Right down to his black-gloved claws, male redpolls are strikingly handsome fellows. The species is a regular wintertime visitor at the lake, though they’re unpredictable and irruptive flocks or a few individuals or none at all might be encountered in any season here. Two springs ago, Barbra saw one carrying nesting material. That same late spring we saw a number of what were surely brand new fledglings. In recent years they’ve joined Pine Siskins and Pine Grosbeaks in what has become the annual late-spring Feast of the Dandelions. As the little yellow flowers go to seed, these finches descend on the school yard and elsewhere to gorge on the tiny seeds. This occurs in large part due to Clinton, the school’s grounds-keeper, whom I’ve convinced to put off mowing till after the main part of the dandelion season is over.
I’m hesitant to say with certainty that the bird in the above photo is a Hoary Redpoll, but he’s got the smallish bill, light side streaking and pinkish breast associated with that species. There is a lot of morphological variation among redpolls. The matter brings up what is to me one of the most interesting questions in biology:
What is a species?
When do two groups of similar flora or fauna differ from each other enough to merit taxonomic separation? The question creates divisions between “lumpers” who advocate for leaning toward the simple “can they interbreed and produce viable offspring” test and “splitters” who observe that even though two types can successfully breed, it may not be useful to group them together as a single species.
My interest in ichthyology has led me to place myself firmly in the “splitters” group. Applying the simple “can they breed and produce viable offspring” test, fisheries managers of bygone eras decimated genetically unique stocks of salmonids (char, trout and salmon) through nearly indiscriminate hatchery breeding policies and stocking programs. What was learned – the hard way – is that although, for example, Chinook Salmon from two different rivers might seem to be the same thing, biologically they aren’t. Each population of Chinook represents a unique genetic strain, specially adapted to the conditions of its own home river. A strain of salmon transplanted from one river to another is unlikely to thrive. Thus, the best approach to ensuring healthy salmon populations is to protect their habitat – river by river, right down to individual spawning tributaries.
Which brings us to the matter of redpolls and the question as to whether there are two species in North America, Hoary and Common, or whether a redpoll is a redpoll is a redpoll. Based on what I’ve read, in addition to any phenotypic or genotypic differences that might exist between the two types, they tend to nest it different areas. Hoaries prefer tundra or other open areas; Commons like more brushy habitat. Which suggests to me that they are different enough that we need to protect both types of habitat if we want to continue to have both types of redpolls. (Nikon D5, 600m f/4 + 2.0 TC, 1/1000 @ f/8, ISO 1600, 1200mm