Intraspecific

• Linear hierarchy


  A ranking system where animals are dominant over those below it and submissive to those above it in the heirarchy.
• How is a hierarchy maintained?

  Ritualised displays and aggression
• Ritualised display


  Ritualised behaviour by which an animal uses to provide specific information to others
• Establishing a hierarchy lowers conflict and aggression in the clan, as the hierarchy is determined early in life during brief fights or threats and displays, after which status is rarely contested except by newcomers.
• Advantages of territorialism

  • Protection from the physical environment
  • Greate ability to detect predators
  • Better defence against predators
  • Greater ability to find resources such as food
  • Mates available
  • provision of learning opportunities for young
  • regulation of population through controlled access to mates/resources
• Disadvantages of Territorialism

  • Increased intraspecific competition
  • increased risk of contracting and spread of diseases
  • restricted access to mates
  • increased risk of infant mortality due to cannibalism
• Advantages for omega individuals:

  There is a slim prospect of eventual reproduction if one or more of the dominant animals die. For an outcast, the prospects of reproduction may be nil. Lower-order animals also benefit by being members of a group – a group means reduced risk of predation, greater chance of obtaining food
• Home range


  Geographical area that animals rarely leave, nest in and search within for food and mates
• Territory


  An area which the animal, breeding pair or group marks and defends
• Lek


  A territory used only for mating
• Polyandry


  One female mates with multiple males. Advantage: females can select who to mate with and will often pick a mix of the fittest males. Some females can select which sperm to allow to impregnate her eggs.
• Parental care


  Any action by which an animal expends energy or assumes risks to benefit its offspring (e.g., nest-building, feeding of young, defence). Increases the chance that offspring will survive but is costly to the parents.
• Sexual dimorphism


  Differences in physical characteristics between males and females of the same species. Evolves due to intraspecific competition for mates eg. males evolve larger horns to impress females in ritualized fights. Advantage: makes mate selection for the fittest mate easy.
• Territorial behaviour


  Competitive behaviour in when an animal tries to adopt and defend a physical area against others of the same species.
• Omega individual

  Most submissive individual in a linear hierarchy
• Pair bond


  One female mates with one male for their whole life. Lots of time and energy is invested in courtship and reinforcing the pair bond. Advantage: share energy investment in caring for young, and protecting territory.
• • Benefits of dominance


  -first access to food

  -spend less time hunting/foraging

  -best access to mates/more mates

  -The fittest individuals do the most survival/mating so the best genes spread through the population
• Costs of dominance

  -Higher metabolic rate so need more food

  -have to use energy to defend territories

  -high levels of stress hormones

  -have to engage in more ritualised fights to defend rank
• Dominance

  High ranking individuals in a group. Often the strongest/most fit, and have the best access to resources including mates.
• Complex hierarchy


  A kind of hierarchy where groups of individuals hold the top rank. Eg. In wolf packs, relatives of the alpha male and female hold a higher rank than other wolves which may be stronger than them.
• Subordinance/submissive


  Individuals who display behaviours that show they are at the bottom of a social ranking eg. rolling over, displaying neck, averting eye contact.
• Eusocial groups


  Highly cooperative species where there is a division of labour into reproductive and non-reproductive groups. All individuals are strongly related eg. all bees come from a single queen.
• Courtship displays


  Behaviours aimed to facilitate attraction with the opposite sex for reproduction
• Purposes of courtship

  • Attraction of opposite sex in same species
  • For animals requiring internal fertilisation, it makes the female more receptive rather than aggressive
  • Both sexes are fertile at the same time
  • Females can select the same mate
• K-strategists


  Heavy investment in few offspring, requiring more parental care and a longer maturation period.
• R-Strategists


  Many offspring are produced in one breeding season, and little to no parental care is given.
• Monogamy


  Males mate with one female in a breeding season
• Why are some animals monogamous?

  The energy required to incubate and feed the offspring is greater than the female can provide on her own, so male must ensure that his genes are passed on
• Polygamy


  Males mate with more than one female in a breeding season
• Why are most mammals polygamous?

  The female requires less energy to rear the offspring on her own. It is better for the male to increase his genes in the gene pool.
• Polygynandry


  A mating system where both males and females have multiple mating partners in a breeding season and young are cared for by several adults.
• More parental care will increase the chance of survival of the offspring but will decrease the chance of survival for the parent
• Viviparous: (of an animal) bringing forth live young which have developed inside the body of the parent, receiving food and protection
• Oviparous: (of an animal) producing young by laying eggs which are hatched after the parent has laid them. Fertilisation is internal.
• Altrical young are born helpless and blind
• Precocial young are born developed and can walk and feed themselves
• Importance of courtship behaviours

  -Innate behaviour must be practised before the outcome to develop a strong pair bond

  -Selection is crucial for reproductive success

  -increases future recognition and reduces aggression and agonistic behaviour between courting couple in future matings