thumbnail

Experimental reintroduction reveals novel life-history variation in Laysan Ducks (Anas laysanensis)

The Auk

By:
,
DOI: 10.1525/auk.2013.13070

Links

Abstract

Subfossil remains indicate that the Laysan Duck (Anas laysanensis) formerly occurred throughout the Hawaiian archipelago, but for more than 150 years it has been confined to a single, small atoll in the northwestern chain, Laysan Island. In 2004–2005, 42 ducks were reintroduced from Laysan to Midway Atoll, where they exhibited variation in life history never observed on Laysan. On Laysan, females have never been observed to breed successfully at age 1 year and few attempt it, whereas on Midway, females routinely raised young at <1 year of age. Mean (± SD) clutch size on Midway (7.0 ± 1.1, n = 41) was larger than the maximum clutch size of six eggs observed on Laysan. On Midway, renesting following nest failure (0.55 probability, n = 27) and double brooding (0.50, n = 54) were routine, and two instances of triple brooding were observed, whereas on Laysan, renesting and double brooding are rare (0.05 probability for both during our study; n = 21 and 19, respectively) and triple brooding has never been observed. Other novel life history on Midway included early cessation of parental care to renest. Altered life history on Midway is likely related to better feeding conditions and low population density compared with Laysan. An especially intriguing possibility is that the phenotypic plasticity observed represents exposure of hidden reaction norms evolved when the species inhabited a range of environments, but several alternative explanations exist. Future reintroductions of this species may provide opportunities to test hypotheses about mechanisms underlying phenotypic plasticity.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Experimental reintroduction reveals novel life-history variation in Laysan Ducks (Anas laysanensis)
Series title:
The Auk
DOI:
10.1525/auk.2013.13070
Volume
130
Issue:
4
Year Published:
2013
Language:
English
Publisher:
The American Ornithologists' Union
Contributing office(s):
Pacific Island Ecosystems Research Center
Description:
7 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
573
Last page:
579
Number of Pages:
7
Country:
United States
State:
Hawai'i