PRRIP 2008-2009 Interior Least Tern and Piping Plover Monitoring and Research Report

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eating prey, in the area but out of view, adult left the area, and forage delivered to an adult, chick, or unknown recipient. We also recorded the habitat class (sandpit, main river channel, secondary river channel, or braided - dendritic channel) associated with each behavior documented. If the adult left the area or stopped foraging for >30 seconds, we selected and observed another foraging adult and record when the new adult was selected. We mapped all locations where foraging was observed and if forage fish sampling occurred that day, we sampled at the most recent successful foraging location observed and at two random locations (see forage fish sampling). PIPING PLOVERS: We used 2 people, when available, to monitored the position and behavior of piping plover adults and accompanying brood (if applicable) at colony and non - colony sites. Our behavioral observations of piping plovers were focused on individual adults, pairs, or adults with broods (hereafter focal unit). Thus, observations were conducted from moveable blinds; relocated specifically to watch the targeted focal unit, regardless of location (i.e., river or sandpit). When possible, we used hand -held telemetry units to locate targeted adults, so observers were able position themselves for observation in a way that minimized disturbance. When marked birds were observed, we recorded the identification of the bird or recorded unknown adult or chick if the identity could not be determined. We allocated 3, 1 -hour sessions per day for behavioral sampling so that up to 3 focal units could be sampled per day of field work. We recorded the dominant habitat class within the foraging area, landform (river shoreline, sandbar, or sandpit), moisture (dry or wet substrate), and vegetative cover [bare ( <30 %), sparse (31 -50 %), or vegetated ( >50 %)]. We recorded behavioral states and habitat classes for each individual within the focal group on 5- minute - intervals. Each individual (adult and chick) was observed for 5 seconds to determine the dominant behavioral state, with behaviors being linked to marked individuals when possible. If any foraging behavior was observed during the 5- second observation period, we classified the period as foraging and spot - mapped the location; otherwise, the dominant behavior class that occurred during the 5- second period was recorded. We mapped all locations where foraging was observed and if invertebrate forage sampling occurred that day, we sampled at the most recent successful foraging location observed and at two random locations (see invertebrate sampling). In the interim time between all focal observation intervals, we selected an adult or chick, at random, and recorded all pecks, including gleans, made by the piping plover during the 3- minute interval. We recorded when the individual went in and out of view. We randomly selected a new adult or chick, alternating between adults and chicks, for each subsequent peck- recording interval. We did not map foraging locations observed during peck- recording intervals. FORAGING HABITAT EVALUATION FORAGE FISH SAMPLING: Foraging habitat data was collected to quantify features of habitats used by foraging interior least terns and piping plovers primarily in support of objective 3. We conducted forage fish sampling to describe fish abundance, species, and size, and aquatic habitats where interior least terns foraged in relation to available sites. We collected samples with minnow traps on sandpit ponds and Mini - Missouri River trawls when on the river. Sampling occurred at successful interior least tern foraging locations and two random points selected within 75 m of the observed foraging location at the end of evening behavior session. River Sampling: When collecting river samples, we always sampled the foraging location prior to random locations. Once at the observed foraging location, we collected a GPS location, water PRRIP 2008 -2009 Tern /Plover Report Page 30 of 42