I'm wondering how the sanderling tire tracks were different. You said
they were always the same ones, from which I infer you could tell the
difference. Were they deeper in the sand? Was it a deeper or shallower
tread than the others? Anything?

David Barber
Vancouver, WA


jbroadus at seanet.com wrote:
> Interesting behaviour viewed while four of us were walking
> along the beach, in stormy weather, on the peninsula north of
> the town of Long Beach. Low tide, not many birds about but
> there were a few flocks of sanderlings. I have read about the
> following described behaviour, but this is the first time I have
> actually seen it:
>
> Driving is allowed on this stretch of beach, so although we saw
> no cars there were tracks from about 5 different cars. One set
> of knobby, but not particularly deep, tracks were interesting to
> the birds. We would see, in the distance, long skinny masses
> of sanderlings. As we came up to them you could see that the
> masses were each one tire width wide. Solid sanderlings
> covering each tire track, for a distance of 20 to 30 feet linearly
> along each track. The birds were probing, of course, and the
> track on the other side was always a little better than the track
> that some were in, as there was a constant running back and
> forth and trading places.
>
> The best thing is that there were several sets of tracks, and it
> was always only the two tracks from one vehicle that interested
> the birds. We saw this going on at two different places on the
> beach, both times the same two tracks. At other places along
> the beach there were very few birds, and only a scattering of
> probe holes. By the way, the tracks were not particularly close
> to the water's edge, but back up where the sand just started to
> get soft.
>
> When we got too close the flocks would run out to the surf line,
> and would probe a little out there, then run back to the tracks
> as we passed.
>
> We walked the same beach two more evenings, and never
> saw a repeat of the tire track feeding frenzy. Just your
> standard more or less random distribution of probing marks.
>
> Wonder what they could see that one day that we couldn't?
> Jerry Broadus
> PLS 17660
>
>
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