🚀 go-pugleaf

Apparently in relation to my post viz-a-viz bird watching at night in which
I wrote:

> On another research project I assisted a woman who was
> studying the nocturnal feeding patterns of shorebirds during
> migration on the upper reaches of the Bay of Fundy.
 (etc.)

In <1993Jan26.164405.13273@cs.utwente.nl> Rolf de By (deby@cs.utwente.nl) writes:

> On the topic of birdwatching at night, I have seen a few people making
> mention of shorebirds actively feeding during that time.
>
> This should not appear strange to you as they obviously will feed at
> the best possible time of day. In fact, this need not be during the day,
> as---it seems to me---to be completely dependent on the tides. When
> the tide is out the biggest feeding area is available, and since many
> shorebirds find their food by touch (I am told) the absence of proper
> light is of no concern.
> 
> In fact, on mudflats the absence of light will probably mean absence of
> predators also . . .

Yes these are all reasonable suppositions. I never suggested that this was
in the least strange, however, the object or research, ornithological or other,
is to confirm or refute such reasonable suppositions. In point of fact until
this study (in which I assisted in a minor way) there had been few
observations of the behaviour of migrating shorebirds in this area at night.
In fact we looked at their behaviour in much finer detail counting the number 
of probes/minute (an index of the intensity of feeding effort) etc. In fact,
if I recall correctly, her research showed that the feeding effort was not
as  great at night as by day.
	Although feeding at night might reduce predation by Peregrines
and Herring Gulls (the only birds which seem to haress them there in the day,
although Ravens, Marsh Harriers and other raptors occasionally make passes)
other predators (such as the mink which we observed or Owls) might take more.
Also the behaviour of certain prey species changes depending in circadian
rythems. In this region the shore birds feed principally on the amphipod
Corophium volutator whose behviour varies according to the tidal cycle. But
another abundant amphipod on the upper parts of the beach, is Talorchestia
longicornis, a species which is active only at night. Moreover because of 
the lack of solar heating the temperature of the mud at night is considerably
cooler, and this, in turn, can affect the behaviour of the amphipods, as well
as other creatures like the bivalve Macoma balthica, the gastropod Hydrobia,
and the various polychaete worms which are also fed upon by the shorebirds.
	All in all, this is quite an interesting area of inquiry.
	Cheers!
	Christopher Majka