TITLE: Supernavigators: The Astounding New Science of How Animals Find Their Way
AUTHOR: David Barrie
Chapter 7: Well, there is a bit of biographical waffling about one of the scientists...and how that scientist came to work on Tunisian desert ants in the middle of nowhere. Apparently the ants' homing abilities did indeed depend partly on their sensitivity to polarized light (and other things). Then there is also figuring out that the ants can measure distance. The "ant odometer" is actually a thing!
The chapter had an interesting "epilogue":
"The estuarine crocodiles of Southeast Asia and Australasia are the world’s largest reptiles—and have the unpopular habit of eating unwary humans. They may give the appearance of being quite sedentary, but they can move fast over short distances and can travel hundreds of miles at a more modest pace.
In 2007, a fascinating study revealed that they are also remarkably good at finding their way home. Three adult males were captured and fitted with satellite trackers. They were then carried in slings under a helicopter to different release sites on the Cape York Peninsula in Queensland, Australia. After spending some time apparently thinking about what to do next, all three of them eventually headed off and returned to the exact places where they had been captured.
One of the crocodiles traveled 62 miles along the coast in fifteen days; another covered 32 miles in only five days. That was quite impressive, but nothing compared to what the third one did. It was transported right across the Cape York Peninsula from west to east—an overland distance of 78 miles. Obviously it could not retrace its journey, but it still managed to get home by paddling right around the northern end of the peninsula and down the other side. It covered a distance of 255 miles in just twenty days.
Nobody has any idea how these animals found their way home, but this experiment provided a valuable practical lesson: There is clearly little point in “translocating” crocodiles that pose a threat to people."
Chapter 8 is particularly interesting since it deals with various human navigational cultures "steering by the sky" throughout history (and prehistory) and goes into a bit of detail on how they did this. I enjoyed this chapter - something different from the bugs and birds.
Chapter 9 is a brief survey of studies dealing with long migrations that birds make seasonally. Chapters 11 and 12 describe various animals (moths, salmon, birds etc) that navigate using smell to find their way home or to potential mates. These two chapters are also fairly interesting.
Chapter 10 describes attempts by scientists to determine how dung beetles can roll their balls in straight lines (hat wearing dung beeltes was part of one experiment), along with all sorts of other interesting dung beetle trivia. This is also an incredibly fascinating chapter.