A Question For The Lone Ranger

[Angakuk]

Some reindeer herds in Alaska mill in a clockwise direction when disturbed and some mill in a counter-clockwise direction. Each individual herd is consistent with regard to the direction in which it mills (or so I was told). When I lived in Alaska I participated in a reindeer round-up. The corral was built so that if the herd were to mill in clockwise direction the milling action would facilitate funneling the animals into the chute for processing. Unfortunately the herd insisted on milling in a counter-clockwise direction. That meant that everytime the herders wanted to put more animals in the chute they had to go into the corral and and break up the milling behavior so they could drive some of the animals into the chute. Either the corral had been originally built for a different herd or, as is more likely, the folks who built the corral had not taken into account the reindeer's natural milling behavior. In any case, it was a very ineffecient design and resulted in a lot of unneccessary labor for the herders and stress for the animals.

The story is told that when the first reindeer herd was brought to the Seward Penninsula from Siberia they were transported by ship and the animals were offloaded into the water offshore from what was then called Teller Station (now known as Brevig Mission). They had a lot more trouble getting the reindeer to land than they had anticipated. Instead of heading for shore the reindeer began swimming in a circle around the ship. They ended up having to put small boats in the water and lead the reindeer to shore one at a time.

[thedoc]

Originally Posted by The Lone Ranger

Turning in circles before lying down or before urinating/defecating is very common in dogs, and their wolf ancestors.

Dogs generally circle before defecating or urinating, as well. One proposed reason for why they do this is that since they're vulnerable while eliminating waste, the circling behavior evolved to promote scanning the immediate area for scents or sounds that might indicate danger before they commit themselves to eliminating wastes.

Curiously, a recent (2013) study indicates that dogs preferentially orient themselves along the Earth's North-South magnetic axis when eliminating waste. This suggests that the circling behavior may, in fact, be at least partly an evolved mechanism to help them orient themselves.

Why do dogs preferentially align themselves along the Earth's North-South magnetic axis when eliminating wastes? So far, no one has provided a good explanation.

Either my daughters dog is deficient in this regard, or it is not generally true. In any case I don't make a habit of watching her when I let her out, but the few times I have looked out, she doesn't seem to have any preference as to which way she is aligning when she eliminates waste.

[The Lone Ranger]

It's generally true, according to the study, but by no means universally true. The authors also note that factors such as ambient magnetic fields seem to affect the behavior, presumably by interfering with dogs' ability to locate magnetic north.

[ceptimus]

If the researchers watched the dogs during normal working hours, it might just be that the dogs tend to face away from the sun (or maybe towards the sun) which would tend to line them up more-or-less north-south.

[JoeP]

You and your logic.

[The Lone Ranger]

They claim (pdf file) that they took the Sun's position into account and ruled it out as a contributing factor.

That having been said, the tendency to orient along a North-South axis occurred only during "quiet magnetic conditions," as they rated them. Whenever there were fluctuations in the local magnetic field, the tendency of dogs to orient themselves along a North-South axis disappeared.

[Dingfod]

Tetra-ethyl lead was removed from gasoline in the U.S. in the 1970s primarily due to the neurotoxic effects on children, lead levels in the blood allegedly causing lower IQs and antisocial tendencies in youths. Since the 1970s, violent crime rates have gone down, but most markedly after 1993 or so. Some attribute this reduction in crime to removing the lead from gasoline, and many studies seem to corroborate this. How established is the science on this? I don't think it is as certain as some people think, that the reduction in crime possibly has many causes, lead, the aging of the population, technology, and maybe even the incarceration rate. What is your opinion on this, The Lone Ranger?

[The Lone Ranger]

I've heard the claim before, and while the neurotoxic nature of lead is well-established, that the decline in violent crime since the 1970s is largely due to removal of tetra-ethyl lead from gasoline seems to me ... unlikely. It may have some role to play (in fact, I'd be surprised if it didn't, given the well-established behavioral effects of lead exposure), but I'd guess that sociographic factors, demographic trends, and other factors have far more importance.


From what I can tell, the evidence in favor of the claim is suspect at best. Given that there have been no really good epidemiological studies on the subject, and that direct experimental studies would be unethical, there just isn't a robust body of evidence to support the claim.

[It doesn't help that Rick Nevin, one of the more prominent promoters of the claim, got much of his data from Murray and Herrnstein's The Bell Curve -- a ... suspect ... source, to say the least.]



The strongest evidence I've seen in favor of the hypothesis comes from Brazil. My understanding is that leaded gasoline was phased out in São Paulo several years before it was phased out in the rest of Brazil, and that homicide rates in São Paulo have declined dramatically in São Paulo since 2000, while remaining unchanged in the rest of the country. That's intriguing, but hardly an open-and-shut case.



The real problem is that leaded gasoline was around long before the 1970s. In fact, as pointed out in the recent Cosmos series, the average American citizen living in a big city was exposed to quite a lot of lead in the early part of the 20th century. By the 1960s, the toxic nature of lead was becoming widely recognized and there was growing pressure to reduce lead exposure. So, it's likely that someone living in, say, New York City, would have been exposed to much more lead in the 1940s than in the 1960s.

That is, if removal of lead from gasoline in the 1970s sparked a drop in crime, why weren't crime rates so high in the 1920s - 1950s when the average U.S. city-dweller was probably exposed to even higher amounts of lead?

[thedoc]

Originally Posted by The Lone Ranger

It's generally true, according to the study, but by no means universally true. The authors also note that factors such as ambient magnetic fields seem to affect the behavior, presumably by interfering with dogs' ability to locate magnetic north.

Is there any indication that some Breeds of dogs are more prone to this kind of behavior than others. My daughter's dog is a Nanny Dog (Pit Bull) and grew up in my house, and while she was young I let her know who was the boss.

[Ari]

Originally Posted by The Lone Ranger

That is, if removal of lead from gasoline in the 1970s sparked a drop in crime, why weren't crime rates so high in the 1920s - 1950s when the average U.S. city-dweller was probably exposed to even higher amounts of lead?

The form of the lead and exposure method may make a difference. TEL was around in the 1920s but I doubt people were being exposed to more of it in similar forms as after the automotive boom. However yes, everything that I've read points to correlation only and given there's no good levels of lead in the body, it's easy to blame the Toxin! and move on.

[ceptimus]

TEL is still used in AVGAS, so we should expect high criminality in the engineers that service and operate vintage planes such as the DC3.

[The Lone Ranger]

Originally Posted by thedoc

Is there any indication that some Breeds of dogs are more prone to this kind of behavior than others. My daughter's dog is a Nanny Dog (Pit Bull) and grew up in my house, and while she was young I let her know who was the boss.

To my knowledge, they didn't try to distinguish between different dog breeds when compiling their data. It might be an interesting comparison to make, though. Perhaps hunting breeds, which have been bred to some degree for their ability to navigate unfamiliar territory (possibly using magnetic fields to orient themselves), are more prone to this behavior, for instance.

[erimir]

Does exposure to lead affect dogs in the same way as well?

Originally Posted by ceptimus

TEL is still used in AVGAS, so we should expect high criminality in the engineers that service and operate vintage planes such as the DC3.

It has a large effect on children, I believe, though. Brain development and all (and also smaller bodies meaning proportionately higher exposure).

The other hypothesis is abortion. It could easily be that more access to abortion and lower lead exposure both have an effect, but do not fully explain the decline in crime. I would assume that criminality is such a complex phenomenon that there would be many factors that affect it.

[Janet]

I was just reading a Free Press article on the water crisis that interviewed people whose dogs were being made ill by the water.

[The Lone Ranger]

In addition, there are quite a few cases of dogs and cats suffering from lead poisoning because they gnawed on paint in older homes.


Lead poisoning is indeed a much greater concern for children than adults, since lead interferes with neurological function and development. Even short-term exposure during childhood can cause long-term harm.

[Ari]

Originally Posted by ceptimus

TEL is still used in AVGAS, so we should expect high criminality in the engineers that service and operate vintage planes such as the DC3.

That depends on what types of exposures are dangerous. It's possible TEL is most dangerous when inhaled in fumes, vs being handled as a liquid, so unless they are riding along on the wings huffing the fumes, it might be safer than in a car.
*Checks over shoulder*
"Shit! I thought she was feeling a bit heavy on the left!"
"Hang on, I'm going to try a barrel roll..."

[Dingfod]

I worked as a gasoline station attendant in 1971-1972. I loved the smell of gasoline. That might explain quite a bit.

[thedoc]

A few weeks ago we got a bird feeder and have been watching several different kinds of birds using it. The feeder is hanging from a branch that is just over my head and I have to teach up to hang it. During this recent snow storm there has been enough accumulation of snow that there is now about 1 foot of clearance to the bottom of the feeder when before there was almost 4 feet. I noticed that individual birds will come in and quickly get something to eat and then fly off. I surmised that this was an instinctive behavior, in that a food source would also attract predators, and by getting some food quickly they were limiting their exposure to potential threats. Among the kinds of birds we see at the feeder are Juncos, Nuthatches, Cardinals, Wood Peckers, and a few others. Am I correct that their behavior is instinctive to avoid predators, even though with 30+ inches of soft snow on the ground, a predator would have extreme difficulty in getting to the bottom of the feeder?

[The Lone Ranger]

Probably so. Anyplace that attracts prey animals is going to attract predators as well, so it's not a good idea for the prey animals to stay still, even though doing so would mean a substantial saving of energy.

It's not just ground-level predators that will be attracted, either. Whenever I set up my bird feeders, I accept that in addition to attracting and feeding the local songbirds, I'm also attracting and occasionally feeding accipiters such as Cooper's Hawks and Sharp-Shinned Hawks. Every now and again, I'll find a scattering of feathers from where a Sharpie or Cooper's Hawk managed to catch one of the songbirds at the feeder unawares.

"I love it when people put up bird feeders, and attract lots of tasty songbirds into my territory!"

[SR71]

I have seen crows raiding the nests of smaller birds' young. After that I understood why smaller birds often harass crows in flight. They're driving them away from their nests.

[The Lone Ranger]

Yup. That's called "mobbing behavior." Smaller birds will often gang up on crows, ravens, owls, and other predatory birds and harass them until they go away. In turn, crows and ravens often mob larger birds of prey, like red-tailed hawks. (This is not without some danger. I once watched a bunch of crows chasing after a Cooper's Hawk when the hawk apparently decided that it'd had enough. It did a perfect end-over flip and came back upon the crows. The last I saw of them, the crows were beating a hasty retreat with the hawk hot on their tails. On another occasion, I saw a bunch of ravens mobbing a red-tailed hawk. One raven dove down upon the hawk just as the hawk decided that it'd had enough; the hawk did a perfect barrel roll and reached up with its talons, very nearly snagging the raven. After that, the ravens apparently decided that it was time to retreat.)


In fact, birders often take advantage of this. Many birders will make "pishing" sounds, similar to the calls many songbirds make when they spot a predatory bird in their territory. The "pishing" often attracts songbirds, looking for the predator so that they can drive it away.

[The Lone Ranger]

It's worth pointing out, by the by, that quite a few terrestrial predators (weasels, for example), can easily walk upon even the softest snow, and so will find it quite a bit easier to get to bird feeders when there's a lot of snow on the ground.

[JoeP]

[JoeP]

not denting the snow

[thedoc]

Originally Posted by JoeP

not denting the snow

I would assume that the snow in this photo is crusted over with ice, rather than soft powder as we have today and in the photo of the bird feeder. Do you have a photo of a weasel on soft powder?

I have some experience with snow, and can't be so easily fooled.

https://www.flickr.com/photos/86834338@N00/318250991