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taxonomy: open Tree of life page and click at Carnivora.
Canidae (dogs)
14 genera and 34 species
adapted more for endurance than for speed
non-retractile claws
Live on all continents (but Antarctica)
Larger species: packs (wolf)
Smaller species: solitary (fox)
Territorial
Visit animaldiversity website for description of taxa.
Wolf
Range: Palearctic, Nearctic, Oriental
Fragmented populations (habitat loss)
Body size: largest of Canidae (30-80 kg)
Hunt in pack for in packs for large prey: moose, elk, bison, musk oxen,
roe, red and reindeer.
Hunt individually for small prey: rabbit, beaver, rodents
May attack livestock
(see the Scandinavian situation, essays by Erik
Granquist, Kristina
Höglund, Tonje
Trinterud and Simon A. Michelet
Reproduction: 2-10 cubs
By a single monogamous pair
Fed by all members
(regurgitated food)
Subordinate animals
Juveniles
Hierarchy once established is signalled: less direct fight
Concept: Ritualization, Antithesis (Darwin)
Pic is from http://www.wolfpark.org/
Packs
Pack size: 2-32 (5-10 typical)
Territory: 130 to 13,000 square kilometers
Size of pack and territory depend on prey
Killing a 450 kg moose needs cooperation
The photo is from an excellent slide show introducing a study done
on wolfe-caribou interaction in the Porcupine Caribou Range in Canada.
Please, visit the site at
http://www.taiga.net/wmac/wolf/index.html
Kill rate = 0.08 caribou per wolf/day
This is 3-5% of herd each year
Natural mortality rate is 15% (15 of every 100 caribou die each year)
Wolves are not the main factor on herd size?
Isle Royal study: wolves kill 7% of moose they „test”
Selective kill: calves and sick adults
Methods: Aerial survey, Population reconstruction,
Primary production by tree growth lines
Control?
Wolf population grows
Moose population declines
Fir production grows
TOP-DOWN CONTROL
details of study at http://www.isleroyalewolf.org/wolf-moose_data.htm
TOP-DOWN hypothesis
Infective agents control wolves, Wolves control moose (selective hunt),
Moose control vegetation
BOTTOM-UP hypothesis
Primary production controls herbivores, Prey population controls predators
Question not resolved (might depend on complexity of food chain)
Group cohesion
alfa pair breeds, other individuals do not. Altruistic behaviour? (see concepts)
Study in Denali National Park and Preserve www
( Smith et al., 1997. Is Incest Common In Gray Wolf Packs? Behav. Ecol.
8(4):384-391. Read
research paper)
an area of 24,400 km2 in central Alaska, USA.
Pack size ranged from 2 to 29, and mean territory size was about 1000
km2
Capture by traps or dart from helicopter radiocollar, blood sample,
microsatellite loci
Results: packs are family units
alfa male and female are not relatives
Most wolf packs consist of relatives of the breeding pair.
See essay of Louise Adolfsson & Anniko Nydal on wolf protection in Sweden (local)
Wild wolves 'good for ecosystems'. Reintroducing wild wolves to the
Scottish Highlands would help local ecosystems, a study suggests. BBC
Red fox (Vulpes vulpes)
Visit www
Range: Palearctic, Nearctic
Weight: 4-5 kg
Omnivore: eats rodents, lagomorphs, insects and fruit
Territory: 1 – 10 square km
Male offspring disperse within 6 – 10 months
Some female offspring might stay (helpers – altruism?)
Helpers are not necessarily relatives Reciprocal altruism?
Ph.D. thesis on this WWW
Population control: Food? Rabies?
Spotted hyena
Carnivora > Hyaenidae > Crocuta crocuta
Body mass: 48-55 kg
Females larger than males
Packs: up to 100 individuals
Territories marked and defended
Cooperation in hunt
No food sharing
Matriarchal system (clans)
Females are dominant
Is it a male or a female?
Enlarged clitoris = pseudopenis
Penis and clitoris used in greeting ceremonies
Signal of dominance (It was suggested, that clitoris has enlarged to
communicate dominance.)
However, recent studies indicate, that pseudopenis was originally a
side effect of selection for masculinization in females.
Advanteges of being masculine:
- Highly competitive environment
- Dominant females get more food
- Reproductive success of high-ranking females is 2.5 times greater than low-ranking females
The most masculinized females in mammals
Costs of being dominant
Elongated birth canal (birth through clitoris)
High prenatal mortality (young mothers)
Small litters (1-2)
One study found, that in 15 years top-ranking female headed clans grew, low-ranking clans vanished. It is now beleived, that the enlargement of clitoris in hyenas started as a side effect of selection for dominance with elevated testosteroen level, but later could be selected directly for communication of dominance.
Cheetah
Carnivora > Felidae > Acinonyx jubatus
fastest terrestrial mammal with a speed range up to 71 mph
Speed maintained for max 300 m.
claws are only semi-retractable
Reduced teeth
Prey: gazelles, impalas, game birds, rabbits, young of larger herbivores
Litter size: 1-8 (3-5 typical)
Females solitary, young leave, male coalitons
Male coalitions defend territory
Males’ territory overlaps with home range of several females
Follow this link: Cheating
cheetahs caught by DNA
Number of cheetah has been dropping
Conservation status: endangered
Fastest terrestrial mammal dying out fast?
Hypothesis 1: Inbreeding depression
WWW
Genetic studies (O’Brian): Extremly low heterozigocity as indicated
by
Protein electrophoresis, Skin grafts, DNA polimorphism
Genetic calculations: Bottleneck 2 times
10,000 years ago (relative species died out)
Last few hundred years
Signs:
Reduced (?) endurance of adults
Misaligned jaws and kinked tails
High mortality of kittens
Low immune response
Reduced sperm quality
Hypothesis 2: habitat loss and increased interspecies competition
Most original data on infant mortality came from captive breeding, and could be caused by poor management.
Infant mortality in the wild (90%) is NOT caused by disease.
Kittens are killed by lions (and hyenas)
Infant mortality might have been enhanced by research (!)
Question not resolved yet.
Cautionary note on inbreeding depression:
northern elephant seal (Mirounga leonina) also highly inbred
Bottleneck: 10-30 individuals around 1900
Following protection: number by thousands
Very low heterozigocity
Low heterozigocity, if the population survived is not necessarily a
problem. However, adaptation to changes in the environment is more difficult.
European wild cat
Carnivora > Felidae > Felis silvestris
Active at night
Prey: rabbit, hare, small mammals, large birds
Solitary, territorial (1-10 sqaure km)
Litter: 2-6 kitten staying with mother for 5 months
High mortality rate
Conservation problems:
Fragmented habitat
Infectious agents from feral cats
Lion
Carnivora > Felidae > Panthera leo
Biomes: tropical savanna & grasslands
Males: 150 - 260 kg, females: 122 - 182 kg
Male lions have a mane
Prey: large herbivores and almost anything
Lionesses hunt, males enjoy. (just
kidding, males do manly jobs, like killing buffalo)
Pride: males + females (up to 30-40 individuals)
TerritorialAdvantages of belonging to pride?
Meat / individual was estimated in 3 studies
Solitary lions, small groups do better than large groups
Hypothesis:
Large group can defend territory and young better
New analysis: larger groups do better when prey is scarce
Reproduction:
Oestrous lasts 5 days
Lioness may copulate with more than one male
Copulation rate: 1/20 min. for 5 days = hundreds of copulations!
Why waste energy for copulation?
No male can defend successfuly lionesses in estrous.
Chances of fathering cubs is increased by number of copulation.
SPERM COMPETITION
Young males leave pride and form coalition
Male coalitions attempt to take over other pride
When successful, males kill all cubs
(10% of total lion mortality is due to infanticide!)
Good for the species? Good for whom?
DNA analysis: males in coalition are relatives, females of pride are relatives, males and females are NOT related
Females get into eostrous when cubs die (males are quite nice to new cubs)
Males can rule pride for about 2 years, first year is important
