What factor primarily explains why Northern Jacanas do not breed further north than the southern US states?

Answer

Freezing temperatures eliminating their necessary floating plant substrate during winter

The northern limit of the Northern Jacana's breeding range is determined by climatic factors that cause the water to freeze or the dominant floating plants to die back completely during winter.

What factor primarily explains why Northern Jacanas do not breed further north than the southern US states?
habitatbirdJacana