Month: December 2018

Joe Corra defends MSc thesis on aerial insectivorous birds, climate, and water quality in urbanizing landscapes

STRIVE Lab MSc candidate Joe Corra presented his research the relationships among water quality, climate, and aerial insectivorous birds, and how urbanization shapes those relationships. Aerial insectivorous birds – swallows, swifts, nightjars, and flycatchers – have experienced alarming declines in North America in recent decades. Declines have occurred across this diverse guild, suggesting that the availability and quality of insect prey is a common factor. Emergent aquatic insects constitute an important prey resource for many aerial insectivorous birds, and thereby connect riparian aerial insectivores to aquatic ecosystems. For his research, Joe used the Tree Swallow (Tachycineta bicolor) to investigate the associations between aerial insectivorous birds and urbanization, climate, and water quality. Building on the research launched by the STRIVE lab in 2014, he evaluated Tree Swallow reproductive success, body condition, and trophic dynamics at seven river-riparian sites representing urban and natural/protected land use in greater Columbus, Ohio over four consecutive breeding seasons (2014-2017).

Findings: Urban sites were associated with earlier clutch initiation in the spring – urban Tree Swallows laid their eggs one week earlier than their non-urban counterparts. In addition, urban-breeding swallows had greater fledging success, with urban nests producing 1.4 more fledglings, on average, than sites in natural/protected landscapes. Body burdens of mercury were higher among nestlings at urban sites but exhibited strong interannual variability. A gradient of stream urbanization was related to greater dietary reliance by Tree Swallows on aquatic insects and aquatically-derived energy; further, urban swallows fed at higher trophic levels than did swallows at natural/protected sites.

Investigation of potential drivers suggested that multiple features of the urban environment, including higher mean temperatures, increased availability of high-quality aquatic insect prey, and fewer days of extreme cold may contribute to fledging success and influence the timing of Tree Swallow breeding in urban areas. Further, stream urbanization was related to increased reliance on aquatic resources and higher trophic position, highlighting the role of aquatic-terrestrial connectivity in urban areas. However, the potential risk from elevated aquatic contaminants in urban areas represents a potentially adverse impact for urban-breeding aerial insectivores. Overall, this research underscores the importance of water quality for terrestrial wildlife, and the results draw attention to the potential role for cities in the conservation of aerial insectivorous birds.


Adult Tree Swallow.


Joe banding a Tree Swallow.


Relationship between Urban Stream Index and Tree Swallow Trophic Position (nestlings: p < 0.0001; adults: p = 0.001).

This research was funded by the Ohio Division of Wildlife through the Ohio Biodiversity Conservation Partnership, The Columbus Zoo & Aquarium, and the National Science Foundation.

STRIVE Lab and GrayFishLab Recruiting Post-doc, Grad Students for ALAN Research

With new funding from the Ohio Department of Transportation, we’re looking for a motivated post-doc, as well as MSc, and PhD students to join our research groups. See below for details! Post-docs applicants apply by Jan. 04, 2019; Grad Student applicants apply by Jan. 01, 2019.

POST-DOC
Aquatic Ecology – Artificial Lighting at Night: Closing date: Jan. 04, 2019. Start date: by March 1st if possible. Salary: $48-50K/annually, plus benefits. The Stream and River Ecology Laboratory at The Ohio State University is seeking a Post-Doctoral Research Associate. The incumbent will be expected to contribute to research on the ecological effects of artificial lighting at night (ALAN) in aquatic and riparian ecosystems (from individuals to ecosystems), including field, experimental (e.g., mesocosms), and lab work. In addition, the s/he will be expected to assist with the analysis of data as well as the preparation of reports, articles, and associated project deliverables. The incumbent will be based at the Schiermeier Olentangy River Wetland Research Park and will be mentored by Dr. Mažeika Sullivan, with opportunities to work with project co-PI Dr. Suzanne Gray. Strong statistical and programming skills, preferably with R, are required. Interest in gaining teaching experience is highly desirable. Applicants must have completed and defended their Ph.D. by the start of the appointment. Interested applicants should submit the following: (1) Cover letter, C.V., and the names and contact information for three references; (2) Unofficial transcripts; and (3) Examples of published work. Funding is available for two years. For more information or to apply, contact Dr. Sullivan @ sullivan.191@osu.edu.

GRAD STUDENTS
PhD position – ALAN 2018-final-ssfr2f

Also check out our previous and current work on ALAN under Projects.

Levon B. defends honor’s thesis on effects of urban stream temperatures on stream fish

After a couple years of hard field and lab work, STRIVE undergrad Levon Bajakian presented his honor’s research on the influences of urban stream temperatures on stream fish. Levon ran two lab trials to quantify the effects of both temperature variability (Trial 1) and consistently elevated temperatures (Trial 2) on Creek Chub, a common stream fish.


Creek Chub (Semotilus atromaculatus)
Photo: Brian Zimmerman

What did he find:
Creek Chub in the Trial 1 treatment group gained more weight and had lower blood plasma glucose concentrations (used as a measure of stress) than the control group, while Creek Chub in the Trial 2 treatment group showed no significant difference in weight compared to the control treatment, but the treatment group had significantly higher blood glucose concentrations. A stress response in a tolerant species like Creek Chub could potentially translate to severe impacts for more sensitive fish species as even minor increases in chronic stress caused by heat or other factors can have substantial consequences for wild fish. Altered temperature regimes are also likely to interact with other urban stressors on streams (e.g., pollution, altered hydrology and stream geomorphology, etc.), and will be an important area of future research.

Levon’s research complements ongoing research on the effects of urbanization on stream and wetland ecosystems. Here, Levon is working in the field filtering water samples, along with a little help from mi hijita Adela Lucía!

Levon shared a few thoughts on his research experience:
“Completing my honors thesis has been one of the most challenging and rewarding experiences of my undergraduate career. I believe my time with Dr. Sullivan and the rest of STRIVE lab has helped me grow and develop both as a student and as a person, and I feel more prepared for life after graduation as a result. Needless to say, I am incredibly grateful to have been granted the opportunity to conduct research and explore my interests regarding urban stream temperatures and fish, and I would certainly recommend considering research to anyone else who might be interested!”

Levon – thanks for all your great work and contributions to our research! Congrats on an excellent presentation, thesis, and your upcoming graduation. We all look forward to seeing where your talents take you in the coming years.