The evolution of crocodilian nesting ecology and behavior

Area of Science:

• Zoology
• Evolutionary Biology
• Ecology

Background:

• Crocodilians are ancient archosaurs with remarkable evolutionary persistence.
• Their long-term survival raises questions about phylogenetic conservatism versus adaptive flexibility.
• Understanding their reproductive strategies is key to explaining their success.

Purpose of the Study:

• To investigate the evolutionary pathways of crocodilian reproductive ecology and behavior.
• To determine the roles of phylogenetic constraint and ecological convergence in trait evolution.
• To analyze 14 reproductive traits across all 24 crocodilian species.

Main Methods:

• Phylogenetic comparative analysis of 14 reproductive traits.
• Assessment of trait evolution for phylogenetic constraint versus ecological convergence.
• Examination of trait correlations, such as communal nesting and nesting mode.

Main Results:

• The ancestral crocodilian was a mound nester with nest attendance and defense.
• Nesting mode evolved from mound to hole nesting, showing habitat-driven convergence.
• Nest attendance and defense are phylogenetically conserved, while nesting seasonality and attendance lodging show convergence.

Conclusions:

• Crocodilian reproductive trait evolution is a mosaic of phylogenetic constraint and ecological convergence.
• Traits like nest attendance and defense highlight evolutionary conservatism.
• Seasonal nesting and nesting mode demonstrate adaptive flexibility and convergence.