Saturday 30 April 2016

Yellow-rumped Warblers and other early Migrants finally arrive



Nature Notes for April 29, 2016

“What’s happening to all the birds with the cold weather?” This question was asked of me last Monday evening, in Peterborough, where it had snowed that day, enough that remnants of the snow still lingered in corners in the evening when I was there.

2016 has certainly been a challenging spring for migrants. The temperatures have yo-yoed up and down. It was warm enough for insect activity and plant growth quite early in the spring, followed by freezing temperatures and snow. This cycle has been repeated several times.

Around mid-April, birders thought that landbirds were finally arriving. Last week, while cleaning up my garden, I was serenaded by Golden-crowned Kinglets. These are very tiny birds, weighing about 5 to 6 grams. Although a few kinglets do winter in Northumberland County, most spend the winter in the continental U.S. They were gleaning small insects from the trees and shrubs in the yard. At this writing, many of the Golden-crowned Kinglets have migrated through, and are being replaced by Ruby-crowned Kinglets.

The first few Yellow-rumped and Pine Warblers have been seen locally. They are two of the earliest arriving warbler species. They will be followed by many more warblers species throughout the month of May. 


Yellow-rumped Warblers are one of the earliest warbler to arrive in southern Ontario.
                                                       Photo © Rob Lonsberry Photography
  
Over the weekend, I could hear Barn Swallows as they migrated over. Barn and Northern Rough-winged Swallows have been found in Northumberland for the past week or so. Some Tree Swallows arrived back as early as the last week of March. If the weather had remained warm, they might have had the advantage of claiming a prime nesting territory. This year, these early birds may have paid with their lives by arriving back so early. I wouldn’t be at all surprised if I found some dead birds when I next check the nest boxes that I monitor.

All swallows eat only flying insects. In cold, rainy weather, there is very little insect activity. Under such conditions, flocks of swallows can often be seen feeding on newly emerging midges over Lake Ontario. These tiny insects often appear as clouds and are a very important food source for all insect eating migrants.

A Song Sparrow has taken a territory in my garden where it sings in hopes of attracting a mate. This morning (Tuesday), he was joined by a White-throated Sparrow singing his familiar “Oh, sweet Canada, Canada, Canada, Canada”.  The White-throat will travel a bit further north to breed, perhaps just to the Ganaraska or Northumberland Forests. Theirs is a familiar song to cottagers and those who camp on the Canadian Shield.

Earlier this week, Vesper and Savannah Sparrows were found singing from agricultural fields. These birds were likely on territory since they nest on the ground in these fields.

Chipping Sparrows have also appeared recently. They nest in conifers next to open grassy areas, where they feed. They frequently nest around houses and buildings with mowed grass and ornamental conifers.

Fox Sparrows and Eastern Towhees have been reported at several backyard feeders. These are two of the biggest and most handsome of our sparrows. They are both relatively early migrants. Fox Sparrows are on their way to the northern boreal forest. Eastern Towhees, on the other hand, are almost at the north edge of their range. Towhees like to nest in brushy tangles. In Northumberland County, they are most common on the moraine.

Although a few birds may succumb to the cold weather with its lack of insect food, most early arriving migrants are hardy enough to survive some cold spells. They may be a bit slow to arrive this year, but that may have as much to do with unfavourable winds as to the cold.

Since the next Nature Notes will not appear until the end of May, most land bird migrants will already have arrived in or passed through Northumberland. In migration, birds can often turn up in unusual places. Willow Beach FieldNaturalists, Northumberland Land Trust and Presqu’ile Provincial Park are all offering outings focused on returning migrant birds during May. Readers are encouraged to take advantage of these events.