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(Terrestrial) Malagasy mammals
Tuomas Aivelo18.9.2012
University of Helsinki
Overview on mammal diversity
Tenrecs: 34
Lemurs: 99
Bats: 46
Euplerids: 10
Rodents: 30
Invasive species: ~10
Mammal colonisation
of Madagascar
Invasives
Black rat, house mouse, dog, cat, pig, zebu, shrew, human…
Tenrecs
34 species, 10 in Ranomafana
Shrewlike, small, insectivores
Bats
46 (of which 35 endemic)
8 species in Ranomafana
Both African and Asian colonisations
Carnivores
10 species – 6 species in Ranomafana
Euplerids – related to mongooses
Lemurs
99 species
13 in Ranomafana
Many recently extinct species
Giant aye-aye – 10 kg
Megaladapis – 50 kg
Pachylemur – 12 kg
Archaeolemur – 10 kg
Hadropithecus – 30 kg
Mesopropithecus – 10 kg
Babakotia – 30 kg
Paleopropithecus – 30 kg
Archaeoindris – 160 kg
Lemurs not the only group of extinct mammals
Hippopotamusmadagascariensis
lemerlei
Laloumena
Bibymalagasia
Parasitism -The force that shapes the world
Tuomas Aivelo18.9.2012University of Helsinki
All the organisms in the world have parasites.
More than half of the organisms in the world are parasites.
1. Systematics: What are the parasites?
2. Ecology: Patches and vectors
3. Evolution: Host-parasite interaction
4. Conservation biology: Vicious circle
What is parasitism?C
lose ness
+
-
Mutualism
Commensalism
Sym
biosis
PredationParasitoidi
sm
Ectoparasites
Endoparasites
Classifying of parasites
Micro- and macroparasites Ecto-, meso- and endoparasites Bacterial, protistan, metazoans By taxa they parasitize Direct or indirect life cycles Mode of transmission
What does the world look like for a parasite?
Ways of transmission Direct Through freeliving stage Via vector
Through skin From mouth
?
Factors affecting transmission (in mouse lemurs)
Testosterone and stress hormones Activity, home range Susceptibility, immunocompetence, body
condition Sharing sleeping nests Hibernation/torpor Gestation Nutrition Amount of parasite species around
Expanding to community level Many parasite species are highly host-
specific Then again, many are not, but target larger
groups Eg. primates, mammals, vertebrates,...
Role of invasive species?
in
Parasite-host interaction
The puzzle: Parasite should use as much as possible its host without compromising its own habitat
= Take all you can without killing your host Sounds familiar?
TRAGEDY OF COMMONS!
Vicious cycle
Infection
Up-regulating immunedefence
Decrease in host condition
More susceptibleto pathogens
New infection
Fragmentation
Infection
Up-regulating immunedefence
Decrease in host condition
More susceptibleto pathogens
New infection
Factors affecting transmission (in mouse lemurs)
Testosterone and stress hormones Activity, home range Susceptibility, immunocompetence, body
condition Sharing sleeping nests Hibernation/torpor Gestation Nutrition Amount of parasite species around
?
??
Effective contacts
Invasive species might be vectors Fragmentation increases contacts of
animals with humans Indirectly or directly
Difficult to tell apart different effects of fragmentation
Broader question marks
Cycle of epidemics How does the parasite cycle differ in
fragmented areas? Will the epidemics be harsher / more frequent?
Host switchs Do fragmented areas drive parasites to more
switches between hosts?