Showing posts with label Bird research. Show all posts
Showing posts with label Bird research. Show all posts

Tuesday, March 3, 2015

The King-of-Saxony Bird-of-Paradise

Pectoral Sandpipers are among the most accomplished non-passerine songsters--researchers look into how



When one ponders why they're interested in birds, song is one of the highlights of experiencing the avian world. From familiar voices like the ethereal warbles of the Hermit Thrush, the nostalgic whistles of a White-throated Sparrow, or the bold notes of the Northern Cardinal, to exotic voices like the incomparable, sizzling gurgle of the King-of-Saxony Bird-of-Paradise, the machine-gun trill of the Brown Sicklebill, or ear-piercingly loud White Bellbird, song is one of the most distinctive facets of Aves. One little detail, however, stands out after a little extra exploration. When people talk about birdsong, most if not all of the go-to examples are songbirds (Passeriformes, or passerines for short). All the examples above, hailing from such diverse families as the Thrushes to New World Sparrows to Birds-of-Paradise to Cotingas, are passerines. Surely song can't be limited to the birds that bear its name!

As I'm sure you've guessed, it's not.

Figure 1 from the first paper cited below, highlighting the

many pieces that make a complete Pectoral Sandpiper

display. See first citation.

Song is a mate-attraction strategy. Whichever sex of a given species competes for mates of the opposite sex (most of the time it's males) is subject to sexual selection, where traits that are more attractive to potential mates are passed on, whereas less attractive traits aren't. Sexual selection is responsible for peacock tails, cardinal reds, and every complex song out there. In some species, like birds of prey, potential mates don't find self-broadcasting behaviors like song attractive. But in others--especially species that have limited time and resources to breed--self-broadcasting is an extremely useful way for the competing sex to communicate their quality and the quality of their resources through the complexity of their songs. It is, to say it with brevity, efficient. Species that require this efficiency will have sexual selection acting on behaviors like song.


Not surprisingly, then, do we find that many arctic-nesting shorebirds have elaborate songs and song displays, and one of the foremost among them is the Pectoral Sandpiper (Calidris melanotos). To quote Andrew Spencer of Earbirding,

"The classic “song” of the species is unlike any other sound on the Arctic, and any other shorebird in the New World – the male bird sits on an exposed tussock, slowly inflating its pectoral pouch and ruffling its black-based breast feathers before suddenly launching itself into the air and flying low over the ground. Partway into the flight its wings slow into a more exaggerated butterfly flight and it begins emitting a low-pitched hooting series, pumping its head in time with each hoot while its expanded pectoral pouch hangs underneath like a bosom. Right after the series ends it suddenly undulates up into the air a few times before circling back around and landing again. It’s a show like no other!"

Having received more and more attention, researchers from the U.S. and Germany banded together to look into how they do it, and they found some fascinating stuff. I'll report on just a few of them here. First, "Pecs" have evolved a vocal organ (syrinx) similar in anatomy to that of songbirds, a fascinating fact given that Pecs must have evolved this vocal complexity completely on its own. In evolution, this is called convergence. Also fascinating, Pecs show an ability to expand their esophagus similar to that found in doves and pigeons. Why? Males fill their throats with around 30 mL of air in preparation for their courtship display, though their throats have a capacity of up to 50 mL. All this just to impress females. Finally, Pectoral Sandpipers' courtship displays are incredibly ritualized: their display includes three phases, each with different vocalizations and locations (ground or in flight). Different vocalizations are directed at different individuals as well, with some meant for competing males and some for females,

Needless to say, if you bird along Pecs' migratory pathways, we would hardly recognize the same bird on their breeding grounds.

Read more here, on Earbirding, and here, in The Auk,

by Nick Minor

The King-of-Saxony Bird-of-Paradise

Pectoral Sandpipers are among the most accomplished non-passerine songsters--researchers look into how



When one ponders why they're interested in birds, song is one of the highlights of experiencing the avian world. From familiar voices like the ethereal warbles of the Hermit Thrush, the nostalgic whistles of a White-throated Sparrow, or the bold notes of the Northern Cardinal, to exotic voices like the incomparable, sizzling gurgle of the King-of-Saxony Bird-of-Paradise, the machine-gun trill of the Brown Sicklebill, or ear-piercingly loud White Bellbird, song is one of the most distinctive facets of Aves. One little detail, however, stands out after a little extra exploration. When people talk about birdsong, most if not all of the go-to examples are songbirds (Passeriformes, or passerines for short). All the examples above, hailing from such diverse families as the Thrushes to New World Sparrows to Birds-of-Paradise to Cotingas, are passerines. Surely song can't be limited to the birds that bear its name!

As I'm sure you've guessed, it's not.

Figure 1 from the first paper cited below, highlighting the

many pieces that make a complete Pectoral Sandpiper

display. See first citation.

Song is a mate-attraction strategy. Whichever sex of a given species competes for mates of the opposite sex (most of the time it's males) is subject to sexual selection, where traits that are more attractive to potential mates are passed on, whereas less attractive traits aren't. Sexual selection is responsible for peacock tails, cardinal reds, and every complex song out there. In some species, like birds of prey, potential mates don't find self-broadcasting behaviors like song attractive. But in others--especially species that have limited time and resources to breed--self-broadcasting is an extremely useful way for the competing sex to communicate their quality and the quality of their resources through the complexity of their songs. It is, to say it with brevity, efficient. Species that require this efficiency will have sexual selection acting on behaviors like song.


Not surprisingly, then, do we find that many arctic-nesting shorebirds have elaborate songs and song displays, and one of the foremost among them is the Pectoral Sandpiper (Calidris melanotos). To quote Andrew Spencer of Earbirding,

"The classic “song” of the species is unlike any other sound on the Arctic, and any other shorebird in the New World – the male bird sits on an exposed tussock, slowly inflating its pectoral pouch and ruffling its black-based breast feathers before suddenly launching itself into the air and flying low over the ground. Partway into the flight its wings slow into a more exaggerated butterfly flight and it begins emitting a low-pitched hooting series, pumping its head in time with each hoot while its expanded pectoral pouch hangs underneath like a bosom. Right after the series ends it suddenly undulates up into the air a few times before circling back around and landing again. It’s a show like no other!"

Having received more and more attention, researchers from the U.S. and Germany banded together to look into how they do it, and they found some fascinating stuff. I'll report on just a few of them here. First, "Pecs" have evolved a vocal organ (syrinx) similar in anatomy to that of songbirds, a fascinating fact given that Pecs must have evolved this vocal complexity completely on its own. In evolution, this is called convergence. Also fascinating, Pecs show an ability to expand their esophagus similar to that found in doves and pigeons. Why? Males fill their throats with around 30 mL of air in preparation for their courtship display, though their throats have a capacity of up to 50 mL. All this just to impress females. Finally, Pectoral Sandpipers' courtship displays are incredibly ritualized: their display includes three phases, each with different vocalizations and locations (ground or in flight). Different vocalizations are directed at different individuals as well, with some meant for competing males and some for females,

Needless to say, if you bird along Pecs' migratory pathways, we would hardly recognize the same bird on their breeding grounds.

Read more here, on Earbirding, and here, in The Auk,

by Nick Minor