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Medientyp:
E-Artikel
Titel:
The Systematics and Biology of the Singing Quail, Dactylortyx thoracicus
Beteiligte:
Warner, Dwain W.;
Harrell, Byron E.
Erschienen:
Wilson Ornithological Society, 1957
Erschienen in:The Wilson Bulletin
Sprache:
Englisch
ISSN:
0043-5643
Entstehung:
Anmerkungen:
Beschreibung:
<p> The Singing, or Long-toed, Quail inhabits a number of forest types from near sea level to about 10,000 feet in Mexico, Guatemala, El Salvador and Honduras. Many of the populations are disjunct. The habitats occupied are extremely variable in climate, forest type and areal extent. Some dense undergrowth for cover is essential. Some populations occur in two, three or more vegetation types; others are restricted to a single type. These vegetation types include deciduous forest, semi-deciduous tropical forest, tropical evergreen forest, rainforest, oak-sweet gum cloud forest, mesic areas in pine-oak, pine-oak-fir-alder, oak-aguacate vapor forest, second growth cloud forest and coffee groves in areas of limited natural forest. Knowledge of biology and behavior of the Singing Quail is fragmentary. It escapes by short, rapid flights or by running or both. Much of its food of seeds, bulbs and invertebrates is obtained by scratching in the litter and humus. Flocks of as many as 12 individuals of both sexes and all age groups have been observed. Even during the breeding season more than two adults may be present in a small area. During two breeding seasons approximately 3.5 pairs per 100 acres were found in climax oak-sweet gum forest in Tamaulipas. Estimates based on this figure for the total populations of each of two isolated volcano populations in El Salvador do not exceed 500 pairs. The breeding season, which extends from February through October or later, is similar for all populations except for indications that in the deciduous forest of Yucatán it may be delayed until May following the three driest months. No nest has been described, but a female was reported to have been incubating five eggs; usually broods have had two to four young. The postnuptial molt begins in June and continues through at least the end of the year; during July and August most of the adult population is in molt. No completely satisfactory criteria were found for separation of first year from older birds. Song and other vocal notes are described. The song is usually in two parts: a series of about four loud, penetrating whistles followed by three to six rapid phrases of notes of differing pitch. The taxonomic history of Dactylortyx thoracicus is reviewed. Nine races had previously been described but one race without a valid name is given the name ginetensis. The following eight new subspecies are described: pettingilli, melodus, dolichonyx, moorei, edwardsi, calophonus, rufescens and conoveri. Over a part of the range of the species there are size and color correlations with altitude and climate respectively, the largest birds living at higher altitudes, the smallest near sea level. The darkest birds are cloud forest inhabitants; the palest occur on the Yucatán peninsula in both deciduous forest and rainforest. Color clines are strongest in the largely continuous Atlantic slope populations and are weaker among the Pacific slope and interior Chiapas populations. Clinal relationships are not apparent among some Honduras populations. In some of these small populations random differentiation seems to be present. The race devius from Jalisco exhibits some characters of the Sierra Madre Oriental populations suggesting a former connection with the eastern populations across the Transvolcanic Belt rather than across the Balsas Basin with melodus. </p>