Spotted Sandpiper songs and calls are relatively similar, in that both consist of weet notes. Variations in calling may include peet or certain squeals, however songs are mostly characterized by a string of the weet note. According to Heidemann and Oring (1976) the specific amplitude, pitch, and intervals of these notes depend on the context, wherein louder, high-pitched song is considered aggressive in nature while longer intervals between notes and lower pitches constitute reproductive song. Reproductive song in Spotted Sandpipers are called “epigamic” song and are often interspersed with quiet pip notes. These preliminary notes are characteristic of epigamic song and make this type of song easy to identify (Heidemann and Oring, 1976). Attached is an image of three variations in Spotted Sandpiper song (Heidemann and Oring, 1976). The topmost spectrogram shows the fast-paced, high amplitude of aggressive song, the middle spectrogram models slow song, and the bottommost image shows epigamic song with its characteristic string of pip pip or pip pip pip preliminary notes. Very little research has been done of the development of song in Spotted Sandpipers, or any of their close relatives. Unfortunately, this leaves a large gap in research on this species, which makes it extremely hard to pinpoint whether or not their song is learned or innate. However, a few clues may strongly point towards their song being innate. First, spotted sandpipers are not a member of the passerines, or more specifically, the oscine songbirds. This is an important distinction, because it has generally been accepted that songbird song is learned. Birds outside of the songbird category are much more likely to have innate song, and therefore it is highly probable that Spotted Sandpiper song is unlearned. A follow-up clue comes from data surrounding relatives of the Spotted Sandpiper. While little has been gleaned from studies on sandpiper song development, a journal article studying Piping Plovers asserts that Piping Plover song is unlearned (Sung et. al., 2005).  Piping Plovers and Spotted Sandpipers both belong to the order charadriiformes,  so if we base song-learning hypotheses on phylogeny and close relatives, it would not be irrational to assume that Spotted Sandpiper song is also unlearned. Miller and Baker (2009) assert that in general, shorebird song evolves very slowly, partially due to the fact that all charadriiformes song is unlearned. It is also interesting to note that shorebirds like sandpipers and their close relatives (all in the order charadriiformes) have very simple syrinx composition (Brown and Ward, 1990). Spotted Sandpipers are extremely widespread throughout North America, however there does not seem to be any indication of specific dialects. This could also reinforce the idea of innate song, because all birds, no matter what population they are surrounded by, develop the same basic song.

Playback experiments prove that song functions in aggressive behavior, indicated by the fact that Spotted Sandpipers that hear a playback song similar to that of a Spotted Sandpiper have increased aggressive tendencies, especially around breeding season (Heidemann and Oring, 1976). This demonstrates that song recognition of other Spotted Sandpipers plays a role in territorial defense. Similar studies have shown that Spotted Sandpipers have a “resource-defense polyandrous mating system” in which song plays a function (Pickett et. al., 1998).

I believe that future research needs to be done on the development of bird song in Spotted Sandpipers and their relatives, because there is an absolute lack of such research in the field. An easy way to conduct such research would be to raise hatchlings of spotted sandpipers either completely isolated or with a “tutor” (an adult sandpiper who sings) and see if there is a difference in the quality or style of song that the young birds develop. If not, then it is very likely that song is unlearned. It would also be interesting to study deaf birds, as Donald Kroodsma did, to make sure that the Spotted Sandpipers aren’t simply learning how to perfect their song by listening to themselves sing.

Citations

Brown, C., and D. Ward. 1990. The morphology of the syrinx in the Charadriiformes  (Aves): Possible phylogenetic implications. Bonner Zoologische Beiträge 41:95–107.

Miller, Edward H. and Baker, Allan J. 2009. Antiquity of Shorebird Acoustic Displays. The Auk 126: 454-459.

Oring, L. W., Reed, J. M., and Alberico, J. A. R. 1994. Mate acquisition tactics in polyandrous spotted sandpipers – the role of age and experience. Behavioral Ecology 1: 9-16.

Pickett, Paul E., Maxson, Stephen J., and Oring, Lewis W. 1998. Wilson Ornithological Society 2: 297-302.

Sung, Ha-Cheol, Miller, Edward H., and Flemming, Stephen P. (2005). Breeding vocalizations of the piping plover (charadrius melodus): structure, diversity, and repertoire organization. Canadian Journal of Zoology 4: 579-595.