Event type
Previous Event
Event status
11 May 2021 6:00pm - 7:30pm
1h 30m

Experts discuss female reproductive failure in birds.

Hatching failure occurs in all birds, but its incidence varies across species, populations and individuals.

Small, threatened populations are particularly vulnerable, with rates of hatching failure sometimes exceeding 70%. Even large populations of common species experience an average failure rate of 10%, and this problem persists in domestic poultry despite optimised conditions and strong selection for hatching success.

Egg hatchability can therefore be considered a weak link in the chain of events that determines avian reproductive success.

Eggs fail for a number of reasons. In this event we explore the different aspects that lead to female reproductive failure from gamete malfunction to developmental environment, and ask why female fertility is so poorly understood not only in birds, but across most species?

Please be aware, this event features images of bird embryos and physiology, and videos of egg dissection.


  • Dr Patricia Brekke, Institute of Zoology, ZSL: "When every egg counts: Hatching failure in conservation"
  • Dr Barbara Tschirren, Centre for Ecology & Conservation, University of Exeter: "Why do birds not lay larger eggs?"
  • Dr Nicola Hemmings, Department of Animal & Plant Sciences, University of Sheffield: "What's in an egg? The biology of avian fertilisation and why it matters for conservation"
  • Dr Jennifer Smart, Royal Society for the Protection of Birds (RSPB) Centre for Conservation Science: "The importance of breeding success in the conservation of lowland waders"
  • Gary Ward, Curator of Birds, ZSL, joins the panel for this event.

Watch the event

Event details
  • This interactive online event was livestreamed to our YouTube channel
  • Each event comprises of 3-4 presentations from experts in the topic, similar to our previous event series.
  • Thank you to everyone who submitted a question - we encourage you to watch our events live so you can take part!
  • There was no charge for this event, and no need to register in advance to watch the livestream
  • The event was produced by Eleanor Darbey, hosted by Charlotte Coales and facilitated by Tendai Pottinger, ZSL. 
  • To read an open access review of hatching failure in birds and Animal Conservation, click here
  • For those wanting to identify the fertility status of unhatched bird eggs, a practical resources guide featuring protocols and video demonstrations can be found here.
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