Early bird catches “worm”

A little Spotted Sandpiper had the entire beach of Vadnais reservoir to itself and moved slowly along the shoreline probing now and then in the mud and under leaves as I stood quietly and watched.

It’s a rather plain looking, medium-sized, chunky-bodied shorebird, missing the spots for which it is named in its winter or juvenile plumage (can’t tell which). But the bird is instantly recognizable as it bobs its tail up and down as it walks, earning it the nickname of “teeter-bob” or “teeter-peep”.
Here and there, the bird probes its bill part way into the mud testing for the presence of buried larvae.
I’m not sure what this behavior is — did the bird hear something, or see something and tilted its head to localize the cue? Spotted Sandpipers hunt primarily by sight, looking for insects or crustaceans in the debris along muddy shores, but they also probe likely looking nooks and crannies where invertebrates may be hiding.
The bird has found something here — it takes a couple of minutes of probing up and down to extract it.
It pulls some yellow and black-striped “worm” from the muddy substrate. The prey might be the larva of a large stone fly or caddisfly.
It looks tantalizing (to a sandpiper) — why not gobble it up?
Nope, have to wash it off — thoroughly! Two or three dunks and swishes should do it.
Now, it’s edible.

Spotted Sandpipers are likely the most widespread breeding sandpiper in North America, nesting from northern most Alaska to the mid-continental U.S. along rivers, lakes, and streams.

And their breeding system is particularly interesting because they exhibit a sex role reversal compared to most other bird species. Instead of the typical female role of incubation and hatchling care, Spotted Sandpiper females “collect” multiple males, laying a clutch of eggs in each male’s nest, which he will then incubate. After they hatch, the male is in charge of protecting and providing food for the chicks, while the female goes off to find another male to mate with.

Female Spotted Sandpipers arrive first on the breeding ground, establish their territory, and then compete with each other for males to mate with. Since females can store sperm from multiple matings for up to a month, the male may be incubating and tending to chicks that are not his offspring! This breeding strategy, called polyandry, is rare among birds but is found in several shorebird species, in Northern Jacanas, occasionally in Acorn Woodpeckers, and in Harris Hawks.

8 thoughts on “Early bird catches “worm”

  1. Thanks for the great photos (especially loved the one with the ‘eye to the sky’ or ‘ear to the ground’) and for the lesson on Spotted Sandpiper sex-ology! I learned something today and will take it with me to FL to share with my beach-walking friends.

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