How long do cowbirds live?
The oldest Brown-headed Cowbird on record lived to 16.9 years, a record from a wild bird. That is a ceiling, not an average: most wild cowbirds live only a few years.
- Longest recorded lifespan
- 16.9 years
- Record from
- Wild bird
- Age at first breeding
- About 1 year
- Eggs per clutch
- Up to 36 eggs per season, one per host nest
- Broods per year
- —
- Size
- 7.5–8.7 in, 1.3–1.8 oz
- Rank in family (of species on this site)
- 5 of 14
Record age versus typical age
Longevity records come from birds that were marked and later found again, usually through bird banding, or from birds kept in zoos. They show what a Brown-headed Cowbird can survive to, not what most do.
For small birds, the first year is the hardest. Many eggs and nestlings are lost to predators and weather, and young birds that leave the nest still have to learn to find food and avoid hawks and cats. A bird that survives its first winter has a much better chance of living several more years. That is why average lifespans in the wild are short even when the record is long.
Cowbirds usually start breeding at about 1 year old. Each season a pair lays Up to 36 eggs per season, one per host nest and raises —, with eggs taking 10–12 days to hatch.
How cowbirds compare with relatives
Oldest recorded ages for other blackbirds on this site.
- Common Grackle23.1 years
- Red-winged Blackbird20 years
- Yellow-headed Blackbird18 years
- Orchard Oriole17.7 years
- Baltimore Oriole14 years
- Boat-tailed Grackle13.9 years
More about cowbirds
Frequently asked
How long do cowbirds live?
The longest-lived Brown-headed Cowbird on record reached 16.9 years, recorded from a wild bird. Most wild cowbirds live far shorter lives, because the majority of young birds don't survive their first year.
How old is a Brown-headed Cowbird when it first breeds?
Usually about 1 year old.
What is the oldest Brown-headed Cowbird ever recorded?
16.9 years, according to the AnAge longevity database.
How many young can a Brown-headed Cowbird raise in a year?
Pairs lay Up to 36 eggs per season, one per host nest and raise —.
Source: AnAge, The Animal Ageing and Longevity Database (Human Ageing Genomic Resources), record quality "acceptable", sample size "medium". genomics.senescence.info