Comparative Breeding Behavior of Ammospiza caudacuta and A. maritimaWoolfenden, Glen Everett
Science
Comparative Breeding Behavior of Ammospiza caudacuta and A. maritima
Woolfenden, Glen Everett
Sparrows
Tomkins (1941:38-51) studied populations of _Ammospiza maritima
macgillivrayii_ near the mouth of the Savannah River in South Carolina
and Georgia and concluded that this form is not territorial. In support
of his conclusions, he quoted Nice (1933:90-91) as follows: "Territory
cannot mean just the nest spot when the adults feed in common; this may
be 'nest territory,' but it is a very different matter from a territory
in its strict sense to which parents confine themselves during the
breeding season. Again, the very essence of a territory lies in its
exclusiveness; if a bird's range is not defended, it is not a
territory."
The feeding and nesting grounds of breeding Seaside Sparrows are often
separated by a portion of the marsh which is not used by the birds.
This complicates study of the territorial habits of the species. It
does not mean, however, that the species is not territorial.
The birds studied by Tomkins had separate feeding and nesting grounds.
Concerning this, Tomkins (1941:43) states that "The Seaside Sparrows of
this locality [Savannah River area] often live where the two
requirements [adequate feeding grounds and suitable nesting cover] are
not always together or even meeting, but also where the feeding grounds
and the nesting place are separated by a short distance."
Six of the eight original pairs of breeding Seaside Sparrows of the
Lavallette colony fed in areas separate from those in which they
nested. I found the eight nests of the original residents and banded
and dyed all of the adults. The owners of two nests did not have
separate nesting and feeding areas. One nest was built within fifteen
feet of the south shore of the island, adjacent to the feeding area.
The other was built within a few feet of the north shore. The female of
this nest obtained food along the shore in the immediate vicinity of
the nest. Her mate was absent; in all probability it was the singing
male which I took from a nearby bush, before I found it advantageous to
use the island as a study area.
The remaining six pairs flew to the south or west shores of the island
in order to feed. None of these six nests was more than 100 yards from
the feeding grounds (pl. 1, fig. b).
It was comparatively easy to see that the males defended an area
surrounding the nest. It was more difficult to see that the pairs fed
on separate plots of shoreline, each defended by the male, but I am
convinced that this was the case.
The nest area was defended by the males through singing and chasing. I
saw no instances of a female entering into territorial disputes;
nevertheless, I did see a female chase a Sharp-tailed Sparrow away from
the vicinity of her nest.
Public-domain text, read in full here on John Shaqi.
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