(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?