Community ecology

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Community ecology
Koala Conga Line.
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• Community- groups of interacting populations

• Primate behavior shaped by interactions with
  other primate species

• Can be potentially influenced by interactions
  with other organisms

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Some definitions

• Niche- a way to define the role an organism plays
  in its environment- multidimensional
• Sympatry- when two organisms share a habitat
• Congeneric- within the same genus (taxonomic
  category)

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When similar species share...

• One may go extinct
• There may be evidence of behavioral character
  displacement (when one species shifts its niche)
• Share if
• Resources are not limited
• There is an area where they dont overlap
• (physical and dietary)

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Ways to look at community

• Trophic structure chart (11.1- coursepak)
• Example plants eaten by hippo, hippo eaten by
  hyenas, hyenas eaten by lions, lions eaten by
  vultures.
• Note trend in population size for each category
• Primate/plant interactions at the bottom
• Primate impact on leaf
• biomass (1) compared
• to insects (15)

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Ways to look at community

• Biomass of everything (coursepak- Fig 11.2)
• Biomass of mammals (coursepak Fig 11.1)
• Body weight representation (Robinson graph
  handout)

• Note- animals make up small part of community
• mammals make up an even smaller part
• Primates very small!

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Ways to look at community

• Guilds-animals that occupy similar niches (role
  played in environment)- use resources in similar
  ways despite being very different organisms.
• Figure 14.4 - Avian guilds (in coursepak)
• Note differences between forests
• Note how partitioned

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Example 1- Howling monkeys and leaf cutter ants
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Ants and Howlers

• Both eat tremendous amount of leaves
• But only overlap on 7 out of 40 plant species
• Howlers, majority of diet New leaves
• Ants almost entirely eat Mature leaves

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Example 2- Howlers and Sloths

• Can have up to 80 overlap in diet.
• But sloths eat little (lower BMR)

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Example 3- Malaysian Fruit eaters
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Malayan Fruit feeders

• Primates eat unripe fruits, hornbills eat ripe
  ones
• Primates feed in upper canopy along with 3 or so
  squirrel species
• Squirrels eat seeds, primates fruit flesh
• Primates supplement with leaves, birdds with
  insects or other fruits.

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Coevolution

• Between plants and animals
• A relationship developes between two organisms
  such that, as they interact with each other over
  time, each exerts a selection pressure on the
  other.
• Evolution of each becomes interdependent on that
  interaction

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Some primate examples

• positive relationships
• Seed dispersal
• Pollination
• Negative relationships
• Seed predation