Waxwings — Family Bombycillidae
Bohemian Waxwing Bombycilla garrulus
A bird of the far north, the Bohemian Waxwing winters irregularly as far south as northern California. The records from San Diego County are the species’ southernmost along the Pacific coast.
Winter: The three records are of two found dead and badly decomposed (not preserved) at Vallecito (M25) 29 March 1920 (Stephens 1920b), four to six at Yaqui Well (I24) 3–5 December 1972 (AB 27:664, 1973), and one at Presidio Park (R9) 3–4 December 1974 (AB 39:743, 1975). The first two occurrences were in invasion years for the species farther north in California, although the third was not.
Conservation: From 1968 to 1977 the Bohemian Waxwing reached California annually, but since then it has been much less frequent. The trend toward warmer winters may result in the species’ winter range shifting north and raises the question of whether the Bohemian Waxwing will ever again make it as far south as San Diego County.
Cedar Waxwing Bombycilla cedrorum
Of the fruit-eaters that come to San Diego County as winter visitors, the Cedar Waxwing is perhaps the most familiar. The birds move in flocks of dozens if not hundreds and feed on the berries of ornamental plants in urban gardens at least as eagerly as they do on the fruits of wild plants. Like other wintering frugivores, their abundance varies much from year to year, on the basis of both the number arriving from the north and movements within San Diego County.
Winter: In most years, the Cedar Waxwing is most abundant in the coastal lowland, becoming less frequent at higher elevations and in drier habitats. During the field seasons for this atlas from 1997 to 2002, San Diego County missed the extremes of variation in this famously irregular species. Numbers were somewhat lower than average in 1997–98 and higher than average in 1998–99, but the number did not approach zero as in 1993–94, nor was there a massive invasion as in 1981–82 or 1983–84. The highest daily counts during the atlas period of 245 near Ross Lake (B7) 18 February 2002 (K. L. Weaver), 260 at Kit Carson Park (K11) 30 December 2000 (P. Hernandez), and 280 at El Camino Cemetery (O9) 3 January 1999 (D. K. Adams et al.) could have been exceeded easily in an invasion year like 1983–84, when 3387 were totaled on the San Diego Christmas bird count.
Above about 2500 feet elevation the Cedar Waxwing is usually uncommon, and in the higher mountains it is rare; in the latter our maximum from 1997 to 2002 was of 20 from Julian to William Heise County Park (K20) 24 January 1999 (E. C. Hall). Nevertheless, there is great variation from year to year: in 1992–93, when the San Diego Christmas bird count yielded only 14 waxwings, its lowest total since 1962, the Lake Henshaw count yielded 496, its second highest since the count’s inception in 1980–81.
On the Campo Plateau and in the Anza–Borrego Desert fruits suitable for the Cedar Waxwing are scarce and the birds are uncommon to absent. In these regions the highest counts are from gardens in Borrego Springs (F24; up to 45 on 21 December 1997, P. K. Nelson et al.). Cedar Waxwings rarely compete for mistletoe with the Phainopepla. During the atlas period we had no records of the waxwing from sites with abundant mistletoe such as Yaqui Well (I24), Vallecito (M25), or Agua Caliente Springs (M26), though the highest count in the Anza–Borrego State Park database is of 45 at Yaqui Well 4 April 1958 (L. Penhale).
Migration: The comings and goings of the Cedar Waxwing are as irregular as its abundance. In some years a few appear in the first week of September, but the mass of winter visitors arrives much later in the fall. During the atlas period our largest concentration of spring migrants was of 250 near Escondido (I10) 16 May 1999 (E. C. Hall), but 2500 were halted by a snowstorm around the Palomar Observatory (D15) 21 March 1983 (R. Higson, AB 37:913, 1983). In most years a few waxwings linger to mid May; after larger incursions numbers then can still be substantial. Our latest date from 1997 to 2001 was 3 June (2000; two near the south fork of San Onofre Creek, Camp Pendleton, D3, R. and S. L. Breisch). After the big invasion of 1983–84 “small numbers” remained in San Diego through “the first half of June” (AB 38:1063, 1984). In 1985 C. G. Edwards noted one at Old Mission Dam (P11) 20 June and a flock of 35 in La Mesa (R12) 27 July. During the atlas period the only summer record for San Diego County is of eight along Roblar Creek (C5) 5 August 1998 (P. Galvin, C. Collier). The Cedar Waxwing has been recorded in summer elsewhere south of its normal breeding range and even nested successfully once in Orange County, in 1964.
Conservation: Ornamental plants offer the Cedar Waxwing many food sources lacking in natural habitats, and these have now replaced the native vegetation over wide areas that once had little to attract the birds. Pyracantha, Cotoneaster, Liquidambar, Peruvian and Brazilian pepper, palms, heavenly “bamboo,” juniper, camphor, and fig are among the cultivated shrubs and trees on which the waxwings now rely. Some of these may even contribute to lessening the species’ nomadism: some urban fig trees that fruit abundantly attract waxwings consistently year after year.
Taxonomy: Burleigh’s (1963) proposal of two western subspecies of the Cedar Waxwing has not been widely supported, and the species is generally regarded as monotypic.