Summer Migration

Baltimore Oriole

Many birds begin migrating in late August, particularly those birds that feed chiefly on insects. It is not unusual to see large numbers of migrants at this time of year, even though it’s still summer according to the calendar. Insectivores leave the north early to ensure food is still plentiful as they make their way to South America, where many of them will spend the winter. I headed over to Andrew Haydon Park and Mud Lake again during the third weekend of August to see if I could find some of these summer migrants, and I wasn’t disappointed!

Andrew Haydon Park was slow. There weren’t any migrant shorebirds on the mudflats, just the usual Killdeer and Spotted Sandpipers that breed here. Two Blue-winged Teals, a Baltimore Oriole and a Purple Martin flying over were the best birds; however, a cooperative Monarch butterfly stole the show with its bright colours.

Monarch Butterfly

Mud Lake was much more active. I tallied 30 species without leaving the ridge or Cassels Street, including a group of mallards and Wood Ducks feeding on the fallen seed beneath one of the bird feeders beside the water, a Black-crowned Night Heron flying over, and a Spotted Sandpiper and a Belted Kingfisher behind the ridge. The songbirds, however, were much more numerous. I found one spot on the ridge where the birds kept moving through and tallied three vireo species (Philadelphia, Red-eyed and Warbling), two Gray Catbirds, a handful of Cedar Waxwings, and this Rose-breasted Grosbeak feeding on the berries.

Rose-breasted Grosbeak

Rose-breasted Berry-beak

I also saw this young Baltimore Oriole gleaning insects from the leaves. Although orioles eat fruit and nectar in addition to insects, they are one of the first blackbirds to leave in the fall. Nectar and ripe fruits are eaten primarily in the spring and fall, as these sugary foods are readily converted into fat which supplies the energy these birds need to migrate.

Baltimore Oriole

Young male Baltimore Orioles do not attain their dark orange adult plumage until their second fall. Nevertheless, a few drab first-year males succeed in attracting a mate and raising young. Females become deeper orange with every molt; some older females are almost as bright orange as males.

Baltimore Oriole

I counted seven species of warbler on the ridge: Black-and-white Warbler, Tennessee Warbler, American Redstart, Cape May Warbler, Yellow Warbler, Chestnut-sided Warbler, and Yellow-rumped Warbler. Cape May Warblers seemed to outnumber every other species except Yellow-rumped, which is something I’d never seen before.

Cape May Warbler

Although this looked like just another “confusing fall warbler” at first, I am pretty sure this is a young Cape May Warbler based on the downward-curving bill, white undertail coverts and yellowish line extending across the nape of the neck.

Cape May Warbler

This Purple Finch sitting quietly on the ridge was a surprise find. Although it appears to be a female based on plumage, the reddish gape suggests it is a young male instead. Robert P. Yunick conducted a study on Purple Finches in which he caught and examined almost 7,500 brown-coloured finches in New York over a period of ten years. After aging and sexing each bird, he found that over 98% of the birds with red or reddish-orange gapes were males. Females tend to have a yellowish gape instead (Yunick, R.P. 1991. Another Assessment of Gape Color in the Purple Finch. No. Am. Bird Bander 16:109-113).

Purple Finch

You can see the red-coloured gape (the fleshy intersection between the upper mandible and lower mandible) more clearly here. In any event, this is the first Purple Finch I can recall seeing at Mud Lake, and the first one that has willingly posed for my camera!

Purple Finch

There weren’t as many birds behind the ridge as I had hoped, but I did find an adult Cottontail rabbit munching on some grass next to the trail.

Eastern Cottontail

While searching (unsuccessfully) for warblers behind the ridge I saw a large dragonfly swoop down and land in one of the trees. When I tracked it down I discovered a beautiful Swift River Cruiser with a tattered wing. These guys seem to be becoming more and more common at Mud Lake!

Swift River Cruiser

Not long after that I headed home, pleased with all the wonderful creatures I’d seen and thrilled that I was finally able to get some great bird photos – not always an easy feat!

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One thought on “Summer Migration

  1. Pingback: Highlights from 2012 | The Pathless Wood

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