Identification
Male and female gray catbirds look nearly identical, but there are some subtle physical differences between the sexes.
In terms of size, males tend to be slightly larger, measuring 8.7–9.8 in (22–25 cm) in length compared to 8.3–9.4 in (21–24 cm) for females. However, this minor size difference can be difficult to discern in the field.
When it comes to plumage, both sexes have a slate gray body, black cap and tail, and a distinctive reddish-brown patch under the tail that is visible in flight. The most notable difference is that adult males tend to have black plumage that is a richer, darker black compared to females. Females have more grayish-black plumage.
Males also develop a small black forehead patch during the breeding season that females lack. However, this patch may not always be visible. Juveniles of both sexes resemble adult females in their first year.
Overall, differentiating between male and female gray catbirds requires very close observation of subtle plumage variations. In most cases, the sexes appear nearly identical to casual observers.
Song
The songs of male and female gray catbirds differ in important ways. According to the Cornell Lab of Ornithology, the male’s song is more complex and melodious than the female’s (1). The male’s song consists of a variable series of slurred, whiny notes, gurgles, whistles, and mews strung together in a flexible series. It often includes mimicry of other birds’ songs and various mechanical sounds. In contrast, the female’s version of the song is a simplified, quiet, gruff-sounding version of the male’s song. She may sing this quiet song back to the male as a form of communication between mates.
Researchers have found that male gray catbirds with larger song repertoires tend to be preferred by females. According to an article in Northern Woodlands, males with more complex songs are thought to be signaling to females that they are more experienced and have survived longer (2). So the complexity and melodiousness of the male’s song plays an important role in courtship and mate selection.
Territory
Gray catbirds are territorial during the breeding season. The male defends a breeding territory of about 1-8 acres in size (Source). Territories often contain dense shrubs and small trees. The male marks the territory boundaries with song and will aggressively defend the territory, chasing away intruders (Source).
During winter, gray catbirds are still territorial but boundaries are less well-defined. They may defend feeding sites rather than a defined area. In migration and wintering grounds, gray catbirds are often found in loose flocks although they maintain individual distance from each other (Source).
Migration
Gray catbirds are short-distance migrants that breed across much of the eastern and central United States and southern Canada. They spend the winter primarily in the southeastern United States, along the Gulf Coast, and in parts of Mexico and Central America (National Zoo, 2022; Audubon, 2022).
In the fall, most catbirds migrate south between August and November. They start their return migration north between late February and mid-May. Their migratory routes span 1000 to 2000 miles between their breeding and wintering grounds (Audubon, 2022).
Experts believe catbirds rely on a combination of innate and learned navigational abilities to find their way during migration. They likely use the sun, stars, and earth’s magnetic field for orientation. Landmark recognition also helps guide them on migration routes they’ve traveled before (National Zoo, 2022).
Diet
Gray catbirds are omnivorous, feeding on both insects and fruits. According to the Audubon Field Guide, gray catbirds eat mostly insects and berries. Their diet consists primarily of beetles, ants, caterpillars, grasshoppers, crickets, true bugs, and other insects in early summer. They also eat wild fruits and berries later in the summer such as dogwood, pokeberry, sumac, black cherry, blackberry, raspberry, and grapes.Animalia notes that catbirds sometimes eat small lizards, tree frogs, snails, spiders, millipedes, slugs, and earthworms. They typically forage on the ground or in low vegetation, using their slender bill to probe into crevices and pick insects off leaves.
Gray catbirds are opportunistic foragers and will eat whatever insects or fruits are abundantly available. Their diet varies throughout the seasons – more insects in spring and summer, more fruits in late summer and fall. They have also adapted well to backyard feeding and will readily eat mealworms, suet, peanut hearts, raisins, currants, cherry jam, and sunflower seeds offered at bird feeders.
Nesting
Female gray catbirds are solely responsible for building the nest, while males sometimes supply materials. The nest is an open cup made of twigs, grass, strips of bark, leaves, rootlets, and other plant fibers. It is loosely woven and has a deep inner cup lined with fine grass, hair, moss, feathers or fur. Nests are typically built low down (3-10 feet high) in dense shrubs or small trees such as dogwoods, hawthorns, or viburnums.
According to All About Birds, the female lays a clutch of 3-5 eggs which are blue-green in color with brown spotting. Incubation duties are performed only by the female and last 12-13 days before the eggs hatch. Both parents feed the nestlings, which fledge 10-11 days after hatching.
Parental Care
Both male and female Gray Catbirds share parental care duties. According to Audubon, “Both parents feed the nestlings”. The Cornell Lab of Ornithology also notes that “Both parents bring food to nestlings and fledglings”.
The male Gray Catbird is very defensive and aggressive in protecting the nest. According to the University of Michigan’s Animal Diversity Web, “During the breeding season, males defend a territory around the nest”. Both parents may swoop at or mob potential predators near the nest in an effort to defend their young.
After leaving the nest at 10-11 days old, the fledglings are fed by the parents for another 2-3 weeks until they become independent. The Gray Catbird is unique in that the male parent often cares for the first brood after they fledge, allowing the female to start a second brood.
Mating
The gray catbird is a monogamous breeder with males and females pairing together for breeding season (March to July). Courtship involves elaborate singing and chasing displays by the male. According to the National Zoo, the male sings constantly in the morning and evening early in breeding season and performs a “wing-droop” display, bowing towards the female with wings lowered and tail fanned while making ticking sounds.
Pairs remain together throughout the breeding season. According to the Audubon Field Guide, the female may sing the male’s quiet song back to him during courtship. After pairing, the male will guard the female and follow her closely as she searches for a nest site.
Lifespan
The average lifespan of the gray catbird is around 2-3 years in the wild, though they can live over 10 years in captivity. According to the Animal Diversity Web, the average lifespan in the wild is about 215 months or 17.9 years. The AnAge Database lists the average longevity as 2.5 years in the wild. The oldest known gray catbird was at least 17 years, 11 months old when recaptured in New Jersey according to the All About Birds overview. In captivity, their lifespan is considerably longer.
There are no major differences in lifespan between males and females. Both sexes can live over 10 years in captivity with proper care. In the wild, their average lifespans are similar at around 2-3 years on average.
Threats
Gray catbirds face threats from predators, habitat loss and degradation, and climate change. Predators like cats, snakes, and hawks prey on adult catbirds, eggs, and nestlings. Habitat loss from development and logging destroys nesting sites and food sources. Climate change alters migration patterns and habitats; for example, sea level rise floods coastal wetlands where catbirds breed (Audubon).
Catbirds rely on thickets and dense vegetation for nesting cover. When these habitats are removed, nests are more vulnerable to predators. Forest fragmentation also creates habitat gaps that expose catbirds during migration. Invasive species can degrade habitats by displacing native plants catbirds depend on for food and shelter (National Zoo).