Last updated: 16 January 2023
The house finch is a widespread and easily recognized species abundant throughout much of North America. They are common backyard visitors and you may notice that they often associate in pairs, even outside the breeding season. However, this does not mean house finches mate for life.
House finches are only socially monogamous. Many house finch pairs breed for consecutive years and stay together throughout those winters, but their bonds are not life-long. After a few breeding seasons, previous partners are likely to find new mates.
Some house finch individuals even switch mates during the breeding season.
We will discuss why this may occur and other house finch mating behavior in greater detail throughout the article. Read on to discover more!
House finches do not form life-long partnerships, but can often breed with the same individual for consecutive years
Male house finches attract a mate through a series of displays known as courtship behavior. Butterfly flight is one such display, performed by the male early on during pair formation. It involves the male finch climbing to a height of nearly 100 feet and then gliding back down to his perch while singing loudly.
We should note that house finch males sing year-round. However, there is a difference between courtship song and everyday song. Singing performed by males during courtship and breeding season (up to incubation) contains a buzz syllable. This syllable is absent from all other singing.
Other courtship displays involve the male hopping closer to the female while holding his tail higher than his head, dropping his wings, and swaying back and forth. Sometimes males perform courtship behavior while holding nesting materials in their beaks.
Male (left) and female (right) House finches perched on a garden fence
House finch pair formation begins in winter while the birds gather in flocks. Between January and February, groups of 10 to 15 finches group up and form a circle - known as a lek. These leks sometimes have an inner circle and an outer circle.
The birds in the outer ring are waiting for an opening in the inner, where they will potentially pair off with a mate. When an inner circle male and female pair off, they fly away together, usually with the male singing. Associations between this newly formed pair will become more constant closer to the breeding season.
Previously existing house finch pairs often associate throughout the winter and remain together for consecutive breeding seasons. However, this is not always the case. Individuals from a pair sometimes form new associations and do not mate a second time.
A small flock of House finches in a tree
Courtship feeding is another form of display between a house finch pair. Typically within a month of nest building, male and female finches begin exhibiting billing behavior, where one bird pecks at the other’s closed beak while giving a twittering call.
Billing gives way to the male performing regurgitation movements while the female begs, displaying by lowering her wings, tilting her head up, and calling excitedly. At this point, the male feeds the female and will continue to do so through the nestling period.
Courtship feeding of House finches
House finches may mate several times throughout the breeding season and lay as many as six clutches. However, typically no more than three of the six are successful.
Individuals commonly re-nest with the same mate all summer - although, extra-pair mating is not uncommon amongst house finches; some may even switch mates entirely.
Mate switching is most likely to occur after an unsuccessful nesting attempt, but sometimes a switch happens seemingly without cause.
House finch perched on a log
When a house finch mate dies, the surviving partner will find a new mate. If the death occurs during the breeding season, the lone mate will likely make a new association and re-nest relatively quickly.
If the loss happens outside of the breeding and nesting period, the surviving male or female will wait until the January and February leks to find a new mate.
House finches are primarily permanent residents within their territories, but some populations migrate a short distance to lower elevations. Those that migrate do so in flocks, and it is not uncommon for pairs to migrate together and associate throughout winter.
The same goes for house finch populations that remain in or near their breeding territories. They gather in large flocks for winter, with pairs remaining closely associated.
Pair of House finches perched in a tree
Little is known about whether wild house finches mourn the loss of a mate. They may exhibit mourning-like behavior, such as waiting for or calling their mate for a time before realizing their partner is gone.
However, the house finch is only socially monogamous, they may remain with their partner for a few consecutive seasons or switch mid-breeding season, depending on the circumstances.
Because this species does not truly mate for life, their associations are likely not as deep as those of birds that do form a life-long partnership.
House finches do not permanently stay together as a family. Juveniles remain with their parents until 2.5 to 3 weeks after fledging.
At this point, young finches can feed themselves, so they leave their family group and form flocks with other juveniles. These flocks often overwinter together, associating until the following breeding season.