Systematic review of avian hatching failure and implications for conservation

Area of Science:

• Avian ecology and conservation biology.
• Reproductive biology and population dynamics in birds.

Background:

• Avian hatching failure affects approximately 10% of eggs, with higher rates observed in threatened and captive bird populations.
• Existing research lacks comprehensive quantification of hatching failure across diverse species and management contexts.

Approach:

• A phylogenetically controlled multilevel meta-analysis was conducted using data from 231 studies and 241 bird species.
• The study analyzed hatching failure rates in relation to species threat status (threatened vs. non-threatened) and management levels (wild, wild managed, captive).

Key Points:

• The overall mean hatching failure rate was 16.79%, significantly higher in threatened species (12.40% in non-threatened wild species).
• Captive populations exhibited the highest hatching failure rates, followed by wild managed and then wild populations.
• Specific interventions like artificial incubation, supplementary feeding, and artificial nest provision were associated with increased hatching failure.

Conclusions:

• Threatened status and intensive management correlate with higher avian hatching failure, potentially indicating conservation efforts are focused on at-risk populations.
• Further research is needed to elucidate the drivers of this correlation and address unexplained heterogeneity in hatching failure.
• Standardizing the definition and reporting of hatching failure is crucial for accurate comparative analysis and informed conservation decisions.