This could be the best winter in years for Tennessee bird watchers to see northern finches at bird feeders.
Northern finches nest mainly in Canadian forests where they feed almost exclusively in fruiting and cone-bearing trees. As long as there are plenty of small tree seeds, most of these finches remain in the North in winter. Their migration is influenced more by food than by weather.
This fall in parts of eastern Canada, following a drought, many berries are hard and dry. There's also a shortage of tree seeds, including seeds in cones, in parts of eastern Canada and New England. The food shortage is sending northern finches scrambling on erratic migrations in search of seeds. As finches irrupt out of northern forests many are flying south.
Northern finches that sometimes winter in Tennessee in irruption years include purple finch, red crossbill, white-winged crossbill (rare), common redpoll (extremely rare), pine siskin, and evening grosbeak. Other irruptive finches — pine grosbeak and hoary redpoll — don't wander this far south.
Read Canadian Ron Pittaway's Winter Finch Forecast 2012-2013 to track the progression of this winter's finch irruption at http://ebird.org/content/ebird/news/ff2012. Ron explains how each finch species uses a different strategy to adjust to the failure of tree seed crops. Explore the links to eBird maps that pinpoint locations of recent sightings for each species.
Bird watchers contribute their personal bird sighting records through eBird's online checklist program launched in 2002 by Cornell Lab of Ornithology and National Audubon Society. The records document the presence or absence and the abundance of every North American bird species in different locations at different times of the year. Records are updated daily. Visit the website at ebird.org to learn how eBird is revolutionizing the study of bird distribution. If there's a particular bird species you want to see, check the eBird map to see locations where you might find it.
The eBird maps for pine siskin and purple finch show both species are already plentiful and widespread in southern states including Tennessee. Look for these two northern finches. They are the two you are most likely to find at bird feeders right now.
Red crossbills (type 3 with small bills) are on the move this year out of northwestern forests. Some are showing up in eastern states. There are 10 different crossbill types. Each may represent a separate species. Types are identified not by appearance but by distinctive call notes. Serious bird watchers now make recordings (even with cell phones) of any crossbill they encounter. Type 1 and type 2 red crossbills occur regularly in the southern mountains.
A northern finch longtime Tennessee bird watchers would love to see at their feeders this winter is the large and spectacular yellow, black, and white evening grosbeak. One reason we don't see them regularly anymore is because the population is now smaller than it was several decades ago. Tennessee bird watchers saw them more regularly in the 1990s when big outbreaks of spruce budworms (eaten by adults and fed to young in northern forests) supported higher populations.
Keep an eye on eBird's evening grosbeak map for signs of arriving birds. Grosbeaks were first reported Nov. 16 in both West Tennessee and Western North Carolina. If you're a newer bird watcher you may not have seen this species.
Evening grosbeaks prefer sunflower seeds placed on large platform feeders with plenty of standing room. If you attract them, be forewarned. They'll put a big dent in your pocketbook and eat you out of house and home.