Many wild bird lovers will offer suet during the winter months and then move to seeds and nuts in the summer. It’s a good idea to wait until the June timeframe to switch UNLESS you are in a very warm climate that would be likely to melt the suet. Even then, there are many no-melt brands of suet that may be perfect for your situation.
Traveling great distances to reach their breeding grounds, wild birds use alot of calories. Nest building, breeding, defending territories and raising young requires a lot of energy and suet provides the much needed energy-rich nutrition.
So hang on a couple more months and buy a couple extra suet cakes to help them along after their long, long journey!