Biology ETDs

Publication Date

12-1-2012

Abstract

Climate change has increasingly become an area of concern in relation to ecological communities. In this study, climatic signals were investigated to determine whether bird diversity indices in the Breeding Conservation Region (BCR) of the Mojave and Sonoran Deserts were related (1) to the oceanic/atmospheric systems El Nino Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and/or the Atlantic Multidecadal Oscillation (AMO); (2) to regional moisture influences determined by the Palmer Drought Severity Index (PDSI); and (3) to local precipitation and temperature. Specifically, an examination was conducted to determine the relationship between climatic variables for thirteen bird species, total abundance (individuals), and species richness observed over a 40 year period from 1970 to 2009 on 14 different Breeding Bird Survey (BBS) routes. Data were analyzed using the Open Source version of the S language called R. Multi-panel scatterplots, Pearson correlation coefficients, and variance inflation factors (VIF) were used to identify collinearity (correlation between covariates). An Information Theoretic (IT) approach was applied to compare a set of 12 climatic models. Generalized linear mixed modeling (GLMM) was applied to analyze multiple observations per route. The results indicated that birds are individualistically responding to climatic signals at different probability intensities at the 95% confidence level: a weak signal (between a probability of 0.001-0.05), and a strong signal (less than a probability of 0.001). Four important IT results utilizing Akaikes Information Criteria (AIC) included each bird species diversity index responding (1) differently to each of the twelve AIC climatic models; (2) differently to covariates or explanatory climatic influences [Multivariate ENSO Index (MEI), AMO, Precipitation, Temperature, and PDSI] established within the models, in a positive or negative manner; (3) differently in relation to the significance intensities [Probability (Pr) values] to covariates or explanatory climatic variables within the models; and (4) differently to climatic influences present during the spring and summer months.

Project Sponsors

Northern New Mexico College

Language

English

Keywords

Key words: desert birds; climatic signal; fundamental niche; IT Evidence Ratios; species abundance; species pool; range; arid environments.

Document Type

Thesis

Degree Name

Biology

Level of Degree

Masters

Department Name

UNM Biology Department

First Advisor

Collins, Scott

First Committee Member (Chair)

Parmenter, Bob

Second Committee Member

Witt, Chris

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