The Warblers of Mayne Island

Right now, at any time of day—but especially the morning—you can hear the sounds of birds: male birds on their territories; parents attending nests; and the first broods of young birds hungrily trilling to be fed. Out of all these sounds, a few species of birds’ songs stand out. The warblers, in particular, are both beautiful to look at and to hear.

Virtually all of the warbler species are migrants, coming to our area to breed and spend their winters mostly in the tropical south, although some species are hardy enough to be found along the Pacific Coast in winter.

There are eight species of warblers that can be found on Mayne Island during migration. Three species – the Orange-crowned, the Townsend’s and the Common Yellowthroat – commonly heard right now, are described below. These species have been chosen because each associates with a different habitat. The Orange-crowned Warbler uses mid canopies and dense shrub understories; the Townsend’s is a top of canopy feeder and nester; and the Common Yellowthroat uses wetland and agricultural field edges to feed and breed.

Orange-crowned Warbler (Oreothlypis celata)

Four subspecies of this highly migratory songbird are found in BC, with O.c. lutescens occurring in our area. In fact, the BC Breeding Bird Atlas notes that its highest abundance is in the Coastal Douglas Fir ecosystems below 250 m—which describes all of Mayne Island. It is the brightest coloured of the subspecies, with its upper and lower parts being bright yellowish olive. The orange part of its crown is covered by olive feathers and seen only when threatened or alarmed. Other distinguishing marks are a split light eye ring and dark eye line. The Orange-crowned mostly feeds on insects from leaves and blossoms. Its song is a fast trill of descending notes ending on a lower pitch. This trill for our subspecies is so fast that individual notes are not distinguishable (avg. 17 notes/sec). 

The Orange-crowned Warbler is found in a variety of habitats, usually associated with dense shrubs, especially riparian (shoreline) areas, but also mature forests with deciduous trees and a mixed, native shrub understory. The long-term population trend for this species in Canada is stable, but for regions of BC, including the Pacific Coast subspecies, there is a decline. The Breeding Bird Atlas notes that this species, among others, are impacted by the loss and degradation of understory in coastal coniferous forests. The Atlas also recommends forestry practices that promote understory growth, and policies that reduce understory browsing and trampling as measures that can be taken.

Here’s a recording of the Orange-crowned Warbler:

Townsend’s Warbler (Setophaga townsendi)

The Townsend’s Warbler prefers tall coniferous and deciduous-coniferous forests, and feeds at the top of the canopy. You will often hear its call but have a hard time seeing it in these high places. Once seen it should be unforgettable, with its striking black and yellow patterns. It appears to be large-headed with a black cheek surrounded by bright yellow, a black cap and chin. Its flanks are black streaked on yellow while its back is black streaked on green. It has two prominent white wing bars and white outer feathers on its tail. The female of this species has the same overall pattern but duller in colour. It feeds by gleaning insects and spiders among the high branches; rarely is it seen feeding in the lower canopy. Its song is variable and consists of high, buzzy notes often rising variously described as zoo zoo zoo zeeee skeea skeea or weezy weezy weezy dzee.

The Townsend’s Warbler is widely distributed in BC and its range and distribution is stable. The Breeding Bird Atlas found that the highest abundances were found in forest-dominated ecosystems away from developments including the Coastal Douglas fir ecosystem and particularly below 250 m. Long term trends in breeding surveys suggest a slight downward trend in the population, but causes are unknown. 

Here’s the song:

Common Yellowthroat (Geothlypis trichas)

I love this tiny, beautiful bird and look forward to seeing and hearing it early in spring. It is a bird of wetland edges, vegetated ditches and shrubby edges of agricultural fields. It is widespread in BC with highest abundances in wetland dominated ecosystem types in valleys and lowlands.  It is easily spotted, as the male will aggressively challenge any intruders into its territory.  To see it is an unforgettable treat with its black mask trimmed in white and bright yellow throat and brownish back. It forages near the ground in dense foliage feeding on insects and the like. It is a ground nester. Its song is presented perched at the top of shrubs and is described as witchety witchety witchety. The challenge is a staccato rattle and is quite distinct.

The Canadian and BC population data show no change in the population and no apparent trends. 

Here’s the song of the yellowthroat:

We hear a lot about the loss of tropical winter habitat for migratory songbird populations and its impacts on these species, and there is much conservation work being done in these areas to slow or stop these losses. We hear less on the losses incurred in the breeding habitats in the Northern Hemisphere, particularly in the temperate forests of western North America. These are international issues that are being addressed at those levels (i.e. North American Bird Conservation Initiative) as well as national and provincial levels. What can an individual do? 

1. Support organizations working on songbird conservation and research such as Bird Studies Canada. 
2. Practice songbird -friendly landscaping such as retaining the mature forest canopy, maintaining the native shrub and deciduous woodland areas, and conserving riparian and wetland edge ecosystems. 
3. Get outside and join others who enjoy watching and photographing birds