Der Alte Fritz
House Bee
- Joined
- Aug 1, 2010
- Messages
- 346
- Reaction score
- 0
- Location
- Rye, East Sussex
- Hive Type
- WBC
- Number of Hives
- 2
Taking Jurgen Tautz's book "The Buzz About Bees", I thought I would use some of his facts and figures to work out an energy budget for a bee colony.
Queen lays 200,000 eggs a year which gives a population of around 50,000 in the summer and 20,000 in the winter.
1 bee collects 30 mg nectar (500 Joules) and makes on average 7 flights a day (using 10 J per flight) and works for around 15 days. So our forager produces 50,000 J and as there are 150,000 bees a year this translates to:
15 million foraging flights a year from the colony. 12 million for nectar, 2 million for pollen and 1 million for propalis and water.
Since our forager collects 30-40 mg nectar or 500 Joules, this translates to:
360-475kg nectar or 6,000 MJ of energy.
On the pollen side this forager collects 15mg pollen which builds up to 30 kg of pollen a year.
At this point Tautz's figures hit a problem as his mid range figures suggest that the average hive actually collects 3-4,000 MJ or 600kg of nectar but the 500 Joules figure gives us 6,000 MJ or around double. But we will work with his stated 4,000 MJ figure as the flight information is based on averages.
The colony collects 600kg of nectar which it reduces down to 300 kg of honey after evaporation. 1 kg of honey burns to produce 12 MJ so the colony has 3,600 MJ available
Energy expenditure
Summer:
Heater bees warming the brood use 2,000 MJ (166 kg of honey)
Other task use under 1,000 MJ (80 kg honey) or under 1/3rd.
Winter:
heater bees warming the colony use 2 MJ - (I think Tautz has this wrong. Beekeeprs would leave 15kg of stores on an average hive which translates to 180 MJ) So I will use 200 MJ.
Other tasks use under 50 MJ
Total budget 3,000 MJ in summer (250kg of honey) and 250 MJ in winter (21kg honey). The beekeeper takes his tithe of 300MJ (25kg of honey) or around 8% of the colony's energy turnover
These other tasks can be estimated as follows:
Energy used by foragers flying to collect nectar: 150 MJ
Food ???????
Royal Jelly production: 5 litres a year costs ?????
Comb production: to build a complete nest of 100,000 cells uses 1200g of wax or 90 MJ 0r 7.5kg of honey. This may be true for a swarm but in subsequent years, comb may only be replaced every 3-5 years, so reducing this down to 30 MJ or 2.5kg honey
If anyone can fill in the gaps to these other figures that would be great.
Queen lays 200,000 eggs a year which gives a population of around 50,000 in the summer and 20,000 in the winter.
1 bee collects 30 mg nectar (500 Joules) and makes on average 7 flights a day (using 10 J per flight) and works for around 15 days. So our forager produces 50,000 J and as there are 150,000 bees a year this translates to:
15 million foraging flights a year from the colony. 12 million for nectar, 2 million for pollen and 1 million for propalis and water.
Since our forager collects 30-40 mg nectar or 500 Joules, this translates to:
360-475kg nectar or 6,000 MJ of energy.
On the pollen side this forager collects 15mg pollen which builds up to 30 kg of pollen a year.
At this point Tautz's figures hit a problem as his mid range figures suggest that the average hive actually collects 3-4,000 MJ or 600kg of nectar but the 500 Joules figure gives us 6,000 MJ or around double. But we will work with his stated 4,000 MJ figure as the flight information is based on averages.
The colony collects 600kg of nectar which it reduces down to 300 kg of honey after evaporation. 1 kg of honey burns to produce 12 MJ so the colony has 3,600 MJ available
Energy expenditure
Summer:
Heater bees warming the brood use 2,000 MJ (166 kg of honey)
Other task use under 1,000 MJ (80 kg honey) or under 1/3rd.
Winter:
heater bees warming the colony use 2 MJ - (I think Tautz has this wrong. Beekeeprs would leave 15kg of stores on an average hive which translates to 180 MJ) So I will use 200 MJ.
Other tasks use under 50 MJ
Total budget 3,000 MJ in summer (250kg of honey) and 250 MJ in winter (21kg honey). The beekeeper takes his tithe of 300MJ (25kg of honey) or around 8% of the colony's energy turnover
These other tasks can be estimated as follows:
Energy used by foragers flying to collect nectar: 150 MJ
Food ???????
Royal Jelly production: 5 litres a year costs ?????
Comb production: to build a complete nest of 100,000 cells uses 1200g of wax or 90 MJ 0r 7.5kg of honey. This may be true for a swarm but in subsequent years, comb may only be replaced every 3-5 years, so reducing this down to 30 MJ or 2.5kg honey
If anyone can fill in the gaps to these other figures that would be great.