Why do some birds like the robin and chickadee only live a year or two, while other birds can live longer? That is so sad. ~ Anonymous
Another theory on why some birds live longer than others is size. Because smaller birds tend to be more prone to predation and other dangers, their life may be cut short. The average lifespan of the littler bird is only a year or two while the bigger birds average around 25-50 years. There are a number of cases in which smaller animals within a given species live longer in captivity. For example it has been recorded that some captive House Sparrows lived for 23 years, and Northern Cardinals 22 years.
Although life expectancy in birds might be correlated closely with size, further information is required. So in addition to collecting data directly by banding and recapturing birds more research needs to be done.
In fact one recent study already found that tropical birds, leading a slower life and expending less energy, tended to live longer than birds that had to survive harsh winters. The researchers traveled to Panama where they captured tropical birds and measured their basal metabolic rate (BMR) – the minimum amount of energy they expend at rest, solely to maintain their vital bodily functions.
They compared these measurements with the BMRs of temperate birds. They found that tropical birds used about 18 percent less energy, as measured by BMR, when compared with temperate birds.
Scientists believe that tropical birds may have a slower pace of life because it fits with the rest of their life history. Tropical birds, compared to those from temperate regions, tend to live longer, and produce fewer offspring which develop slowly and mature relatively late in life.
Makes me glad I feed the hardy birds that choose to stay year-round in Michigan. As the temperatures dip and natural food sources may become covered with snow or locked in ice, I know that the supplemental food and water that I provide is more widely appreciated and has a bigger impact on the birds’ survival.
Source: Ohio State University (2007, May 23). Tropical Birds Have Slow Pace Of Life Compared To Northern Species, Study Finds. http://www.biosci.ohio-state.edu/~patches/publication/wiersma%20et%20al_2007_PNAS.pdf