NATIONAL BIRD DAY: JANUARY 5
Tomorrow is National Bird Day! Read about the astounding story of the oldest known wild bird in the world!
Surprised scientists have discovered that some birds live longer than they had thought. Scientists had been observing albatrosses for a long time. These seabirds spend much of the year at sea, just soaring over the oceans in search of food. They only come back to land to breed, lay eggs and raise chicks.
For example, in 1975 Harvey I. Fisher (Fisher, Harvey I., Pacific Science (1975), Vol 29, NO. 3, p. 279-3000) reported that after a 13-year study of 27,667 banded Laysan Albatrosses on Midway Island, they had a life expectancy of 16-18 years. The study reported the mortality (the percentage of birds that died) at each stage of their life. For example, during egg incubation, there could be up to 25% loss in some seasons.
It seemed to be the definitive study.
And yet, scientists still continued to band birds. Why? Because there was still more to learn. What else could they learn?
BIG IDEA: Sometimes, scientists don’t know what they’ll find. They do the work and then let the data tell them things.
BIRD BANDING: Surprised Scientists Find Banding Data Helpful
How do you know the age of a wild bird? Usually, you can’t.
Banding birds (or Bird ringing, as it’s known in some countries) means that a band or ring of a durable material is places on a bird. Usually it’s a metal band places on a bird’s leg. It needs to be durable, yet lightweight enough that it doesn’t interfere with the bird’s normal life. The Bird Banding Laboratory is a UGSG program that keeps track of all bird banding in the US. (https://www.usgs.gov/centers/pwrc/science/bird-banding-laboratory)
On December 10, 1956, ornithologist Chandler Robbins banded 99 incubating Laysan Albatrosses on Sand Island, Midway Islands. One of those banded birds would later astound the world. The bird banded with number 587-51945 is still alive today, over 62 years later. She is Wisdom, now banded with a special red band, Z333.
The 1975 study said that Laysan albatrosses lived about 16-18 years. And yet, Wisdom is now over 67 years old and still laying eggs and still raising chicks. They assumed that she was at least 5 years old at the time of banding 62 years ago. She could be much older and we would have no way of knowing.
In 2012, Robbins said, “While I have grown old and gray and get around only with the use of a cane, Wisdom still looks and acts just the same as on the day I banded her.”
Wisdom has astonished scientists by living 3.5 times as long as expected. Statistically, if she’s lived over 60 years, there are other Laysan albatrosses who’ve also lived a long time.
What else could scientists learn from her? They are now banding each of her chicks with a special band. Her mate wasn’t banded originally, but has been banded for several years.
Questions for your students – think about what testing/observations methods would help answer these questions:
- What else could scientists learn from Wisdom?
- Do all Laysan albatrosses live longer than expected? Is a normal lifespan 16-18 years, and Wisdom is just an unusual bird?
If there are short-lived and long-lived albatrosses, how are they different?
- Will Wisdom pass her long-life to her children? Will they also live a long time? How long will be before we know the answer to this question?
- How long has her “husband” lived? Has she had more than one husband?
Sometimes, previous research, such as the 1975 study of Laysan albatross populations seems to answer all the questions. However, science is about repeating the observations over time. Scientists observe, collect information and data, and then do it again. Only after observations have been repeated many times will they call the results a fact. Scientists will continue to band albatrosses, re-catch some albatrosses and report the data, and do it again.
Banding gives information about how long a bird lives, nesting habits, and migration habits.
FUTURE OF BANDING
With new technology, scientists would like to track the location of birds over time. However, there are technological challenges. A tracking system is known as a GPS or Global Positioning System. The problem is the weight of these systems. Birds weight very little and can only carry certain weights; of course, each species will need a different size GPS unit.
For example, purple martins spend the summer months in the northern hemisphere. But as fall approaches in July to September, they fly south to the summer in the southern hemisphere. In July-August, a group of purple martins collect at a staging area near me in Arkansas. I’d like to know where my “Arkansas flock” travels to in South American. We suspect it’s somewhere in Brazil, but no one knows. A GPS system would answer that question.
While the GPS system is too heavy for purple martins, scientists can add a tracking unit that measures how much sunlight the bird gets. The length of each day tells scientists the latitude where the bird traveled. But without the GPS unit, they can’t pinpoint the longitude. Someday, when miniaturization technology is more advanced, we may be able to track the flight patterns of the purple martins.
We may be able to track Wisdom as she soars out over the vast Pacific ocean. That’s what we hope our students will be able to do for science. Add to our knowledge of our amazing world.