Conclusions

1. Elevational Abundance of Bird Species In Borneo Ryan Burner, PraveenkumarKondikoppa, KennetCarabante, José Estrada Experimental Statistics 7015 – Fall 2013 Analysis of Covariance (ANCOVA) was used to model the relationship between bird species richness (DV) and elevation (IV), using count data from a mountain in central Borneo. Number of species decreased with elevation. Survey time of day is an important factor in bird species detection, necessitating a model with separate intercepts for surveys conducted early in the morning and later in the day. Summary Introduction Results & Discussions Deforestation is occurring at a rapid rate on the island of Borneo, but so little is known about the distribution of bird species that it is difficult to predict the effect of these changes. Much of the remaining forest is found at higher elevationsand variation in bird species numbers as elevation increases has never been quantified. Survey methods can have a significant impact on survey results, and survey time of day is often found to be the most important factor. The Type I SS analysis revealed that the model with common slope and separate intercepts yielded the same P values for the effects of linear model, and separate intercepts; however the AIC value was lower in the model with common slope and separate intercepts than in the model with separate slopes and intercepts. The Shappiro- Wilk analysis showed normality for both models (table 1). Objectives The common slopes ANCOVA model indicated that bird species richness declines as elevationincreases (graph 1). Our objectives were to: Quantify the number of bird species found at four elevations in the transition zone between lowland and montane forests. Determine the effects of survey time (early and late) of day on bird species detection. Materials& Methods The multi-source regression models are shown in table 2, where bird species richness during late morning served as the baseline model (Yi = bo + b1Xi) and bird species richness during early morning as the adjusted model [Yi= bo + b2 + (b1+ b3Xi)]. • Data Collection in Mt. Topap Oso • Bird species were counted at points spaced 200 m apart along transects. • Transects were placed at four elevations of interest: 600, 800, 1000, and 1200 MASL. • All bird species heard or seen were recorded during a 10-minute period at each point, and time of day was recorded. • Data Analysis • Multi-source regression models were fitted using ANCOVA of bird species richness by elevation. • Tested the importance of survey time of data and initially a model with separate slopes and separate intercepts was fitted; however, the separate slopes effect was not significant, while separate intercepts and the linear model were significant. A second analysis was performed fitting separate intercepts and a common slope. tested models with separate slopes and intercept. • Data was analyzed using PROC MIXED in SAS® V. 9.3 (α=0.05). Conclusions A multi-source regression model with common slope and separate intercepts showed a slightly better fit than a model with separate slopes and separate intercepts to describe the number of species identified at Topap Oso based on altitude and daytime. Bird species numbers decline significantly with elevation, highlighting the importance of conserving lowland forests to provide quality habitat for the rich bird diversity of Borneo. Survey time of day is a very important factor, and surveys should be planned for earlier in the morning before bird numbers decline as a result of decreased singing.