Spotted Sandpiper: A Local Polyandrous Species

This week a Spotted Sandpiper (at least one) has been foraging along the Rouge River in Eliza Howell Park. Seeing it reminded me of how unusual this species is. Its mating system, polyandry, occurs in less than one percent of bird species.

(The photos are courtesy of Margaret Weber. )

20200508_144650Polyandry means the mating of one female with more than one male while a male mates with only one female. Spotted Sandpiper is the only polyandrous species I am aware of that breeds in Southeast Michigan.

There are some other members of the sandpiper family that have a similar mating system, but most sandpipers nest only in the very far north. The Spotted Sandpiper spends its summers in much of North America. (The range map is from the Cornel Lab of Ornithology. )

20200507_174221

In the spring, the female arrives first and establishes a breeding territory before males arrive. When they do, she selects a mate and they prepare a nest together (on the ground). After the female lays eggs (usually 4), the male incubates them while the female selects another mate and repeats the process, perhaps up to 4 times (laying as many as 16 eggs).

Sometimes the female mates with only one male. In these cases, she participates in incubation and care of the young.

Resized_spotted_sandpiper_reflection_11946309438772I see a Spotted Sandpiper most years in May, but have not yet seen evidence of them nesting in the park. The female and male look alike, so I don’t know if the Spotted I spotted is a female or male, don’t know if it is establishing its territory or just pausing on its way to a different breeding location.

20200508_144706Most of us have heard/used the “a rare bird” idiom. The Spotted Sandpiper is indeed a rare bird, being so different from most other birds in mating behavior.

It’s great to see part of the One Percent right here in Eliza Howell.

2 thoughts on “Spotted Sandpiper: A Local Polyandrous Species

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s