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<br />Disoersal Patterns: Breeding site fidelity of coastal and California <br />least terns is very high (Atwood et a1. 1984, Burger 1984). This may also <br />be true for the interior least: tern in its riverine environment. An <br />interior least tern banded in 1988 as a breeding adult on the Missouri <br />River in North Dakota returned i in 1989 to breed on a Missouri River <br />sandbar in North Dakota (Mayer a~d Dryer 1990). In the Mississippi River <br />valley, a bird banded as a breedi~g adult in 1987 was observed nesting at <br />the same site in 1989, and three others,banded as breeding adults in 1988 <br />returned to nest within the same ~tretch of the Mississippi River in 1989 <br />(Smith and Renken 1990) . Two of those birds had returned to within 4.8 krn <br />of their former nesting site. Along the Platte River in Nebraska, <br />interior least terns demonstrate a strong re'turn pattern to previous <br />nesting sites on the river and :at sand and gravel pits regardless of <br />reproductive success (E,Kirsch, q. Lingle, personal communication). One <br />interior least tern captured in 1987 as a breeding adult at a Mississippi <br />River ternery in Missouri had b~en banded as a chick in 1980 by Marsha <br />Waldron; this bird was nesting at a site 131 km upriver from its natal <br />Tennessee colony (Smith 1987, Smith and Renken 1990). Chick dispersal may' <br />be as far as that reported by Boyd and Thompson (1985) for a breeding <br />Kansas bird that had been banded 'as a chick on the Texas coast. <br /> <br />Home RanlZe and Territorialitv; The interior least tern's home range <br />during the breeding season usually is limited to a reach of river near the <br />sandbar nesting site. At Salt: Plains National Wildlife Refuge, home <br />ranges were highly variable, ranging from 11 to 1,015 ha (Talent and Hill <br />1985). Variation likely was due ~o food limitations and chick loss. The <br />home range may change if renesting birds select a different breeding site. <br />At sand and gravel pits along the central Platte River in Nebraska, <br />nesting interior least terns util,ize the pit area as well as an adjacent <br />stretch of river. Nesting territories ar~ defended and birds defend any <br />nest in the colony. In defendingithe territory, the incubating bird will <br />fly up and give an obvious a1arm:call followed by repeated dives at the <br />intruder (Hardy 1957). The str~ng defense of territories facilitates <br />locating terneries during census ~urveys. <br /> <br /> <br />14 <br />