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Mammalogy (Fall 2013 Althoff - reference FDVM Chapter 5). LEC 15. Zoogeography. ZOO GEOGRAPHY--the study of the distribution of animals. Nearly every region of the world contains fauna that reached the “region” at ___________ times , from ____________ regions , by __________ means .
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Mammalogy (Fall 2013 Althoff - reference FDVM Chapter 5) LEC 15 Zoogeography
ZOOGEOGRAPHY--the study of the distribution of animals Nearly every region of the world contains fauna that reached the “region” at ___________times, from ____________regions, by __________means. How, when, and from where did animals reach the areas they now occupy?
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 1972Mammalogy W.B. Saunders Co.Philadelphia, PA
“A high __________ premium is placed on dispersal ability”T.A. Vaughn 1972Mammalogy 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 1969Dynamic 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
Northern mammals Southern 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
EQUATOR latitude longitude
Evidence for “Origin”...fossil recordsThis 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 RegionFamiliesEndemic 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
Center of Origin concept— where taxon arose… COO Criteria are: • Earliest known fossil evidence • 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 102:105-1121-3 species, depending on size, distance between woodlots • Nupp and Swihart (2000) studyJournal of Mammalogy 81:512-526 1-6 species, depending on size, distance between woodlots