Monday, June 25, 2012

Homing Pigeons: Better than FedX?


    I've been distracted the past few weeks, but thought it was time I make another entry. Since this blog is entitled "doggedly writing," and since I do enjoy pretty much everything that has anything to do with dogs, I was thinking of coming up with something clever (or at least something) that related to the art of inserting dogs into works of fiction. I started researching the ways animals have been used in warfare and found a lot of interesting stuff about war dogs, but then I got sidetracked by something shiny (this is par for the course with me). So the Jennings dog and Sergeant Stubbs will have to wait. This week, I'm writing about messenger pigeons.
            Messenger birds do come into fantasy fiction sometimes. I make a couple of references to them in my own novel, so I thought it might be nice to have a better idea how these birds have been used to send messages throughout history so that my treatment of them will be more accurate.
            Messenger (or carrier) pigeons are specially bred members of the same species (Columba livia) of "rock dove pigeon" that we see befouling statues in large cities. These birds mate for life and have a remarkable ability to find their way back to their home nest over long distances and unfamiliar terrain. Over thousands of years, pigeon fanciers have created a special breed of these birds that are capable of flying hundreds of miles in a day at average speeds well in excess of 50 miles per hour and that can carry up to 75 grams.
            Research suggests that these birds normally use a combination of visual cues and will use landmarks, when in familiar terrain, and the angle and polarization of sunlight calibrated against their internal clock when unfamiliar terrain. Olfaction also appears to play a role in their navigational abilities, which is interesting, because birds are generally thought to have a poor sense of smell. Most intriguingly, birds that are hooded or blinded are also able to find their ways home. The discovery of iron containing short nerve branches in the upper beaks of these birds provides a possible clue as to how they are able to detect the magnetic field of the Earth.
            After reading all this, I don't think I'll ever look at those messy birds crowding city squares in quite the same way again. There is still a lot we don't know about how pigeons' nervous systems decode and interpret magnetic data, but people have been taking advantage of, and honing, these remarkable abilities for millennia. The Egyptians and Persians were using messenger pigeons 3000 years ago, so it is certainly well within the technological capability of any fantasy world to have a messenger bird service.
            Like anything else, there are limitations to the use of carrier pigeons, however. As a rule, they only carry messages one way--back to their home coop. So to use messenger birds, they must first be transported to a desired location via overland or sea travel, and kept in cages. When you need one to carry a message back to its home coop, you write a message on thin, light paper, attach it to a tube on one of the bird's legs and release it. Of course, what this means is that you want to have the capability of sending and receiving messages between many locations, you will need a large number of pigeon coops. In fact, at the Marne during World War I, the French troops had 72 pigeon lofts, which they advanced with their troops.
            Evidently, there have been a few cases where birds were trained to carry messages in two directions over relatively short distances. This was achieved by feeding the birds in a location away from their home coop. So messages could be attached to birds that were flying away to feed and then the same birds could carry messages back to their home coop later.
Some interesting carrier pigeon trivia:

-modern racing pigeons have been clocked at speeds of 92 miles per hour in 400 mile races. Birds can fly in excess of 100 mph for shorter distances.
-They can fly up to 700 miles in a day.
-Homing pigeons were used in both world wars
-pigeons are still used today by the French, Israeli and Iraqi armies.
-they were used in the gulf war, because they are immune to electronic jamming
-they can live for over 30 years
-in the 1800's, a pigeon flew from Africa to England in 55 days, a distance of over 7000 miles.
-32 pigeons have received the Dickin medal, the highest medal available to animals in the UK.
-Between 1977-1983, two English hospitals used carrier pigeons to transport laboratory specimens.
-During WWI, A carrier pigeon named Cher Ami delivered a message in spite of having his foot shot off. The message saved a group of American soldiers who were surrounded. This bird was awarded the Criox de Guerre medal.
-pigeons were used to carry aerial reconnaissance cameras during WWII.
-Modern pigeon races can have purses in excess of $600,000
-The Taliban banned the keeping or use of carrier pigeons in Afghanistan.
-Pigeons were used to announce the winners of the Olympics in ancient Greece.
Cher Ami: WWI Pigeon Hero

Tuesday, June 5, 2012

Transit of Venus, 2012

No words of wisdom to impart today, but I do have a couple of pictures I took of the last transit of Venus that will occur in more than 120 years. Venus orbits the sun more rapidly than we do, and so it crosses from one side of the sun to the other quite frequently, from our perspective here on Earth. However, the alignment of the Earth, Venus and the sun only allow us to actually see the disc of Venus crossing the sun's surface quite rarely, in a pattern that repeats every 243 years. Visible transits occur in pairs, eight years apart. Then a gap of either 105 years or 121 years will occur before the next pair. Today's transit was the second (the first occurred in 2004) of the current pair. The next pair won't occur until December of 2117 and December of 2125.

The top image was taken (with my smartphone camera) via a reflective viewer (called a sunspotter), while the second one was taken through a Dobsonian telescope with a mylar solar filter at Sac City College today. The second picture looks like it is "upside down" because telescopes invert their images (and I didn't flip the picture around the way I did the top one). You can also see some sunspots in the picture if you zoom in a bit.