1. printed by www.postersession.com Percent cover of biotic and abiotic components around nest cups of Ruddy Turnstone (Arenaria interpres) at Woolley Lagoon, Seward Peninsula, Alaska. Jennifer Johnson Biology Department - Brigham Young University Hawaii Ruddy Turnstone (Arenaria interpres) is a migratory shorebird that winters in Hawaii and returns to its breeding grounds in Alaska during the months of June and July. Many shorebirds actively select nest sites on the basis of vegetation structure rather than by random placement (Colwell and Oring 1990). The amount and variability of microrelief plays an important role in influencing nest site selection in tundra birds (Rodrigues 1994). A compositional analyses of macrohabitat and nest substrate habitats for American Avocet (Recurvirostra avocetta), Black-necked Stilt (Himantopus mexicanus), Killdeer (Charadrius vociferous), and Snowy Plover (Charadrius alexandrinus) in the Playa Lakes Region of Texas found that the presence of water was the most important indicator for potential habitat use by nesting shorebirds (Conway 2001). Shorebirds avoid nesting in habitats dominated by invasive species (Weins 2007). The vegetation surrounding a typical shorebird nest may be described as native grassland species which are relatively short and sparse (Weins 2007). Studies of the Black-bellied Plover (Pluvialis squatarola), American Golden-Plover (Pluvialis dominica), and Pacific Golden-Plover (Pluvialis fulva) found that habitat cover around each nest cup was different for each species (Nekoba 2002). Sixty percent of Black- bellied Plover (P. squatarola) nest cups were located in quadrants which contained over 60 percent abiotic cover (Nekoba 2002). Forty percent of American Golden- Plover (P. dominica) nest cups were placed in quadrants that had greater than 30 percent abiotic cover (Nekoba 2002), while Pacific Golden-Plover (P. fulva) selected sites with higher biotic cover. Ninety-five percent of their nest cups were located in quadrants with over 20 percent biotic cover (Nekoba 2002). Figure 1. Ruddy Turnstone in full breeding plumage sitting on a nest cup at Woolley Lagoon, Seward Peninsula, Alaska. 30 Ruddy Turnstone nests were marked and photographed 5,996 total data points collected Table 1. The amount of substrate recorded for each nest is given, in addition to the totals and averages of all data collected. 1 m² area around each nest cup was marked and photographed Photograph was computer adjusted to give a view from straight above the nest Photograph was digitally enhanced with a grid of one hundred equally sized squares Each square contained four equally spaced dots Two dots from every square were chosen using a random numbers chart Substrate directly beneath these dots was recorded as vascular plant (woody, herbaceous) non-vascular plant (lichen) non- vegetative (soil, rock) Amount of substrate found in each nest was calculated and averaged Figure 2Figure 3 Figure 2 is the unadjusted photograph of a nest cup. Figure 3 is the centered and digitally enhanced photograph shown in figure 2. Colwell, M. A., and L. W. Oring. 1990. Nest Site Characteristics of Prairie Shorebirds. Canadian Journal of Zoology 68:297-302. Conway,W.C. 2001. Breeding Ecology of Shorebirds in the Playa Lakes Region of Texas. Wildlife Science. pp 174-184. Nekoba, W.S. 2002. Habitat Selection for Nest Cups in the Genus Pluvialis at Nome, Alaska. Poster presented at the 3 rd North American Ornithological Conference in New Orleans, Louisiana. Rodrigues, R.1994. Microhabitat Variables Influencing Nest-Site Selection by Tundra Birds. Ecological Applications 4: 110-116. Wiens, D. 2007. Nest Success and Nest site Selection of Shorebirds in North Dakota. M.S. Thesis Louisiana State University and Agricultural and Mechanical College. pp 39. Ruddy Turnstone (A. interpres) eggs are green and speckled with brown spots which blend in very well with the herbaceous and woody plants. The choice of a nest site that affords camouflage of the nest may enhance the reproductive success. Abiotic substrate may also contribute to nest site selection. Rock and soil in the area of the nest cup may also provide beneficial camouflage from aerial predators due to the dark rusty brown dorsal plumage of the incubating parent. Additional studies will address the percent cover of the entire territory. These data will be used to determine if there is a non-random selection of the nest site. The purpose of this study was to determine the percent cover of biotic and abiotic elements in a 1 m² area around the nest cups of Ruddy Turnstone (A. interpres) nesting at Woolley Lagoon, Seward Peninsula, Alaska. Purpose Materials and Methods Results Discussion Works Cited Ruddy Turnstone Nest Habitat Data NestWoodyHerbaceousLichenSoilRock RT-1-04911344034 RT-1-05317213012 RT-1-06401910140 RT-1-07247453166 RT-1-0801543844 RT-1-093490352120 RT-1-99774452270 RT-2-0501722305 RT-2-06104394719 RT-2-07547757012 RT-2-0878685301 RT-3-04485326073 RT-3-0563557174 RT-3-05 (06)87224681 RT-3-05 (09)706613249 RT-3-07707721032 RT-3-0964805123 RT-4-04106355810 RT-4-054245356018 RT-4-072322110144 RT-4-09397521952 RT-5-064647173555 RT-5-07604148051 RT-5-07 (08)78681152 RT-5-07 (09)336855422 RT-5-097440491819 RT-6-07744749300 RT-7-07257968235 RT-7-09797232170 RT-8-0915112131248 Totals151920548963461181 Averages25%34%15%6%20% Acknowledgments BYUH FAST Program for funding Phil Bruner for counsel and research direction BYUH Biology Faculty for research assistance Friends for advice and aid in photograph adjustment and enhancement Results (cont.) 75 % nest cover on average was biotic 25 % nest cover on average was abiotic 25 % of the nest plot was woody plant cover 34 % of the nest plot was herbaceous plant cover 15 % of the nest plot was lichen cover 20 % of the nest plot was rock cover 6 % of the nest plot was soil cover Background