naturalist 102:105-112
1-3 species, depending on size,
distance
between woodlots
• Nupp and Swihart (2000) study
Journal of Mammalogy 81:512-526
1-6 species, depending on size,
distance
between woodlots