Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird

Inbreeding depression plays a major role in shaping mating systems: in particular, inbreeding avoidance is often proposed as a mechanism explaining extra-pair reproduction in socially monogamous species. This suggestion relies on assumptions that are rarely comprehensively tested: that inbreeding de...

Full description

Bibliographic Details
Main Authors: Hajduk, G, Cockburn, A, Margraf, N, Osmond, H, Walling, C, Kruuk, L
Format: Journal article
Language:English
Published: Wiley 2018
_version_ 1826274690117664768
author Hajduk, G
Cockburn, A
Margraf, N
Osmond, H
Walling, C
Kruuk, L
author_facet Hajduk, G
Cockburn, A
Margraf, N
Osmond, H
Walling, C
Kruuk, L
author_sort Hajduk, G
collection OXFORD
description Inbreeding depression plays a major role in shaping mating systems: in particular, inbreeding avoidance is often proposed as a mechanism explaining extra-pair reproduction in socially monogamous species. This suggestion relies on assumptions that are rarely comprehensively tested: that inbreeding depression is present, that higher kinship between social partners increases infidelity, and that infidelity reduces the frequency of inbreeding. Here, we test these assumptions using 26 years of data for a cooperatively breeding, socially monogamous bird with high female infidelity, the superb fairy-wren (Malurus cyaneus). Although inbred individuals were rare (∼6% of offspring), we found evidence of inbreeding depression in nestling mass (but not in fledgling survival). Mother-son social pairings resulted in 100% infidelity, but kinship between a social pair did not otherwise predict female infidelity. Nevertheless, extra-pair offspring were less likely to be inbred than within-pair offspring. Finally, the social environment (the number of helpers in a group) did not affect offspring inbreeding coefficients or inbreeding depression levels. In conclusion, despite some agreement with the assumptions that are necessary for inbreeding avoidance to drive infidelity, the apparent scarcity of inbreeding events and the observed levels of inbreeding depression seem insufficient to explain the ubiquitous infidelity in this system, beyond the mother-son mating avoidance.
first_indexed 2024-03-06T22:47:18Z
format Journal article
id oxford-uuid:5d9b7e6e-75a5-4036-9d5e-6a19d4d28709
institution University of Oxford
language English
last_indexed 2024-03-06T22:47:18Z
publishDate 2018
publisher Wiley
record_format dspace
spelling oxford-uuid:5d9b7e6e-75a5-4036-9d5e-6a19d4d287092022-03-26T17:35:29ZInbreeding, inbreeding depression, and infidelity in a cooperatively breeding birdJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5d9b7e6e-75a5-4036-9d5e-6a19d4d28709EnglishSymplectic Elements at OxfordWiley2018Hajduk, GCockburn, AMargraf, NOsmond, HWalling, CKruuk, LInbreeding depression plays a major role in shaping mating systems: in particular, inbreeding avoidance is often proposed as a mechanism explaining extra-pair reproduction in socially monogamous species. This suggestion relies on assumptions that are rarely comprehensively tested: that inbreeding depression is present, that higher kinship between social partners increases infidelity, and that infidelity reduces the frequency of inbreeding. Here, we test these assumptions using 26 years of data for a cooperatively breeding, socially monogamous bird with high female infidelity, the superb fairy-wren (Malurus cyaneus). Although inbred individuals were rare (∼6% of offspring), we found evidence of inbreeding depression in nestling mass (but not in fledgling survival). Mother-son social pairings resulted in 100% infidelity, but kinship between a social pair did not otherwise predict female infidelity. Nevertheless, extra-pair offspring were less likely to be inbred than within-pair offspring. Finally, the social environment (the number of helpers in a group) did not affect offspring inbreeding coefficients or inbreeding depression levels. In conclusion, despite some agreement with the assumptions that are necessary for inbreeding avoidance to drive infidelity, the apparent scarcity of inbreeding events and the observed levels of inbreeding depression seem insufficient to explain the ubiquitous infidelity in this system, beyond the mother-son mating avoidance.
spellingShingle Hajduk, G
Cockburn, A
Margraf, N
Osmond, H
Walling, C
Kruuk, L
Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird
title Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird
title_full Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird
title_fullStr Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird
title_full_unstemmed Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird
title_short Inbreeding, inbreeding depression, and infidelity in a cooperatively breeding bird
title_sort inbreeding inbreeding depression and infidelity in a cooperatively breeding bird
work_keys_str_mv AT hajdukg inbreedinginbreedingdepressionandinfidelityinacooperativelybreedingbird
AT cockburna inbreedinginbreedingdepressionandinfidelityinacooperativelybreedingbird
AT margrafn inbreedinginbreedingdepressionandinfidelityinacooperativelybreedingbird
AT osmondh inbreedinginbreedingdepressionandinfidelityinacooperativelybreedingbird
AT wallingc inbreedinginbreedingdepressionandinfidelityinacooperativelybreedingbird
AT kruukl inbreedinginbreedingdepressionandinfidelityinacooperativelybreedingbird