Swarming (honey bee)

Swarming is the process by which a new honey bee colony is formed when the queen bee leaves the colony with a large group of worker bees. In the prime swarm, about 60% of the worker bees leave the original hive location with the old queen. This swarm can contain thousands to tens of thousands of bees. Swarming is mainly a spring phenomenon, usually within a two- or three-week period depending on the locale, but occasional swarms can happen throughout the producing season. Secondary afterswarms, or cast swarms may happen. Cast swarms are usually smaller and are accompanied by a virgin queen. Sometimes a beehive will swarm in succession until it is almost totally depleted of workers. Swarming is the process by which a new honey bee colony is formed when the queen bee leaves the colony with a large group of worker bees. In the prime swarm, about 60% of the worker bees leave the original hive location with the old queen. This swarm can contain thousands to tens of thousands of bees. Swarming is mainly a spring phenomenon, usually within a two- or three-week period depending on the locale, but occasional swarms can happen throughout the producing season. Secondary afterswarms, or cast swarms may happen. Cast swarms are usually smaller and are accompanied by a virgin queen. Sometimes a beehive will swarm in succession until it is almost totally depleted of workers. Swarming is a honey bee colony's natural means of reproduction. In the process of swarming, the original single colony reproduces to two and sometimes more colonies. For instance, one species of honey bee that participates in such swarming behavior is Apis cerana. The reproduction swarms of this species settle 20–30 m away from the natal nest for a few days and will then depart for a new nest site after getting information from scout bees. Scout bees search for suitable cavities in which to construct the swarm's home. Successful scouts will then come back and report the location of suitable nesting sites to the other bees. Apis mellifera participates in a similar swarming process. Worker bees create queen cups throughout the year. When the hive is getting ready to swarm, the queen lays eggs into the queen cups. New queens are raised and the hive may swarm as soon as the queen cells are capped and before the new virgin queens emerge from their queen cells. A laying queen is too heavy to fly long distances. Therefore, the workers will stop feeding her before the anticipated swarm date and the queen will stop laying eggs. Swarming creates an interruption in the brood cycle of the original colony. During the swarm preparation, scout bees will simply find a nearby location for the swarm to cluster. When a honey bee swarm emerges from a hive they do not fly far at first. They may gather in a tree or on a branch only a few metres from the hive. There, they cluster about the queen and send 20 - 50 scout bees out to find suitable new nest locations. This intermediate stop is not for permanent habitation and they will normally leave within a few hours to a suitable location. It is from this temporary location that the cluster will determine the final nest site based on the level of excitement of the dances of the scout bees. It is unusual if a swarm clusters for more than three days at an intermediate stop. Swarming creates a vulnerable time in the life of honey bees. Swarms are provisioned only with the nectar or honey they carry in their stomachs. A swarm will starve if it does not quickly find a home and more nectar stores. This happens most often with early swarms that leave on a warm day that followed by cold or rainy weather in spring. The remnant colony, after having produced one or more swarms, is usually well provisioned with food. But, the new queen can be lost or eaten by predators during her mating flight, or poor weather can prevent her mating flight. In this case the hive has no further young brood to raise additional queens, and it will not survive. A caste swarm will usually contain a young virgin queen. The propensity to swarm differs among the honey bee races. Africanized bees are notable for their propensity to swarm or abscond. Absconding is a process where the whole hive leaves rather than splits like in swarming. Being tropical bees, they tend to swarm or abscond any time food is scarce, thus making themselves vulnerable in colder locales. Mainly for lack of sufficient winter stores, the Africanized bee colonies tend to perish in the winter in higher latitudes. Generally, a weak bee colony will not swarm until the colony has produced a larger population of bees. Weak bee colonies can be the result of low food supply, disease such as Foulbrood Disease, or from a queen that produces low quantities of eggs. A good nesting site for honey bees must be large enough to accommodate their swarm (minimum 15 liters in volume, preferably ≈40 liters). It should be well protected from the elements, and have a small entrance (approximately 12.5 cm squared) located at the bottom of the cavity. It must receive a certain amount of warmth from the sun, and should not be infested with ants. In addition to these criteria, nest sites with abandoned honeycombs, if the scout bees can find one, are preferred, because this allows the bees to better conserve their resources. The scout bees are the most experienced foragers in the resting swarm cluster. An individual scout returning to the cluster promotes a location she has found. She uses the waggle dance to indicate its direction, distance, and quality to others in the cluster. The more excited she is about her findings, the more excitedly she dances. If she can convince other scouts to check out the location she found, they take off, check out the proposed site, and choose to promote the site further upon their return. Several sites may be promoted by different scouts at first. After several hours and sometimes days, a favorite location gradually emerges from this decision-making process. In order for a decision to be made in a relatively short amount of time (the swarm can only survive for about three days on the honey on which they gorged themselves before leaving the hive), a decision will often be made when somewhere around 80% of the scouts have agreed upon a single location and/or when there is a quorum of 20-30 scouts present at a potential nest site. (If the swarm waited for less than 80% of the scouts to agree, the bees would lack confidence in the suitability of the site. If they waited for more than 80% of the scouts to agree, the swarm would be wasting its stored honey.)