Language English Laurentian Maple Forest Photo: Biodôme Photo: Biodôme OngletsDescriptionDistinguishing featuresThe male can be recognized by its greenish-yellow cap, bordered in black, and by the broad, brown-coloured stripe down each side of the body. The back is also marked with greenish-yellow stripes and the breast and belly are white. A black spot in front of the eyes and a white spot near the ears are other distinguishing features. ReproductionIn the Spring, the male arrives in Quebec before the female to search for a nesting territory. Perched at the top of a shrub or in the lower branches of a tree, the male sings continually to attract a female. As soon as the couple is formed, the female searches for a good spot to build the nest. It is usually well camouflaged at the height of about a metre from the ground in the branches of a tree or shrub. The female builds the nest and incubates the eggs alone. Both parents, however, feed the young. DietLike all warblers, the chestnut-sided warbler is insectivorous. It hunts its prey, hopping from branch to branch and turning over the foliage. Sometimes, it catches its prey on the wing, but usually at less than 10 metres from the ground. PredatorsChipmunks sometimes steal the warbler eggs and newly hatched young. Nest parasitism, however, is much more common. The female brown-headed cowbird spies on the nest of the chestnut-sided warbler and as soon as the parents leave the nest unguarded, the cowbird replaces one of the warbler eggs with one of its own, and then leaves. The cowbird egg generally hatches before those of the warbler and the young cowbird pushes the eggs and young of its host out of the nest. Often, the warbler doesn't notice the switch and raises the cowbird youngster as if it were its own. To reduce the threat of parasitism, the female warbler sometimes covers its eggs and that of the cowbird with a layer of plant material and starts a new clutch of eggs. HabitatThis species prefers areas of re-growth such as abandoned agricultural fields and cut over forests. It colonises this habitat about four to 10 years after the re-growth starts. Ecology, behaviourSince the colonisation of North America, the population of chestnut-sided warblers has been increasing. Formerly rare, it is now one of the most common warblers in Quebec because of forest re-growth. French nameParuline à flancs marron Scientific nameSetophaga pensylvanicaPhylumChordataClassBirdsOrderPasseriformesFamilyParulidaeSize12 to 14,4 cmWeight9,8 gLife span6 years and 11 monthsStatusLately, the chestnut-sided warbler population seems to have increased in abandoned agricultural areas returning to forest. Least Concern (IUCN).