[This story appears as an on-going series in the "Gilroy Dispatch"]
Visitors from the North – An Irruptive Year for Pine Siskins, Red Crossbills andRed-breasted Nuthatches March, 2013 By Amy Yee
A what year for what?
Many of our feathered friends from Canada are enjoying the relative warmth, sunshine and especially the abundant food of Santa Clara County this winter.
In particular, Pine Siskins, Red Crossbills and Red-breasted Nuthatches have been seen in unusually high numbers in this area. This "irruptive" year (defined as "irregular migratory movements, depending on factors other than a change of seasons, such as food availability" Cornell Lab of Ornithology, Handbook of Bird Biology) that we have been experiencing usually occurs once every few years. However, this is an even more unusual event than an "irruptive" year the great abundance of these birds in 2013 is called a "Super Flight" year, the likes of which hasn't been seen here since 1997.
These three species in particular are common to the boreal forests of southern Canada and the far northern United States. Every 10 to 15 years the trees that produce the birds' favorite seeds stop producing them in their usual abundance, forcing the birds to fly further and further south to obtain food. Because the birds' native home is scarcely populated, there are few bird feeders to help make up for the lack of food.
Bird watchers throughout the United States are thrilled with the influx of these beautiful seed-eaters. Santa Clara County birders have been excitedly posting sightings on various birding eLists. "Birders learn what species they can expect to find in their area throughout the seasons and we just don't often see Pine Siskins, Red Crossbills or Red Breasted Nuthatch in the valley. When they do show up it's always special and the word spreads quickly. However, this year all three of these species are wintering right here in our yards or someplace near. Reports are coming in everyday. Once spring arrives these birds will depart and it may be years before we see them in our neighborhoods again." Lisa Myers, professional birder and owner of LetsGoBirding.com.
You may well have seen these birds in your own backyard or nearby park. Pine Siskins look similar to our common House Finches, but have yellow streaks on their wings. Red Crossbills, aptly named, have an unusual crossed bill which makes them an orthodontist's dream. Red-breasted Nuthatches are similar to our more common White-breasted Nuthatches, perky little birds that are often seen "upside down" on a tree, but are a bit smaller and have a cinnamon colored breast instead of the more usual white breast.
The Red Crossbills consist of at least ten distinct sub-types, each with a unique bill designed to obtain seeds from different types of conifers. In other words, each sub-type of Red Crossbill has a beak specially designed to eat the seeds of a particular type of pine cone. Each sub-type also has a distinct call. On January 3 of this year, according to a South Bay Birders eList report, "Red Crossbills were found in yellow pines at Henry Coe State Park. Later video recordings revealed both Type 2 (yellow pine specialists) and 4 (Douglas fir specialists) birds in these flocks."
What does this mean for human residents in Santa Clara County? If you put out bird feeders, you can expect extra guests. Extra guests can mean squabbles over food, so you may want to put out additional feeders, spaced to minimize territoriality and aggression. You can also vary the types of seed you offer, to attract these unusual species. Red-breasted Nuthatches have been observed to particularly enjoy hulled sunflower seeds, mixed nuts and suet. Pine Siskins favor hulled sunflower seeds and nyjer (thistle) seeds. You will have to travel to some place like Henry Coe State Park to see Red Crossbills, as their diet is pretty much limited to pine cone seeds.
Extra guests always mean extra work, too. When large numbers of birds are present, diseases are more easily spread. Be extra diligent about keeping the feeders clean. Washing the feeders and then soaking them in hot vinegar is recommended, in order to kill the viruses and bacteria, often fatal, which are so easily transmitted among feeder birds. Vinegar will also kill the mold that often develops when seeds get damp.
Mostly, enjoy our Canadian visitors. It may be many years before they return.
Amy Randall Yee has lived in Santa Clara County for 35 years and has volunteered at WERC for six years. She is the President of the Board of Directors of WERC. Contact her at email@example.com.
W.E.R.C., the Wildlife Education and Rehabilitation Center provides the community with rehabilitation services for orphaned, injured and sick native wildlife. Through our educational programs, W.E.R.C. encourages a peaceful coexistence between civilization and our native wildlife. Federal tax ID #77-0324296