Methods in the Field Oak, Eucalyptus, and Singing Birds Surveys - PDF document

Methods in the Field Oak, Eucalyptus, and Singing Birds • Surveys of lots in Fall and Spring of 2003 and Spring of 2004 • Walk slowly length of Or the effects of exotic versus native transect (~10 forest cover on abundance, minutes) composition, diversity, and evenness of • Count all birds seen avian species or heard Diana Kiyo Wakimoto, UC Santa Cruz Microsoft clip art Field Sites Purpose of this Study • Paired sites of eucalyptus and oak • Determine the abundance and species diversity of birds in both eucalyptus and • Four small paired sites of oak and oak groves eucalyptus were surveyed in spring 2003 and fall 2003 • Use this information to form a preliminary assessment of eucalyptus for bird habitat • Four small paired sites and three large paired sites were surveyed in spring 2004 • Use results as an impetus for further population/banding studies Microsoft clipart Data Analysis Why use Birds as an Indicator Species? • Rarefaction curves for sampling effort • Birds are part of a large, diverse taxonomic order using EcoSim 7.0 (Gottelli and Entsminger 2001) • Easy to count both by ear and by sight • ANOVA for differences in species • Birds are charismatic megafauna= people abundance levels between habitat types are interested in what happens to them • Shannon-Weaver indices for diversity • Birds are cool! (H value) • Evenness (equitability) indices (J value) Microsoft clipart

Diversity Indices (H) Evenness Indices (J) 3 .9 .8 Evenness Index 2.5 .7 Diversity Index .6 2 .5 1.5 .4 .3 1 .2 .5 .1 0 0 eucalyptus oak eucalyptus oak None of the overall results are statistically significant (P> 0.05) Rarefaction Curve Spring 2004- Small lots 35 30 25 eucalyptus 20 oak lower 95% 15 upper 95% 10 5 0 1 19 37 49 67 79 97 109 127 144 174 204 234 Sampling effort sufficient to determine composition of woodlots Summary Results- Spring Overall Number of Species Abundance per plot 40 120 35 Number of Individuals 100 Number of Species 2003 30 80 25 20 60 15 40 10 Eucalyptus Oak 20 5 0 Abundance: 430 0 Abundance: 473 eucalyptus oak eucalyptus oak Richness: 37 species Richness per plot Total Abundance Richness: 38 species Number of Individuals 22.5 Number of Individuals 400 Shannon-Weaver: 2.93 Shannon-Weaver: 3.03 20 350 17.5 300 Evenness: 0.812 Evenness: 0.831 15 250 12.5 200 10 150 7.5 100 5 2.5 50 0 0 eucalyptus oak eucalyptus oak

Summary Results Spring 2004 Spring 2003- Results of ANOVA Small Tracts Oak Eucalyptus Song Sparrow Eucalyptus Oak Spotted Towhee European starling Abundance- 257 Abundance- 145 Bewick’s wren Allen’s hummingbird Richness- 32 species Richness- 22 species Bushtit Shannon-Weaver- 2.75 Shannon-Weaver- 2.59 Evenness- 0.793 Evenness- 0.838 Microsoft clipart Spring 2004 (small tracts) ANOVA Summary Results for Fall 2003 results Eucalyptus Eucalyptus Oak Abundance: 101 Abundance: 125 Total abundance Richness: 18 species Richness: 22 species Pacific-slope flycatcher Shannon-Weaver: 2.36 Shannon-Weaver: 2.44 European starlings Evenness: 0.816 Evenness: 0.788 Microsoft clipart Summary Results for Large Tracts Fall 2003- ANOVA Results Spring 2004 Eucalyptus Oak Eucalyptus Abundance: 135 Abundance: 129 European Starlings Richness: 23 species Richness: 26 species 10 Shannon-Weaver: 2.73 Shannon-Weaver: 2.64 8 Evenness: 0.870 Evenness: 0.810 Abundance 6 4 2 Microsoft clipart 0 eucalyptus oak

Effects of size and woodlot type on Spring 2004 (large tracts) ANOVA Total abundance results Eucalyptus 300 Number of Individuals 250 California quail 200 eucalyptus 150 oak 100 50 Microsoft clipart 0 large small house finch Size P= <0.0001 Microsoft clipart Bewick’s Wren Effects of Woodlot and Season Bewick’s Wren 12 10 Number of Individuals 8 eucalyptus www.gos.org/meetings/ cedw-20010706.jpg 6 oak 4 Cedar Waxwing 2 0 fall spring Season P= 0.0273 www.ktsweb.com/tweeters/ images/Bewicks_Wren.jpg European Starling Woodlot & Effect of size and woodlot type on Season effects abundance per plot 35 80 30 70 Number of Individuals Number of Individuals 25 60 20 50 eucalyptus eucalyptus oak 40 15 oak 30 10 20 5 10 0 0 fall spring large small Season Size P= 0.0508 P= 0.0110

Species only found in one type of Areas for further research woodlot (not statistically significant but interesting) • Need to do banding and population • Found only in eucalyptus: American kestrel, studies to determine if the habitats are sharp-shinned hawk, tree swallow, Northern source/sinks mockingbird, cedar waxwing, red-winged blackbird • Look at landscape-level dynamics • Found only in oak: red-shouldered hawk, • Experimental studies, manipulations yellow-rumped warbler, ruby-crowned kinglet, golden-crowned sparrow, house finch • Results from pooling all seasons and woodlots Microsoft clipart So what do we know from this Conclusions observational study? • Eucalyptus are not dead-zones for birds • Both oak and eucalyptus are utilized by many species of birds • Eucalyptus have equivalent species richness, diversity and evenness to oak • Abundance values and H values are often higher in eucalyptus, but oak has higher J • This study is a starting point values for more research on the topic of eucalyptus effects and • The two woodlot types share many of the management same species, although there are some significant differences Microsoft clipart Anecdotal observations about Acknowledgements eucalyptus tracts Big Sur Ornithological Lab • ESNERR for support of this research reports gumming at the base • Kerstin Wasson for being my senior thesis of the bill on yellow-rumped advisor warblers • Dan Doak for help with statistics • Susie Fork, Todd Newberry, and Monika PRBO reports catching fewer Rohrer for help with fieldwork birds in mist-nets set in eucalyptus than expected by chance alone Microsoft clipart Microsoft Clipart

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