Degrees
M.S. Wildlife Sciences, 2007, New Mexico State University
B.S. Biology, 1996, Northern Illinois University
Current Research
I just started here in the Biology Department at MU so I am currently figuring this part out. More to come later!
Past Research
My master's thesis investigated condition of sage sparrows (Amphispiza belli nevadensis) wintering along a gradient of mesquite (Prosopis glandulosa) encroachment in the Chihuahuan desert of south-central New Mexico.
Beautiful Chihuahuan Desert New Mexico! This is the Jornada Long Term Ecological Research Station outside of Las Cruces, NM with the San Andreas mountains in the background.
My last sage sparrow!Abstract
The southwestern United States is important for wintering shrub-adapted birds. Shrub encroachment has led to an increase in available shrub dominated habitat, yet many shrub-associated bird species are declining. Landscape level changes in vegetation due to shrub encroachment have the potential to alter habitat quality for shrub-adapted birds wintering in this region. Variation in winter habitat quality should influence the condition of birds occupying each habitat type. I hypothesized that sage sparrow (Amphispiza belli) winter condition would differ with degree of shrub encroachment and predicted condition would be poorer in more highly encroached habitats. To test this hypothesis, sage sparrows were captured within areas of high (dune), medium (mesquite) and low (grass) mesquite encroachment. I measured a combination of corticosterone, metabolite and body condition indices to compare avian condition among these habitat types.
My data did not support my original prediction that sage sparrows wintering in southern New Mexico would be in poorer condition in highly shrub encroached habitats. Habitat type explained little variation in condition when considered alone. Instead, sex, habitat and year differences interacted to create a less straight-forward pattern. Differing precipitation and vegetation conditions between the two years of this study contributed greatly to differences in avian condition between years. Higher precipitation in the second year (season 2) led to a three-fold increase in grass and forb production. Sage sparrow distribution and avian community composition differed between winters. In a year of probable higher food availability, large flocks of conspecifics were present throughout the region and no sage sparrows were captured in low encroachment habitats. Lower baseline corticosterone (baseline CORT) in the second winter suggested that sage sparrows were in better condition that winter, possibly due to improved seed production. Reduced corticosterone response (CORT response) when food availability was lower further supported that sage sparrow condition responded to food availability. When food resources were lower, body condition varied with sex and habitat but did not differ with year. This indicated that sage sparrows were able to maintain adequate energy intake to protect protein reserves regardless of food availability. Metabolite concentrations suggest birds were periodically fasting when food resources were lower during the first winter (season 1). A skew in sex ratio favoring males during season 1 was consistent across habitats indicating that sexual habitat segregation was not occurring, however, sexes did appear to respond differently to habitat conditions. Future studies on sage sparrow winter condition should focus on demography and habitat selection. Further information on over winter survival and social interactions would help interpret patterns in sage sparrow condition discovered with this study.
Drawing blood from brachial vein with microhematocrit tube.
My field vehicle with 4 sage sparrows awaiting sampling.
Tumbling tumbling tumble weed! Ah, life in the west!Publications
Yunger, J.A. and C.J. Joos. In Review. Foraging behavior of Peromyscus leucopus following vertebrate predator exclusion. Acta Oecologia.
Harrison, Devin A., Cara Joos, and R Ambrosio, Jr. 2003. Morphology of corneal basal epithelial cells by In Vivo slit-scanning confocal microscopy. Cornea 22:246-248.
Presentations
Joos, C.J., M Desmond and R.A. Holberton. Are Shrub Encroached Chihuahuan Desert Grasslands Sub-optimal Habitat for Wintering Sage Sparrows? Oral presentation at 2007 Wilson Ornithological Society Annual Meeting, Wakefield, MA
Joos, C.J., M Desmond and R.A. Holberton. Are Shrub Encroached Chihuahuan Desert Grasslands Sub-optimal Habitat for Wintering Sage Sparrows? Oral presentation at 2006 North American Ornithological Societies Joint conference. Veracruz, Mexico.
Joos, C.J., M Desmond and R.A. Holberton. Are Shrub Encroached Chihuahuan Desert Grasslands Sub-optimal Habitat for Wintering Sage Sparrows? Oral presentation at 2006 Southwestern Association of Naturalist annual conference. Colima, Mexico.
Joos, C.J. and Yunger, J. Is it better to be high? Vertical structure, predation risk and foraging of Peromyscus leucopus. Poster presented at 2005 American Society of Mammalogists Conference.
Grants
T&E, Incorporated Research Grant (2005), Funded $2500.00
Sigma Xi Grant-in-Aid-of-Research (2005), Funded $800.00
New Mexico State Graduate School Travel Grant $250
SWAN Student Travel Grant – $500.00, 2006 Annual Meeting in Colima, Mexico
Wilson Ornithological Society Student Travel Grant - $250, 2007 Annual Meeting Wakefield, MA