Description of Residence for Kirtland’s Warbler (Dendroica Kirtlandii) in Canada (final version) 2007
Section 33 of the Species at Risk Act (SARA) prohibits damaging or destroying the residence of a listed threatened, endangered, or extirpated species. SARA defines residence as: “a dwelling-place, such as a den, nest or other similar area or place, that is occupied or habitually occupied by one or more individuals during all or part of their life cycles, including breeding, rearing, staging, wintering, feeding or hibernating” [s.2(1)]. With respect to a listed wildlife species that is an aquatic species or a species of bird protected under the Migratory Birds Convention Act, 1994, the prohibition applies wherever residence of the species is found. For any other listed wildlife species, the prohibition applies automatically when the residence of the species is on federal lands and will only apply on non-federal lands if an order is made pursuant to sections 34 or 35 of SARA. Under section 97 of SARA every person who contravenes section 33 of the Act commits an offence.
The following is a description of residence for the Kirtland’s warbler (Dendroica kirtlandii), created for the purposes of increasing public awareness and aiding enforcement of the above prohibition. Kirtland’s warblers are known to have one type of residence - the nest.
Long description for Figure 1
Figure 1 shows the distribution of the species in southern Ontario. The historic (pre 1980) data represent approximately half of the recent (post 1980) distribution. The historic distribution has small patches mainly between Lake Ontario and Lake Huron, with an additional patch near Hamilton, near Bruce Peninsula National Park, near Parry Sound, near Glenora, near Kingston, and two out near Pembroke. The current distribution has a few patches along the northern coast of Lake Erie, and Lake Ontario. Three additional patches are found between Lake Erie and Lake Huron, and three more on the northern coast of Georgian Bay. A single patch is found outside of Kingston and near Orillia.
In Michigan, Kirtland’s warblers breed in extensive (at least 32 ha in size, preferably >80 ha) stands of young jack pine (Pinus banksiana) Footnote1, Footnote2 created by wildfire or in specially designed plantations that mimic wildfires Footnote1, Footnote2. They prefer areas of dense trees interspersed with small openings, moderate canopy cover (35-65%) as well as branch cover close to the ground, and dry well-drained sandy soils Footnote2. Preferred ground cover includes blueberry (Vaccinium spp.), bearberry (Arctostphylos uva-ursi), bracken fern (Pteridium aquilinum), shadbushes (Amelanchier spp.), northern dwarf cherry (Prunus pumila), sweet fern (Comptonia peregrine), grasses (Andropogon spp.), sedges (Carex spp.), and goldenrods (Solidago spp.) Footnote2. Canopy cover may also include small percentages of deciduous hardwood tree species Footnote2. The cup-shaped nest is built on the ground, typically made out of grasses, sedges, pine needles, and small twigs, and concealed with low vegetation and branches Footnote3. The outside diameter of the nest is approximately 100mm, while the inside diameter is 58mm with a depth of 38mm3. Kirtland’s warbler nests are heavily parasitized (70% of nests) by the brown-headed cowbird (Molothrus ater), a species that lays its eggs in other birds’ nests. In Ontario, suitable habitat may be largely inaccessible for surveying, due to rough terrain and a lack of roads making determination of whether the species is currently breeding in Canada difficult Footnote1.
The nest provides a container in which adult Kirtland’s warblers lay and incubate eggs, and rear hatchlings. Typical clutch size is 4-5 eggs (range 3-6); eggs are pale buff, whitish, or faintly pinkish with fine brown spots gathered in cap or wreath at larger end Footnote3. The female incubates eggs for 13-15 days and broods young hatchlings for the first 3-4 days, although young do not leave the nest for 8-10 days Footnote3. Both adults feed hatchlings Footnote3.
Any activity that moves or otherwise disturbs the eggs or nest, changes the microclimate of the nest, or blocks access to the nest could result in damage or destruction of the residence.
Due to the lack of certainty of the presence of breeding Kirtland’s warblers in Ontario, the timing of their return to Canadian breeding grounds is unknown. The warblers would likely return sometime in mid-May and begin nest construction shortly afterwards. Use of the nest site would last at least 5 weeks, but due to re-nesting attempts after nest failure, nest sites may be used into August. Kirtland’s warblers have been known to double brood where the first brood is fledged before the end of June. Footnote3. There is no evidence that they reuse nest sites either for re-nesting attempts within the same season or between years3, so the nest site should be protected as a residence from mid May until the end of August.
For more information on the Kirtland’s warbler, please visit the species' profile.
For more information on SARA, Please visit the SAR Registry
Please cite this document as:
Government of Canada. Species at Risk Act Public Registry. Residence Descriptions. Description of residence for Kirtland’s Warbler (Dendroica kirtlandii) in Canada. December 2006.