Methods in the Field Surveys of lots in Fall and Spring of 23 and Spring of 24 Walk slowly length of transect (~1 minutes) Count all birds seen or heard,, and Singing Birds Or the effects of exotic versus native forest cover on abundance, composition, diversity, and evenness of avian species Diana Kiyo Wakimoto, UC Santa Cruz Microsoft clip art Field Sites Paired sites of and Four small paired sites of and were surveyed in spring 23 and fall 23 Four small paired sites and three large paired sites were surveyed in spring 24 Purpose of this Study Determine the abundance and species diversity of birds in both and groves Use this information to form a preliminary assessment of for bird habitat Use results as an impetus for further population/banding studies Data Analysis Rarefaction curves for sampling effort using EcoSim 7. (Gottelli and Entsminger 21) ANOVA for differences in species abundance levels between habitat types Shannon-Weaver indices for diversity (H value) Evenness (equitability) indices (J value) Why use Birds as an Indicator Species? Birds are part of a large, diverse taxonomic order Easy to count both by ear and by sight Birds are charismatic megafauna= people are interested in what happens to them Birds are cool!
Diversity Indices (H) Evenness Indices (J) 3 2. 2 1. 1. Rarefaction Curve Spring 24- Small lots 3 3 2 2 1 1 lower 9% upper 9% 1 19 37 49 67 79 97 19 127 144 174 24 234 Sampling effort sufficient to determine composition of woodlots 22. 2 17. 1 12. 1 7. 2. Number of Species 4 3 3 2 2 1 1 Overall Number of Species Abundance per plot 12 1 8 6 4 2 4 3 3 2 2 1 1 Diversity Index Evenness Index.9.8.7.6..4.3.2.1 None of the overall results are statistically significant (P>.) Summary Results- Spring 23 Abundance: 43 Richness: 37 species Shannon-Weaver: 2.93 Evenness:.812 Abundance: 473 Richness: 38 species Shannon-Weaver: 3.3 Evenness:.831 Richness per plot Total Abundance
Summary Results Spring 24 Small Tracts Abundance- 27 Richness- 32 species Shannon-Weaver- 2.7 Evenness-.793 Abundance- 14 Richness- 22 species Shannon-Weaver- 2.9 Evenness-.838 Spring 23- Results of ANOVA Song Sparrow Spotted Towhee Bewick s wren Bushtit European starling Allen s hummingbird Spring 24 (small tracts) ANOVA results Summary Results for Fall 23 Total abundance Pacific-slope flycatcher European starlings Abundance: 12 Richness: 22 species Shannon-Weaver: 2.44 Evenness:.788 Abundance: 11 Richness: 18 species Shannon-Weaver: 2.36 Evenness:.816 Summary Results for Large Tracts Spring 24 Fall 23- ANOVA Results Abundance: 13 Richness: 23 species Shannon-Weaver: 2.73 Evenness:.87 Abundance: 129 Richness: 26 species Shannon-Weaver: 2.64 Evenness:.81 Abundance 1 8 6 4 European Starlings 2
Effects of size and woodlot type on Total abundance 3 Spring 24 (large tracts) ANOVA results 2 2 1 1 California quail house finch Bewick s Wren www.gos.org/meetings/ cedw-2176.jpg Cedar Waxwing www.ktsweb.com/tweeters/ images/bewicks_wren.jpg Effect of size and woodlot type on abundance per plot 8 large small Size P= <.1 Bewick s Wren Effects of Woodlot and Season 12 1 8 6 4 2 P=.273 fall spring Season European Starling Woodlot & Season effects 3 3 2 2 1 1 P=.8 fall spring Season 7 6 4 3 2 1 P=.11 large small Size
Areas for further research Need to do banding and population studies to determine if the habitats are source/sinks Look at landscape-level dynamics Experimental studies, manipulations Species only found in one type of woodlot (not statistically significant but interesting) Found only in : American kestrel, sharp-shinned hawk, tree swallow, Northern mockingbird, cedar waxwing, red-winged blackbird Found only in : red-shouldered hawk, yellow-rumped warbler, ruby-crowned kinglet, golden-crowned sparrow, house finch Results from pooling all seasons and woodlots Conclusions are not dead-zones for birds have equivalent species richness, diversity and evenness to This study is a starting point for more research on the topic of effects and management So what do we know from this observational study? Both and are utilized by many species of birds Abundance values and H values are often higher in, but has higher J values The two woodlot types share many of the same species, although there are some significant differences Acknowledgements ESNERR for support of this research Kerstin Wasson for being my senior thesis advisor Dan D for help with statistics Susie Fork, Todd Newberry, and Monika Rohrer for help with fieldwork Anecdotal observations about tracts Big Sur Ornithological Lab reports gumming at the base of the bill on yellow-rumped warblers PRBO reports catching fewer birds in mist-nets set in than expected by chance alone Microsoft Clipart