scholarly journals Factors affecting reproduction and population growth in a restored elk Cervus elaphus nelsoni population

2002 ◽  
Vol 8 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Jeffery L. Larkin ◽  
David S. Maehr ◽  
John J. Cox ◽  
Michael W. Wichrowski ◽  
R. Daniel Crank
2009 ◽  
Vol 123 (3) ◽  
pp. 230 ◽  
Author(s):  
Jessica R. Piasecke ◽  
Louis C. Bender ◽  
Stephen M. Schmitt

Uncertainty exists as to which factors are most closely related to probability of pregnancy in Elk (Cervus elaphus), which thresholds are key for managers who want to assess the potential productivity of free-ranging Elk herds, and whether these thresholds vary among populations. We examined relationships among pregnancy, age, and mass for 513 harvested free-ranging Elk in Michigan, and compared relationships with other published models and with thresholds derived from other free-ranging and penned populations to see if relationships were consistent among populations. Pregnancy rates varied (chi22 = 136.3; P < 0.0001) among yearling (0.30), prime-aged (2.5-11.5-year-olds; 0.88), and old (> 12.5-year-olds; 0.60) cows. Probability of pregnancy in adult cows was related to mass (chi2 = 7.4; P = 0.006), age (chi2 = 12.6; P = 0.0004) and age class (chi2 = 16.4; P < 0.0001), but not to lactation status (chi2 = 0.4; P = 0.515); pregnancy was also positively related (chi2 = 15.8; P < 0.0001) to mass in yearlings. Probability of pregnancy increased 1.02× and 1.04× for each 1 kg increase in body mass of adult and yearling cows, respectively, and prime-aged cows were 4.9× more likely to conceive than old cows. Compared to thresholds derived primarily from penned or farmed Elk, both adult and yearling free-ranging Elk in Michigan and elsewhere were able to achieve higher levels of pregnancy at lower body mass. Thresholds also varied among free-ranging Elk populations. Given variation among populations, managers should calibrate mass-pregnancy relationships for their respective populations to determine whether condition is potentially limiting pregnancy in their populations.


2002 ◽  
Vol 80 (5) ◽  
pp. 789-799 ◽  
Author(s):  
Mark Hebblewhite ◽  
Daniel H Pletscher ◽  
Paul C Paquet

Gray wolves (Canis lupus) recolonized the Bow Valley of Banff National Park in the mid-1980s after a 30-year absence. Wolves recolonized one zone of the Bow Valley in 1985 and another in 1991, but human activity excluded wolves from a third zone throughout the study. Elk (Cervus elaphus) are the primary prey of wolves in Banff National Park. We studied the effects of wolf predation, snow depth, elk density, and human-caused mortality on the elk population growth rate in the three different wolf recolonization treatments from 1985 to 2000. We constructed a set of generalized linear models of factors affecting population growth, and used Akaike Information Criteria to guide model selection and inference. In the low wolf predation zone, elk population growth was density-dependent and limited by human-caused mortality. In the zone that wolves recolonized in 1991, elk population growth was limited by the combined effects of snow depth and wolf predation after wolf recolonization, in addition to preexisting mortality caused by humans and other predators. Our correlative approach failed to yield insights into population dynamics in the zone where wolves were present throughout the study. However, by comparing zones we demonstrate important differences in ungulate population dynamics in the presence and absence of wolf predation.


2007 ◽  
Vol 3 (1) ◽  
Author(s):  
M. P. O. Olsson ◽  
J. Cox ◽  
J. Larkin ◽  
D. Maehr ◽  
P. Widén ◽  
...  

2018 ◽  
Vol XI ◽  
pp. 81-90
Author(s):  
Adam Mohr ◽  
Antoni Przybylski ◽  
Małgorzata Zimnicka – Pluskota ◽  
Damian Spieczyński

The paper presents the current methods of management and environmental conditions of the functioning of red deer population on the Wolin Island. The inventory carried out in 2014 using the drive census method revealed the prevalence of stags in the population (0.86 hinds/1stag) and the population density of 225 individuals/1,000 hectares of the forest, whereas harvest conducted in this season showed merely 22 individuals/1,000 hectares. In the analysed seasons before the inventory, harvest was also low (about 10% of the probable actual state) and despite harvesting mainly hinds, it did not curb the population growth. In the years 2006 – 2014, the yearly harvest in the largest hunting district fluctuated within the range of 14.5 to 60.5, x̅=27.0 individuals/1,000 hectares (n=9), while in the remaining four smaller population management units, the average yearly harvest amounted to only 0.2 to 9.8 individuals/1,000 hectares (n=9). The realized rate of population growth determined by the method of summer deer observation in 2015 amounted to 42.2% of the hinds number. Applying the simulation of the model population meeting the parameters indicated in the inventory, the researchers calculated and proposed the optimal indicators of harvesting individual age and sex groups. The proposed model of hunting monitoring and management assumes optimization of environmental conditions, structure and size of the actual population within the next 10 years.


2013 ◽  
Vol 49 (2) ◽  
pp. 270-278 ◽  
Author(s):  
Ryan J. Monello ◽  
Jenny G. Powers ◽  
N. Thompson Hobbs ◽  
Terry R. Spraker ◽  
Katherine I. O’Rourke ◽  
...  

1995 ◽  
Vol 32 (3) ◽  
pp. 215-220 ◽  
Author(s):  
J. C. Rhyan ◽  
D. A. Saari

Sections of tuberculous lesions from 23 elk ( Cervus elaphus nelsoni) and red deer ( Cervus elaphus elaphus), 12 fallow deer ( Dama dama), 10 sika deer ( Cervus nippon), and 30 cattle were examined and compared. Lesions were scored for caseous necrosis, mineralization, neutrophils, macrophages, giant cells, and acid-fast bacilli. Some differences in lesion morphology between the species were noted. Elk/red deer lesions had marked variation and often differed from bovine lesions in several characteristics; elk/red deer lesions usually had scattered peripheral mineralization rather than central mineralization and contained more neutrophils and fewer giant cells than did bovine lesions. Fallow deer lesions contained more giant cells but were otherwise indistinguishable from elk lesions. Sika deer lesions had more giant cells and fewer neutrophils than did lesions from cattle or other cervid species. Sika deer giant cells were larger and contained more nuclei than did giant cells in the other species.


2008 ◽  
Vol 89 (5) ◽  
pp. 1324-1328 ◽  
Author(s):  
Matteo Perucchini ◽  
Karen Griffin ◽  
Michael W. Miller ◽  
Wilfred Goldmann

Variation in PrP prion gene sequence appears to modulate susceptibility to chronic wasting disease (CWD), a naturally occurring prion disease affecting four North American species of the family Cervidae. Wapiti (Cervus elaphus nelsoni) PrP is polymorphic at codon 132 [methionine (M) or leucine (L)]. We genotyped 171 samples, collected between 2002 and 2005 from CWD-infected and uninfected wapiti from three free-ranging populations in Colorado, USA, to study influences of PrP polymorphisms on CWD susceptibility further. Overall genotype frequencies for 124 apparently uninfected animals were 65.3 % MM132, 32.3 % ML132 and 2.4 % LL132; for 47 CWD-infected animals, these frequencies were 70.2 % MM132, 27.7 % ML132 and 2.1 % LL132. Surprisingly, our data revealed that, among recent (approx. 2002–2005) CWD cases detected in free-ranging Colorado wapiti, the three PrP codon 132 genotypes were represented in proportion to their abundance in sampled populations (P≥0.24) and all three genotypes showed equivalent susceptibility to infection.


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