A consistently warmer than normal November and December, with scattered days and even nights above freezing, resulted in a mid-winter landscape exhibiting a dearth of snow and local rivers and streams open their entire courses. Average temperatures were well above normal for the period. The mild weather pattern defined the 115th Audubon Christmas Bird Count (CBC) in our local Soldotna count circle. The count was held Dec. 20.
With virtually no sea ice in Cook Inlet, area bird counters found two species of ducks not previously recorded on the count — Greater Scaup and Surf Scoter. These two open water species are normally excluded from our ice-choked marine waters. Both species winter in Kachemak Bay in large numbers with scattered flocks occasionally occurring as far north as Ninilchik, to the extent where marine waters usually remain ice-free. While two Surf Scoters were found, sixty Greater Scaup were observed in a single flock — a surprisingly large number for a first CBC record!
Open marine waters have become more common during our last several counts, resulting in recent CBC “firsts” of White-winged Scoter, Common Loon, and Common Murre — species usually restricted to the lower Cook Inlet in winter. Additionally, in November, a Steller’s Eider and a Horned Grebe were both observed in the ice-free lower reaches of the Kenai River. These species were previously unknown so late in the year. As our winter climate warms, the occurrence of new winter species is happening almost annually.
Three other duck species were found in record numbers this year: Mallard (482), Long-tailed Duck (87), and Common Goldeneye (411). Mallards and Common Goldeneyes are species found in both fresh and marine winter waters while Long-tailed Ducks are strictly marine in winter. Nearly every duck species recorded on the count far exceeded or approached previous all-time highs. More open water, not surprisingly, is attracting more wintering waterfowl to our area.
Among land birds, Rock Pigeons, Red-breasted Nuthatches, Brown Creepers, and White-winged Crossbills also were recorded in record numbers. The increase in Rock Pigeons (56) can be attributed to an increase in suitable urban habitat with its associated artificial food sources. But, accordingly, this species’ existence is tenuous at best as they depend nearly solely on hand-outs and are quickly predated upon outside their urban haunts. Red-breasted Nuthatches (47) and Brown Creepers (6) are temperate species that gained a toehold in our area nearly fifty years ago and continue to slowly but steadily increase and grow more widespread in our receding sub-arctic climate.
White-winged Crossbills took the title as the count’s most numerous bird species. This irruptive finch species is directly benefiting from the area’s banner crop of spruce cones (see Matt Bowser’s Aug. 15 Refuge Notebook article). This winter you cannot escape these ubiquitous and noisy flocks as they are everywhere in our conifer-dominated forest habitats. Large numbers should remain and breed in these habitats. As an irruptive species they are characterized by magnificent boom and bust cycles — plentiful one year and nearly absent another. Unlike snowshoe hares, when preferred local foods become scarce, they don’t die-off but instead migrate great distances in search of huge cone crops among the continent’s vast coniferous forests.
But as notable as the record highs counts are, so too are species that were detected in significantly lower numbers. Bald Eagles (259) and Common Raven (272) numbers were down markedly. The vast majority of both species are found in the Soldotna landfill each year. This year, however, with so much open water, especially along the Kenai and Kasilof Rivers and Skilak and Tustumena Lakes, both species widely dispersed along these and other water bodies, foraging more on native foods and less on human waste. So these “declines” don’t indicate so much as a change in population as a temporary change in distribution.
Not only do CBC counters note what we see but also what we don’t see. Barrow’s Goldeneyes, never abundant or widespread in our specific count area, but a fairly consistent winter resident of the recent past, are becoming increasingly difficult to find. Over the last seven counts we’ve been unable to document them within our count circle. Understandably, some years they are nearly absent, as in very cold years when there is little open fresh water along the Kenai River. But, lately, counters are unable to find them even when there is sufficient open water and even when their closest relative, the Common Goldeneye, is found in abundance. Questions abound.
As our sub-arctic climate grows temperate and our wild habitats become urbanized, our local bird populations respond to those changes — sometimes rapidly and conspicuously, and sometimes slowly and imperceptibly. Local Christmas Bird Count citizen-scientists revel in uncovering these gross and fine trends, cycles, and patterns, both locally and continentally.
Toby Burke is a biological technician at the Kenai National Wildlife Refuge who is intrigued by the status and distribution of Alaska and Kenai Peninsula birds. Find more information about the Refuge at http://www.fws.gov/refuge/kenai/ or http://www.facebook.com/kenainationalwildliferefuge .