Desert bighorn sheep (Ovis canadensis) recognition from camera traps based on learned features

2021 ◽  
pp. 101328
Author(s):  
Manuel Vargas-Felipe ◽  
Luis Pellegrin ◽  
Aldo A. Guevara-Carrizales ◽  
A. Pastor López-Monroy ◽  
Hugo Jair Escalante ◽  
...  
2014 ◽  
Vol 5 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Philip W. Hedrick ◽  
John D. Wehausen

Abstract Founder effects, genetic bottlenecks, and genetic drift in general can lead to low levels of genetic diversity, which can influence the persistence of populations. We examine genetic variation in two populations of desert bighorn sheep Ovis canadensis from New Mexico and Mexico to measure change over time and evaluate the impact of introducing individuals from one population into the other. Over about three generations, the amount of genetic variation in the New Mexico population increased. In contrast, over about two generations the amount of genetic variation in the Mexican population decreased by a great extent compared with an estimate from another Mexican population from which it is primarily descended. The potential reasons for these changes are discussed. In addition, although both populations have low genetic variation, introduction of Mexican rams into the New Mexico population might increase the amount of genetic variation in the New Mexico population. Overall, it appears that management to increase genetic variation might require substantial detailed monitoring and evaluation of ancestry from the different sources and fitness components.


Author(s):  
C. Haas ◽  
Gar Workman

The ecology of a reintroduced population of desert bighorn sheep (Ovis canadensis nelsoni} is being investigated in Arches National Park. National Park Service objectives are: (1) determine general ecological parameters, including population and social dynamics, seasonal distribution and habitat use patterns, and general health characteristics; and (2) develop a comprehensive program of habitat analysis and evaluation that can be used to determine habitat suitability and identify transplant sites in other National Park Service units.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Grant M. Harris ◽  
Matthew J. Butler ◽  
David R. Stewart ◽  
Eric M. Rominger ◽  
Caitlin Q. Ruhl

Abstract With most of the world’s Caprinae taxa threatened with extinction, the IUCN appeals to the development of simple and affordable sampling methods that will produce credible abundance and distribution data for helping conserve these species inhabiting remote areas. Traditional sampling approaches, like aerial sampling or mark-capture-recapture, can generate bias by failing to meet sampling assumptions, or by incurring too much cost and logistical burden for most projects to address them. Therefore, we met the IUCN’s challenge by testing a sampling technique that leverages imagery from camera traps with conventional distance sampling, validating its operability in mountainous topography by comparing results to known abundances. Our project occurred within a captive facility housing a wild population of desert bighorn sheep (Ovis canadensis) in the Chihuahuan desert of New Mexico, which is censused yearly. True abundance was always within our 90% confidence bounds, and the mean abundance estimates were within 4.9 individuals (average) of the census values. By demonstrating the veracity of this straightforward and inexpensive sampling method, we provide confidence in its operability, urging its use to fill conservation voids for Caprinae and other data-deficient species inhabiting rugged or heavily vegetated terrain.


1984 ◽  
Vol 62 (7) ◽  
pp. 1227-1231 ◽  
Author(s):  
Jack C. Turner

The life-span of red blood cells (RBCs) in captive and free-ranging desert bighorn sheep was measured with [32P]diisopropylfluorophosphate. The mean winter RBC life-span (156.6 days) was not significantly affected by season for captive animals maintained on a high nutritional plane and water, ad libitum. Free-ranging bighorn demonstrated a significant (P < 0.001) difference between mean winter (155.9 days) and summer (203.9 days) RBC survival. Dehydration of captive bighorn significantly increased RBC survival, closely approximating that found in summer free-ranging animals. Desert bighorn RBCs exhibited an aseasonal facultative response to the availability of water. RBC life-span was significantly (P < 0.05) increased from 153.5 to 197.7 days in animals experiencing extreme dehydration. The large spleen, relative to body weight, may accommodate extensive fluctuations in total RBC volume measured during dehydration and rehydration, preventing premature RBC degradation and an increased water requirement.


1993 ◽  
Vol 40 (3) ◽  
pp. 237-243 ◽  
Author(s):  
WILL L. GOFF ◽  
DAVID A. JESSUP ◽  
KENNETH A. WALDRUP ◽  
JOHN W. THOMFORD ◽  
PATRICIA A. CONRAD ◽  
...  

2006 ◽  
Vol 51 (3) ◽  
pp. 430-434 ◽  
Author(s):  
Karla Pelz-Serrano ◽  
Eduardo Ponce-Guevara ◽  
Rodrigo Sierra-Corona ◽  
Rurik List ◽  
Gerardo Ceballos

1958 ◽  
Vol 22 (4) ◽  
pp. 444 ◽  
Author(s):  
M. Clair Aldous ◽  
Frank C. Craighead ◽  
George A. Devan

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