BIO3052 Lecture Notes - Lecture 21: Design Of Experiments, Selective Breeding, Biological Pest Control
30 May 2018
School
Department
Course
Professor
BEHAVIOURAL VARIATION I
INTRASPECIFIC BEHAVIOURAL VARIATION, CORRELATIONS AMONG BEHAVIOURS AND
BEHAVIOURAL SYNDROMES
• Behavioural variation: Behaviours of the same species may vary differently
o This is what natural selection acts upon and some will do better than others
o Ma also lead to seual seletio traits that do’t eessaril help surie ut helps
animal reproduce)
o You get decrease in behavioural variation when selecting for behaviour
• Intraspecies: among individuals within a species
o Differences in individual behaviour changes the individuals susceptibility to predation
eg. a’t ru fast
o If individuals of the same population are isolated for a long time, what happens when
they interact again?
• Interspecies: among individuals from different species
• Why should we care?
o Selection acts upon behavioural variation
o Selection acts to erode variation
o It has evolutionary and ecological consequences
-> influences how species interacts
• How is variation generated and maintained?
o You expect direction of selection/optimal combination of traits to differ between
populations
o Variation is maintained by mutations
• Phenotypic variation is well established eg. morphology and colour
• Behavioural variation was once considered a nuisance and only focused on mean behaviours
• Behavioural syndromes: a suite of correlated behaviours reflecting between individual
consistency in behaviour across multiple situations
o An be exhibited by a population or species
o Correlations can be negative or positive
o Embraces individual variation in behaviour
o Obtains a lot of ideas from psychology
o Syndrome: a suite of correlated characters/traits
-> can predict what other associated traits will be
-> needs to have at least 2 behaviours
o Needs to be repeatable
o Parallels to r/K selection of life histor theor oe aspet of ehaiour o’t eole o
its own)
o Within a syndrome, individuals have a behavioural type
Is a spectrum
Is characteristic of an individual (syndrome is a correlation between two traits
that is characteristic of a population on a species level)
find more resources at oneclass.com
find more resources at oneclass.com
o Involves repeated observations of behaviours of the same set of individuals across
multiple contexts or situations
o Within-individual consistency: tendency for any given individual to exhibit consistent
behaviour across situation
o Behavioural syndrome studies need to be repeated with the same individual over
multiple context
o Among individual consistency: consistent differences among individuals in behaviour
(rank-order) – if one individual is ranked high for one behaviour, the associated
behaviour will also rank high
• Behavioural syndrome in Funnel-web spider (agelenopsis aperta):
o Aggression, territorial behaviour, foraging and anti-predator behaviour
o Antipredator behaviour:
Experimental design: use camera cleaner to blow air that mimics flapping of bird
wings -> does the spider retreat into tunnel? And what is the time until re-
emergence (gives a sense of how wary an individual is/how bold)
o Aggressive behaviour:
Experimental design: two spiders put into same area and let them fight it out.
Winner is the ownership of funnel -> sense how aggressive individuals are
o Foraging and territorial behaviour:
Experimental design: in presence of food source, see how quickly the individual
responds to prey item. Also introduced an intruder to see how quickly it
responds
o If the individual was highly aggressive, you would also expect to see 3 other traits
increased
o Why are behaviours linked?
-> might be regulated by same genes or hormones
-> ability to predict will depend on strength of trait
o Aggression – boldness syndrome
-> traits evolve as a group
• Evolutionary implications:
o Limited plasticity of individual behaviours
Constraints and trade-offs
o Need to embrace individual variation
o Potential explanations for non-optimal behaviour
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Intraspecies: among individuals within a species: differences in individual behaviour changes the individuals susceptibility to predation (cid:894)eg. (cid:272)a(cid:374)"t ru(cid:374) fast(cid:895) Interspecies: among individuals from different species: why should we care, selection acts upon behavioural variation, selection acts to erode variation. > can predict what other associated traits will be. > needs to have at least 2 behaviours: needs to be repeatable, parallels to r/k selection of life histor(cid:455) theor(cid:455) (cid:894)o(cid:374)e aspe(cid:272)t of (cid:271)eha(cid:448)iour (cid:449)o(cid:374)"t e(cid:448)ol(cid:448)e o(cid:374) its own, within a syndrome, individuals have a behavioural type. Is characteristic of an individual (syndrome is a correlation between two traits that is characteristic of a population on a species level) And what is the time until re- emergence (gives a sense of how wary an individual is/how bold: aggressive behaviour: Experimental design: two spiders put into same area and let them fight it out. Winner is the ownership of funnel -> sense how aggressive individuals are: foraging and territorial behaviour:
