What determines the breeding time of birds? Does the breeding of most tropical birds depend on the season? Why?

For birds and other organisms found in seasonal environments, time (laying date) and breeding rate (sleeve size) are two key decisions in the annual cycle. Many bird species breed in early years with high spring temperatures, but little is known about the causal effect of temperature. Temperature can directly affect the timing of reproduction, but the correlation can also be indirect, for example, through the phenology of food. Climate change has led to significant shifts in the timing of bird breeding.