Influences on Release-Site Fidelity of Translocated Elk

Several eastern states are considering the restoration of free‐ranging elk populations via translocation from western populations. Optimal habitat immediately surrounding release sites has been found to enhance elk reintroduction success in western states. Little information exists, however, to aid eastern managers in identifying release sites with the highest chance of restoration success. We monitored the movements of 415 translocated elk released at three sites in southeastern Kentucky to identify landscape characteristics that enhance release‐site fidelity. The distance elk moved after release differed among sites (F_2,322 = 4.63, p = 0.01), age classes (F_2,322 = 4.37, p = 0.01), and time intervals (F_2,322 = 40.74, p < 0.001). At 6 and 12 months post‐release, adults (15.81 ± 17.32 and 16.38 ± 20.29) and yearlings (13.91 ± 16.44 and 14.61 ± 21.11) moved farther than calves (8.06 ± 14.03 and 9.37 ± 14.40). The release site with the highest fidelity was privately owned, 15% open, and had the highest amount of edge compared with the other release sites. The two remaining sites contained large amounts of expansive openland or forest cover with lower amounts of edge. Additionally, both sites were publicly owned and experienced a higher degree of human‐generated disturbance compared with the site to which elk were most faithful. When selecting release sites, managers should avoid areas dominated by a single cover type with little interspersion of other habitats. Rather, areas with high levels of open‐forest edge (approximately 5.0 km/km²) and limited‐human disturbance will likely enhance release‐site fidelity and promote restoration success.     

A comparison of postrelease survival parameters between single and mass stranded delphinids from Cape Cod,Massachusetts, U.S.A.

The viability of healthy single stranded dolphins as immediate release candidates has received little attention. Responders have been reluctant to release lone delphinids due to their social needs, even when they pass the same health evaluations as mass stranded animals. This study tracked postrelease success of 34 relocated and released satellite tagged delphinids from single and mass strandings. Three postrelease survival parameters (transmission duration, swim speed, and daily distance) were examined to evaluate whether they differed among single stranded/single released (SS/SR), mass stranded/single released (MS/SR), or mass stranded/mass released (MS/MR) dolphin groups. Comparisons were also made between healthy and borderline release candidates. Satellite tags transmitted for a mean of 21.2 d (SD = 19.2, range = 1–79), daily distance traveled was 42.0 km/d (11.25, 20.96–70.72), and swim speed was 4.3 km/h (1.1, 2.15–8.54). Postrelease parameters did not differ between health status groups, however, SS/SR dolphins transmitted for a shorter mean duration than MS/MR and MS/SR groups. Postrelease vessel‐based surveys confirmed conspecific group location for two healthy, MS/SR dolphins. Overall, these results support the potential to release healthy stranded single delphinids; however, further refinement of health assessment protocols for these challenging cases is needed.     

Patterns of Mortality and Factors Influencing Survival of a Recently Restored Elk Population in Ontario,Canada

This study examined patterns of mortality and determinants of survival among elk recently restored to four sites in Ontario, Canada (1998–2005). We predicted that: (1) elk located in release sites closer to the core of their historic range would have higher survival; (2) survival would increase as an animal's time and experience on the landscape increased; and (3) survival rates would decline as animals moved farther away from the release site. During the study, 443 elk were radiocollared and released; 218 mortalities were documented. Predation by wolves was the most important proximate cause of mortality, followed by death due to injuries from translocation and/or capture myopathy, accidents, emaciation, poaching, and Parelaphostrongylus tenuis infection. Overall, annual survival of elk across Ontario ranged from 0.45 (0.37–0.53) to 0.81 (0.66–0.90), with rates being lowest in the years immediately following release and highest in the final years of the study; this pattern was due to high initial mortality from translocation injuries and/or capture myopathy and possibly lack of familiarity with novel habitat. Model‐averaged hazards further support this finding, as the most important factor influencing elk survival was the length of holding period, with elk released after limited holding being less likely to survive than those held for longer periods. Our results suggest that mortalities caused by capture myopathy and transportation‐related injuries are important sources of risk for translocated elk. The method of introduction to the novel landscape and behavior in the first year should be accommodated via soft‐release and appropriate release areas.     

Postrelease movement and habitat selection of translocated pine martens Martes martes

Monitoring postrelease establishment and movement of animals is important in evaluating conservation translocations. We translocated 39 wild pine martens Martes martes (19 females, 20 males) from Scotland to Wales. We released them into forested areas with no conspecifics in 2015, followed by a second release in 2016, alongside the previously released animals. We used radio‐tracking to describe postrelease movement and habitat selection. Six martens (15%) were not re‐encountered during the tracking period, of which four undertook long‐distance dispersal. For the remaining individuals, we characterized two phases of movement, “exploration” followed by “settlement,” that differed between releases. In the first release, martens remained in exploration phase for a mean of 14.5 days (SE = 3.9 days) and settled at a mean distance of 8.7 km (SE = 1.8 km) from release sites, whereas martens released in year two, alongside resident conspecifics, traveled away from release sites at a faster rate, settling sooner, at a mean of 6.6 days (SE = 1.8 days), but further, at a mean distance of 14.0 km (SE = 1.7 km) from release sites. Animals released in year one did not exhibit habitat preferences overall but within forests they favored recently felled areas, whereas animals released in year two showed strong selection for forested habitat but did not discriminate between forest types. The presence of conspecifics appeared influential for settlement and site fidelity of translocated martens and was associated with more rapid but more distant dispersal of the later cohort. Releases of animals in close proximity appeared to promote site fidelity and rapid establishment of ranges in the recipient environment.     

No long-term effect of black bear removal on elk calf recruitment in the southern Appalachians

In 2001 and 2002, 52 elk (Cervus canadensis; 21 males, 31 females), originally obtained from Elk Island National Park, Alberta, Canada, were transported and released into Cataloochee Valley in the northeastern portion of Great Smoky Mountains National Park (GRSM, Park), North Carolina, USA. The annual population growth rate (λ) was negative (0.996, 95% CI = 0.945–1.047) and predation by black bears (Ursus americanus) on elk calves was identified as an important determinant of population growth. From 2006 to 2008, 49 bears from the primary elk calving area (i.e., Cataloochee Valley) were trapped and translocated about 70 km to the southwestern portion of the Park just prior to elk calving. Per capita recruitment (i.e., the number of calves produced per adult female that survive to 1 year of age) increased from 0.306 prior to bear translocation (2001–2005) to 0.544 during years when bears were translocated (2006–2008) and λ increased to 1.118 (95% CI = 1.096–1.140). Our objective was to determine whether per capita calf recruitment rates after bear removal (2009–2019) at Cataloochee were similar to the higher rates estimated during bear removal (i.e., long-term response) or if they returned to rates before bear removal (i.e., short-term response), and how those rates compared with recruitment from portions of our study area where bears were not relocated. We documented 419 potential elk calving events and monitored 129 yearling and adult elk from 2001 to 2019. Known-fate models based on radio-telemetry and observational data supported calf recruitment returning to pre-2006 levels at Cataloochee (short-term response); recruitment of Cataloochee elk before and after bear relocation was lower (0.184) than during bear relocation (0.492). Recruitment rates of elk outside the removal area during the bear relocation period (0.478) were similar to before and after rates (0.420). In the Cataloochee Valley, cause-specific annual calf mortality rates due to predation by bears were 0.319 before, 0.120 during, and 0.306 after bear relocation. In contrast, the cause-specific annual mortality rate of calves in areas where bears were not relocated was 0.033 after the bear relocation period, with no bear predation on calves before or during bear relocation. The mean annual population growth rate for all monitored elk was 1.062 (95% CI = 0.979–1.140) after bear relocation based on the recruitment and survival data. Even though the effects of bear removal were temporary, the relocations were effective in achieving a short-term increase in elk recruitment, which was important for the reintroduction program given that the elk population was small and vulnerable to extirpation.     

Winter predation patterns of wolves in Northwestern Wyoming

Wolf (Canis lupus) diets and potential effects on prey have been a prominent subject of interest to wildlife researchers and managers since reintroduction into Yellowstone National Park, Wyoming, USA, in 1995 and 1996. Post-reintroduction, wolves expanded south and recolonized areas in the southern Yellowstone ecosystem. Elk (Cervus elaphus) in this area are supplementally fed during winter (Dec–Mar) at state-managed feedgrounds, resulting in high-density congregations of elk. From December to March 2000–2007, we determined the winter predation patterns of wolves by examining the remains of 289 wolf kills on 3 state-managed feedgrounds and adjacent winter range near Jackson, Wyoming. During winters 2002–2005, we also monitored the movements of radio-collared elk on feedgrounds to describe the response of elk to the presence of wolf kills. Thirty-seven percent (n = 106) of kills were located on elk feedgrounds where elk composition included 49% calves, 42% adult females, 5% adult males, and 5% unknown. Sixty-three percent (n = 183) of kills were located on winter range adjacent to feedgrounds and prey species consisted of 90% elk (38% calves, 35% adult females, 24% adult males, 2% unknown), 9% moose (Alces alces; 13% calves, 69% adult females, 6% adult males, 1% unknown), 1% mule deer (Odocoileus hemionus; 1 fawn, 1 adult female), and 0.5% adult female bison (Bison bison). Mean age of elk killed on feedgrounds was 4.2 years (range = 0–20) and 4.6 years (range = 0–23) on winter range. Calves were selected more than available in most years with female elk killed less than expected. Adult males were killed more than expected in 2005–2007. Eighty-eight percent (n = 198) of the time elk remained on the feedground even when wolves made a kill. Less commonly, elk left the feedground, gathered in larger herds on adjacent feedgrounds absent of wolves, and returned within a few days (6%, n = 13) or left the feedground for another feedground and did not return for the rest of the winter (6%; n = 14). Elk were less likely to leave feedgrounds in the presence of a wolf kill when there were more elk on that feedground. Elk left feedgrounds with greater topography and tree cover (Alkali and Fish Creek) and gathered on the flat, open feedgrounds (Patrol Cabin) more frequently than they left flat, open feedgrounds for feedgrounds with greater topography and tree cover. Our results indicate wolves in our study area primarily preyed on elk and exhibited a strong preference for elk calves. High-density concentrations of elk on feedgrounds will continue to be an attractant for wolves. Although elk leave feedgrounds for reasons other than wolf presence, any displacement of elk from feedgrounds due to wolves will be temporary. State managers have the ability to alter management strategies (e.g., increasing wolf harvest, phasing out elk feeding, increasing the intensity of elk feeding) in an effort to affect predator-prey relationships. © 2019 The Wildlife Society.     

Age‐ and temperature‐dependent oviposition model of Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) with Tetranychus urticae as prey

In this study, we developed an oviposition model of Neoseiulus californicus (McGregor) with Tetranychus urticae Koch as prey. To obtain data for the model, we investigated the longevity, fecundity and survivorship of adult female N. californicus at six constant temperatures (16, 20, 24, 28, 32 and 36°C), 60–70% RH and a photoperiod of 16 : 8 (L : D) h. Longevity (average ± SE) decreased as temperature increased and was longest at 16°C (46.7 ± 5.25 days) and shortest at 36°C (12.8 ± 0.75 days). Adult developmental rate (1/average longevity) was described by the Lactin 1 model (r² = 0.95). The oviposition period (average±SE) was also longest at 16°C (29.8 ± 2.93 days) and shortest at 36°C (6.7 ± 0.54 days). Fecundity (average±SE) was greatest at 24°C (43.8 ± 3.23 eggs) and lowest at 36°C (15.9 ± 1.50 eggs). The oviposition model comprised temperature‐dependent fecundity, age‐specific cumulative oviposition rate and age‐specific survival rate functions. The temperature‐dependent fecundity was best described by an exponential equation (r² = 0.81). The age‐specific cumulative oviposition rate was best described by the three‐parameter Weibull function (r² = 0.96). The age‐specific survival rate was best described by a reverse sigmoid function (r² = 0.85).     

Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico

For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state‐space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their “final” foraging sites. We identified new foraging “hotspots” where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13‐year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at‐sea foraging habitats for this imperiled species.     

Habitat use and spatial fidelity of male South American sea lions during the nonbreeding period

Conditions experienced during the nonbreeding period have profound long‐term effects on individual fitness and survival. Therefore, knowledge of habitat use during the nonbreeding period can provide insights into processes that regulate populations. At the Falkland Islands, the habitat use of South American sea lions (Otaria flavescens) during the nonbreeding period is of particular interest because the population is yet to recover from a catastrophic decline between the mid‐1930s and 1965, and nonbreeding movements are poorly understood. Here, we assessed the habitat use of adult male (n = 13) and juvenile male (n = 6) South American sea lions at the Falkland Islands using satellite tags and stable isotope analysis of vibrissae. Male South American sea lions behaved like central place foragers. Foraging trips were restricted to the Patagonian Shelf and were typically short in distance and duration (127 ± 66 km and 4.1 ± 2.0 days, respectively). Individual male foraging trips were also typically characterized by a high degree of foraging site fidelity. However, the isotopic niche of adult males was smaller than juvenile males, which suggested that adult males were more consistent in their use of foraging habitats and prey over time. Our findings differ from male South American sea lions in Chile and Argentina, which undertake extended movements during the nonbreeding period. Hence, throughout their breeding range, male South American sea lions have diverse movement patterns during the nonbreeding period that intuitively reflects differences in the predictability or accessibility of preferred prey. Our findings challenge the long‐standing notion that South American sea lions undertake a winter migration away from the Falkland Islands. Therefore, impediments to South American sea lion population recovery likely originate locally and conservation measures at a national level are likely to be effective in addressing the decline and the failure of the population to recover.     

The Restoration of Elk (Cervus elaphus) in Ontario, Canada: 1998–2005

In 1997, a plan to restore Elk (Cervus elaphus) to Ontario was approved by the provincial government. The objective of the Ontario elk restoration program, a multipartnered collaboration, was to restore a species that had been extirpated from the province during the 1800s. During 1998–2001, 460 elk were acquired from Elk Island National Park, Alberta, for release in four areas of Ontario. As greater than 90% of the elk were radio collared, monitoring provided detailed information on the dynamics of the four populations. Comprehensive research projects using graduate students were implemented to determine the environmental impact of releasing elk in Ontario. Those studies are in progress or have been completed and include the effect of wolf predation on restored elk, white‐tailed deer and elk resource overlap, the development of genetic profiles for elk, and solutions for elk/human conflicts. Mortality of the released elk averaged 41% (190/460) during 1998–2004 with annual mortality generally declining over time in each release area. The primary causes of elk mortality included wolf predation (25% of mortalities), illegal shooting (13%), stress‐related emaciation (13%) (partially due to the stress of relocation), bacterial infections (7%), and collisions with vehicles (6%). Productivity has been high in one of the release areas with 24–65% of the cows being observed with calves during late winter surveys. However, productivity has been low in two of the northern release areas due to a variety of factors including wolf predation. In some areas, dispersion of elk appeared to be related to the length of time animals were kept in pens prior to release. The precalving population estimate for Ontario in March 2004 was 375–440 elk. A comprehensive program review was conducted in 2003/2004 that included recommendations relating to the future management of elk in Ontario.     

Evaluation of the Efficacy of Florida Key Deer Translocations

Abstract: The endangered Florida Key deer (Odocoileus virginianus clavium) is endemic to the Lower Florida Keys. In recent years, habitat fragmentation and restricted dispersal have resulted in small, isolated herds on some islands. Recovery biologists proposed translocations to increase the island herds that had declined or remained low; however, efficacy of Key deer translocations had yet to be evaluated. Our objective was to evaluate survival, ranges, reproduction, and dispersal of translocated deer. During 2003–2005, we translocated 39 adult or yearling deer to Sugarloaf (approx. 19 km from trap site; 10 M, 14 F) and Cudjoe (approx. 15 km from trap site; 6 M, 9 F) keys. We kept deer in large, high-fenced holding pens (Sugarloaf = 7.7 ha, Cudjoe = 10.7 ha) on the destination islands for 3–6 months (i.e., soft release). We observed low mortality (n = 6 mortalities) of translocated deer with average annual survival (S) of 0.796 for both sexes. We found translocated deer had larger seasonal ranges than did resident deer (i.e., those located on Big Pine and No Name keys). In evaluating effects of acclimation period on ranges and dispersal, we found no difference in 95% ranges or 50% core areas ≤4 month postrelease versus 4–8 months postrelease. We found, however, postrelease dispersal distances were dependent on time kept in pen. Only 2 of 39 (5%) translocated deer left the destination islands by the end of the study. With high survival and low dispersal indicating success, we credit soft release translocation in establishing deer herds on Sugarloaf and Cudjoe keys. Our data support translocations as an effective strategy for creating sustainable outer-island Key deer herds.     

Site fidelity of Svalbard polar bears revealed by mark-recapture positions

Quantifying the degree of site fidelity in polar bears’ (Ursus maritimus) use of denning and mating areas in spring is of considerable interest for both basic and applied purposes. We analyzed 276 spring-to-spring movements (displacements) of 178 polar bears obtained from mark-recapture in the period 1987–2010 in Svalbard, Norway. Male and female subadults and adults showed site fidelity (only subadult females non-significantly) when their movements were compared to a scenario of random movements between all capture locations. The median observed displacement was 47.6 km (bootstrapped 95 % CI: 38.6–57.8 km), significantly smaller than the median potential displacement for random movements of 206.3 km (bootstrapped 95 % CI: 187.3–219.6 km). Subadult females tended to have the longest displacements, followed by adult males and adult females. However, large individual variation both in displacement distances and recapture frequency tended to blur age and sex differences. Analysis restricted to one movement for each bear showed that the difference between adult males and adult females was small and non-significant. This indicates that findings based on telemetry, which is almost always restricted to females, may be relatively representative of the whole adult Barents Sea population in the spring season.     

Short‐term survival and movements of Atlantic sharpnose sharks captured by hook‐and‐line in the north‐east Gulf of Mexico

Ultrasonic telemetry was used to compare post‐release survival and movements of Atlantic sharpnose sharks Rhizoprionodon terraenovae in a coastal area of the north‐east Gulf of Mexico. Ten fish were caught with standardized hook‐and‐line gear during June to October 1999. Atlantic sharpnose sharks were continuously tracked after release for periods of 0·75 to 5·90 h and their positions recorded at a median interval of 9 min. Individual rate of movement was the mean of all distance and time measurements for each fish. Mean ± s.e . individual rate of movement was 0·45 ± 0·06 total lengths per second (L_T s^?1) and ranged from 0·28 to 0·92 L_T s^?1 over all fish. Movement patterns did not differ between jaw and internally hooked Atlantic sharpnose sharks. Individual rate of movement was inversely correlated with bottom water temperature at capture (r² = 0·52, P ≤ 0·05). No consistent direction in movement was detected for Atlantic sharpnose sharks after release, except that they avoided movement towards shallower areas. Capture‐release survival was high (90%), with only one fish not surviving, i.e. this particular fish stopped movement for a period of 10 min. Total rate of movement was total distance over total time (m min^?1) for each Atlantic sharpnose shark. Mean total rate of movement was significantly higher immediately after release at 21·5 m min^?1 over the first 1·5 h of tracking, then decreased to 11·2 m min^?1 over 1·5–6 h, and 7·7 m min^?1 over 3–6 h (P ≤ 0·002), which suggested initial post‐release stress but quick recovery from capture. Thus, high survival (90%) and quick recovery indicate that the practice of catch‐and‐release would be a viable method to reduce capture mortality for R. terraenovae.     

Ranging behaviour of a large freshwater invertebrate, the white-clawed crayfish Austropotamobius pallipes

• 1 Radio‐telemetry and mark‐recapture methods were used to study the summer movements of adult and juvenile white‐clawed crayfish, Austropotamobius pallipes from a wild population in a small braided stream, Dalton Beck, North Yorkshire, U.K. Radio‐transmitters were attached to the chelae of 18 large (> 35 mm carapace length) crayfish and individuals were subsequently located to within 0.15 m. Additionally a total of 888 crayfish were marked with carapace brands, and 83 were recaptured.
• 2 Radio‐tracked crayfish exhibited significantly greater local activity at dusk (21.00–00.00) than at dawn (03.00–06.00), or during morning (09.00–12.00) and afternoon (15.00–18.00) monitoring periods.
• 3 The greatest movements of radio‐tracked crayfish occurred within 2 days of release. After this time, periods of residence were interspersed by movements to new locations, interpreted as establishment of ephemeral home areas. It is suggested that the initial large movements were the result of a ‘fright response’ following capture.
• 4 Movements varied widely between individuals, some moving more than 300 m in 10 days, while others showed little movement over an equivalent time period. Mean (±SE) daily movements were 4.6 ± 3.0 m for males and 1.5 ± 1.0 m for females. Although crayfish often used specific home sites for in excess of 7 days, displaced animals did not return to home sites.
• 5 The total distances travelled and the mean distance travelled per day by individual radio‐tagged crayfish did not differ significantly between upstream or downstream directions or between males and females. This was also the case for marked crayfish used in mark‐recapture studies.
• 6 Positive correlations between distance moved per day and size (carapace length) were found for downstream movements by male and female crayfish, but not for upstream movements.
• 7 Some preliminary observations of the response of crayfish to flood events suggested that these could be catastrophic with two out of five tracked crayfish found dead after a high stream‐discharge event.

     

Comparative migration strategies of wild and captive‐bred Asian Houbara Chlamydotis macqueenii

For migratory species, the success of population reintroduction or reinforcement through captive‐bred released individuals depends on survivors undertaking appropriate migrations. We assess whether captive‐bred Asian Houbara Chlamydotis macqueenii from a breeding programme established with locally sourced individuals and released into suitable habitat during spring or summer undertake similar migrations to those of wild birds. Using satellite telemetry, we compare the migrations of 29 captive‐bred juveniles, 10 wild juveniles and 39 wild adults (including three birds first tracked as juveniles), examining migratory propensity (proportion migrating), timing, direction, stopover duration and frequency, efficiency (route deviation), and wintering and breeding season locations. Captive‐bred birds initiated autumn migration an average of 20.6 (±4.6 se) days later and wintered 470.8 km (±76.4) closer to the breeding grounds, mainly in Turkmenistan, northern Iran and Afghanistan, than wild birds, which migrated 1217.8 km (±76.4), predominantly wintering in southern Iran and Pakistan (juveniles and adults were similar). Wintering locations of four surviving captive‐bred birds were similar in subsequent years (median distance to first wintering site = 70.8 km, range 6.56–221.6 km), suggesting that individual captive‐bred birds (but not necessarily their progeny) remain faithful to their first wintering latitude. The migratory performance of captive‐bred birds was otherwise similar to that of wild juveniles. Although the long‐term fitness consequences for captive‐bred birds establishing wintering sites at the northern edge of those occupied by wild birds remain to be quantified, it is clear that the pattern of wild migrations established by long‐term selection is not replicated. If the shorter migration distance of young captive‐bred birds has a physiological rather than a genetic basis, then their progeny may still exhibit wild‐type migration. However, as there is a considerable genetic component to migration, captive breeding management must respect migratory population structure as well as natal and release‐site fidelity.     

A Seventy-Year History of Trends in Yellowstone's Northern Elk Herd

ABSTRACT We analyzed counts of northern Yellowstone elk (Cervus elaphus) in Yellowstone National Park, Wyoming, USA, over 70 years to evaluate the effects of changing management on population trends. Population reduction efforts and hunter harvests during 1932–1968 removed 71,330 elk and decreased estimated abundance from 16,000 to 6,000 elk. Abundance increased to approximately 17,000 elk (λ = 1.19) when removals ceased and harvests were very small during 1969–1975. Moderate to liberal hunter harvests of antlerless elk outside the Park during 1976–2004 removed a relatively consistent proportion (26 ± 0.1 [SD]%) of females that migrated outside the park, mostly from prime-age (3–15 yr) classes with high reproductive value. Substantial winterkill was infrequent (1989, 1997), but it significantly reduced calf survival when it occurred. Wolves (Canis lupus) were reintroduced in 1995–1996 and rapidly increased in abundance (λ = 1.23) and distribution. Estimated wolf kill of elk now exceeds hunter harvest, but has a smaller effect on population dynamics because wolves concentrate on calves and older females (>14 yr) with low reproductive value. During 1995–2004, estimated abundance decreased from 23,000 to 12,000 elk. The recent ratio of wolves to elk is relatively low compared to the estimated equilibrium ratio, suggesting that the wolf population may yet increase in the future. Thus, reduction of harvests of prime-aged female elk to decrease removals of animals with high reproductive value and increase adult female survival appears essential. We analyzed the relative impact of removals by hunters and by wolves using Fisher's (1930) reproductive value and found that the impact of hunters is far more important than that by wolves, a finding of broad significance.     

Know Thy Enemy: Experience Affects Elk Translocation Success in Risky Landscapes

ABSTRACT To maximize success, reintroduction programs generally select predator-free release areas having high habitat quality. Past studies provide little insight into recovery efforts where multiple, potentially novel, mortality hazards occur. The ability of translocated animals to cope with novel environments can be affected by both pre- and postrelease experiences with habitat and mortality risks. We experimentally released elk (Cervus elaphus) having different background experiences into an area where predators and hunters were prevalent and habitat quality varied. Using a competing risks approach, we predicted the postrelease survival of individuals and their fidelity to release areas as a function of animal source and postrelease encounters with forage resources and areas used by wolves (Canis lupus) or humans. Mortality patterns were consistent with prerelease exposure to mortality risks but not habitat differences among source areas. Wolf predation, poaching, and legal Native hunting were equivalent in magnitude and accounted for the majority of elk mortalities. Familiarity with either wolves or hunters prior to release yielded first-year survival rates 1.9-2.2 times greater than observed for animals naive to both risks. These 2 primary sources of mortality traded off temporally as well as spatially given the proximity of roads, which wolves avoided. The prevalence of forage resources in release areas increased fidelity to release sites but coincided with higher mortality risk during the critical first year, potentially setting an ecological trap for animals naïve to local risks. Translocated individuals largely mediated their respective vulnerabilities over time, showing second-year survival rates equivalent to resident elk. In addition to using source populations that are able to adjust to mortality risks in release areas, spatial and temporal variation in mortality risks might be exploited when planning releases to increase the success of translocations into risky landscapes. (JOURNAL OF WILDLIFE MANAGEMENT 71(2):541–554; 2007)     

Spatial and temporal factors influencing sightability of elk

Few tracking studies consider seasonal changes in ability to re-sight wildlife, despite potential for biases in sightability to mislead our interpretation of models of movement and abundance. We developed seasonal sightability models based on visual observations of radio-collared elk (Cervus elaphus) in Manitoba, Canada, through 6 seasons. We located 377 elk 8,862 times using aerial telemetry from 2002 to 2009. We tested the hypothesis that sites where we were able to visually observe radio-collared elk during aerial telemetry differed from sites where collared elk were known to be present but could not be sighted. Relationships varied with season and elk sightability was influenced by forest type, habitat openness, distance to edge, and time of day. Our results confirm that observers have the highest probability of detecting elk in early and late winter. However, factors such as day length, which increases by 64% during this period, suggest that fewer impediments to detection exist in late winter. Our findings reinforce the need to account for seasonal as well as spatial changes in habitat-specific sightability models. © 2011 The Wildlife Society.     

Survival of captured and relocated adult spring-run Chinook salmon Oncorhynchus tshawytscha in a Sacramento River tributary after cessation of migration

We studied the efficacy of the process for capture and upstream relocation of 26 adult spring-run Chinook salmon in Butte Creek, California in 2009. These fish had ceased volitional upstream migration prior to reaching their summer holding habitat. The purpose of the relocation was to move fish upstream of two water diversion dams and release them in a part of the stream from which they could presumably swim to cool summer holding habitat, then spawn in the fall. Fish were netted, transported by truck, given an esophageal radio tag/temperature tag, and released. Radio tagging proved to be a useful technique for determining the survival and movement of relocated fish and temperature tags provide useful information to determine thermal exposure and time of death. Twenty-three tags (88 %) were recovered, compared with a 10 % tag recovery rate for an earlier study using fin clips. Most tags were recovered within 3.5 km upstream and 1 km downstream of the release site. A single tag was recovered 6 km upstream. No fish were determined to have survived to spawn. Temperature tag data indicate that most of the salmon died within 2–6 days after the relocation operation. After preventative measures have been exhausted, future relocations efforts, in any setting, should consider (1) intervention as soon as fish cease volitional migration but before they are exposed to further deleterious conditions (2) monitoring environmental conditions to choose appropriate release sites (3) evaluation of disease transmission risk, and (4) handling practices that minimize potential stress due to air immersion and thermal shock.