Left: Ruby-throated hummingbird patient at Wild Bird Rescue.
Last night I was at a dinner and someone asked me, "What is interesting about birdwatching?" I did a poor job of answering the question, in part because I did not want to get cranked up and talk too long, as I can be prone to do on one of my favorite topics.
I like to use the ruby-throated hummingbird as an example of why birds are so interesting. If you will hold in your hand 4 cotton balls, you can feel the approximate weight of a full-grown hummingbird. The bird itself is about the size of one of those cotton balls. Now that you have an idea of how small and delicate one of these little guys is, imagine that bird flying 600 miles non-stop over the Gulf of Mexico on migration--18 hours.
We think of flight when we think of birds, although not all birds fly. There are a number of physiological adaptations in addition to the anatomical ones that make flight possible. Flying uses a lot of energy and the muscles have to be well oxygenated. Consequently, oxygen has to be carried by the blood in large amounts. A hummingbird at rest has a heart rate of about 250 beats per minutes, which can rise to 1200 beats per minute in flight--the aveerage heart rate for humans is 70 beats per minute.
Not only does the heart beat fast but the heart empties entirely with each heartbeat. Our heart always has some blood in it. The amount of pressire required to empty the heart is substantial--therefore, birds have high blood pressure, making them susceptible to heart attacks. In rehab, we have to be careful about stress on birds that already have health issues when they are brought in. It is common for birds to "faint," and occasionally die from a heart attack when stressed.
This is just one example of the thousands why birdwatching is constantly interesting. Although all of nature provides similar fascinating stories, birds can be watched anywhere, anytime, by anyone, making it an accessible and low cost hobby--well, low cost if you can avoid all the cool gadgets, interesting books, trips and other fun things that you can get to help you enjoy the hobby more.