Tetrapod Zoology

A few posts ago the subject of giraffes and lightning came up in the comments (go here, and scroll down to comments 7, 9 and 10).

Thanks to an aborted book project that I’ve mentioned once or twice (I try not to talk about it too much, it still hurts), I have voluminous files on accidental or surprising deaths. I said I have something on death by lightning and – here – I deliver. It’s not much, but then, that’s not much of a surprise is it?

Lightning represents a significant hazard in the natural world and animals large and small may be killed during storms. The death of elephants following lightning strikes has been reported and Spinage (1994) discussed two individuals in Uganda that died this way. Norma Jean, a circus elephant, was struck and killed by lightning in Illinois in 1972 (more on that case here; it includes a photo of Norma Jean’s tombstone). There are also cases where wild deer have been killed by lightning, also rhinos (the image above, by the way, shows an Australian cow that apparently survived a lightning strike. Story here) [below: sheep killed by lightning. Read on].

Lightning strikes may be a significant danger to giraffes in environments that have few tall trees and are topographically or geologically predisposed to attract lightning. One eyewitness report suggests that, during lightning storms, giraffes lower their heads and may even compete with one another to become lower in height (J. Schamotta, pers. comm.), though whether this is accurate was doubted by giraffe specialist Anne Dagg. Between 1996 and 1999 the Rhino and Lion Reserve near Krugersdorp, South Africa, had two of its three giraffes killed by lightning – the third animal (a juvenile) was also struck but survived. Betsy the giraffe was killed by lightning at Walt Disney World in Florida in 2003 (in front of lots of witnesses).

While it should be noted that, in the Krugersdorp case, the giraffes had been experimentally introduced into an unsuitable habitat, giraffes, cows and other artiodactyls in natural conditions elsewhere are susceptible to death by lightning and entire herds can be killed by a single strike, typically while sheltering under a tree [examples: 16 Scottish cattle killed, 2009; 52 cattle killed in Uruguay, 2008; 11 German cows killed, 2008; 13 cattle in British Columbia killed, 2008]. A juvenile giraffe at Louisiana’s Global Wildlife Center, named Dusty, was killed after lightning struck a nearby tree. Huge numbers of sheep have been killed when the ground was struck by lightning: in 1918, 654 sheep were killed at once in American Fork Canyon, Utah, and 835 were killed in 1939 in the Raft River Mountains, also in Utah (for photos, go here; the Raft River photo is shown above). Wild cattle, antelopes and other animals have also been reported killed in this way (e.g., Carnaby 2005).

It’s often said that quadrupedal animals are more suspectible to death by electrocution than bipedal ones. This is because a significant potential difference is induced by the distance between their fore- and hindlimbs (and if I’ve screwed up on the terminology here that’s because I don’t know the first thing about electricity), thereby encouraging electricity to flow through the animal and to cause a fatal heart attack (though death via electromagnetic pulse can also occur). There are conflicting reports as to how common this is: I once had to phone up the Met Office press inquiries section and ask questions about it, but they weren’t able to provide any useful information!

If you have more info: please, I’d love to hear it. Is it true that animals sometimes explode when hit by lightning? And do so many cows die from lightning strikes that farmers are actually entitled to a special ‘lightning compensation’?

For other articles on weird or unfortunate deaths see…

Refs – -

Carnaby, T. 2005. Beat about the Bush: Mammals. Jacana Publishers, Johannesburg.

Spinage, C. A. 1994. Elephants. T & A D Poyser, London.

Comments

#1 Jerzy
July 15, 2009

Imagine how many sauropods were struck by lighting. And when Brachiosaurus fell, how loud would be the thud!

And this , of course, explains why two-legged hardosaurs replaced them.
#2 Darren Naish
July 15, 2009

I can’t tell you how many times I’ve been asked about sauropods and lightning. There is one painting (by Jan Sovak) that shows a Barapasaurus heading for shelter during a storm. The caption states ‘Barapasaurus looks fearfully for a safe haven where it will not be the highest point for lightning to strike. This is only one of the unique problems such huge animals must have had’. This is from Špinar & Currie’s The Great Dinosaurs: A Story of the Giants’ Evolution (Sunburst Books, 1994).
#3 Greg Laden
July 15, 2009

I know the Krugersdorp reserve quite well. Yes, the place where the strikes occurred, if I have my facts straight, was pretty much treeless but also somewhat hilly (as the whole area is). What is interesting, though, is that a couple of years after that incident not at all far away, there was a major thunderstorm (that I had the dubious pleasure of driving through) that took out a half dozen or so soccer players at a match.

It will be interesting to watch the southern Kalahari over the next few years, as reintroduced giraffes are living in a part of the world said to have the highest rates of lightning.

I do have a very interesting giraffe death story. I should blog it. (I was not a witness but I did interview the main witness).. but no lightning was involved.
#4 Luna_the_cat
July 15, 2009

I’ve never, ever heard of an animal “exploding” when being struck by lightning.

On the other hand, I can confirm that farmers in the UK can certainly get at least private insurance for loss of stock from lightning, as long as they have a vet certify the death. I’m not sure if there is still a government compensation fund, although I believe there used to be at one point.

(On a side note, there was a very funny James Herriot story from some years ago about getting called out to certify one such death, a cow with absolutely characteristic burn marks. Only one problem, he told the farmer in question: “You did a wonderful job on those shoulder burns, sir, but I can’t certify it. You dripped candle wax into the hair.” “Aw, damn,” farmer said. “Next time I’ll be more careful.”)
#5 tdh
July 15, 2009

The advice to crouch during a lightning strike ought, then, to include a warning to stay on two feet (although lying down flat seems an alternative). From the one time that a bolt hit so close that its sound and light seemed simultaneous, I’d guess this to be instinctive (along with a yell to force the air out), and although the notion of having been roused (instinctus) to crouch is rather amusing, lightning is a mighty big stick. Astonishing.
#6 Greg Laden
July 15, 2009

The advice as to how to do a lightning crouch most decidedtly includes staying on two feet. In fact, you are supposed to be on your toes while crouching in the fetal position, and don’t forget to cover your ears.

I was once virtually surrounded by St. Elmo’s fire less than 10 meters away and I couldn’t remember if I was supposed to crouch or go flat out. I ended up dong both, then getting up and watching the light show which continued for five or so minutes.
#7 daedalus2u
July 15, 2009

Height for objects near the ground has only a modest effect on likelihood of being struck by lightning. The heuristics for the use of lightning rods for lightning protection calculate the protected area as being equal to a circle with the diameter of the height of the lightning rod (more precisely the protected volume is considered to be the volume outside a sphere with radius equal to the lightning rod height tangent to the lightning rod).

What is usually fatal is the ground current, not the direct lightning strike which is illustrated nicely by the pictures you have. The cow with the surface burns is alive; those burns probably came from a direct strike, not ground current. Multiple deaths are always from ground currents.

Many people have survived direct lightning strikes. The reason for this is that the body has a fairly high resistance, and the current of the lightning strike is so high that the voltage needed to drive current through that high resistance is so high that the air breaks down instead. Once air breaks down it becomes an excellent conductor (as conductive as metal), so the current bypasses the organism. In the case of ground current following a nearby lightning strike, the current is not so high, so the air doesn’t break down, so current is driven up one leg and down the other.

If an organism was running, it would be completely protected from ground current because there is no path. I very strongly suspect that protection from lightning is the reason for many herd animals to stampede. Even if lightning hit a running herd, it could only kill the animal it struck. The running animals would either be in the air, or have only one leg in contact with the ground and so be completely protected.

Standing on one leg should be substantially (if not completely) protective from ground currents. Standing on one foot, or running around a tree would be much safer than standing on two feed under it. Running out in the open is (probably) safer, but being inside a metal object (such as a car) is safer still.

After Lee Trevino was nearly hit by lightning he said that the next time he would hold up his one iron “because not even God can hit the one iron”.
#8 Hai~Ren
July 15, 2009

I wonder if there are documented incidents in which lightning struck a tree with a large flock of birds roosting in it, resulting in dead birds being scattered all around the base of the tree.
#9 Robert Jaques
July 15, 2009

How about cetaceans? Is there any records of lightning strikes affecting any sea life? What effect would sea water have? These may be silly questions but I’m intrigued by the idea
#10 Barn Owl
July 15, 2009

Last year there was a lightning strike incident at a polo club in New Jersey- the lightning struck an aluminum horse trailer, and knocked six horses and two humans unconscious (but did not kill any of them). The six horses were tied to the trailer, and apparently fell over like dominos. The two humans fell clear of the trailer, with some bruises and broken bones. To me it seems that the greatest risk of injury to the horses in the case would arise when they regained consciousness, and potentially thrashed around or pulled back on the ropes. All the horses would likely have been shod both front and back for polo; not sure what that might have contributed to the outcome.

There’s a myth among some equestrians that horses attract lightning, but of course it’s rather that they’re large animals that typically live outdoors in exposed areas. My Thoroughbreds will run around their paddock manically at the slightest provocation (new trailer, fireworks, javelinas, other horses playing, cold front), and after reading #7 above, I hope that they do this during thunderstorms as well.
#11 Mu
July 15, 2009

My guess is that they are as susceptible to the potential difference as land animals, but seawater is probably the better conductor than the animal itself. So you don’t get the current jumping up one leg and going down the other effect which killed the herds in the pictures. I’d be more worried about an explosive shock wave from flash evaporated water hitting and killing fish.
#12 daedalus2u
July 15, 2009

In a tree struck by lightning, the current is taking a single path from the tip that gets hit to the bottom (pretty much). There might be some parallel paths for the precursor currents but only birds roosting on branches involved in the direct current path are likely to be injured.

Lightning is propagating as a “traveling wave”, where you can’t really treat its interactions with matter using “lumped” parameters. You have to treat it as time varying and not as a DC current which makes the calculations a lot harder and subject to error if you don’t know the time derivatives of things like the current. The rise time of current in lightning is nanoseconds (and quite variable). The precise path depends on breakdown of air which depends on the local electron concentration (in air which is always very low), and how the electric field accelerates those electrons and causes secondary ionization. That is what makes lightning so unpredictable.

Water is a pretty good insulator for very short periods of time. The charge carriers in water are ions, which have a low concentration and a low mobility. Even sea water isn’t a very good conductor at a high current density. I would think that the current would tend to spread out on the surface of the ocean rather than be conducted down in a channel through it. Cetaceans might be protected if they had a layer of blubber but that would be quite difficult to calculate.

To prevent injury due to current by a parallel conductor, the parallel conductor has to be very conductive, many orders of magnitude better. A lightning bolt can be 100,000 amperes, and 1 ampere DC can kill you, so the parallel conductor needs to be ~100,000 times better conductor. Ionized air is that much better a conductor. Sea water isn’t. I think you would be safer in a boat than in the water, even if the boat was struck by lightning. A modest lightning rod with a conductor into the water would greatly increase safety in a boat. The conductor needs to be pretty straight with no bends greater than 90 degrees. Bends add inductance which at the very high di/dt of lightning strikes can cause enough voltage drop that the current leaves the conductor.
#13 Darren Naish
July 15, 2009

If water is such a good insulator, how does electro-fishing work? And I know it does – I’ve seen it done on TV (and, no, I am not referring to all those videos of alien Asian carp).
#14 Jerzy
July 15, 2009

So, wearing shoes with rubber soles – how it affects being hit by lighting?

Should cattle wear shoes for safety?
#15 The other Adam
July 15, 2009

Awesome, I helped spark (heh) a post. Loads of neat information to consider. Also, a note on electrofishing…I’ve done it, or at least been present when it was done. Electrofishing doesn’t kill fish, it just stuns them. That’s one reason why it’s so popular for fish surveys. I’d say the threshold for stunning is rather lower than to kill. But I’d say lightning and water are probably a dangerous mix–every pool I’ve ever been to gets closed on first hint of lightning in the area.
#16 Mu
July 15, 2009

The rubber boots work great during dry lightning storms. When poring wet, not so much.
As for the electro-fishing,there you don’t have the current densities you get of a lighting strike. At moderate currents, sea water is an excellent conductor.
#17 Mike Keesey
July 15, 2009

James Herriot, of All Creatures Great and Small fame, discussed this phenomenon in one of his books. Apparently insurance would pay for livestock killed by lightning, so he sometimes had to deal with scammers. One of his anecdotes involves a scammer who alllmost got him.

Unfortunately I can’t recall offhand which book it was in.
#18 Darren Naish
July 15, 2009

Re: James Herriot and cows and lightning, the relevant sequence was also in either the TV series, or perhaps the 1975 film (both of which are titled All Creatures Great and Small). See also comment 4!
#19 Nathan Myers
July 15, 2009

Thank you, daedalus2u, for the clear (and counterintuitive!) expositions.

Might we expect to find lots more electrocutions of shallow-freshwater animals than marine? I imagine a water buffalo or moose providing a better path to ground than the water it’s in. I wonder, too, if the practice of standing or roosting on one leg (I’m thinking of flamingos, particularly, but I see ducks doing it) has roots in lightning pressure.

Am I correct in thinking the ground current electrocutions are a result not of the lower currents in the ground, but of voltage gradients too small to result in dielectric breakdown of the air? I can see rubber boots protecting against this sort of death, but not against air strikes. If you’re barefoot, keep your feet together, heels touching!
#20 Bruce J. Mohn
July 15, 2009

I can at least confirm that humans don’t explode when struck by lightning. I was struck in 1983 and am still very much in one piece. There was no outward physical trauma, but I had a tremor that lasted about five years.
#21 daedalus2u
July 15, 2009

The breakdown strength of air is complicated because it depends on the gap (larger gaps lower volts/meter), voltage rise time (faster rise time higher volts/meter), background electron concentration (higher concentration lower volts/meter). The composition of the conductors matter too, how clean they are, the degree of irradiation with UV. The critical factor is the location and number of free electrons. The field does work on these electrons, they then collide with air molecules and form an ion and a new electron. This results in an exponential increase in electron concentration as the field does work on them and raises their energy enough to produce secondary electrons via ionization of the air.

The voltages from ground currents could be high enough to go through rubber boots but not high enough for air break down. You need about 30 kV per centimeter for slow air break down for a 1 inch gap (60 kV), but if your feet are 10 inches apart it is more like 14 kV/cm or (350 kV). I wouldn’t want to trust rubber boots for anything like that.

If you had a piece of aluminum foil, standing on it would keep both feet at the same potential.

The practice of flamingos standing on one leg might be related to lightning, or reduced heat loss to the water through one leg instead of two. It also might be a necessary ability to survive with only one leg if one of them got bitten off by a predator. I suspect that is a common occurrence that would provide a pretty strong evolutionary pressure.
#22 Vasha
July 15, 2009

A few years back, I read an article about veterinary care for pet fish. One case was a fish who couldn’t be saved after being injured by lightning. If I recall rightly, it was a large carp living in a small backyard pond. Its spine had been snapped by a shockwave when lightning struck the pond.
#23 Nathan Myers
July 15, 2009

If the hydrogen-inflated head-crest/balloon that helped to hold up a sauropod’s neck ever took a strike, it would be curtains. (So to speak, but literally too.) So, they would have had to vent it whenever a storm blew up; but they would have needed to keep their heads down, then, anyhow. It would take a long time to re-inflate it, during which time they would need to walk backwards, with their head bump-bump-bumping along the ground.
#24 Greg Laden
July 15, 2009

They did not have hydrogen inflated heads!!!!!

did they?
#25 Darren Naish
July 15, 2009

Nathan thinks they did: he’s even published on it.
#26 Noni Mausa
July 15, 2009

And then there was the Elgin Goose Shower, rather a jokey account of which you can find here: http://www.lac-bac.gc.ca/cool/002027-2303-e.html.

I have heard a much more detailed account. My source for the event is an elderly friend who was a schoolgirl in Elgin when this happened. She and the other kids ran to the school window to see a Model T driving by with so many geese inside that necks and wings and feet poked out every which way. The driver had been passing a field after a storm when he noticed a dead goose there. Upon alighting and going to look at it, he realized the field was studded with dead geese, of which he picked up 52. He drove them into town (must have been an awful load for the old jalopy) and distributed the geese to the townspeople.

She said the roast goose was pretty good.

Noni
#27 JenW
July 15, 2009

A small follow-up on what daedalus said (#7)…sorry if someone already said it. I skimmed, but didn’t read thoroughly, the rest of the comments.
While being inside something metal (a Faraday cage) *would* be protection from a lighting strike, most cars are no longer made completely of metal…something I realized in the middle of giving a lecture on electricity. One of my students was able to helpfully confirm that newer cars mostly just melt. Old car: probably safe (as long as the tailpipe isn’t dragging). New car: not so much.
#28 Graham King
July 15, 2009

This is a fascinating and topic, and occurs in some ancient literature.. the Bible’s Book of Job has a lot of lightning in it, and abundant extreme weather references generally. Specifically, sheep-kill. Taking Chapter 1 verse 3 with verse 16 would seem to indicate 7,000 sheep killed on one occasion (though not necessarily by a single lightning strike).
Whether we take this account as fact or fiction in a sense doesn’t matter here; it demonstrates ancient awareness of a phenomenon. I wonder how old, and if it’s the oldest recorded mention?

I heard a funny story from my Dad. He said that Danny (my sister’s partner) had pointed out to him this week, at the boat club, a man who had been ‘struck with lightning along with his dog’. ‘Afterward’, Danny said, ‘the dog would not speak to the man for 8 months – because it thought he was responsible for what had happened.’
#29 Graham King
July 15, 2009

Re the multiple dead cows picture – Why are their heads through the fence? Reaching from a lush crop field to feed in a more sparsely-vegetated one?! Or – Were they stampeding to escape but collided with this fence? One broken post suggests it.. but may have been broken before, unrelated to cows or lightning.
Or did they get struck while standing against the fence, fall, and convulse, throwing heads through fence in then process?

Was the fence implicated in the strike and their deaths?
#30 Jerzy
July 16, 2009

Darren – you are brilliant!

I thought that whether sauropod could be struck by lightning is about such an impractical problem as it gets. And it turns that lots of people think about it. You restored my faith in human imagination!

Now – following another James Herriot cow story: was sauropod stomach be big enough, that the constipated beast could explode from the buildup of methane? And how loud would be the bang? Or could a theropod attacking a constipated sauropod die in an explosion?
#31 Jerzy
July 16, 2009

PS. Don’t blame me. I didn’t start the thread!
#32 Barn Owl
July 16, 2009

@ #29 – I can’t say whether the fence had anything to do with the multiple cow-kill, but the orientation of the cows might have something to do with behavior in driving rain. When caught without shelter in blowing rain, a horse will turn its caudal end (trying to be scientific here) into the wind, and rostral end away. I’ve seen horses do this many times, regardless of a human rider. I imagine that other ungulates would naturally protect their heads and ears from driving rain as well, so it’s possible that the cows were lined up facing one direction because of wind and rain preceding the lightning strike.
#33 Mike Keesey
July 16, 2009

Whoops, missed the earlier comment about Herriot. It was told better there, too.
#34 Darren Garrison
July 16, 2009

Re Giraffes vs. lightning, this old documentary clip comes to mind:

http://www.youtube.com/watch?v=kF-eYA5XifI
#35 Nathan Myers
July 16, 2009

To get a chemical explosion you’d need an explosive mixture. Methane alone is stable; it has to be mixed with air in a fairly narrow range of proportions to explode — too much air or too much methane in the mix and it won’t ignite. I doubt a ruminant would have enough air in the right place, even assuming a good buildup of methane.

If you want something to explode, it seems like a flightless herbivorous bird should be your best bet, if any actually do accumulate methane instead of venting it continuously. You would have to breach the gut and air-sac walls and jump a spark at the point where the gases start to mix.

It seems easier all around to get whatever you want blown up to swallow an explosive charge, and then set it off.
#36 cfrost
July 18, 2009

I’ve done a good deal of electrofishing, boat and backpack. You can kill fish by electrocuting them. You can also break their backs. You tweak the controls to fit the job you’re doing. You can adjust AC – DC, waveform, pulse rate, voltage, etc. Generally one uses the least amount of voltage necessary to stun the fish one wants to catch. Backpack electroshockers have a hand switch and boat electroshockers have a foot switch that must be pressed to keep the current going. As soon as one sees a fish that should not be shocked (protected species for instance), one releases the switch and if the fish hasn’t been stunned too badly it swims away immediately. Fresh water in lakes, rivers, and streams has enough dissolved ions that it will conduct electricity. Water in clear, unpolluted streams in drainages with insoluble rock has fewer ions and consequently conducts less well and one has to increase the output voltage to get the same effect. One usually records water conductivity, temperature, and applied output voltage(s).

Electroshocking can only be done in fresh water as it depends on the fishes’ body being a much better conductor than the surrounding water. The longer a fish is, the greater the voltage potential from head to tail, so voltages set for large fish tends to stun small fish relatively mildly, while the converse, voltages set for small fish, can injure or kill large fish.

Larger boats and ships often do have a lightning rod/conductor. It works just like the one on a house: a fat cable or strap of conductive metal from the top of the mast to the water with as few kinks and bends as possible.

My great grandparents nearly lost their homestead when lightning struck a tree around which their cattle had gathered in a storm. Several cattle were killed outright and most the rest stampeded over a cliff into a coulee.
#37 Nathan Myers
July 20, 2009

Just for the record, here’s where I posted before about hydrogen-inflated sauropod head crests.

Or just search in Google for “sauropod parsimony FAIL”.
#38 another mike
July 25, 2009

Grew up near a dairy farm. Lightning hit one of the metal outbuildings (a small feed silo I think) and a good number of cows were dead in the field the next day.
The reporter had apparently never heard of such a thing and was surprised by the pattern of dead cows. Every one facing toward or away from the silo was dead, but the ones broadside to it survived. (Cows clustered around the thing still got flash-burned but survived).
When the reporter got around to interviewing the farmer, the guy was like, “You must be new here. This sort of thing happens every lightning storm.”
#39 DDeden
July 28, 2009

Another scorching post from Darren!