Grade 9 Science Journal Q1

Factor: Weather

Unlike many insects and mammals, bees don’t hibernate when the weather gets cold, in fact they do the opposite. When the temperature drops thousands of bees crowd inside their hive and begin working, working even harder than they did in the summer. High wind speeds can significantly reduce the efficiency of a honey bee’s search for food. Experts at the University of Sussex found that the foraging rate of honey bees significantly decreased in higher wind speeds due to increased hesitancy to take off. If it is raining and the raindrops are too heavy then the raindrop will simply kill the honeybee because it is too heavy and causes the bee to drown. In the summer when heat temperatures get to high bees can actually get heat stroke as well as us and can actually die if it gets too hot. Most of these different weathers have a negative affect on the bees all around the world and the reason for that is Climate change.

Factor: Predation

Human beings have had a dramatic impact on the ecosystems of the earth, which has affects on many pollinator species. Artificial light attracts insects, pulling them from their natural ecosystems. Their frenzied activity around lights also exhausts them and makes them easy prey for predators in that ecosystem.

Honey bees are herbivores. The populations of many herbivores are mainly controlled by predators. If the population of the prey species becomes dense, predator species bring up their numbers to take advantage of the food source. The result is typically an oscillating predator/prey population dynamic.

Although predators of foraging bees may take a bite out of the population of older bees in the hive, they do not appear to be a primary limiting factor of the overall bee population. An exception to this rule might be the Asian Hornet that can decimate small colonies of bees by picking off returning foragers.

A more intense form of predation is direct invasion of the hive. A healthy colony has to evacuate small invaders such as ants, wasps, and Small Hive Beetles. More problematic are those large mammalian predators willing to ignore the bees’ defensive stinging, such as bears, skunks, honey badgers, and humans.

Factor:  Competition For Nest Cavities

Bees are extremely picky about the nest cavities that they choose, strongly preferring elevated tree cavities having small, defendable entrances. In treeless areas, the lack of suitable nest sites could well have been a limiting factor for the honey bee population. Not all beekeepers are aware that intra- and inter-species parasitism is common among bees, wasps, and ants. For example, queens of a number of bumblebees species parasitically invade and take over other bumblebee colonies. And the Cape Bee (Apis mellifera capensis) is famous for its ability to parasitically take over colonies of the Savannah Bee (Apis mellifera scutellata). This sort of deplorable behavior appears to be ingrained in the bee genome– bees covet the fruits of their neighbors’ hard work.

Part of the Africanized honey bees ability to rapidly expand its range in the Americas was likely its ability to invade and usurp the established nests of European bees.

Such takeovers give the usurping swarm a profound advantage. Rather than needing to establish a nest and provision it with stores from scratch, it can simply take over an established colony, essentially hijacking its combs, stores, and entire workforce.

Factor: carrying capacity of the habitat

The maximum population density for the realized niche of a population is set by the carrying capacity of that particular environment, typically limited by resources such as food. However, the honey bee is a special case similar to the bear, the colony can gorge when food is plentiful, and store fat (honey and beebread) as reserves for lean times during overwintering.

There are indeed areas in which colonies can barely put on enough honey during the main flow in order to make it through the winter. But by definition, such areas would not meet a primary requirement of the fundamental niche of the honey bee, so we can disregard such areas from this discussion. What we are interested in is the limiting factor of the bee population in areas that normally produce a good honey flow.

Factor: The timing of the bloom

Honey bees are defined by their ability to store food reserves know as honey and beebread—to see them through lean times. But there are times other than the main honey flow during which the availability of nectar, and especially pollen, are of critical importance to the ability of colonies not only to survive, but also to reproduce. Colonies must build up and produce a swarm early enough in the season that both parent and swarm colony have fighting chances to store enough honey to make it through the following winter. Such buildup requires the initiation of brood rearing in the middle of winter, which is in turn dependent upon having stored a large supply of beebread during the fall pollen flow.

A colony of bees is only effective at putting away a honey surplus if it has grown a large enough population to efficiently forage upon and store the available nectar. Too large a population at the wrong time of the year would be counterproductive, since those hungry mouths would consume more honey than they were able to store. A locally-adapted population of bees times its buildup to coincide with the main flow, and then quickly shrinks back to survival mode.

Bees adapted to colder winters, such as the Carniola’s or Russians, are far more responsive to the environment, especially to the availability of pollen. As soon as plants start producing pollen in spring, bees of these races explode into action-working even in cool and wet weather, and madly brood up.

The reason for their frenzy is that they must build up their population early enough to produce a swarm in time for it to have a decent chance at establishing a nest and putting away adequate winter honey stores during the brief main honey flow (typically May through June in temperate climates, colonies may only gain weight for a few weeks a year.

Factor: Competition for those food resources

Competition for food resources, either against other species or one’s own species, is a common limiting factor of the realized niche. Anywhere that there are flowering plants, there are pollinators that have coevolved with them. Most are insects although in some areas, birds, bats, or other mammals may be important. Since one can place a hive of bees into most any favorable habitat and still make honey despite the presence of established populations of native pollinators, I suspect that competition with other species is not normally the limiting factor of the honey bee population. On the other hand, as any beekeeper quickly recognizes, honey bee colonies certainly compete with one another. Beekeepers tend to focus upon the amount of nectar available during the main honey flow, and understand that one can overload an area with managed hives. 

In areas with well-established populations of feral bees (Australia, Hawaii, normally in the U.S), one can bring in additional managed colonies, yet still produce a substantial honey crop during the main flow—clearly, nectar is produced in excess of what an established natural population of bees can harvest. It follows then that at a “normal” population density of unmanaged colonies, competition for nectar during the main flow wasn’t the limiting factor for colony survival.

Video link:https://www.youtube.com/watch?v=pPw51fDTl68