Biodiversity and springtime patterns of egg production and development for parasites of the Chisana Caribou herd

• Main Authors: Bryanne Hoar, Michelle Oakley, Rick Farnell, Susan Kutz
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Key words; climate change; development rates; fecal plots; Ostertagia gruehneri; periparturient rise; Proto; Yukon; Canada; Rangifer
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.542.3525; http://septentrio.uit.no/index.php/rangifer/article/viewFile/204/187/

Abstract: We investigated the biodiversity and springtime patterns of parasite egg/oocyst and larval production from feces and parasite development in the environment for the Chisana caribou herd in the southwest Yukon Territory, Canada from 29 March to 14 June 2006. Fecal samples from 50 adult cows that were housed in a temporary enclosure within the herd’s natural range at Boundary Lake, Yukon Territory were collected and analyzed during 5 sampling periods. A minimum of 6 parasite genera were recovered: eggs of Trichostrongylidae species (most likely Ostertagia gruehneri and Teladorsagia boreoarcticus), Marshallagia sp., Anoplocephalidae cestodes, and Skrjabinema sp.; oocysts of Eimeria spp.; and dorsal-spined first-stage protostrongylid larvae, including Parelaphostrongylus andersoni. Prevalence of Trichostrongylidae spp. eggs in fresh fecals was at or near 100 % throughout the sampling period, however, the median intensity increased significantly from 8 to 34 eggs per gram (epg) at the peak of calving and then decreased to 12 epg 2 weeks post-calving (P = 2.83e-07). Three plots of feces collected from these animals were established outside of the enclosure on 4 May 2006 and monitored every 10 days to investigate patterns of parasite development under natural conditions. The total number of Trichostrongylidae spp. (eggs + larvae) in fecal plots did not change over time, but as the number of larvae increased, egg counts decreased. The presence of other parasite species in the fecal plots remained constant over time. This study is the first to document the parasite diversity for the Chisana caribou herd and to exam-ine the development and survival of eggs and larvae in feces throughout the spring and early summer.