Birds of Indian Subcontinent

Unhatched eggs: methods for discriminating between infertility and early embryo mortality

Publication Type:Journal Article
Year of Publication:2008
Authors:Birkhead, TR, HALL, J, SCHUT, E, HEMMINGS, N
Date Published:2008
ISBN Number:1474-919X
Keywords:embryo mortality, Estrildidae, infertility, parthenogenesis, Passer, Passer montanus, Passeridae, Poephila, Poephila guttata, Salicipasser, Salicipasser montanus, Taeniopygia, Taeniopygia guttata, tree sparrow, zebra finch
Abstract:Unhatched eggs are a common phenomenon in birds and are often referred to as being ‘infertile’, which (confusingly) can mean at least two things: (1) that the ovum has not been fertilized or (2) that the embryo has died during development. These two broad categories of hatching failure can be difficult to distinguish, particularly in the early stages of embryo development. We describe methods to distinguish between infertility (due to insufficient sperm) and early embryo mortality in passerine eggs using the Zebra Finch Taeniopygia guttata as a model. We also describe how we successfully adapted these methods for use on eggs from a wild species, the Tree Sparrow Passer montanus, collected after the incubation period, and show that sperm can be visualized on the perivitelline layer of unhatched eggs even several weeks after laying.
Short Title:Ibis
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith