Female Tree Swallows (Male vs Female Identification)

Tree swallows are common songbirds in North and Central America. Compact, streamlined and highly agile tree swallows are often found deftly catching flying insects. Here’s a guide to female tree swallows and how to identify them from males.

By the second year, female tree swallows are similar to males, with a lighter belly and dark blue upper body. However, they are usually dull overall and sometimes retain a brown patch on the head.

At the start of the breeding season, males tend to arrive on territory a week or so earlier than females. They choose a nesting cavity and wait for the return of the female, who selects the males based on their nest cavity as well as their courtship performance and appearance.

Female tree swallows continue to line up in empty nests, while male tree swallows watch from perched on nearby branches. The female is usually responsible for the incubation, but both parents will feed the chicks.

There are some other ways to identify female tree swallows from males – read on to find out!

First year female tree swallows are easily distinguished from males as they are mostly brown

How do you know if a tree swallow is male or female?

The easiest way to tell if a tree swallow is male or female is by the color of its plumage – but the difference is only noticeable in first-year birds. 1-year-old male tree swallows have a bright blue upper body and white underbelly, while female tree swallows have a dark brown upper body and off-white underbelly.

Also, the blue plumage of males can be a shiny blue, while the upper wings of females have only a small portion of blue.

As you might expect, color differences allow males to stand out with brighter, contrasting colors. Smarter male tree swallows are more likely to mate with more than one mate, the study found.

However, as mentioned earlier, this color difference is only reliable for first-year females. In their second year, female tree swallows look very similar to males, with darker blue plumage, although some tree swallows are still duller overall. Females may also retain some brown feathers on their heads, while males do not.

female tree swallow

male tree swallow

What does a female tree swallow look like?

Adult female tree swallows are similar to males and are relatively dark blue in color with a white to off-white underside. However, women are more brown overall, although this difference is often exaggerated.

First-year females are much duller than first-year males, and although some females develop light blue iridescent plumage on their upper wings and upper body, they lack the darker blue iridescent plumage of males.

Female tree swallows look more like males after one year of age, but are usually duller

Are female tree swallows bigger than males?

Male tree swallows are slightly larger than females, but the difference is negligible in most cases. Precise measurements of the wings, body and beak revealed that the males were slightly larger.

behavioral difference

sing and call

There are few significant differences between the songs and calls of male and female tree swallows.

However, the analysis revealed that males’ songs have greater complexity and variability. Females sing primarily to communicate, while males sing to find mates and establish territories.

Interestingly, both males and females will sing all day – usually only the males will sing for no reason. This may be because both males and females are aggressive due to high competition for nesting cavities.

Interestingly, males sing at night during the breeding season, possibly to maintain their territory and prevent other males from trying to rob them of their mates.

Breeding a pair of tree swallows – male on the left, female on the right

nesting

The male arrives on the territory first and protects the nest until the female returns. The male will then show his cavity to the female in an upright position and sing. The female tree swallow does most of the heavy lifting of nest building and hatching. Male tree swallows often assist in procuring material, but females carry most of the material to the nest.

Male tree swallows usually take a more active role in foraging and bringing food to chicks. The females usually hatch, but when the weather is cold, the males will also tuck themselves into the nest and sit on the eggs to keep warm.

aggression

Males can be quite aggressive and may even kill other chicks if they spot a widowed female.

Females can also compete in the nest, but their behavior is usually self-limiting, while the males are ready to kill the young. However, two females rarely nested in the same cavity, possibly due to the extremely low availability of effective cavities.

Female tree swallow perched on a wire

Can female tree swallows raise offspring alone?

If the male tree swallow dies or is abandoned at some point, the female tree swallow is likely to raise her young alone. This can happen if male tree swallows form additional pairs, but this is rare because male and female tree swallows share parenting responsibilities and ideally mate for life.

While tree swallows are generally socially monogamous, some males tend to be polygamous (approximately 8% in one study). Therefore, it is possible to find a male tree swallow to mate with more than one partner, especially if there is a shortage of males.

Also, even though tree swallows mate for life, male tree swallows can be very relentless if they determine their mate is engaging in additional mating. Often, they abandon the female and the nest and seek out new mates.

Nesting pair of tree swallows – female on right, male on left

What color is the female tree swallow?

First-year female tree swallows are relatively pale, with white to off-white undersides, but in their second year they darken and appear almost identical to males. However, their plumage may retain a dull brown tinge, although this is not always noticeable.

Can female tree swallows bark?

Female tree swallows have almost the same calls as males.

Tree swallows nest in pairs – female on left, male on right

Can female tree swallows sing?

Like their male counterparts, female tree swallows sing primarily during courtship and mating. These songs can be classified as clucks, whines, or chirps. Women sing the same as men throughout the day.

However, male tree swallows are able to sing complex songs, while females have a slightly smaller repertoire.