Why are many pigeon species monogamous?

Many pigeon species are monogamous because this mating system is favored when environmental resources are limited and the maximum survival of their young requires the care of both parents.1

In pigeons, both members of a pair share the duties of incubation, ensuring that the eggs are rarely left uncovered. Furthermore, pigeon parents provide their young with "pigeon milk," a proteinaceous substance produced in the crop. Because the production of this milk is limited, it constrains the number of young a pair can successfully rear, and the involvement of both parents is essential for the care and feeding of the squabs.23

This social monogamy—where a single male and female form a stable, long-term pair bond—is a common reproductive strategy among birds, as it allows for the cooperative division of labor necessary to raise offspring effectively.314