I recently experienced an earthquake; well that was something ticked off the bucket list. My mother-in-law later asked if the hens noticed and as a chicken keeper and beekeeper that got me thinking: can they sense earthquakes?
Note about this blog: I’m learning to blog so I’m experimenting with this slightly different style. I’ve assumed that readers have knowledge of keeping bees and chickens but if you don’t I’ve included loads of links with explanations. I don’t pretend to have any answers, just lots of meandering questions, and this is a type of thinking out loud. I hope you like it.
Can animals sense earthquakes?
Like most people, I asked Google. According to the National Geographic animals have been recorded as acting unusually before earthquakes since 373BCE, with descriptions including hens that stop laying and bees leaving their hive “in a panic”. Further anecdotal and observed evidence is reported by the US Geological Service, BBC Nature and the Smithsonian but it’s also clear that more research is required.
Hens and laying
- Diet — protein, calcium and water are really important.
- Access to daylight.
- Flock — mainly if there are new members which can cause a bit of stress.
- Breed — some just lay more than others.
- Age — youngsters don’t lay until their about 20 weeks old and older hens slow down their laying.
- Health — in some illnesses hens stop laying with resources diverted to fighting the problem.
Laying also stops if a hen is molting. Regrowing feathers requires a lot of protein which doesn’t leave enough to go into eggs. It also makes them a bit grumpy.
Did the hens react?
I have no idea, I wasn’t looking. On the basis that there was no indignant squawking or alarm calls I think they were fine. As they’re not laying due to short day length (or possibly sheer bloody mindedness) I can’t comment on that either.
Bees and “panic”
Some beekeepers observed their bees behaving strangely before an earthquake. There are a few occasions I can think of when a lot of bees could be on the wing and appear to be “in a panic” to the casual observer:
- Swarming, the process of the colony as a whole reproducing itself, when the old queen leaves with at least a third of the workers to set up a new home.
- When a queen goes on a mating flight. Some of the workers can get really excited and take to the wing.
- Due to the beekeeper, for example when feeding or taking off honey, although I’d expect an observer to remark on the presence of a beekeeper.
- An attack by a predator such as a bear, although again I’d expect its presence to be noted.
- Some sort of feeding frenzy due to a really good food source or robbing.
- Possibly lots of workers during orientation flights at the same time. This would be more unusual and due to the loss of a lot of foragers in a short time.
Of all of these, swarming and mating flights are the most likely explanations but they’re part of the colony’s lifecycle and not related to geological happenings: a beekeeper should be able to recognise these events and not consider them panic.
But what about the queen?
The queen is quite trim when she goes on mating flights as she hasn’t completed her development. For swarming the workers reduce her food for a few days to slim her down for flight. So if she’s at full weight how can she leave with her daughters? A colony without a queen or the means of making one is doomed as workers can’t lay worker eggs: it isn’t in the colony’s interest to leave the queen behind. Perhaps the workers take to the wing to save as many as possible if their home is at risk of damage; if there’s enough structural integrity and eggs after an earthquake they can sort themselves out.
Bees and vibration
Vibration is one of the ways bees communicate in the hive and so is very important to them and so I’d expect the earth shaking to lead to the bees’ equivalent of saying “Oh I say!”. Unwanted vibration, such as if I accidentally knock the hive during an inspection, is met with protests and I usually end up with a bee complaining against the outside of my veil. Having said that my bees are about 200m from a railway line and may be able to pick up the vibrations of trains: I’m fairly certain they could tell the difference between a regularly passing Intercity 125 and something that could threaten the hive otherwise they’d be permanently annoyed as it’s the main line between Cardiff and Swansea.
Were my bees “panicking”?
Our apiary is a few miles away without webcams so observation is impossible. Certainly it would have been strange for a lot of bees to be on the wing on a cool February day, they would have been tucked up inside the hive. There were definitely a lot of them there when we fed them later in the day (we’d been planning the feed, this was nothing to do with the earthquake) and their behaviour was what I’d expect for the time of year.
How would hens and bees sense an earthquake?
So after considering the possible different responses of hens and bees to an earthquake I started to wonder if they had anything in common. Unlike us both species can see ultraviolet light, so if something happens before an earthquake to release this they could see it; lights prior to earthquakes have been reported although we’d only see what’s visible to us. But would this only work if the bees and hens were close to the epicentre? I don’t know and to be honest the internet isn’t sure either.
Bees use polarised light from the sun to help them navigate. If there was a change or a source from a different direction, that could in theory confuse their internal GPS system and bee could conceivably be flying around the hive in confusion. But again could an earthquake cause this?
Not all members of the flock/colony are necessarily outside at the same time: some hens may be laying inside the hen house and only the older worker bees are foragers so a mechanism of spreading the message is required. This isn’t impossible as hens have about thirty different calls and bee communication is complex using pheremones, dancing and other behaviour. They’d both need to pass the message in time though.
Could they distinguish between our own 4.4 magnitude and larger earthquakes that could cause them and their flock/colony damage? I have no idea. Bees have been on this planet far longer than we have so who knows how evolution has adapted them during this time.
Correlation vs causation
So is this a case of correlation not causation? Well possibly but I’d hate to dismiss first-hand observations without good reason. The difficulty is how to prove it either way as you’d need to set up experiments observing bees and hens and wait for a notoriously unpredictable earthquake. It’s not impossible to set up some monitoring equipment in an earthquake zone and being patient but for reliable data several observations on many flocks/colonies would be needed as well as control flocks/colonies in less earthquake prone areas to show the behaviour was due to the earthquake.
Did you experience an earthquake? A bit of citizen science
If you experience an earthquake then you can get involved in earthquake research. The British Geological Society would like to hear about your observations via their Earthquake Questionnaire, a great bit of citizen science. Interestingly one of the questions asks if any animals were frightened:
I’m proud that, in some small way, my experience will help earthquake research.
Cover photo from image4you/Pixabay. No it’s not a honey bee but you have to admit it’s a great picture.
As usual, thanks to Laura for her splendid proof reading skills and suggestions. All the mistakes are now my own.