scholarly journals SURVIVAL RATES AND BLOOD METAL CONCENTRATIONS IN TWO SPECIES OF FREE-RANGING NORTH AMERICAN SEA DUCKS

2008 ◽  
Vol 27 (3) ◽  
pp. 698 ◽  
Author(s):  
Mark Wayland ◽  
Kiel L. Drake ◽  
Ray T. Alisauskas ◽  
Dana K. Kellett ◽  
Joshua Traylor ◽  
...  
Keyword(s):  
North American ◽  
Survival Rates ◽  
Metal Concentrations ◽  
Sea Ducks ◽  
Free Ranging

SURVIVAL RATES AND BLOOD METAL CONCENTRATIONS IN TWO SPECIES OF FREE-RANGING NORTH AMERICAN SEA DUCKS

2007 ◽  
Vol preprint (2007) ◽  
pp. 1 ◽  
Author(s):  
Mark Wayland ◽  
Kiel Drake ◽  
Ray Alisauskas ◽  
Dana Kellett ◽  
Joshua Traylor ◽  
...  
Keyword(s):  
North American ◽  
Survival Rates ◽  
Metal Concentrations ◽  
Sea Ducks ◽  
Free Ranging

Reproductive senescence in free-ranging North American elk Cervus elaphus Cervidae

Mammalia ◽  
2019 ◽  
Vol 83 (6) ◽  
pp. 593-600 ◽  
Author(s):  
Louis C. Bender ◽  
Jessica R. Piasecke
Keyword(s):  
Age Structure ◽  
Cervus Elaphus ◽  
North American ◽  
Reproductive Senescence ◽  
Female Age ◽  
North American Elk ◽  
Age Related ◽  
Consistent Manner ◽  
Multiple Species ◽  
Free Ranging

Abstract Successful production of calves is necessary for growth of North American elk (Cervus elaphus Linnaeus 1758) populations, but few studies have evaluated age-related effects on both the conception and survival of a calf to weaning in multiple free-ranging populations. Conception and survival of calves to weaning were both affected by maternal age, with old (age 9 and older) females showing reproductive senescence as compared to prime-aged (ages 2–8) females despite achieving similar or greater size and condition. Reproductive senescence in our free-ranging populations ultimately resulted in old females weaning fewer calves (0.42 calves/female) than did prime-aged females (0.64 calves/female). Other factors, especially maternal size, also influenced conception and survival to weaning, and these interacted with age in a consistent manner, i.e. larger females or females in better condition were more likely to conceive and successfully wean calves within each age class. Female age structure receives less consideration in ungulate management than does male age structure, despite demonstrated impacts on population productivity of multiple species because of reproductive senescence. Because of the large proportion of individuals in senesced age classes in elk populations, low productivity in populations may simply reflect female age structure, rather than other frequently hypothesized factors.

scholarly journals Long-term trends and drought: spatiotemporal variation in juvenile sex ratios of North American ducks

2021 ◽  
Author(s):  
Sage Ellis ◽  
Madeleine Lohman ◽  
James Sedinger ◽  
Perry Williams ◽  
Thomas Riecke
Keyword(s):  
United States ◽  
North American ◽  
Sex Ratios ◽  
Survival Rates ◽  
The United States ◽  
Avian Communities ◽  
Eastern United States ◽  
Bird Populations ◽  
Long Term Trends

Sex ratios affect population dynamics and individual fitness, and changing sex ratios can be indicative of shifts in sex-specific survival at different life stages. While climate- and landscape-change alter sex ratios of wild bird populations, long-term, landscape scale assessments of sex ratios are rare. Further, little work has been done to understand changes in sex ratios in avian communities. In this manuscript, we analyse long-term (1961-2015) data on five species of ducks across five broad climatic regions of the United States to estimate the effects of drought and long-term trends on the proportion of juvenile females captured at banding. As waterfowl have a 1:1 sex ratio at hatch, we interpret changes in sex ratios of captured juveniles as changes in sex-specific survival rates during early life. Seven of twelve species-region pairs exhibited evidence for long-term trends in the proportion of juvenile females at banding. The proportion of juvenile females at banding increased for duck populations in the western United States and typically declined for duck populations in the eastern United States. We only observed evidence for an effect of drought in two of the twelve species-region pairs, where the proportion of females declined during drought. As changes to North American landscapes and climate continue and intensify, we expect continued changes in sex-specific juvenile survival rates. More broadly, we encourage further research examining the mechanisms underlying long-term trends in juvenile sex ratios in avian communities.

NEPHROLITHIASIS IN FREE-RANGING NORTH AMERICAN RIVER OTTER (LONTRA CANADENSIS) IN NORTH CAROLINA, USA

2014 ◽  
Vol 45 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Jennifer N. Niemuth ◽  
Charles W. Sanders ◽  
Charles B. Mooney ◽  
Colleen Olfenbuttel ◽  
Christopher S. DePerno ◽  
...  
Keyword(s):  
North Carolina ◽  
North American ◽  
Lontra Canadensis ◽  
River Otter ◽  
American River ◽  
Free Ranging

Cerebral Larva Migrans Caused by Baylisascaris spp. in a Free-ranging North American Porcupine (Erethizon dorsatum)

2016 ◽  
Vol 52 (3) ◽  
pp. 763 ◽  
Author(s):  
Annette Roug ◽  
Chad S. Clancy ◽  
Cassie Detterich ◽  
Arnaud J. Van Wettere
Keyword(s):  
North American ◽  
Larva Migrans ◽  
Erethizon Dorsatum ◽  
Free Ranging

scholarly journals Adaptive selection of a prion strain conformer corresponding to established North American CWD during propagation of novel emergent Norwegian strains in mice expressing elk or deer prion protein

2021 ◽  
Vol 17 (7) ◽  
pp. e1009748
Author(s):  
Jifeng Bian ◽  
Sehun Kim ◽  
Sarah J. Kane ◽  
Jenna Crowell ◽  
Julianna L. Sun ◽  
...  
Keyword(s):  
Prion Protein ◽  
North American ◽  
Cultured Cells ◽  
Strain Selection ◽  
Lymphoid Tissues ◽  
Prion Strain ◽  
Adaptive Selection ◽  
Natural Hosts ◽  
Free Ranging ◽  
Selection Of

Prions are infectious proteins causing fatal, transmissible neurodegenerative diseases of animals and humans. Replication involves template-directed refolding of host encoded prion protein, PrPC, by its infectious conformation, PrPSc. Following its discovery in captive Colorado deer in 1967, uncontrollable contagious transmission of chronic wasting disease (CWD) led to an expanded geographic range in increasing numbers of free-ranging and captive North American (NA) cervids. Some five decades later, detection of PrPSc in free-ranging Norwegian (NO) reindeer and moose marked the first indication of CWD in Europe. To assess the properties of these emergent NO prions and compare them with NA CWD we used transgenic (Tg) and gene targeted (Gt) mice expressing PrP with glutamine (Q) or glutamate (E) at residue 226, a variation in wild type cervid PrP which influences prion strain selection in NA deer and elk. Transmissions of NO moose and reindeer prions to Tg and Gt mice recapitulated the characteristic features of CWD in natural hosts, revealing novel prion strains with disease kinetics, neuropathological profiles, and capacities to infect lymphoid tissues and cultured cells that were distinct from those causing NA CWD. In support of strain variation, PrPSc conformers comprising emergent NO moose and reindeer CWD were subject to selective effects imposed by variation at residue 226 that were different from those controlling established NA CWD. Transmission of particular NO moose CWD prions in mice expressing E at 226 resulted in selection of a kinetically optimized conformer, subsequent transmission of which revealed properties consistent with NA CWD. These findings illustrate the potential for adaptive selection of strain conformers with improved fitness during propagation of unstable NO prions. Their potential for contagious transmission has implications for risk analyses and management of emergent European CWD. Finally, we found that Gt mice expressing physiologically controlled PrP levels recapitulated the lymphotropic properties of naturally occurring CWD strains resulting in improved susceptibilities to emergent NO reindeer prions compared with over-expressing Tg counterparts. These findings underscore the refined advantages of Gt models for exploring the mechanisms and impacts of strain selection in peripheral compartments during natural prion transmission.

Emigration and survival of orphaned female deer in Illinois

1995 ◽  
Vol 73 (3) ◽  
pp. 440-445 ◽  
Author(s):  
Dwayne R. Etter ◽  
Jeanette A. Thomas ◽  
Charles M. Nixon ◽  
Joseph B. Sullivan
Keyword(s):  
Odocoileus Virginianus ◽  
Survival Rates ◽  
Early Summer ◽  
Social Position ◽  
Maternal Support ◽  
East Central ◽  
Annual Survival ◽  
West Central ◽  
Free Ranging

Emigration and survival were examined for 13 orphaned and 94 nonorphaned female white-tailed deer (Odocoileus virginianus) captured at < 10 months of age from free-ranging populations in Illinois. Emigration rates were higher (P = 0.026) for female orphans than for nonorphans. Nine of 13 (69%) orphans emigrated in spring through early summer. In contrast, only 35 of 94 (37%) nonorphans emigrated. Annual survival rates for all females from three Illinois study areas were 0.59, 0.71, and 0.80 for the east-central, west-central, and northern study areas, respectively. Possible stimuli for emigration among orphaned female white-tailed deer include pregnancy, low social position, and loss of maternal support.

scholarly journals Exposure to raccoon polyomavirus (RacPyV) in free-ranging North American raccoons (Procyon lotor)

Virology ◽  
2016 ◽  
Vol 489 ◽  
pp. 292-299 ◽  
Author(s):  
M.E. Church ◽  
F.N. Dela Cruz ◽  
M. Estrada ◽  
C.M. Leutenegger ◽  
P.A. Pesavento ◽  
...  
Keyword(s):  
North American ◽  
Procyon Lotor ◽  
Free Ranging
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