Frances Cassirer Idaho Department of Fish and Game How important are super-spreaders for disease persistence in bighorn sheep populations? Frances Cassirer Idaho Department of Fish and Game

Time series of pneumonia: 1995 - 2010 16 bighorn sheep populations (km) km Pneumonia in adults Pneumonia in lambs Pneumonia in both age classes No pneumonia detected

Population dynamics post-outbreak: three Hells Canyon populations

Patterns of Movi shedding: Proportion of animals that tested positive for Movi at capture in 8 Hells Canyon populations, 2010 - 2012

Patterns of Movi shedding: consistency within individuals Negative Intermittent Chronic Lostine bighorn sheep through 2013 WSU domestic sheep flock

Research hypothesis Respiratory disease persists within bighorn sheep populations through the infection of a relatively small number of chronic or super shedders that drive disease transmission

Presence and implications of individual variation in disease transmission Lloyd-Smith, Schreiber, Kopp, and Getz. 2005. Superspreading and the effect of individuaal variation on disease emergence. Nature

Hells Canyon: Capture and sampling

Samples collected Sample type Media Test Nasal swab Mycoplasma broth PCR M. ovipneumoniae Dry, frozen qPCR Movi Nasal wash 50 ml saline qPCR Movi, IgA (mucosal) antibodies, 16S PCR-sequencing Blood Red top Antibodies to Movi, IgG Oropharyngeal swab Port-a-cul or broth Culture for Pasteurella, PCR leukotoxin qPCR for leukotoxin

Testing results Movi: Lostine

Testing results Movi: Asotin

Will removing chronic Movi shedders in the field increase lamb survival? Experiment 1 – Remove ewes and lambs that consistently (2 or more times) test positive in at least two populations. Experiment 2 – Translocate a group of animals that consistently test negative to a new area. Predictions - both experiments would reduce pneumonia-caused mortality (improve summer lamb survival) and reduce Movi infection prevalence in adults.

Captive experiment South Dakota State University Commingling study to monitor health and survival of lambs born to ewes of different shedding status. Designed for three replicate populations, 10 sheep per population over three years. Study started this year with sheep from Hells Canyon.

Captive experiment – Year 1

Captive experiment year 1 predictions

Captive experiment – Year 2 (breed with negative ram from the same population) Prediction – all lambs get pneumonia and die

Captive experiment year 3

Acknowledgments