In:
Oecologia, Springer Science and Business Media LLC, Vol. 198, No. 1 ( 2022-01), p. 67-77
Abstract:
The New Zealand huia ( Heteralocha acutirostris ) had the most extreme bill sexual dimorphism among modern birds. Given the quick extinction of the species, the cause of the dimorphism could only be hypothesised to reflect different trophic niches and reduce male/female competition. We tested that hypothesis by combining museum specimens, geometric morphometrics, and isotopic analyses. We used geometric morphometrics to describe bill shape; measured bulk ( δ 15 N bulk ) and ( δ 13 C bulk ) values from feather as proxies of the birds’ foraging habitat and diet; and compared compound-specific stable isotopes analyses (CSIA) of nitrogen in amino acids ( δ 15 N AA ) in male–female pairs to estimate their trophic position. Sexes had significantly different, but overlapping feather δ 15 N bulk and δ 13 C bulk values, but δ 15 N AA indicated identical trophic positions and δ 15 N bulk was not related to bill shape. Trophic position was less variable among females, consistent with a specialised foraging behaviour and, thus, supporting a partial male/female foraging segregation.
Type of Medium:
Online Resource
ISSN:
0029-8549
,
1432-1939
DOI:
10.1007/s00442-021-05082-8
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2022
detail.hit.zdb_id:
1462019-4
detail.hit.zdb_id:
123369-5
SSG:
12
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