Movement patterns of a small-bodied minnow suggest nomadism in a fragmented, desert river.

Background: Unfettered movement among habitats is crucial for fish to access patchily distributed resources and complete their life cycle, but many riverscapes in the American Southwest are fragmented by dams and dewatering. The endangered Rio Grande silvery minnow (Hybognathus amarus, RGSM) persists in a fragmented remnant of its former range (ca. 5%), and its movement ecology is understudied.

Trophic niches of native and nonnative fishes along a river-reservoir continuum.

Instream barriers can constrain dispersal of nonnative fishes, creating opportunities to test their impact on native communities above and below these barriers. Deposition of sediments in a river inflow to Lake Powell, USA resulted in creation of a large waterfall prohibiting upstream movement of fishes from the reservoir allowing us to evaluate the trophic niche of fishes above and below this barrier. We expected niche overlap among native and nonnative species would increase in local assemblages downstream of the barrier where nonnative fish diversity and abundance were higher.

Do fine-scale experiments underestimate predator consumption rates?

Understanding ecological processes across spatial scales helps link observations and predictions from experiments to ecological patterns occurring at coarser scales relevant to management and conservation. Using fish, we experimentally manipulated the size of arenas to test the spatial scaling of predator-prey interactions. We measured variation in predator consumption and prey behaviour (prey aggregation, spatial overlap with predators and movement) across arena sizes.

Fine-scale movement and habitat use of a prairie stream fish assemblage.

Measuring an organism's movement and habitat use is highly dependent on the spatial and temporal scale of the study, with most studies measuring distributions once a day or at less frequent intervals. Yet, to fully understand the rates of intra- and interspecific encounters among individuals, observations at finer spatial and temporal scales might be necessary. We used passive integrated transponder tags and antenna arrays to continuously monitor habitat use and vagility of three stream minnows; southern redbelly dace Chrosomus erythrogaster, central stoneroller Campostoma anomalum, and creek chub Semotilus atromaculatus, among and within pools of an intermittent stream.

Barriers to Testing and Treatment for Chagas Disease among Latino Immigrants in Georgia.

Background. The lack of testing and treatment of Chagas disease (CD), caused by Trypanosoma cruzi, amongst infected immigrants in the USA increases the risk of serious health complications and transmission (congenital or via blood transfusions). Goal.