One of the first birds I learned to recognize was a white breasted nuthatch. (My mom says I called it an upside down bird, because they often feed and forage with their heads facing the ground). So when I noticed in the official big year counts that the Sullivan’s had seen one on the island, I shot off an email to the people most likely to see the bird– those with a feeder. Anne replied that she and Jack had been seeing them at their feeders, and I came over to see one of my childhood favorites. I made several trips to spy on the feeders, and finally caught a glimpse of a white-breasted nuthatch. I didn’t get the camera up fast enough, so I’ve added Cathy Miller’s great shot, above, so you can get a sense of what a white-breasted nuthatch looks like.
When the flock of mixed birds (chickadees, cardinals, woodpeckers, etc.) was foraging near the creek that feeds Chapel Pond, I heard the insistent nasal “hank-hank” of a nuthatch, and looked up to focus the camera on the bird. The sun was in my eyes, so it wasn’t until I got home that I realized that this was a new bird for me. This was a red-breasted nuthatch, a bird of the northern pine and spruce forests. The call is similar enough to its white-breasted brethren that I mistook it for that species. Once I paid attention, it does sound a little more like a tin horn.
What’s a bird from the northern forests doing in the maritime pine and oak forest on the island? Sometimes a shortage of food in its native range can lead to large numbers of birds moving southward in search of food. A massive temporary influx (migration) of a species to new grounds is known as an irruption. This might be due to a failure in the cone crops of spruce and fir trees in the northern part of its range. According to Birds of North America,
It is unique among North American nuthatches, however, as the only species to undergo regular irruptive movements that appear to be primarily driven by a shortage of winter food on the breeding grounds. During irruption years, large numbers of individuals often invade uncharacteristic habitats as far south as the Gulf Coast of Louisiana and the desert washes of northern Mexico. With its propensity for long-distance movements, the Red-breasted Nuthatch is the only North American nuthatch to have crossed the Atlantic to Europe as a vagrant.
While they will come to feeders (click here for Cathy Miller’s blog post detailing the nuthatch as the 106th recorded bird in her James Island yard.) they are most likely in search of the seeds in pine cones. The word nuthatch comes from their tendency to pound seeds to “hatch” them or stash them in crevices in bark.
In 20 years of record keeping, we have only recorded this northern forest dweller on the island one other time– at the 2011 Christmas bird count on January 2, 2011. Contrast that to almost daily sightings this month! All across the state, sightings are up in large numbers. This 10000 Birds post also has information about the nuthatch irruption, and one theory that really seems to make sense. If the food source for nesting birds is plentiful, then those birds have more offspring. That new larger generation is now competing for the same food sources. If, in the subsequent winter, there is a sudden drop in the availability of food, then more of the new offspring have to range farther afield in search of food, creating a larger irruption because the initial plenty led to a larger population in the first place.
This theory makes a lot of sense to me– and could explain last year’s irruption of snowy owls. If you didn’t hear about that, it was a pretty impressive movement of snowy owls far south of their usual range. They haven’t ranged as far south as South Carolina, but one was reported on the Georgia coast in 1931. This video has some gorgeous footage and an explanation of that better known irruption.
In the meanwhile, if you are traveling the course of the island and hear a nasal hankhank like a toy horn, look up at the nearest pine tree. You might be rewarded with a good look at a rare visitor!