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<br />14 <br /> <br />approximately 64 sites visited three time in the spring provides sufficient power to detect change <br />in bird abundances between years for the 18 most common bird species, In FY05, due to <br />funding limitations, bird surveys will be suspended with the anticipation that they will be re- <br />initiated in FY06, In FY2001, this program was combined with vegetation monitoring and <br />insect, reptile and mammal inventories to provide an integrated picture of the terrestrial resources <br />and long-term patterns associated with these resources and Glen Canyon Dam operations, <br />Surveys to assess riparian bird abundance and distribution were done in April, May and June of <br />2002, 64 vegetation patches were surveyed in 2002 and 17 of these sites were repeated from the <br />previous year, A total of 2627 passerine birds of 66 species were detected in the three surveys, <br />Bird detections were highest in May when birds are both migrating through and establishing <br />nests, Bird abundance and density, which included migrants and permanent winter and summer <br />residents, was greater in the New High Water Zone (t=3,4, p=O,OOI) (Yard and Blake 2002), <br />Species richness was also higher in the New High Water Zone, This was in contrast to 2001 <br />where species abundance was greater in the Old High Water Zone, Comparison of 15 common <br />species between years showed a significant difference in abundance for only 2 species: Black- <br />chinned Hummingbirds had increased in abundance in 2002 and Mourning Doves had decreased <br />in abundance in 2002, The shift in bird abundance between Old and New High Water Zones <br />may be associated with lower abundance and diversity of arthropods or seeds from annual <br />grasses and herbs in the Old High Water Zone related to the drought conditions, Synthesis of <br />invertebrate data will take place in 2003-04 and it is anticipated that trophic level interactions <br />will be more developed by 2004. <br />Lastly, Kanab ambersnail monitoring at Vasey's Paradise has continued to follow the <br />protocols begun 1997. Data collection efforts continue at two trips per year: one in spring and <br />one in fall. Population estimates for the snail indicate that the snail numbers vary widely <br />throughout the year (10,000 in the spring to 100,000+ in the fall), influenced by climatic and <br />concomitant habitat variability (SWCA, 1999), Measured snail habitat at Vasey's Paradise <br />increased 6 % in area between spring and fall of2002, Total surveyed habitat changed from <br />270.QI m2 in April to 288,36 m2 by August 24,2002, Yearly average total habitat has increased <br />steadily and significantly since 1998 (p = 0.014; F=5,19 4.5) from 176 m2 in 1998 to 279 m2 in <br />2002. <br /> <br />GCMRC FY2005-2006 Draft Annual Work Plan (November 10,2003) <br />