Coastal Shorebirds Delay Maturity More Than Inland Ones.

Area of Science:

• Avian Ecology
• Conservation Biology
• Evolutionary Biology

Background:

• Migratory shorebirds often delay first breeding, potentially impacting reproductive success.
• Understanding factors influencing delayed maturity is crucial for shorebird conservation.
• Previous research highlights differences between coastal and inland shorebird populations.

Purpose of the Study:

• To determine the age of first return migration (maturity) in 37 shorebird species migrating to Australia.
• To analyze the relationship between maturity and non-breeding habitat use (coastal vs. inland wetlands).
• To investigate the influence of body size and habitat type on delayed maturity.

Main Methods:

• Utilized data from non-breeding and breeding season counts.
• Incorporated recapture and long-term banding study data.
• Employed statistical analyses controlling for latitudinal and phylogenetic factors.

Main Results:

• A positive correlation was found between body size and age of first return migration.
• Habitat type showed a stronger association with delayed maturity than body size.
• Coastal shorebird species exhibited delayed maturity compared to inland wetland species.

Conclusions:

• Non-breeding habitat use is a significant factor in the timing of first breeding for migratory shorebirds.
• Coastal foraging environments, with complex tidal dynamics and prey, may necessitate a longer period to achieve foraging competence.
• These findings contribute to understanding ecological and physiological divergence between coastal and inland shorebird guilds.