Experiments on Species Discrimination in Blue-Winged Warblers

Quality of anthropogenic habitats for Golden-winged Warblers in central Pennsylvania

“…A point count comprised (1) a 3.0-min pre-playback period, (2) a 1.3-min playback stimulus period, and (3) a 3.0-min post-playback period (total ϭ 7.3 min), whereupon all male warblers observed by sight and sound during the count were noted. The playback period consisted of seven Type I (Gill andLanyon 1964, Ficken andFicken 1967) Golden-winged Warbler songs broadcast at 10-sec intervals with the use of a custom-made compact disc provided by the Macaulay Library of Natural Sounds (Ithaca, NY, USA; MLNS Job #2002073) and a small compact disc player with portable speakers. Each song consisted of one zee note and three bee notes because this song structure produces a relatively strong response from Goldenwinged Warblers (Ficken and Ficken 1973).…”

Discrimination Behavior and Hybridization of the Blue-Winged and Golden-Winged Warblers

“…Male Blue-winged Warblers in Michigan discriminate between heterospecific and homospecific song type I better than do male Blue-wings in Maryland, where Golden-wings are absent: 14 of 18 discriminated in Michigan as compared with 2 of 9 in Maryland (Table 3). Gill and Lanyon's (1964) experiments in a Long Island Blue-wing population were of a completely different design and hence not statistically comparable, but support these conclusions in that three out of six males were weakly responsive to heterospecific song. Allopatric and sympatric Goldenwinged Warblers discriminate equally well with regard to song type I (Table 3).…”

“…We used a Uher (4000 L) tape recorder without external speaker or amplifier in all playback experiments. The tapes were copies of those used and illustrated by Gill and Lanyon (1964). Experiments were not begun unless a territorial male was singing song type I within 200 feet, which insured he would hear the playback and was in an "undisturbed" motivational state (see Ficken and Ficken, 1969) .…”

“…Subsequent duration of the response was either Complete (4) or Incomplete (0), depending on whether or not the male continued to respond until the playback of 15 renditions terminated. Other features of the behavior of the responding bird also received scores (in parentheses): Active Behavior, a constant flitting about the experimental area or the flicking of wings and tail of a perched bird (2); Study Behavior, a bird sitting almost motionless within three meters of the tape recorder with occasional, low-intensity vocalizations (2); and Passes, a direct flight over the playback (2) (a fuller description of these is given by Gill and Lanyon, 1964). Also responding males were typically Silent (i.e.…”

Genomic divergence in allopatric Northern Cardinals of the North American warm deserts is associated with behavioral differentiation

“…In birds, a particularly salient prezygotic reproductive barrier comes in the form of song. Male songbirds sing to defend their territories and attract mates, and behave aggressively towards conspecific songs and intruders (Gill & Lanyon, 1964;Catchpole & Slater, 1995). Juveniles learn their songs from nearby singing adults (e.g., Jenkins, 1978) and thus slight variations in dialect are retained in very localized areas as a consequence of low dispersal (Lemon, 1975;Lanyon, 1979;Slater, 1989;Marler, 1997).…”