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INVERTEBRATE SAMPLING: We conducted invertebrate sampling to describe the invertebrate
<br />taxa, abundance, and terrestrial habitats where piping plovers foraged in relation to available
<br />sites. Sampling occurred at brood - specific foraging locations and two random locations selected
<br />within 75 in of the foraging location at the end of each I -hour behavior session, if foraging was
<br />observed. Invertebrate sampling occurred after behavioral observations during the morning
<br />interval (0600 -1000 hours) and when there was minimal chance of rain and wind speeds were
<br />expected to be below 18 mph during the sampling period.
<br />We collected habitat characteristics at each sample site prior to collecting the sample. Once at
<br />the observed foraging location, we collected the GPS location, distance to nearest semi-
<br />permanent water source, landform (river shoreline, sandbar, or sandpit), substrate moisture (dry
<br />or wet substrate), vegetative cover [bare ( <30 %), sparse (31 -50 %), vegetated ( >50 %)], visual
<br />coverage estimates for vegetation of each class (wetland herbaceous, terrestrial herbaceous,
<br />woody vegetation), mean height of vegetation, maximum height of vegetation, visual coverage
<br />estimates for each substrate size class (silt, sand, small pebble, gravel, cobble, and boulder), and
<br />visual coverage estimate for each debris class (terrestrial leaf litter, small debris, and large
<br />debris). Similar to forage fish sampling, we used a 2- column random number table to modify the
<br />GPS location of the observed foraging location and generated random points within 75 in of the
<br />forage location and within the same habitat classes (i.e., landform, moisture, and vegetation) as
<br />those of the foraging location. We navigated to random locations using a GPS and if we
<br />determined a random point was not within the same habitat classes as those of the forage
<br />location, we selected the next set of numbers from the table and recorded the GPS location of
<br />unsuitable points. When a foraging location was within a narrow linear habitat class, random
<br />point selection was constrained to the same habitat class by changing the distance from the
<br />forage sampling location (i.e., positive number we moved N or E; negative number we moved S
<br />or W). If the random point was within 100 in of an active interior least tern or piping plover nest
<br />or brood, we chose another location.
<br />We conducted invertebrate sampling at foraging and 2 random locations using 4, paint stir -stick
<br />insect traps coated with Tanglefoot® (The Tanglefoot Company, Grand Rapids, MI), 2 placed
<br />horizontally and 2 vertically within a 1 -m2 exclosure (hereafter, sticky sticks). We covered 20
<br />cm of one side of the 2- horizontal sticks and 20 cm of both sides of the 2 vertical the sticks with
<br />a thin film of Tanglefoot®. We drove the vertical sticks into the ground handle first with the
<br />wide side facing into the wind so that the start of the Tanglefoot® was even with the surface of
<br />the substrate. We placed the horizontal sticks flat on the substrate 10 cm away from the vertical
<br />stick with the sticky side up and perpendicular to the direction of the wind. The handle of the
<br />sticks were labeled with study area, site, brood /nest number, point type (i.e., foraging or random
<br />location), stick number, date, and time set. We constructed small exclosures around sticky sticks
<br />to keep piping plovers and other birds from being entangled during sampling. The exclosures
<br />were made of 0.25 in tall 1 -cm2 nylon mesh netting held up in the corners by four wooden stakes.
<br />We retrieved the traps after 2 -3 hours and recorded the end time. We limited disturbance to
<br />interior least tern and piping plover adults and chicks to 10 minutes during setup and tear down
<br />of traps. We identified and counted invertebrates on the sticky sticks immediately outside study
<br />area. Invertebrates <3 mm were counted, but not identified. Invertebrates 3 mm or greater were
<br />counted and identified to order (all) and to family if in the Diptera order. If unknown
<br />invertebrates were encountered, we consulted reference materials for identification and when
<br />identification was still unresolved we preserved a voucher specimen in ethanol, named and
<br />labeled it (e.g., "unknown A "), and made sure all references in data used the same name;
<br />PRRIP 2008 -2009 Tern /Plover Report Page 32 of 42
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