Yellow warbler

Yellow warbler

American yellow warbler

Setophaga petechia
Population size
97 mln
Life Span
10 yrs
7-25 g
10-18 cm
16-22 cm

Yellow warblers are small widespread songbirds found in the Americas. The summer males of this species are generally the yellowest warblers wherever they occur. They are brilliant yellow below and greenish-golden above. Winter females and immature birds all have similarly greenish-yellow uppersides and are a duller yellow below. Young males soon acquire breast and, where appropriate, head coloration. Females are somewhat duller, most notably on the head. In all, the remiges and rectrices are blackish olive with yellow edges, sometimes appearing as an indistinct wing-band on the former. The eyes and the short thin beak are dark, while the feet are lighter or darker olive-buff.


















Serial monogamy








starts with


Bright Yellow



Yellow warblers breed in almost the whole of North America, the Caribbean, and down to northern South America. They winter to the south of their breeding range, from southern California to the Amazon region, Bolivia and Peru. The breeding habitat of Yellow warblers is typically riparian or otherwise moist land with ample growth of small trees, in particular willows. The other groups, as well as wintering birds, inhabit mangrove swamps and similar dense woody growth. Less preferred habitats are shrubland, farmlands, and forest edges. Yellow warblers can also be found in suburban or less densely settled areas, orchards, and parks, and may well breed there. On the wintering grounds, these birds inhabit mangrove forests, marshes, tropical moist forests, and shrubland.

Yellow Warbler habitat map

Habits and Lifestyle

Outside the breeding season, Yellow warblers usually spend time in small groups, but while breeding they are fiercely territorial and will try to chase away any conspecific intruder that comes along. Males perch near the tops of the bushes or trees and sing in order to claim their territory; they also establish their territories by performing a “circle flight” display. Yellow warblers are active during the day and find their prey by gleaning in shrubs and on tree branches; they will also hawk prey that tries to fly away. These birds communicate with postures, perhaps with touch and vocally. Their song is a musical strophe that can be rendered 'sweet sweet sweet, I'm so sweet', although it varies considerably between populations. Their call is a soft or harder 'chip' or 'ship' which is frequently given by females after a male has finished his song. In territorial defense, Yellow warblers give hissing calls, while 'seet' seems to be a kind of specialized alert sound. Other calls are given in communication between pair-members, neighbors, or by young begging for food.

Seasonal behavior
Bird's call

Diet and Nutrition

Yellow warblers are carnivores (insectivores). They feed mainly on insects and will also eat other invertebrates and some berries and similar small juicy fruits, especially in their winter quarters.

Mating Habits

starts in May/June
11-14 days
3-4 weeks
3-6 eggs

Yellow warblers are generally serially monogamous and form pairs that remain together only during a single breeding season. Some males, however, may be polygynous and mate with more than one female. Yellow warblers start breeding in May/June. They nest in trees, building a small but very sturdy cup nest. The female lays 3-6 eggs and incubates them alone for 11-14 days. The chicks are born helpless and weigh 1.3 g (0.046 oz) on average; they are brooded for 8-9 days after hatching and leave the nest the following day or the one thereafter. Around 3 to 4 weeks after hatching, the young are fully independent of their parents. They become reproductively mature at one year of age and attempt to breed right away.


Population threats

Being generally common and occurring over a wide range, Yellow warblers are not considered a threatened species. Some local decline in numbers has been found in areas, mainly due to habitat destruction and pollution. The chief causes are land clearance, the agricultural overuse of and herbicide and pesticide, and sometimes overgrazing.

Population number

According to Partners in Flight resource the total breeding population size of the Yellow warbler is 97,000,000 birds. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.

Ecological niche

Due to their insectivorous diet, Yellow warblers are important predators of a wide range of insect species, especially those that are considered pests in their ecosystem. For example, they reduce the number of coffee berry borer beetles in Costa Rica coffee plantations by 50%. These small birds also help to disperse seeds of fruits that they regularly consume in their wintering grounds.

Fun Facts for Kids

  • The Yellow warbler is sometimes colloquially called the "summer yellowbird".
  • There are usually a few wide, somewhat washed-out rusty-red streaks on the breast and flanks of Yellow warblers. These markings are the reason for their scientific name 'petechia', which roughly translates to 'liver spotted'.
  • Female and male Yellow warblers rear the young about equally, but have different tasks: females are more involved with building and maintaining the nest, and incubating and brooding the offspring. Males are more involved in guarding the nest site and procuring food, bringing it to the nest and passing it to the waiting mother, which does most of the actual feeding. As the chicks approach fledging, the male's workload becomes proportionally higher.
  • Yellow warblers arrive in their breeding grounds in late spring (about April/May) and move to winter quarters again starting as early as July, as soon as their chicks are fledged. Most, however, stay a bit longer; by the end of August, the bulk of the northern populations has moved south, though some may linger almost until fall. At least in northern Ohio, Yellow warblers do not linger and leave as they did 100 years ago!
  • Cowbirds often lay eggs in the nests of Yellow warblers. Upon recognizing one of cowbirds' eggs warblers will often smother it with a new layer of nesting material. They will usually not try to save any of their own eggs that have already been laid but produce a replacement clutch. Sometimes, the parents desert a parasitized nest altogether and build a new one.


2. Yellow Warbler on The IUCN Red List site -
3. Xeno-canto bird call -

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