Ecology and Management of Large Mammals in North America

Recurrent environmental changes often prompt animals to alter their behavior leading to predictable patterns across a range of temporal scales The nested nature of circadian and seasonal behavior complicates tests for effects of rarer disturbance events like fire Fire can dramatically alter plant community structure, with important knock-on effects at higher trophic levels, but the strength and timing of fire's effects on herbivores remain unclear We combined prescribed fire treatments with fine-scale location data to quantify herbivore responses to fire across three temporal scales Between 2001 and 2003, 26 stands of fir (Abies spp) and Douglas-fir (Pseudotsuga menziesii) were thinned and burned; 27 similar stands were left untreated as experimental controls Analyzing female elk (Cervus canadensis) locations across 21 yr (1996-2016), we found crepuscular, seasonal, and successional shifts in behavioral responses to fire Elk displayed "commuting" behavior, avoiding burns during the day, but selecting them at night Elk selection for burns was strongest in early summer and the relative probability of elk using burns peaked quickly (5 yr post burn) before gradually returning to pre-treatment levels (15 yr post burn) Our results demonstrate that fire history has complex, persistent effects on herbivore behavior, and suggest that herbivores benefit from heterogeneous landscapes containing a range of successional stages

https://www.fs.fed.us/pnw/pubs/journals/pnw_2018_spitz001.pdf

Fire history influences large-herbivore behavior at circadian, seasonal, and successional scales.

We investigated survival, reproduction, and population growth (λ) for a declining elk (Cervus canadensis nelsoni) population in South Dakota, USA, 2011–2015. We obtained survival data from 125 calves and 34 yearlings. We determined survival and pregnancy rates for 42 adults (2–8 years old) and 39 old adults (≥8 years old). We combined population vital rates into a matrix model, which indicated a slightly growing population but with considerable uncertainty (λ¯ = 1.03, 95% CI = 0.93–1.13). Our elasticity analysis suggested asymptotic growth rates were most sensitive to proportional changes in old adult and adult female survival, followed by proportional changes in calf and yearling survival. Our life-stage simulation analysis further supported asymptotic growth rates being most sensitive to variation in survival, and most of the variation in λ we observed was a consequence of variation in annual calf survival (R2 = 0.58). Annual calf survival was low (0.26, 95% CI = 0.05–0.52), and puma (Puma concolor) predation was the primary cause-specific mortality factor of calves (0.63, 95% CI = 0.51–0.76). Adult female survival was near its biological maximum (0.95, 95% CI = 0.87–0.99); therefore, managing for increased calf survival may be the most practical strategy for promoting elk population growth in this system. Managing this puma population at the lower end of the population objective and reducing white-tailed deer (Odocoileous virginianus) numbers (primary prey source) may allow for elk population growth in this system. © 2017 The Wildlife Society.

https://www.fs.fed.us/rm/pubs_journals/2017/rmrs_2017_lehman_c002.pdf

Pumas affect elk dynamics in absence of other large carnivores

Group size variation has been examined within a framework of costs and benefits to ecological factors. Social factors might also influence group size particularly in polygynous males. To explore the role of social and ecological factors on group size outside the mating season I examined the influence of abundance on male grouping patterns in a population of Roosevelt elk (Cervus elaphus roosevelti) in northwestern California, USA. Male grouping patterns are complex, males often group with other males, but they can be transient members of female groups. Because male–male competition is pervasive even outside of the mating season, male only groups display fusion–fission dynamics which should be coupled to abundance of the male population. Whereas the number of males in female groups is governed by female abundance. Males associating with females is more likely at low female abundance because per capita forage should be abundant. Across a 23-year study I examined whether male or female abundance was related to male only group sizes and the number of males in female groups. Male only group size displayed a positive, linear relationship (frequency associated) with male abundance and the number of males in female groups displayed an inverse, positive relationship (density associated) with female abundance. The female population varied in K carrying capacity which influenced relationships with number of males in female groups. Uncovering factors influencing male grouping patterns required using the appropriate metric of abundance. Social factors influenced male only group sizes and ecological factors influenced male prevalence in female groups.

/pdf/frequency-and-density-associated-grouping-patterns-of-male-l6cbwcqu6w.pdf

Frequency and Density Associated Grouping Patterns of Male Roosevelt Elk

Abstract Conservation translocations—the intentional movement of animals to restore populations—have increased over the past 30 years to halt and reverse species declines and losses. However, there are many challenges translocated animals face that should be considered for restoration programs to be successful. Understanding how long it takes for translocated animals to acclimate to these challenges and their new landscape is a critical component of post-release population management. Physiological measures such as hormone responses are increasingly used to assess animal responses and acclimation to disturbances including translocation. We determined the physiological acclimation period of elk (Cervus canadensis) translocated to the Missouri Ozarks, USA, as part of a restoration effort. From 2011 to 2013, we translocated 108 GPS-radio-collared elk from Kentucky, USA, to Missouri, USA, and collected faecal samples for glucocorticoid metabolite extraction to use as an indicator of physiological acclimation. We modelled the response of population-wide faecal glucocorticoid metabolites (fGCMs) across the initial 9 years of the restoration in response to days following release and additional site-specific covariates. Presence of white-tailed deer (Odocoileus virginianus) hunts and monthly precipitation levels were positively and negatively associated with fGCM levels, respectively. Concurrent with influences from site-specific conditions on the release landscape, fGCM levels declined following release. We identified a breakpoint in fGCM decline at ~42 days following translocation releases suggesting elk acclimated physiologically relatively quickly compared to other species. The fast physiological acclimation by Missouri elk suggests effective use of temporary post-release management efforts. Determining how quickly animals acclimate following translocations allows researchers to tailor post-release management plans to each species’ needs, thus maximizing the success of future translocation efforts while minimizing costs. 

OUP accepted manuscript

The timing of births in ungulates has significant implications for juvenile survival and population growth. For North American elk (Cervus elaphus), typical parturition season ranges from late May to early Jun., and juveniles born outside of this peak characteristically exhibit lowered survival. We observed abnormally long parturition seasons in free-ranging elk populations in Missouri and South Dakota during 2012. Both populations exhibited late births; the last known births occurred on 26 Sep. in Missouri and 4 Sep. in South Dakota. Duration of parturition season was 112 and 119 d in Missouri and South Dakota, respectively. In Missouri, late births likely resulted from breeding by both yearling females and males. Late parturition in South Dakota may be caused by extended estrous cycles of elk that occurred on high quality range where few adult males were located.

https://www.fs.fed.us/rm/pubs_journals/2015/rmrs_2015_keller_b001.pdf

Extended Duration of Parturition Season in North American Elk (Cervus Elaphus)

On the basis of reports in the literature, incidence of dystocia in wild elk (Cervus elaphus) across the west is rare. In 2011, one of 34 (3%) pregnant cow elk in our study experienced dystocia during birth. Our visual observations indicated that it took approximately 4 days for a radio-collared cow elk to succumb to dystocia in our study. Little is known about dystocia in wild elk populations, and our observation provides some insight about fetal malpresentations. RESUMEN.—Con base en los reportes en la literatura, en el occidente no es muy frecuente la incidencia de distocia en el ciervo rojo (Cervus elaphus). En 2011, 1 de cada 34 (3%) hembras prenadas en nuestro estudio experimento distocia al momento de parir. Nuestras observaciones visuales indican que durante nuestro estudio pasaron aproximadamente 4 dias para que una hembra prenada con un collar de telemetria sucumbiera a la distocia. Se conoce muy poco sobre la distocia en las poblaciones de ciervos rojos, y nuestra observacion proporciona informacion sobre la mala presentacion fetal.

/pdf/observation-of-dystocia-in-wild-elk-18gw3jassz.pdf

Jackie J. Kragel

Papers

Extended Duration of Parturition Season in North American Elk (Cervus Elaphus)

Observation of dystocia in wild elk