Research Projects

My research interests have focused primarily on ecology, evolution and conservation. However I have worked with a range of species, in a variety of habitats to address an array of questions. I am most interested in conducting research regarding the ecology, evolution and conservation of amphibians and birds in tropical ecosystems.

Most recently I worked in Costa Rica on an NSF funded research project studying bird verses bat seed dispersal. I designed the study to address six research questions; 1. Whether bats or birds play the dominant role in dispersing early successional species in Costa Rica’s disturbed habitats. 2. If there is a significant difference in frugivor dispersal, in terms of seed quantity and number of seed species. 4. If dispersal differs with increased forest cover (plantation vs. pasture). 5. Whether or not planting has an effect on seed dispersal by bats, as has been found to be with bird. 6. If plots near undisturbed forests differ in seed dispersal by birds or bats from those far from undisturbed forest. To further inform my research on ecological analysis of forest recovery potential, I also designed and conducted an independent project which analyzed bird-species specific seed consumption patterns.

As an undergraduate while volunteering as a field assistant for two graduate students conducting research on the effects of an invasive competitor species (bullfrog) and two parasitic species (chytrid and trematode) on the survival rates of the threatened California red-legged frog , I co-designed and conducted a pilot study on Ribeiroia trematode infection of planorbid and physid snails. Our goal with this study was to gain better understanding of the trematode life history stage preceding amphibian infection and better inform their work on trends in amphibian infection. We measured trematode cercaria release rates as well as various environmental factors thought to influence these rates.

I became really interested in phylogenetics and comparative methods when working on my senior thesis.  The larger project (of which my thesis was a part) was the design and compilation of a database of life history traits for 330 seabirds with the Island Conservation Project.  The purpose of the larger project was to provide a comprehensive database of the life histories of seabirds worldwide to inform researchers, resource managers, and policy makers.  My early reading while preparing to work on this project revealed the importance of controlling for phylogeny in the comparative analysis of life history traits.  On the other hand, my project advisor (a graduate student) suggested that phylogenetic information would be of little importance. I decided to test the importance of controlling for phylogeny, and found it to be significant for a majority of the life history correlations that I tested.  I really enjoyed compiling a tree for those species with full data, and I was excited to learn of its practical applications.  Since then, I've realized that researchers are increasingly using systematics data to more effectively address questions in conservation biology, e.g., in biodiversity, population genetics, and speciation (especially in rare or threatened taxa).  For me, systematics work is an appealing combination of field work, lab work, and intellectual work, with the potential to contribute really useful information to conservation efforts.  

I have also been involved in a range of other research projects: quantifying tree growth and monitoring plant succession on degraded lands and reforested plots in Costa Rica for an NSF funded project; conducting cormorant diet analysis for the PRBO; measuring fish and snail abundance and species richness in Cabo Blanco, Costa Rica; running transects to monitor marine mammals for the Wind to Whales project; and investigating the landscape scale effects of riparian habitat on natural pest control on farms in the Sacramento Valley as an employee at UCSC on a sustainable landscapes project.

Below I have included a subset of the papers I have written.

Research Paper Topics :

The Comparative Method: The Importance of Controlling for Phylogeny in the Study of Seabird Breeding Biology

Rose Alina Sniatowski

University of California Santa Cruz
June 10, 2007


Interspecific comparative biological analysis has undergone a fundamental change over the past two decades in order to account for phylogenetic relationships between species. Traditionally, comparative methods have incorporated the simplifying assumption that species are independent, when in fact, biological groups are related differentially depending on their unique phylogenetic history (Felsenstein 1985, Mahler 2002). Comparative methods have been widely utilized to infer evolutionary adaptation and it is believed that the incorporation of phylogenetic information can increase both the quality and the type of inference possible from comparative data (Garland 2005). Here I investigate the importance of controlling for phylogeny in the comparative analysis of seabird life history traits. I examine the effects of phylogenetic correction on the correlation between traits. My findings demonstrated that the failure to correct for phylogenetic history affects the outcome of statistical analysis in two ways. First it can influence the relative strength of reported correlations even when a significant relationship is detected by both methods. Second, when phylogeny is important to an apparent correlation, the likelihood of conducting a Type I error is increased and these falsely detected correlations can be avoided by accounting for phylogeny in statistical methodology. Results from this study suggest that controlling for phylogenetic relationships is important when conducting comparative studies between related species groups.

Full Text

An Analysis of Prey Selection in Brandt’s Cormorants:
A three year study of foraging on Alcatraz Island

Chries Mok, Rose Alina Sniatowski, Julie Van Tran, , Kate Wheatley
Bio 141L Ecological Field Methods, UCSC
June 10, 2006


We assessed prey consumption and foraging strategies of Brandt’s Cormorants, Phalacrocorax penicillatus, in the San Francisco Bay Area. Our study site was located on Barker Beach, Alcatraz Island where sampling was conducted over a three-year period (2003, 2004, and 2005). Using pellet samples and otolith identification, we found no significant difference in the diversity of species consumed from 2003-2005 (ANOVA). Through the use of the Shannon-Wiener’s Index we found an increase in the diversity of prey consumed (2003: 0.5715, 2004: 0.9354, and 2005: 1.0853). The location of foraging shifted significantly (X2=74.62; d.f. 4; X2 crit= 9.49) from primarily bottom feeding to a more generalized strategy. Changes in the diversity of prey species, as well as cormorant foraging strategies, may be a consequence of decreased upwelling and declining fish species diversity and abundance in the San Francisco Bay. The information gathered from these analyses may be particularly important in monitoring cormorant population dynamics and the status of multiple trophic levels within an ecosystem.

Full Text

California Sea Otter Time Budgets and Population Growth Implications: A comparative analysis of four study years

Rose Alina Sniatowski
Field Ecological Methods, UCSC
May 13, 2006


Daily time budgets and activity patterns of sea otters (Enhydra lutris) were determined by scan sampling at 15 locations along the Big Sur coastline. Activities were determined by direct observation and categorized into appropriate units of behavior; resting, foraging and other. We compared this data to data collected in three previous studies to determine if percent time allocation of otter activity had changed for the studies conducted over the past twenty-four years. For every year a study was conducted, we calculated an average diurnal activity budget for the observed otters. In 2006 otters spent an average of 22% of the day foraging, 57% of the day resting and, 22% of the day engaged in other activities. When comparing across years we found no significant difference in percent time allocated for each activity, P=0.69. We compared diurnal activity patterns between 1986 and 2006, both studies showed peaks in foraging during the morning and afternoon with a period of resting mid day. This comparative analysis suggests that population growth of the California sea otter is not limited by food availability. This is consistent with three other studies conducted over the past twenty-four years (Estes et al 1986, Giles1988 and Buckelew 1998).

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A Spatial Analysis of Threatened and Endangered Avian Populations on the Island of Kauai’i, Hawaii

Rose Alina Sniatowski
Gis for environmental applications, UCSC
December 5, 2005


The preservation of habitat for rare and endangered species is necessary in the Hawaiian Islands to mitigate the future loss of biodiversity integral to the biological and cultural heritage of the Hawaiian Islands. This need is in response to a wide range of human activities resulting in removal, fragmentation, and alteration of habitat, which threaten biological diversity. The area of interest in this spatial analysis included all unprotected or unmanaged lands on the island of Kauai’i. These regions contained eleven different species of endangered aves, five of which were forest birds and six of which were lowlands or wetlands birds. GIS was implemented in performing three types of analysis to clarify what areas best met the protection needs of endangered avian species on the island. A density analysis provided information regarding the distribution of each individual species, while probability contours were used to define home ranges and priority areas for protection. After a brief gap analysis, the coastal and wetlands birds were chosen for more careful examination, due to the lack of protected areas that fit their habitat requirements. The priority protection areas defined by the combination of these three types of analysis included three key sites for protection: the restoration of wetlands in what is now unused military land; the acquisition of a patch of low elevation land both high in density for individual species and in which the probability of finding many of the endangered species is high; as well as a small plot of land adjacent to currently protected areas that contains all remaining records of unprotected forest birds.


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