828 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



The seasides at Lavallette started singing the morning after their 

 nocturnal arrival. Song is then at its maximum intensity among the 

 resident birds, and they maintain it at a high level throughout incu- 

 bation. After the eggs hatch and the males start helping feed the 

 young song dechnes sharply. The birds start to sing at daybreak. 

 One male I checked at Chadwick on May 6, 1955, sang 395 times be- 

 tween 6:00 and 7:00 a.m., or 6.6 times per minute. Morning song 

 decreases when the temperature rises markedly by 9 or 10 a.m., but 

 in cloudy weather lasts longer into the day. Singing again increases 

 toward dusk, but not to the frequency of the morning peak. 



The species has a soft, lisping call note, probably the one Saunders 

 (1951) refers to as a squeaky tseep, which functions as a social call 

 to keep groups together. Migrating birds utter it frequently, and 

 you hear it often from the wintering flocks. In early summer 

 when the marshes are inhabited only by a stable breeding population 

 this note is seldom used. 



Both sexes use two types of alarm notes. One, a short chip or tick^ 

 seems to signify apprehension for it is given when an intruder comes 

 onto the territory and near the nest. The other, a high, sharp tsip 

 uttered with a downward jerk of the tail, is indicative of a higher 

 degree of excitement, as when a nest with well-grown young is being 

 investigated. 



Field marks. — In its salt marsh habitat, which it seldom leaves 

 unless driven by storm tides, the seaside sparrow is likely to be con- 

 fused only with the sharp-tailed, swamp, or Savannah sparrows. 

 The only other passerines apt to be found there are the two little 

 marshes wrens and an occasional red-winged blackbird, which are 

 readily distmguishable. When the birds can be seen clearly, as 

 when the males are on territory and singing from the grass tops, the 

 yellow spot before the eye and the white mustache mark along the 

 jaw are unmistakable and diagnostic. 



When not nesting the seaside is often hard to observe, for it is 

 shy, retiring, and likes to stay hidden down among the marsh grass 

 stems from which it can be difficult to flush. One's usual view of it is 

 of a very dark grayish sparrow that rises on fluttering wings, scales 

 away just above the grass tops for perhaps 50 to 100 yards, and then 

 quicldy drops out of sight again. The other three sparrows commonly 

 found in the salt marshes in fall and winter act much the same way, 

 but with a little practice and experience are easily differentiated. 

 The swamp sparrow is slightly larger, much ruddier, and has a distinc- 

 tively longer tail. The Savannah sparrow is slightly smaller and much 

 lighter in color. Both species strike me as flying more strongly, with 

 less fluttering of the wings than the seaside and sharp-tail. The 



