Forster’s Tern

Sterna forsteri Nuttall

 

 

 

Field Guide IDs:
NG-216; G-152; PE-96; PW-pl 36; AE-pl 66; AW-pl 45; AM(II)-96


Nest
Location
Nest
Type
Eggs &
Mating System
Dev. &
Parental Care
Primary &
2ndary Diet
..
Foraging
Strategy
MF
I: 23-24 DAYS
SEMIPRECOCIAL
GROUND
SAUCER
MF
3
(2-5)
MONOG
F: ? DAYS
MF
INSECTS
AQUATIC
.....INVERTS
AERIAL
.....FORAGE

BREEDING:

Freshwater and saltwater marshes, marshy borders of ponds and lakes. 1 brood.

DISPLAYS:

?

NEST:

Deeply hollowed, well rounded, compactly woven platform; lined with bits of reeds, grass. Also makes depression in mud and sand or pats down grass and soil, lined with shells, grass. Often on muskrat houses, Occ nests of Western Grebe.

EGGS:

Buff, marked with dark brown, often enwreathed. 1.7" (43 mm).

DIET:

Insects taken flying over marshes. Also dead fish, live and dead frogs.

CONSERVATION:

Winters s to Guatemala (w), Bahamas and Greater Antilles (e). Often associates with wetlands affected by agriculture but impact on terns unknown.

NOTES:

Usu in loose colony; often associates with Yellow-headed Blackbird. Site tenacity weak. Larger clutches typically result of 2 females. Usu large, elaborate, well-built nests, similar to those of Franklin's Gull. Vigorous nest defense. Nests occ parasitized by American Coots and Red-necked Grebes. Hostile to other birds, including Franklin's Gull.

STANFORD. NOTES:

Uncommon and irregular forager at Lagunita.

ESSAYS:

Parent-Chick Recognition; Swimming; Site Tenacity; Coloniality; Brood Parasitism.

REFERENCES:

Bergman et al., 1970; McNicholl, 1982; Salt and Willard, 1971.

Except for Stanford Notes, the material in this species treatment is taken, with permission, from The Birder's Handbook (Paul Ehrlich, David Dobkin, & Darryl Wheye, Simon & Schuster, NY. 1988).