Resource acquisition by societies part 2 Flashcards
Categories of collective foraging strategies in social organisms
- Individual recruitment.
- Mass recruitment.
- Collective foraging.
what does individual recruitment describe?
it describes mechanisms where one individual directly leads another individual to the food source
individual recruitment - what is communication used for?
constant contact
individual recruitment - what does recruitment rely on
relies on maintained connection between recruiter and recruit, and both actively maintain connection
define teaching
Behavioral modification by an experienced individual in the presence of a naive observer, at some initial cost, in order to set an example so that the naive observer learns more quickly.
individual recruitment - example
Tandem running in the acorn ants
individual recruitment - tandem running in the acorn ants
- The recruit follows the leader closely, frequently touching recruiter
- If this touching is interrupted, the leading ant will remain in place and wait until the recruit catches up.
tandem running in acorn ants - how does it fulfill the criteria for teaching
because the recruiter modifies its behavior for naive recruits, and pattern of interaction is adjusted among individuals — each recruit is different
What are the main limitations of individual recruitment?
Individual recruitment is 1 to 1, does not persist for reuse, and requires slowed performance during recruitment.
what is mass recruitment characterized by?
by broadcast information that goes from one-to-many
mass recruitment - explain the signal
Repeatable and or persistent signal to food source that is both followed by recruits in the absence of the recruiter, and potentially reinforced by recruits.
mass recruitment - what controls the long-term rate of recruitment?
reinforced information by recruits
mass recruitment - how can the signal decay
Signal strength will decay as food resources become depleted and recruits return with diminished or no loads and do not reinforce the signal
Benefits of mass recruitment
- Collective problem solving
- Increased efficiency in conveying information
- Rapid recruitment to large food sources
- Rapid defense of large food sources
benefits of mass recruitment - what does collective problem solving do?
reduces individual error
benefits of mass recruitment - what does increased efficiency in conveying information do?
it broadcasts information and allows rapid dissemination, not limited to individual contact.
benefits of mass recruitment - what does rapid recruitment to large food sources do?
Elevates competitive capacity due to group-level presence at resources.
benefits of mass recruitment - what does rapid defense of large food sources do?
Extends access to rich food resources
define collective foraging
a strategy where food is both discovered and harvested by a communicating social group.
collective foraging - examples
- army ants
- many mammals that practice group hunting
collective foraging - mammals and group hunting
- lions, chimpanzees, hyenas
- they are all “pack hunters”, where prey is stalked and then captured by an integrated, communicating group of individuals
Most likely form of communication used in collective foraging?
mass communication
collective foraging and mass communication - examples
- group hunting of termites
- group hunting of leaf-litter arthropods
Collective foraging is ________________________ that has __________________________________ in insect societies, and in the form of _____________________________.
- a derived social foraging strategy
- evolved many times independently
- group hunting in mammal societies.
what are considered the extremes of collective foraging
Collective load retrieval and specialized foraging castes
collective load retrieval and specialized foraging castes - example
army ants
Collective load retrieval and foraging castes in army ants
Specialized transport castes (“porters”, or “submajors”).
Collective load retrieval and foraging castes in army ants - explain the team formation
- Team formation for items too large to be transported by one individual.
- Porter caste leads, smaller individuals carry in the rear of the object.
Collective load retrieval and foraging castes in army ants - explain the team composition
- it is a dynamic team composition
- driven by frictional interaction with the substrate and a decrease in optimal retrieval speed
Collective foraging and load retrieval without teams
- Per capita efficiency (speed and loading) is lower in groups.
- Large items represent resources that would be unattainable without groups
Collective foraging and load retrieval without teams - as groups get larger, what happens to efficiency
- they get less efficient per capita, but retrieval speed of item increases
- they sacrifice individual efficiency for group success in accessing novel resources.
Ecological influences on the evolution of food acquisition — all may be interlinked in association with what major transition in foraging strategy?
- Habitat preferences.
- Resource distribution.
- Group size.
- Capacity for social foraging.
Evolution of seed milling
Phylogenetic analyses with ecological data reveals seed miller transition evolved early and often, and coupled with multiple origins of extra caste.
Evolution of fungus agriculture
Culminates in most complex form in
leaf-cutting ants
evolution of fungus agriculture: leaf-cutting ants - what does it involve
- Highly specific fungal strains.
- Complex group foraging strategies for harvesting leaf material.
- Complex caste system for harvesting, transporting, and processing leaf material
evolution of fungus agriculture - simplest form
growing free-living fungus on insect frass (aka poop) and dead bits of insects
evolution of fungus agriculture - most complex form
growing obligate fungal mutualist on freshly harvested and extensively processed plant material.
Habitat conditions and transitions in agriculture
Shift to highly specific fungal lineages and “higher agriculture” is associated with evolutionary history in dry tropical habitats
