Do northern cardinals mate for life?

Quick Answer

Yes, northern cardinals generally mate for life. Once a male and female cardinal form a pair bond, they will usually stay together throughout the breeding season and often until one mate dies. However, extrapair copulations are not uncommon among cardinals.

Do Northern Cardinals Mate for Life?

The northern cardinal (Cardinalis cardinalis) is a mid-sized songbird native to North America. Northern cardinals are socially monogamous, meaning a male and female cardinal will form a pair bond and work together to defend a territory, build a nest, raise young, and provide food for one another. This pair bonding begins early in the breeding season and cardinals will often stay paired until one mate dies.

While cardinal pairs do remain together season after season, their bond may not always be sexually exclusive. Extrapair copulations, where one mate will mate with an individual other than their primary partner, are common among northern cardinals. One study found that 15-37% of cardinal nests contained young that were not related to one of the social parents. However, even when seeking extrapair copulations, most cardinals will eventually return to their primary mates.

Some key facts about mating behaviors in northern cardinals:

• Pairs form in early spring as breeding season starts
• Pairs remain together throughout the breeding season
• Most cardinals keep the same mate year after year
• Pairs often stay together until one mate dies
• 15-37% of young are the result of extrapair copulations
• Even when mating outside the pair, cardinals most often return to primary mates

So while extrapair copulations are not uncommon, most cardinals do show fidelity to a primary mate year after year. This lifelong bonding and coordination of parental duties are why northern cardinals are considered socially monogamous and mostly faithful for life.

Courtship and Pair Bonding

Northern cardinals undergo a clear courtship process to form lasting pair bonds:

1. Males start defending breeding territories in late winter
2. Females visit multiple male territories, assessing males
3. The male performs courtship displays for visiting females
4. If receptive, the female allows the male to approach and mate
5. After mating, the female joins the male on his territory
6. The pair works together to build a nest and raise young
7. The bond lasts through the breeding season and often for life

Courtship displays by the male include behaviors like singing, wing flicking, crest raising, and feeding the female. These displays help the pair assess one another for reproductive compatibility and coordinate breeding activities. Once the female consents and mates, the pair bond is formed.

Cardinals that lose a mate are quick to form a new bond. Unpaired males sing persistently to attract new mates. Unpaired females assess singing males and rapidly form new bonds so they can nest again that same breeding season.

Coordinated Parenting

Cardinal pairs work closely to build nests, incubate eggs, feed nestlings, and defend territories:

• Nest building is done primarily by the female but the male helps gather twigs
• Only the female incubates eggs, but the male guards the nest
• Both parents feed the quickly growing nestlings
• The male assumes the lead in defending the territory from intruders
• Parents continue feeding fledglings for several weeks after they leave the nest

This coordinated parenting effort requires extensive communication and trust between the mates. It also helps ensure each clutch of eggs has the best chance of survival. Continued cooperation through each breeding season further strengthens the lifelong pair bond.

Fidelity and Extrapair Copulations

While most cardinal pairs remain faithful for life, extrapair mating is fairly common:

• 15-37% of nestlings are the result of extrapair matings
• Younger females are more likely to seek extrapair copulations
• Older males with the brightest red plumage are more often chosen for extrapair matings
• Even when one mate strays, they most often return and feed the young of their primary partner

These occasional dalliances provide a chance to assess potential alternative mates. But lifelong pairs still work cooperatively to raise young, whether or not the nestlings are genetically related to both parents.

Advantages of a Lifelong Bond

Remaining with one mate year after year has several advantages for northern cardinals:

• Increased familiarity and bonding between mates
• Less time and energy spent on courtship each breeding season
• Greater coordination and efficiency in nesting and parenting
• Improved ability to defend territories from intruders
• Potential higher lifetime reproductive success

The benefits help explain why most cardinals remain in lifelong partnerships. Even birds that occasionally stray outside the pair bond reap rewards from staying with a primary, familiar mate over the long term.

Older Cardinals Often Recouple

When a mate dies after a long-term bond, the remaining cardinal will almost always form a new pair:

• Widowed males sing persistently to attract new mates
• Widowed females assess potential new partners
• Speedy recoupling allows breeding attempts that same season
• Older females often choose much younger males
• Younger males help feed nestlings of the older female

Reforming a pair allows the older cardinal to keep breeding after losing its lifelong mate. This demonstrates the species’ strong drive to maintain a monogamous breeding relationship, even into old age.

Territorial Defense and Coordination

Northern cardinals defend established territories as lifelong pairs:

• Pairs occupy and defend the same territory across years
• Living in the same areas year-round strengthens site familiarity
• Males engage intruders, while females provide backup
• Coordinated defense reduces territorial losses
• Familiarity with food, water, and cover aids breeding success

This territorial fidelity and coordinated defense provide benefits that enhance the lifelong pair’s breeding efforts.

Conclusion

In summary, most evidence indicates northern cardinals form lifelong monogamous bonds built on courtship displays, mutual selection, coordinated breeding efforts, territorial fidelity, advantages of familiarity, and strong instincts to maintain pair bonds. While extrapair copulations occur, most cardinals remain faithful to primary mates season after season for increased breeding success and survival. So once a pair bond forms, northern cardinals can indeed be considered mated for life.