As I mentioned in my previous post, I attended two lectures instead of going out to bird. There were no field trips scheduled in the conference, and the weather was iffy enough to keep me from going out on my own (they are calling for severe, potentially tornadic, thunderstorms in Louisiana today and tonight).
The two lectures were quite interesting. The first was about the use of weather radar to detect migratory birds. The second was about the psychology of identifying birds.
The weather radar lecture provided me a nice "duh!" moment. Weather radar is designed to bounce microwaves of of material that is in the atmosphere. Rain, snow, sleet, hail and other forms of precipitation are examples of material that will reflect the waves broadcast by radar, but so are insects, bats and birds. When you get enough insects, bats and birds, then the image produced by a weather radar will indicate their presence. The number of birds involved in spring or fall migration are easily enough to show up on a weather radar. Since birds migrate at night, you have to look at certain times of day to see it. And you have to know which radar imagery to use: many local television station's filter their radar images to only show reflectivity caused by precipitation. I will definitely be looking into this some more.
The second lecture, on the psychology of bird identification, was given by David Sibley. In his opening remarks, he said he was always interested in the topic, but the recent debate over the rediscovery (or not) of the Ivory-billed Woodpecker, and its associated evidence, really has intrigued him. He provided lots of interesting observations on phenomenon and human behaviors that prevent us from being entirely objective. In general, as our experience in bird watching grows, we evolve from a step-wise form of identification to a holistic one. This evolution allows us to make very educated shortcut guesses as identification, that tend to be correct (out of experience) but can also be risky (because the process skips the stepwise approach). There are other factors as well that I will not delve into. All in all it was a very interesting lecture that hit home with me several times. In many ways, the process of identifying a bird with limited information is very similar to the process of figuring out a software problem with limited information. In both cases it is not uncommon for what I would call "conspiracy theories" to form and grow. Human tendency is to note evidence that supports the theory instead of evidence that contradicts the theory. It requires a purposely objective approach to consider the alternatives and reach root cause (or identity).
Tomorrow is another field trip day. Because of the weather tonight (the storms are here, but no tornadoes near Lafayette), it is possible that all of the migrating birds that were going to leave tonight will be combined with all of the birds arriving tonight. If that happens, there might be a lot of birds flitting about tomorrow. We shall see.