The one surviving queen from last year appears to have died along with her entire colony. It's hard to know exactly what killed them, though, I see no obvious signs of disease and the state they were in when they died seems to be consistent with freezing caused by an inability to maintain cluster temperature.
Over time, different bee species have developed different strategies for dealing with the winter season. For instance, each spring a young bumblebee queen will awaken from hibernation and begin building a new colony, which will grow from one bee (her) to an entire colony. This colony will grow throughout the summer and will be maintained and fed by the queen's female offspring. Just as with a honeybee colony, these female worker bees will be sterile. However, at the end of the summer, a new generation of young fertile queens will hatch and eventually leave the colony. The colony will then die, but these new queens will find a sheltered place to survive the winter and, if they make it, will build new colonies in the spring. Thus, for bumblebee colonies, the number one priority is to raise the largest number of strong healthy young queens at the end of the summer. While pollen and nector are collected, honey is made, and wax cells are built, these things are only done to the extant that they support this grand finale at the end of summer.
Unlike bumblebees, the honeybee strategy is to live longer through multiple years via what I would term the "high volume" approach. Queens can live in a colony for several years and the colony can survive with several successive queens for probably a decade or more under ideal conditions. To do this they need to have a way to survive the winter as a group and the way they do this is to hang closely together in a cluster, eat pounds of honey, and vibrate so much that they generate enough heat to keep from freezing. They will do this all winter with the queen buried deep in the center of the cluster. While this method does enable the colony to survive the cold winters, there are a number of critical things they must do correctly for it to work. First, they must store many pounds of honey in an easy to access part of the hive. If they run out of honey or can't directly reach the honey during a particularly cold spell they won't have enough energy to vibrate and will die. Second (this is related to the first item), they need to follow the right kind of strategy during the warmer winter days. If the temperature warms up for a day or two in the winter, these bees need to take advantage of the situation by bringing in honey from other parts other hive. Finally, they must be able to keep the cluster population large enough during the winter to keep the vibrating cluster warm enough. If the cluster gets too small, they won't be able to get through the colder parts of winter.
In my hive it appears that, for some reason, the cluster population became too small to make it through one of the several cold spells we've had. When I first opened the hive I could see a number of bees on the floor of the hive that had died during the winter. Bee death in a wintering colony is very normal. When they die they are pushed from the cluster and fall to the bottom. Eventually, on warmer days, they will be dragged out to the hive entrance and pushed out the door. However, in the case of the doomed cluster, the last bees to die will died in place as if they had suddenly been frozen in motion. Some bees will look like they were in the middle of eating some honey while others will look like they were casually walking somewhere. Probably most startling, though, is the arrangement of bees at the center of the cluster. These bees will be tightly clustered in a series of circles all facing inward towards their now deceased queen. Its as if they all died awaiting some final phermonic order that never came. Or maybe it did.
Anyway, in spite of this unfortunate end to last year's bees, I've decided to renew my beekeeping efforts this coming spring and even expand things a little. A few weeks ago, I ordered five new bee packages from a local distributor and just last week finished constructing four new three foot top bar hives. I plan on putting three of the new hives and one of the five foot hives from last year on our ranch and keeping one of the new three foot hives in my back yard. I'm expecting to be able to pick up the new packages on April 1st.
Finally, over the past few months, I've finished a number of bulky ranch-related projects (beehives, welding equipments, bison gate, etc.) in my garage to the point that I am now barely able to move around in there. For this reason, we've now begun the practice of moving some of the less valuable bulky items down to the ranch every time we visit. Just yesterday, we moved the three new hives down there and placed them out of the weather under an old half-caved-in shed until we can set them up properly.
