Sexual Imprinting in Zebra Finch Populations

1
Sexual Imprinting in Zebra Finch Populations

• Diane Livio
• November 29, 2004

2
Taeniopygia guttata (Zebra Finches)

• Estrildid passerines (family, order)
• Monomorphic, dichromatic
• Monogamous
• Biparental care, continues past fledging (until
  independence)

3
Previous research on mate choice in zebra finches

• Burley and others study mate choice (sexual
  selection),
• both on natural traits (beak color)
• and artificial traits (leg bands, crests)

4
Previous research on mate choice in zebra finches

• Burley and others study mate choice (sexual
  selection),
• both on natural traits (beak color)
• and artificial traits (leg bands, crests)
• Sensory bias nonfunctional, neurophysiological
  bias for mates, even on completely novel traits
• Burley, N.T., Symanski, R. 1998. A taste for
  the beautiful latent aesthetic mate preferences
  for white crests in two species of Australian
  grassfinches. The Amer. Natur. 152(6)792-802.

5
Sexual Imprinting

• Young learns characteristics to select for in
  choosing an appropriate mate

6
Sexual Imprinting

• Young learns characteristics to select for in
  choosing an appropriate mate
• Sensitive period (occurs past fledging, 50 approx
  50 days)

7
Sexual Imprinting

• Young learns characteristics to select for in
  choosing an appropriate mate
• Sensitive period (occurs past fledging, approx
  50 days)
• Observe through offsprings mate choice
• Irwin, D.E., Price, T. 1999. Sexual imprinting,
  learning and speciation. Heredity 82347-54.

8
Novel Trait Crest

• All extant species of estrildine finches
  (includes zebra finches) lack crest, though
  crests appear in other orders of birds and even
  some passerine families

9
Previous research on imprintingBurley, N.T.,
Symanski, R. 1998. A taste for the beautiful
latent aesthetic mate preferences for white
crests in two species of Australian
grassfinches. The Amer. Natur. 152(6)792-802.

• Latent aesthetic preferences, sex differences
• Applied different crest color treatments for mate
  choice options
• Test birds reared in non-crested population
• Females preferred white crests
• Males preferred no crests

10
Previous research on imprintingX, under review.
Oedipus, yes Electra, no sex differences in
sexual imprinting on artifical crests in zebra
finches.

• Sex differences in sexual imprinting
• Reared in all grey crest, all white crest, or no
  crest population
• Both parent, one or the other with crest
• Females prefer white crest
• Females dont imprint on grey crest
• Males prefer maternals phenotype

11
Previous research on imprintingY, under review.
An eye for detail selective sexual imprinting in
zebra finches.

• Selection for detail in sexual imprinting
• All white crest, either vertical or horizontal
  stripe, or non-crested populations
• Females preferred white crest
• Females preferred design
• of population raised in
• Males preferred phenotype
• of population raised in

12
Previous research on imprinting

• To summarize
• Preference for white crests in females
• Preference for detail in crest to match
  parents/population in white crests in females and
  males
• Preference for parental (maternal) phenotype in
  males

13
Not how evolution works

• Previous studies New phenotype 100 frequency
  in population
• Mock evolutionary scenario
• Strong enough for speciation event?
• Begin at smaller frequency, though substantial
  for comparisons

14
Set-up 2 populations

• Outdoor flight 1 30 pairs
• Apply crests to ?
• Ample food, water, resources nesting material

• Outdoor flight 2
• 30 pairs
• Apply crests to ?
• Ample food, water, resources nesting material

15
Basics

• Keep track of pairings,
• nest choices
• Perform daily nest checks, band young
• Note birth fledge dates
• Using offspring of crested and of non-crested
  parents, perform mate choice trials

16
Mate Choice Trials Apparatus

• Testing both sexes, offspring of parents with
  either phenotype, both populations
• Stimulus bird crested, non-crested

Test Bird
Crested Bird
Non- crested Bird
17
Collecting data

• 30 minute trials (not including hours preceding
  for acclimation to apparatus and set-up)
• Amount of time (seconds) on perch in front of
  cage of stimulus bird
• Preferences for crested vs. non-crested in mate
  choice (heterosexual)

18
Hypothesis

• Frequency does affect amount of imprinting
  (particularly in males), effect for speciation
• Offspring of non-crested parents in lower
  frequency not exposed to crests much during
  sensitive period, not imprint on crests.

19
Some points data analysis can lead into

• Imprinting on parents or on population
• Sensory bias in spite of imprinting

20
Some points data analysis can lead into

• Imprinting on parents or on population
• Sensory bias in spite of imprinting
• Effect of frequency in population
• Compare with previous findings (all crested
  population)
• Possibly lead into more studies of other
  frequencies (e.g. ½)

21
Thank you. Any questions?

• Burley, N.T., Symanski, R. 1998. A taste for
  the beautiful latent aesthetic mate
  preferences for white crests in two species of
  Australian grassfinches. The Amer. Natur.
  152(6)792-802.
• Irwin, D.E., Price, T. 1999. Sexual imprinting,
  learning and speciation. Heredity 82347-54.
• X, under review. Oedipus, yes Electra, no sex
  differences in sexual imprinting on artifical
  crests in zebra finches.
• Y, under review. An eye for detail selective
  sexual imprinting in zebra finches.