Lea este artículo en español aquí.
Many birds and some mammals form monogamous pairs, and some achieve long term bonding with their mates. These bonds can last until a mate dies, or until irreconcilable differences force the pair to part.
Long term bonding is rare in mammals, however. Locally, long term bonding is found in coyotes, grey fox and North American beaver.
According to birdful.org, the duration of pair bonds varies significantly among bird species. Some major patterns of pair bond duration include:
- Seasonal monogamy—Pairs only associate for a single breeding season to raise one clutch. They form new bonds the next year. Common in migratory songbirds.
- Annual monogamy—Pairs stay together during a breeding season but may form new pairs in following years. Seen in some seabirds including albatrosses.
- Multi-year bonds—The pair bond lasts across multiple breeding seasons. One or both birds usually return to the same territory and mate every year. Common in larger birds like geese, eagles, and swans.
- Lifelong monogamy—The bonded pair remains together throughout their lives. Often seen in seabirds, vultures, corvids (such as ravens, crows and blue jays), and parrots.
Why do birds form pairs?
Birdful.org lists the following as evolutionary advantages to pair bonding in birds:
- Increased reproductive success: pair bonding allows for cooperation in raising young, improving the chances of offspring survival. Both parents work together to build the nest, incubate eggs, protect the nest site, and find food.
- Access to resources: by pairing up, birds can better establish and defend high-quality nesting and feeding territories from competitors.
- Increased chance of mating: pair bonding ensures easier access to mating opportunities throughout the breeding season.
- Long term compatibility: maintaining a long-term bond with a compatible mate means birds don’t have to expend time and energy searching for and courting new mates every breeding season.
Sexual adventures in the wild
Long term bonding does not mean sexual monogamy, however. Extra pair copulation is common in most socially monogamous birds. In his book Animal Behavior, John Alcock states that in 90% of all bird species the female engages in extra pair coupling. The number for males is unclear since DNA testing compares the chromosomes of chicks in a nest. As Alcock writes, this allows males to supplement their genetic fitness by having chicks in other nests while not tending to them, and the female has a better chance of offspring surviving if she has chosen a male with weaker genes as her mate.
Below is a list of just some of the bird species found in San Benito County that form long term bonds (taken from Cornell Lab and Sibley Bird Guide).
Songbirds
Corvids: Common raven, American crow, Steller’s Jay, California scrub-jay and Yellow-billed magpie
New world sparrows: Spotted towhee and California towhee.
Wrens: Bewick’s wren and House wren.
Woodpeckers
Most woodpeckers and most flickers.
Columbiformes
Mourning doves and Rock doves (pigeons)
Hawks and eagles
Red-tailed hawk, Red-shouldered hawk, black-winged kite, Swainson’s hawk, Cooper’s hawk, golden eagle and bald eagle.
Falcons
American kestrel, peregrine falcon, Prairie falcon.
New World Vultures
Turkey vulture and California condor.
Owls
Great horned owl and barn owl
Geese
Canada goose
We need your help. Support local, nonprofit news! BenitoLink is a nonprofit news website that reports on San Benito County. Our team is committed to this community and providing essential, accurate information to our fellow residents. Producing local news is expensive, and community support keeps the news flowing. Please consider supporting BenitoLink, San Benito County’s public service nonprofit news.
The post Long-term commitment is not just for humans appeared first on BenitoLink.