Spectrum of Sociality - mammals Flashcards
Mammals are united by _________________________________ and __________
- milk production by the mother
- hair/fur
Mothers and offspring _____________________________ for some period of time for the purposes of milk feeding.
always form maternal-offspring groups
“solitary” in arthropods are equivalent to what in mammals
the “subsocial” category for arthropods since at least one parent engaged in parental care in regarding mammals
mammal society trends - roaming animals
Groupings of reproductive units are common for roaming animals
mammal society trends - monogamy and polygyny
- monogamy is rare
- polygyny is common
mammal society trends - larger mammal social groups
typical to see many mother-offspring units with few males
mammal society trends - bonding
Bonding across generation is typically matrilineal
mammal society trends - eusociality
exceptionally rare
mammal society trends - hierarchal scaling compared to arthropods
Less of a hierarchical scaling of complexity than in arthropods, but still lots of repeated “convergent evolution” on distinct social structures
define herd
Grouping of mother-offspring social units and other classes of individuals that display collective grouping behavior.
herd benefits
Herd provides protection in numbers and collective defense
herds do not have what
they don’t have:
- shared parental care.
- bias in female reproductive opportunities
- variability in the degree of bias in male reproductive opportunities
define monogamy
A single female and male join to cooperate in parental care to rear at least one cohort of offspring
monogamy - cooperation is limited to what
Cooperation typically limited to the breeding season and often only extended to the end of the weening period (end of milk from mother)
In monogamy, it is the standard mammal mother offspring relationship, ______ the participation of the male.
plus
rare cases in monogamy
In rare cases, the monogamy bond extends multiple breeding seasons and/or extends to prolonged offspring care, well beyond weening.
define polygyny
The tendency for males to mate with two or more females, gaining some degree of reproductive bias and increased fitness relative to other males
when is polygyny more often seen
less mobile mother-offspring aggregations
In polygyny, male mating opportunities are often gained by _________________ that females observe and select from — Associated ___________________ for competition.
- male-male contests
- male-only traits
define harem
A group of reproductive females guarded by a male, preventing mating with other males
harems are polygyny with the addition _____________________________________ over some prolonged period of time.
of males defending access to females
___________________ in harems are used to secure and protect ____________________ opportunities.
- Male-male contests
- long-term mating
A byproduct of harems is a ______________________
surplus of males
Younger males with future possibilities for winning a harem may persist in battles and form _____________ with other males to help usurp a harem.
coalitions
Surplus males and usurpation attempts by coalitions create instability — _____________________________________
turnover dynamics for social structure
bonding across generation is largely limited to more ___________________ that can recognize individuals and ______________________ with them
- intelligent mammals
- maintain relationships
what is the result of bonding
persistent, multigenerational female group or male-female groups with a higher turnover of males that seek to monopolize reproductive opportunities.
bonding is exemplified by the stability in _____________________ of lion prides, elephants, and ape species — __________________________, contrasting male dynamics
- female membership
- social mechanism for stability
Naked mole rats are one of only two _____________________
eusocial mammal species
naked mole rat - reproduction
Reproduction is monopolized by a single female (queen) and one to a few males
naked mole rat - those that are not the female or the few males the female selects for reproduction are what
functionally sterile (workers).
naked mole rat - what do the workers do
Workers forage in the tunnels for tubers and engage in offspring care
When food is scarce, slime molds form a “social slug” with ____________________________ that seeks out new resources.
coordinated social foraging behavior
Some slime molds become non-reproductive stalks, while other become dispersal-ready spores — ______________________________
a reproductive division of labor
