Hive Scales : 31
this being particularly true in northern climes where springs can be unpredictably wet and cool. Even if they do not die, colonies that were subject to stress by starvation are smaller, weaker and more susceptible to disease and are ultimately less productive. Timely feeding can not only save the bees but also the beekeeper’s time by reducing unnecessary trips to the apiary when there is no need to feed.
Sudden Changes
Beside the absolute weight, further consideration of weight data highlighted the signifi cance of weight change over time. Thus two further alerts evolved – sudden weight loss or gain. A drastic decrease in weight can mean one of two things: a swarm has departed or a colony is being robbed.
Detecting that a swarm has left that day improves your chances of fi nding it, but knowing within couple of hours that a swarm has departed can help minimise disruption to the public, particularly in urban environments.
Robbing, if left unchecked, almost certainly spells the death of the robbed colony. It tends to occur in weaker colonies at times of dearth or, if a colony perishes, its stores tend to be discovered and robbed by the neighbouring bees. The latter case is also undesirable as it is a potential source of disease transfer. Figure 5 shows a typical weight loss pattern in a robbing
event. However, the addition of acoustics reveals that the robbing was a cause rather than the consequence of this colony’s demise. This colony was weakened through swarming earlier in the season, but was otherwise fi ne and had plenty of stores. Its fl ight activity shows a typical daily pattern of fl ight and a gradual decrease in weight until 13 August. Subsequently, the weight decreases rapidly by 11 kg over two days and this is refl ected in a sharp increase in fl ight activity. This dramatic fl ight activity, however, is a record of bees from neighbouring hives robbing the resident colony of its stores in a very short period of time, ultimately causing its death. Following a timely alert, the beekeeper can intervene and take measures to save the robbed colony by restricting the entrance or even moving it away. The signifi cant weight gain alert is a way of knowing when your bees have collected a lot of nectar that day. It is the least practical of the alerts as it calls for no intervention but possibly is the most thrilling to receive. Furthermore, it brings a new dimension to beekeeping by conveying real-time information, rather than just the summary of the past events.
Bee Informed Partnership
So far we have considered the applications of hive scale data to both honey bee research and bee husbandry, but hive weight data have even more to offer. It has been said that if the world is our coal mine then the bees are our canaries as bees can be considered an ecosystem indicator species. A project run by Dr Wayne Esaias, of NASA, wonderfully illustrates this point. In this study, beehives in
April 2015 Vol 97 No 4 Bees are an ecosystem indicator species, like the canaries in the coal mines
www.bee-craft.com
Maryland (USA) were weighed daily throughout the nectar fl ow. The sobering results showed a gradual but constant advance of stores accumulation. In other words, the spring fl owering of the nectariferous plants in the area has been brought forward by four weeks since the 1970s, caused by warming due to urbanisation of the area. The long-term implications on agriculture and ecosystems in general are yet to be fully assessed. This project has now become part of a much larger Bee Informed Partnership (BIP), encompassing all of the USA. This aims not only to link these data with vegetation and climate change but also to uncover the links between forage resources and honey bee colony health. We are honoured to play a
small part in this project by supplying equipment to BIP but also, closer to home, we will be involved in a similar initiative with the BBKA. To fi nd out more and how you can help, visit our website:
www.arnia.co.uk ♠
References
Seeley, TD (2101). Honey Bee Democracy. Princeton University Press, Princeton and Oxford.
Downs, SG and Ratnieks, FLW (1999). Adaptive shifts in honey bee (Apis mellifera L.) guarding behavior support predictions of the acceptance threshold model. Behavioral Ecology, 11, 326–333.
Meikle, WG, Rector, BG, Mercadier, G and Holst, N (2008). Within- day variation in continuous hive weight data as a measure of honey bee colony activity. Apidologie, 39, 694–707.
Girling, RD, Lusebrink, I, Farthing, E, Newman, TA and Poppy, GM (2013). Diesel exhaust rapidly degrades fl oral odours used by honeybees. Nature Scientifi c Reports, 3, 2779.
Ju
a
n E
m
i li
o
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48
