Posted | filed under Weekly Reports.

Here at the Lesser Slave Lake Bird Observatory (LSLBO) we are over half-way through our MAPS program, which focuses on breeding birds. So far in MAPS 44% of our captures were recaptures – that’s a bird that is already banded. 

Recapturing banded birds is the only way for us to accurately know the age of a bird and to estimate a species’ longevity. For example, we recently recaptured a female Hairy Woodpecker that was at least 12 years old. Had she not been banded in 2014, we would have said she was “at least two” when we caught her in May. Every year, we commonly recapture birds that are over eight years old, most coming from local breeders in our MAPS program.

Above: In 2021, the LSLBO recaptured two Mourning Warblers that broke the longevity record for Mourning Warblers at over 9 years of age. One of which was this guy.

When we think of animals that live long, the first animals that come to mind are tortoises which can live over 190 years. While no birds can live that long, when considering their size and weight, they are equally impressive to tortoises. Generally, the larger and heavier the animal, the longer it can live 1. But, when comparing birds to mammals of the same size, that is not true. Voles, which are similarly sized to songbirds, only live up to 20 months maximum 2. Whereas some songbird species, like the Red-eyed Vireo, can live up to 12 years 3!

Why do birds, which are small, live so long compared to mammals? First, we need to understand what causes aging.  One factor is a product of our metabolism, which converts food into energy we can use. This process, while it makes the energy we need to survive, also creates reactive molecules called oxidants. Oxidants can damage DNA and can eventually cause cancer and aging. Thankfully, our body creates proteins and uses the vitamins we eat to transform oxidants and prevent this damage. Smaller animals have much faster metabolisms, which means they have more oxidants and become damaged more quickly. Because of this, smaller animals usually have shorter lifespans. 

Birds, because of their size and active lifestyle, have a high metabolism and burn much more energy than mammals of the same size 4. However, scientists believe that birds are better at preventing oxidative damage which is likely why they can live long despite their fast metabolisms.

Larger birds, especially seabirds, can live much longer than songbirds. The oldest known bird is a Laysan Albatross named Wisdom, who is at least 73 and still migrates across the Pacific Ocean every year 5. Scientists can identify and age Wisdom yearly because she is banded and returns to the same Pacific island to breed each year. Because birds return to the same breeding location year after year, programs like the one monitoring Wisdom, and MAPS here at the LSLBO are important tools to study the longevity of all birds – from Albatrosses to the songbirds that breed around Slave Lake.

By Julia Ritter, LSLBO Field Assistant

References and Further Reading

1. Speakman JR. Body size, energy metabolism and lifespan. Journal of Experimental Biology. 2005 [accessed 2024 Jun 27];208(9):1717–1730. 

2. Merritt JF. Clethrionomys Gapperi. Mammalian Species. 1981;(146):1. 

3. Longevity Records Of North American Birds. Version 2023.1 . Bird banding laboratory. [accessed 2024 Jun 27]. 

4. Travin DY, Feniouk BA. Aging in birds. Biochemistry (Moscow). 2016;81(12):1558–1563. 

5. Powell H. Wisdom, Laysan Albatross Super Mom, is 73 and still going strong. All About Birds. 2024 May 12 [accessed 2024 Jun 27].