Northern Mockingbird back on winter territory

Nature Notes for November 11, 2011

It’s back! For the third year in a row, a NorthernMockingbird has arrived in the same neighbourhood in west end Port Hope. Where this bird nests is a mystery, but last winter it was in the same area from mid-November until March.

Readers who winter in the south will know this bird. It is about the size of a robin, but much slimmer with a very long tail. It is gray, darker gray on top and paler gray underneath, with white patches on the wings and white outer tail feathers.

The plumage is not too exciting, but it’s song certainly is. Although it doesn’t sing much in the winter, in the breeding season, it sings up a storm.

Northern Mockingbirds have long and varied songs. They imitate other birds’ songs. Several years ago, I noted in my field notebook the songs I heard from a Northern Mockingbird. They included Blue Jay, Northern Cardinal, Eastern Phoebe, Tree Swallow, Great Crested Flycatcher, a shorebird, Red-winged Blackbird call and American Robin. I have heard them singing Tufted Titmouse (a bird that occurs here only rarely) and Carolina Wren (an uncommon species in  this area). In urban areas they are known to mimic such things as car alarms and sirens.

This species is also known for singing through the night.

Northern Mockingbirds belong to the family of mimic thrushes, a group which includes Brown Thrasher and Gray Catbird. There are other members of this family in North America, but only these three occur in this area.

Northern Mockingbirds are birds of the suburbs. They like to nest in isolated shrubs surrounded by short grass. Urban parks and gardens are among preferred real estate.

During the spring and summer, they eat mostly insects. In the winter, they switch to mostly small fruit. They don’t seem to be too fussy, since much of the fruit that they eat is from non-native trees and shrubs. The Port Hope bird was attracted by a multiflora rose hedge. In the same block are also euonymus, a tangle of  bittersweet vine, European buckthorn and juniper. Although the multiflora hedge has been thinned by a construction project, there is still quite a lot of fruit available in this area.

Northern Mockingbirds establish a winter feeding territory and defend it from all other fruit-eating birds. It would be a bad thing for a mockingbird if a flock of waxwings or starlings swooped in and stripped the fruit from all the trees and shrubs.

Ontario is on the northern edge of this species’ range. In the first Ontario Breeding Bird Atlas, the centre of its breeding range was in the Niagara Peninsula. Twenty years later, the second Ontario Breeding Bird Atlas recorded more records from the Toronto area and around Kingston.

Locally, the centre of abundance of Northern Mockingbirds seems to be west of Port Hope in the Wesleyville area. I am aware of one breeding season record from Camborne.

The spread of the mockingbird range seems to have followed railroad right-of-ways.

In Northumberland, the 2009 Port Hope-Cobourg Christmas Bird Count recorded three Northern Mockingbirds. This was a record high number for this species.

I will be planning to revise the route of my daily walk to keep track of this bird throughout the winter. Hope it makes it through another one.