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.