Since mid-September summer has lingered in Pittsburgh with temperatures spiking 15-20 degrees above normal.  Does this mean fall arrivals will be delayed?

Here’s what normally happens outdoors in late October and early November.  Let’s watch to see if it’s on schedule.

• Fall colors peak in mid-October, especially red and sugar maples.  The oaks turn red at the end of the month.
• First frost in Pittsburgh around October 20.  First hard frost around Halloween. (Really?!?  Keep your eye on this one.)
• Most trees will lose their leaves by November 8.
• Most flowers have gone to seed though witch hazel, bottle gentian, hardy goldenrods and asters are blooming.
• The warblers are gone but white-throated sparrows, dark-eyed juncos and American tree sparrows will arrive to stay through winter.
• Broad-winged hawks are gone but red-tailed hawks, kestrels and sharp-shins are now on the move. Don’t miss seeing golden eagles at the Allegheny Front Hawk Watch from late October through November.
• Fill your hummingbird feeder in October in case a rufous hummingbird shows up.
• Big flocks of robins, grackles and starlings form at dusk and dawn. The Pittsburgh crow flock becomes noticeable in early November.
• The first wave of migrant ducks and geese arrive with October cold fronts.
• Chipmunks, squirrels, and groundhogs are storing food and putting on weight.
• It’s hunting season. Wear blaze orange and be aware of Pennsylvania’s hunting seasons.  Remember: Though Sunday is generally safer, some game can be hunted on Sundays.
• Be prepared to “fall back” on the first Sunday in November when we set our clocks to Standard Time.  After that, evening rush hour will be in the dark.

When will the first frost come? When will the first junco arrive?

Stay tuned.

For more information, see Chuck Tague’s Western Pennsylvania Phenological Perspective for October, first published in 2010.

(photo by Bobby Greene)

Will we see northern finches in the eastern United States this winter?  It depends on where you are.

Last month Ron Pittaway published his Winter Finch Forecast for 2017.  The good news is that northern finches are on the move.  The bad news for Pittsburgh birders is that they won’t come this far south.

Northern finches such as evening grosbeaks, crossbills, redpolls and purple finches don’t care about cold weather but they do care about food and that means seed cones on spruce, fir, pine and birch trees.

Pittaway says that seed crops in northeastern North America are excellent this year — the best they’ve been in ten+ years — so finches have already moved to those areas in good numbers.  In fact the seed crop is so good up north that purple finches and evening grosbeaks probably won’t leave home this winter.

The Winter Finch Forecast predicts that if you’re in central or northeastern Ontario, Quebec, Canada’s Atlantic provinces, northern New York state, or northern New England, you’ll see red crossbills (Loxia curvirostra), white-winged crossbills (Loxia leucoptera) and pine siskins (Spinus pinus) this winter.

But not here.  As he says, “This is not an irruption year south of traditional wintering areas in the Northeast.”

Read the entire forecast here including predictions for three indicator species: blue jays, red-breasted nuthatches, and Bohemian waxwings.

The blue jay prediction surprised me.  We have a big influx of blue jays in Schenley Park right now. I wonder where they came from.

p.s. I saw red-breasted nuthatches at Cape Cod last week.

(photo of a white-winged crossbill by Shawn Collins, 2012)

When a migratory bird population is declining, what’s the cause?  Is it poor breeding success? Perils during migration? Decline on the wintering grounds?  Or all of the above?

For common cuckoos in the U.K. there’s a surprising answer. Though equally successful on their breeding and wintering grounds the birds have two fall migration routes, one more dangerous than the other.  The population that takes the deadly route is declining.

Researchers attached tiny transmitters to 42 male common cuckoos (Cuculus canorus) across the U.K. and tracked them on migration from 2011 to 2014.  All of the birds spend the winter in Central Africa but they choose two routes during fall migration.  The eastern route goes east over Europe then south over Italy, the Mediterranean, and the Sahara.  The western route is a shortcut over France, Spain and the western Sahara.  Mortality was highest along the western route, especially in Spain.

Cuckoos that breed in Scotland and Wales take the long eastern route in the fall.  Cuckoos nesting in southern England split with about 60% flying east, the remainder taking the west shortcut.  Midlands and East Anglia cuckoos favor the western route.

Common cuckoos have a stable population in Scotland and Wales but a declining one in the midlands and eastern England.  When the researchers matched migration routes with population trends in the Breeding Bird Survey and Bird Atlas they found a close correlation.  Indeed, population decline in the common cuckoo is linked to their choice of migration route.

See the migration maps and read the 2016 study here at Nature Communications: Population decline is linked to migration route in the Common Cuckoo.

(photo of common cuckoo from Wikimedia Commons; click on the image to see the original)