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 offspring’s mate choice Irwin, D.E., Price, T. 1999. Sexual imprinting, learning and speciation. Heredity 82:347-54.

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 don’t imprint on grey crest Males prefer maternal’s 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

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 82:347-54. 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.