Orioles are an occasional wintertime visitor

Bullock's Oriole

Why do orioles appear in the region at this time of year? Aren't they supposed to be enjoying their winter in Central America?

It's unusual for an oriole to be seen this far north during winter but it does happen. In fact, orioles have shrugged off snow and cold in at least four out of the past five years in northern Montgomery County.

In January and early February, a female Baltimore Oriole was seen at a feeder at a house near Green Lane Reservoir.

A Bullock's Oriole was spotted at a feeder in January and early February 2015 in Gilbertsville. A similar sighting was reported around the same time at the same site in 2014 and 2012. In both cases, the orioles were seen at feeders.

Orioles are neotropical birds. They spend the summer in their breeding range in the United States or Canada, then migrate to the neotropical region of Mexico, Central America, Cuba or the Caribbean islands for winter. 

Orioles favor insects, nectar and ripe fruit, foods commonly available around flowering trees and vines. For an oriole to have an abundant supply of food, the bird must migrate before winter sets in.

But there are exceptions to this rule. 

Orioles that choose not to migrate are found primarily at feeding stations, according to Gerald M. McWilliams and Daniel W. Brauning, authors of The Birds of Pennsylvania. 

Baltimore Oriole

Over the years, wintertime orioles have been reported in Bucks, Delaware, Montgomery, Northampton and Philadelphia counties. Most sightings are of single birds but up to seven wintered in 1969 at Pennypack Park in Philadelphia, according to the book.

Birds of the Lehigh Valley and Vicinity, which is published by the Lehigh Valley Audubon Society, said there have been several recorded sightings of Baltimore Orioles in our region during winter. 

Oriole-lovers should not expect to see the birds locally in any numbers until at least the third week of April. As the years go by, that timetable could change.

A study by wildlife biologists Benjamin Zuckerberg and Karine Princé, of the University of Wisconsin-Madison, say global warming may be expanding the wintering range of migratory birds such as orioles. 

Using two decades of data derived from Project FeederWatch, the biologists found that birds typically found in more southerly regions are gradually pushing north. The researchers ruled out the possibility that birds are staying north longer simply because of the existence of feeding stations. The number of stations has in fact declined slightly since 1991, indicating that environmental factors beyond the availability of food sources are at play.

"People will likely start seeing new species in their backyards," said Princé, a UW-Madison post doctoral fellow. "There can also be subtle changes in species abundance."

Oriole eats from a sliced orange

ORIOLES' DIET
Orioles may come to your backyard if you have the right habitat: open woodland, leafy deciduous trees, groves of trees, orchards, or fruit-producing vines. 

During the breeding season, their primary diet is insects, which are rich in protein needed for their young to thrive. Offer mealworms in spring and fall, nectar and ripe fruits become a larger portion of their diet. These sugars are converted into fat, which supplies energy for migration. Orioles prefer soft, ripe fruit. 

To attract orioles, plant fruit-bearers or bright nectar-bearing flowers in your yard. Fruit-bearers include raspberries, mulberries, blackberries, elderberries, serviceberries, blueberries, huckleberries and crabapples. Orioles choose trumpet vines, honeysuckle, petunias and other nectar-producing flowers. 

If you don't have fruit-bearing vegetation in your yard, you might lure an oriole with oranges. Cut an orange in half and hang them from trees or spear them onto specially designed oriole feeders. Peaches also work.

Another option is to place small amounts of grape jelly or orange marmalade into a cup-like feeder. Don't put out too much jelly at a time, however. It can soil the birds' feathers, impinging their flight ability. Also, do not use sugar-free jellies; it is the jelly that gives the birds the energy and calories they need for flight.

Other food options for use in feeding cups include berries and fresh peas. Mealworms are especially valuable during the height of breeding season when protein is essential.

Sugar water offered through a feeder also will attract them, though with less success.