Possibly the most critical change in a hive happens in the winter bee to spring bee "change-over."
The fat bees (bees with larger fat bodies) produced by the colony last fall are old now, putting the last of their life’s energy into raising the brood that replaces them. This changeover has already happened for many beekeepers in Western Washington. A hive has truly overwintered when that first brood successfully emerges as young, fuzzy new adults ready to take over from the aging, dying winter bees. Congratulations to all the beekeepers who had the patience to NOT open hives too early for inspection, and who did not expose that first brood to unnecessary chilling and dying.
The second part of that critical spring changeover is the change from using winter stores to foraging. Extended cold, damp spring weather can prevent hives from foraging as much as they need and can keep them from building population in time for the main flow, the blackberry flow in Western Washington. Also, a late spring can delay blooms of the early nectar flows that provide the carbs that overwintered hives and nucs need in order to build up. Beekeepers can help their hives make the changeover by providing the 1:1 syrup (and possibly pollen sub) to replace that forage, particularly important when spring in Western Washington remains cold and damp.