A Critical Review of Home Range Studies

Abstract No consensus currently exists for the methods of estimation of home range size or for reporting home-range analysis results. Studies currently employ a variety of disparate methods or provide inadequate information for reproducing their analyses. We reviewed 161 home range studies published in 2004, 2005, and 2006 to assess what methods are currently employed and how results are reported. We found that home range reporting was generally inadequate for reproducing studies; that the methods employed varied considerably; that home range estimates were often reported and analyzed using inappropriate methods; and that many comparisons were made between studies that may produce spurious results. We urge for minimum editorial standards for reporting home range studies and we urge researchers to follow a unified methodology for estimating animal home ranges. We supply recommendations for such reporting and methodology. These recommendations will increase the reproducibility of studies and allow for more robust comparisons between studies.     

Tourism and the Conservation of Critically Endangered Frogs

Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism''s financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts.     

Elephant both Increase and Decrease Availability of Browse Resources for Black Rhinoceros

Despite the apparent dual role of elephant Loxodonta africana in shaping the food niches of large herbivores, empirical studies focus on their role in facilitating foraging opportunities, while declining resource opportunities (a necessary requirement for competition) are rarely quantified. Our study investigates the relative importance of elephant in these processes by quantifying potential browsing opportunities (using total and preferred biomass, between‐bite distances and bite mass) for black rhinoceros Diceros bicornis along a gradient of elephant utilization in the succulent thickets of the Addo Elephant National Park, South Africa. We show that browse biomass and potential between‐bite harvest rates initially increase with the intensity of elephant utilization through the formation and spread of elephant pathways in otherwise impenetrable thicket. At the maximum, modeled estimates of total and preferred biomass are on average 223 percent and 254 percent higher, respectively, than that recorded in the absence of elephant (Exclosures); potential between‐bite harvest rates are 75 percent higher. With continued elephant utilization, however, browse biomass declines and between‐bite distances increase as the pathways expand and coalesce and canopy height declines. Our model of the change in potential browsing opportunities for rhinoceros reflects the accumulated effects of elephant over time, i.e., the effects accumulate until the relationship switches from increased to reduced availability. With this we demonstrate the key role of elephant for rhinoceros foraging, linked to a potential loss of this role at higher levels of utilization.     

Home Range Size and Habitat Use in the Black Lion Tamarin (Leontopithecus chrysopygus)

The black lion tamarin (Leontopithecus chrysopygus) is a threatened species due to past destruction of its natural habitat, thus knowledge of its home range size and use is essential in planning for its conservation. I studied one group for 4 months in the Morro do Diabo State Park, in São Paulo State, Brazil. I estimated the home range of the group to be 64 and 127 ha via the quadrat and convex polygon methods, respectively, while a composite method yielded an estimate of 106 ha. They ate insects most frequently (38% of scans), a resource which was distributed throughout their home range. Fruit was the second major resource, but when it was not available, they ate more gum. The exploitation of fruits was associated with dryland forest, while gum-feeding occurred mainly in swamp forest. The study group used a transition zone between dryland and swamp forest most frequently, and all of their sleeping trees were located there. Although the vegetation reached 15–20 m, the group spent most of the time (55%) in the upper understory, between 4 and 8 m high. The study group revealed more specific habitat needs than thought previously, suggesting that the current population may be smaller than estimated.     

Reserve Size,Conspecific Density,and Translocation Success for Black Rhinoceros

Abstract: Fighting and accidental injury commonly cause black rhinoceros (rhino; Diceros bicornis) death after release. Smaller reserves and higher conspecific density after release (release density) might increase a rhino's encounter rate with hazards like fenced boundaries and conspecifics. We conducted a science-by-management experiment on the influence of reserve size and release density on rates of movement, association, and injury and death amongst 39 black rhinos during the first 100 days after their release into 4 Namibian and 8 South African reserves ranging in size from 670 ha to 45,000 ha. Association rates were negatively related to reserve size and positively correlated with release density. There was also a negative relationship between the proportion of the reserve traversed by individual rhinos and reserve size. In reserves ≥18,000 ha association rates were consistently zero but became elevated in reserves ≤11,500 ha and at release densities ≤9 km²/rhino. Daily displacement did not increase with increasing reserve size >8,500 ha but in smaller reserves daily displacements indicated higher encounter rates by released rhinos with fenced boundaries. Three rhinos received fight-related injuries requiring intervention and 2 of 4 deaths were fight-related. All injuries and 3 deaths occurred in reserves ≤11,500 ha. Model selection based on Akaike's second-order Information Criterion indicated that the parameter release density alone best explained mortality risk. Traditionally considered risk factors, rhino sex, age, and presence of resident conspecifics, were superseded by the risk posed by releases into smaller reserves. Reserves ≤11,500 ha and release densities ≤9 km²/rhino pose an increasing risk to rhino survivorship and so larger reserves and lower densities than these should be favored as release sites.     

Cold spot microrefugia hold the key to survival for Brazil's Critically Endangered Araucaria tree

Brazil's Araucaria tree (Araucaria angustifolia) is an iconic living fossil and a defining element of the Atlantic Forest global biodiversity hotspot. But despite more than two millennia as a cultural icon in southern Brazil, Araucaria is on the brink of extinction, having lost 97% of its extent to 20th‐century logging. Although logging is now illegal, 21st‐century climate change constitutes a new—but so far unevaluated—threat to Araucaria's future survival. We use a robust ensemble modelling approach, using recently developed climate data, high‐resolution topography and fine‐scale vegetation maps, to predict the species' response to climate change and its implications for conservation on meso‐ and microclimate scales. We show that climate‐only models predict the total disappearance of Araucaria's most suitable habitat by 2070, but incorporating topographic effects allows potential highland microrefugia to be identified. The legacy of 20th‐century destruction is evident—more than a third of these likely holdouts have already lost their natural vegetation—and 21st‐century climate change will leave just 3.5% of remnant forest and 28.4% of highland grasslands suitable for Araucaria. Existing protected areas cover only 2.5% of the surviving microrefugia for this culturally important species, and none occur in any designated indigenous territory. Our results suggest that anthropogenic climate change is likely to commit Araucaria to a second consecutive century of significant losses, but targeted interventions could help ensure its survival in the wild.     

A rare contemporary record of the Critically Endangered Ganges shark Glyphis gangeticus

The first record of the Ganges shark Glyphis gangeticus from anywhere in its range in over a decade is reported from the Arabian Sea. One female specimen was recorded at Sassoon Docks in Mumbai, India in February 2016, measuring 266 cm total length. In light of the Critically Endangered status of this species and its rarity, urgent management actions are needed to determine population size and trends in abundance in combination with fisher education and awareness campaigns.     

Genomic Analysis of Demographic History and Ecological Niche Modeling in the Endangered Sumatran Rhinoceros Dicerorhinus sumatrensis

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A survey for the Critically Endangered Liben Lark Heteromirafra archeri in Somaliland,north-western Somalia

The Critically Endangered Archer's Lark (now Liben Lark) Heteromirafra archeri was formerly considered to be endemic to north-western Somalia and known only from the Tog Wajaale Plain, where 18 specimens were collected between 1918 and 1922. Fifteen visits between 1970 and 2008 failed to relocate the species there, although popula- tions are now known from adjacent Ethiopia. We conducted three days of intensive surveys on the Tog Wajaale Plain in May 2010. Despite the three other lark species present being in full display, and H. archeri being recorded to have bred in early June, no Liben Larks were found. Vegetation structure surveys indicated that the plain has a taller and denser growth of grass than either of the other known localities for Liben Lark (the Liben and Jijiga Plains) making Tog Wajaale Plain seem superficially more suitable for the species, which prefers areas of taller grass elsewhere. However, previous large-scale agricultural activities may have altered the composition of grass species and precipitated the observed invasion of exotic weeds, notably Parthenium hysterophorus. Importantly, the Tog Wajaale Plain has a greater density of bushes than either the Liben or Jijiga Plains, possibly making ground-nesting birds more susceptible to predation by perch hunters.     

Scale of Management for Mature Male White-Tailed Deer as Influenced by Home Range and Movements

Abstract: The scale at which populations use landscapes influences ecological processes and management. We used dispersal and home-range data of 3 age groups of male white-tailed deer (Odocoileus virginianus) to determine the scale at which management will be effective. Home-range size at 5.5 years of age (182 ha ± 24.9 SE) was 56% smaller (P < 0.001) than home-range size of the same 13 males as yearlings (416 ± 59.4 ha). Percent overlap of yearling and 5.5-year-old home ranges was 62.7 6 10.3% (n = 13). Distance between home-range centers of yearling and mature deer was 1,264.9 ± 407.4 m, including 3 deer that dispersed after 2.5 years of age. Average 95% fixed-kernel home-range size was 207.4 ± 20.4 ha and 225.7 ± 30.1 ha for all mature males in years 1 and 2 of our study, respectively. We found that properties >10,000 ha were needed to manage >50% of original yearling males found on the property, whereas properties of 4,500 ha would maintain 50% of original middle-aged (2.5-4.5 yr of age) and mature males (≥4.5 yr of age). Movements after dispersal were minimal, with deer shifting their center of activity <600 m and <350 m each year for middle-aged and mature males, respectively. These data could be used by managers developing management plans, recommending harvest rates, and interpreting harvest data of male white-tailed deer and by biologists attempting to understand ecological processes such as spread of disease.     

灵长类家域的研究

灵长类家域的研究李保国刘安宏（西北大学生物学系,西安７１００６９）（西安市林业局,７１０００３）ＨｏｍｅＲａｎｇｅＳｔｕｄｙｏｆＰｒｉｍａｔｅｓ．￥ＬｉＢａｏｇｕｏ（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｌｇｙ,ＮｏｒｔｈｗｅｓｔＵｎｉｖｅｒｓｉｔｙ,Ｘｉａ...     

极度濒危植物大果木莲种子的休眠与萌发

大果木莲种子具吸水性,胚未完全发育。新鲜种子25℃下的萌发率仅2％,在30／20℃和20／10℃的条件下30d内分别有27％和36％种子萌发。在20／10℃下,1000mg·L^-1浓度的GA3可以有效打破种子休眠。冷层积120d的种胚生长不显著,大果木莲种子具有条件休眠特性,属于浅度简单型形态生理休眠。种子经冷层积60d的萌发率最高,而后下降,提示其可能有休眠循环现象。     

Human-Assisted Spread of a Maladaptive Behavior in a Critically Endangered Bird

Conservation management often focuses on counteracting the adverse effects of human activities on threatened populations. However, conservation measures may unintentionally relax selection by allowing the ‘survival of the not-so-fit’, increasing the risk of fixation of maladaptive traits. Here, we report such a case in the critically-endangered Chatham Island black robin (Petroica traversi) which, in 1980, was reduced to a single breeding pair. Following this bottleneck, some females were observed to lay eggs on the rims of their nests. Rim eggs left in place always failed to hatch. To expedite population recovery, rim eggs were repositioned inside nests, yielding viable hatchlings. Repositioning resulted in rapid growth of the black robin population, but by 1989 over 50% of all females were laying rim eggs. We used an exceptional, species-wide pedigree to consider both recessive and dominant models of inheritance over all plausible founder genotype combinations at a biallelic and possibly sex-linked locus. The pattern of rim laying is best fitted as an autosomal dominant Mendelian trait. Using a phenotype permutation test we could also reject the null hypothesis of non-heritability for this trait in favour of our best-fitting model of heritability. Data collected after intervention ceased shows that the frequency of rim laying has strongly declined, and that this trait is maladaptive. This episode yields an important lesson for conservation biology: fixation of maladaptive traits could render small threatened populations completely dependent on humans for reproduction, irreversibly compromising the long term viability of populations humanity seeks to conserve.     

Early Management of the Critically Injured

A plan for the early management of the critically injured patient is described with emphasis on the priorities of management of injuries to certain organ-systems. The most important priorities are the establishment and maintenance of adequate ventilation and adequate circulation. The general surgeon is best qualified to assume full responsibility for the proper care of the critically injured, of patients with multiple injuries, and of patients in traumatic shock. He must assume the risk of transfusing unmatched whole blood and of deferring non-essential radiographs. The emergency and radiology departments may have to be by-passed to save the life of the critically injured patient. The measures required to establish a clear airway, to treat complications which can impair ventilation, to manage shock and hemorrhage and the possible complications of massive transfusions of blood are reviewed.     

Gathering Local Knowledge in Madagascar Results in a Major Increase in the Known Range and Number of Sites for Critically Endangered Greater Bamboo Lemurs (Prolemur simus)

Greater bamboo lemurs (Prolemur simus) are endemic to Madagascar and are the only recognized species within their genus. The IUCN lists the species as critically endangered, with very few confirmed distribution records and <200 individuals known in the wild. With the aim of contributing to its conservation, we attempted to find previously unknown sites containing the species. Working closely with local communities, and basing our methodology on the gathering of local knowledge, we surveyed 44 sites in and around the Ankeniheny-Zahamena Corridor. We found evidence of the presence of Prolemur simus at 18 sites. We made direct sightings at 6 sites, of a total of 65 confirmed individuals, and identified their characteristic feeding remains at the other sites. Twelve of the sites are located in midaltitude rain forest within the corridor, and 6 lie in isolated and degraded lowland areas outside the corridor. These discoveries more than double the number of sites where the species is known to occur, and extend its known range 85 km further north. We identified numerous threats to the newly discovered sites, including hunting pressure, habitat destruction, habitat disturbance, and habitat fragmentation. Demographic factors related to small population sizes and population isolation may also impact the viability of the populations. Our results illustrate the benefits of systematic gathering of local knowledge when searching for rare or secretive primates.     

Massasauga Home Range Patterns in the Midwest

Abstract: The massasauga (Sistrurus catenatus) has drastically declined throughout its range mainly due to habitat loss and human persecution. Populations of the massasauga that occur north and east of the Missouri River, USA, are currently candidates for listing under the United States Endangered Species Act. In areas where land managers wish to improve habitat for existing populations or create habitat for repatriation efforts, an understanding of massasauga spatial ecology is necessary to ensure that adequate sized blocks of habitat are created and properly managed. We studied spatial ecology of massasaugas at 2 sites in Wisconsin and 3 sites in Missouri over an 11-year period. Our results indicated that male massasaugas had larger spatial requirements than all other cohorts. Our study sites supporting viable populations indicated that managers interested in restoring or enhancing massasauga habitat should use 100 ha as a minimum restoration or management target. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):754–759; 2008)     

不同天然居群小蓬竹的遗传多样性

从分子水平探讨不同居群小蓬竹的遗传多样性以及与环境因子的相关性,揭示其濒危原因,为小蓬竹的保护和后续开发利用提供理论支撑,助力实施极危物种最佳保护策略。运用RAPD标记技术和POPGENE32对16个小蓬竹天然居群进行遗传多样性研究和遗传变异分析。结果表明,8个RAPD随机引物共扩增出105条清晰、重复性高的条带,其中多态性条带有98条,分子量300~2000bp;物种水平多态性位点百分率PPL=93.33%,有效等位基因数Ne=1.4942,Nei’s基因多样性H=0.3005,Shannon多样性指数I=0.4586;落湾(ZY1)居群的遗传多样性水平最高(PPL=60.95%,H=0.2329,I=0.3451),[JP3]桃坡(PT1)居群的最低(PPL=44.76%,H=0.1700,[JP]I=0.2523);16个天然居群的遗传分化系数Gst=0.3231,基因流Nm=1.0478,基于Shannon’s多样性指数的分化系数[(HSP-HPOP)/HSP]为0.3429。小蓬竹居群内存在丰富的遗传多样性,各个天然居群间具有一定的遗传分化但分化水平并不高,主要的遗传变异存在于居群内部。