@article {Reed:1990:0156-1383:58, title = "Does an Absence of Gape Markings Affect Survival of Leucistic Young in the Zebra Finch?", journal = "Bird Behavior", parent_itemid = "infobike://cog/bb", publishercode ="cog", year = "1990", volume = "9", number = "1-2", publication date ="1990-12-01T00:00:00", pages = "58-63", itemtype = "ARTICLE", issn = "0156-1383", url = "https://www.ingentaconnect.com/content/cog/bb/1990/00000009/f0020001/art00009", keyword = "ZEBRA FINCH, GAPE MARKINGS, SURVIVAL, LEUCISTIC", author = "Reed, H.J. and Freeman, N.H.", abstract = "It has been reported that Zebra Finches that hatch without gape markings fail to thrive, probably because they lack a releaser for an evolved parental feeding mechanism. It is likely that the success of leucistic young (i.e. those without pigmentation and gape markings) and fostered young is largely dependent on prevailing environmental conditions. Where food is abundant, and social and territorial conditions are favourable, they will thrive; under adverse conditions, they will be sacrificed to ensure the survival of their normal siblings. This study found that the lack of gape markings in leucistic nestlings was no disadvantage under optimal environmental conditions. Gape markings may be an extra resource for the young to encourage parental investment, one that only comes into play in times of overall adversity.", }