Kingfisher evolution

In this scenario, rainforests will most likely be gone in 100 years due to global warming. So that means the Kingfisher will have to evolve to live in the desert. It'll also have to evolve to have brighter feathers; why exactly? Well since the rainforest is gone, that means fewer birds the kingfisher can mate with. So they'll have to have brighter feathers to attract more mates, considering the smaller amount of mating birds. This scenario isn't really guaranteed to happen to kingfishers when they evolve, but it COULD happen to the kingfishers in 100 years. Who knows though? Maybe this scenario is 100 percent accurate. Only time will tell...