Fine‐scale habitat preferences and habitat partitioning by three mycophagous mammals in tropical wet sclerophyll forest,north‐eastern Australia

Abstract Fine‐scale habitat preferences of three co‐occurring mycophagous mammals were examined in a tropical wet sclerophyll forest community in north‐eastern Australia. Two of the three mammal species responded to fine‐scale variation in vegetation and landform around individual trap locations. At a broad scale, the northern bettong (Bettongia tropica), an endangered marsupial endemic to the Australian wet tropics region, showed a preference for ridges over mid‐slopes and gullies, irrespective of forest type. In contrast, the northern brown bandicoot (Isoodon macrourus), a widespread marsupial, displayed a preference for Eucalyptus woodland over adjacent Allocasuarina forest, irrespective of topographic category. The giant white‐tailed rat (Uromys caudimaculatus), a rodent endemic to the wet tropics, showed no particular preference for either forest type or topographic category. A multiple regression model of mammal capture success against three principal habitat gradients constructed from 21 habitat variables using principal component analysis indicated strong species‐specific preferences for fine‐scale vegetation assemblages. Bettongs preferred areas of Eucalyptus woodland with sparse ground cover, low densities of certain grass species, high density of tree stems and few pig diggings. Bandicoots, in contrast, favoured areas in both forest types with dense ground cover, fewer tree stems and greater numbers of pig diggings; that is, characteristics least favoured by bettongs. The striking differences in fine‐scale habitat preferences of these two mammals of similar body size and broad habitat requirements suggest a high degree of fine‐scale habitat partitioning. White‐tailed rats did not show preference for any of the habitat gradients examined.     

Specific nest box designs can improve habitat restoration for cavity‐dependent arboreal mammals

Tree‐cavity‐dependent wildlife faces future shortages of cavities due to a decline in the abundance of large, old trees in many parts of the world. Nest boxes are proposed as a tool to restore habitat value but evidence of their effectiveness for arboreal mammals remains equivocal. This may arise from a poor understanding of design preferences. We conducted investigations in two landscapes in eastern Australia to determine whether species show a preference for specific designs. We observed a preference by some mammal species for particular designs (33–78% occupied/used), suggesting that design refinement can improve the frequency with which nest boxes are used. Although feral species may out‐compete target species for nest boxes, we did not observe this. We recorded feral honeybees (Apis mellifera) in 6–9% of nest boxes but they did not remain, and many occupied boxes were later used by mammals. The introduced common myna bird (Acridotheres tristis) was prevalent in one landscape, but competition for nest boxes was localized. For nest boxes to be an effective habitat restoration tool, they must be able to be occupied over long periods of time. We investigated this for the squirrel glider (Petaurus norfolcensis), an arboreal marsupial threatened through part of its geographic range. Squirrel gliders occupied and bred within nest boxes (100% used) at two locations continuously over a 10‐year period with minimal nest box maintenance. Individuals occupied boxes for up to 7 years. This confirms that targeted nest box programs can be an effective restoration tool for cavity‐dependent arboreal mammals.     

How global extinctions impact regional biodiversity in mammals

Phylogenetic diversity (PD) represents the evolutionary history of a species assemblage and is a valuable measure of biodiversity because it captures not only species richness but potentially also genetic and functional diversity. Preserving PD could be critical for maintaining the functional integrity of the world's ecosystems, and species extinction will have a large impact on ecosystems in areas where the ecosystem cost per species extinction is high. Here, we show that impacts from global extinctions are linked to spatial location. Using a phylogeny of all mammals, we compare regional losses of PD against a model of random extinction. At regional scales, losses differ dramatically: several biodiversity hotspots in southern Asia and Amazonia will lose an unexpectedly large proportion of PD. Global analyses may therefore underestimate the impacts of extinction on ecosystem processes and function because they occur at finer spatial scales within the context of natural biogeography.     

青藏高原东缘高寒森林小型兽类地表洞穴选择与生境特征

高寒森林地表的小型兽类洞穴是生态系统重要的景观特征,对于认识小型兽类的分布格局及其生态功能具有重要意义.为此,以青藏高原东缘典型高寒森林生态系统小型兽类洞穴为对象,于2015年夏季(7—9月)研究了其地表分布与生境特征.结果表明: 小型兽类洞穴平均洞口密度为182.8个·hm^-2,不同森林植被类型显著影响洞穴密度,表现为针叶林(328.6个·hm^-2)>针阔混交林(160.0个·hm^-2)>灌木林(125.0个·hm^-2)>阔叶林(81.5个·hm^-2)>竹林(66.7个·hm^-2). Mann-Whitney U Test和主成分分析表明,小型兽类栖息样地的乔木郁闭度、乔木均高、乔木胸径、乔木密度、地表植被盖度、倒木密度、倒木覆盖度、灌木均高都显著大于非栖息样地;乔木因子是决定小型兽类生境选择的首要因子,贡献率最大(44.8%),其次是倒木因子(23.2%)和灌草丛因子(13.9%).说明高寒森林地表有明显的小型兽类洞穴分布,其分布格局主要受植被和倒木的影响.     

Limited use of bat boxes in a rural landscape: implications for offsetting the clearing of hollow‐bearing trees

Bat boxes frequently form part of hollow‐bearing tree offsets; however, their effectiveness is poorly documented. We investigated the effectiveness of a bat box program designed to partially offset tree hollow loss from clearing for a coal mine. During the first year of monitoring, we detected bats in 5% of 1,308 box checks. Only 3 of 13 local tree cavity‐roosting bat species/species groups used boxes and occupancy was not strongly associated with modeled box and site attributes. In the second year, we tested two hypotheses that may explain the relatively low box use: (1) solar exposure of boxes was inadequate for heterothermic bats and (2) available box designs were of low suitability. Relocating boxes to increase solar exposure did not increase use, or enhance the temperature profiles of relocated boxes. Introduction of a new box design led to 11 times higher use compared with existing designs for Nyctophilus spp. (long‐eared bat). Overall, our data suggest that the bat box program was ineffective due to few bat species using boxes, infrequent box use by three species, and rarity of maternity roosting. The knowledge gap of species‐specific box designs and roosting ecology limits the effectiveness of boxes to offset cleared hollow‐bearing trees. Lack of knowledge and the widespread use of bat boxes to offset lost tree hollows highlights the need to (1) rigorously protect hollow‐bearing trees and (2) advance our understanding of species‐specific roost ecology, box design preferences and mechanical hollow creation into trees, before artificial hollows can be considered a meaningful offset measure.     

Relationships between survival and habitat suitability of semi‐aquatic mammals

Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche‐based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), a North American semi‐aquatic, herbivorous, habitat generalist. We also tested the prediction of ideal free distribution that animal fitness, or its surrogate, is independent of habitat suitability at the equilibrium. We estimated beaver monthly survival probability using the Barker model and radio telemetry data collected in northern Alabama, United States from January 2011 to April 2012. A habitat suitability map was generated with Maxent for the entire study site using landscape variables derived from the 2011 National Land Cover Database (30‐m resolution). We found an inverse relationship between habitat suitability index and beaver survival, contradicting the predictions of niche theory and ideal free distribution. Furthermore, four landscape variables selected by American beaver did not predict survival. The beaver population on our study site has been established for 20 or more years and, subsequently, may be approaching or have reached the carrying capacity. Maxent‐predicted increases in habitat use and subsequent intraspecific competition may have reduced beaver survival. Habitat suitability‐fitness relationships may be complex and, in part, contingent upon local animal abundance. Future studies of mechanistic SDMs incorporating local abundance and demographic rates are needed.     

On‐ground habitat restoration: Interview with Nancy Pallin

Nancy Pallin has been involved in bush regeneration practice for over 25 years as well as being involved in conservation advocacy. Her main work, helping to establish the Ku‐ring‐gai Flying‐Fox Reserve and coordinating its ecological restoration, draws on an ability to interpret nature to others and inspire collective action     

Outcomes of decades long installation of nest boxes for arboreal mammals in southern Australia

Nest boxes are commonly installed to support hollow‐using species where the abundance of hollow‐bearing trees is deficient. Recent studies have provided equivocal evidence about the effectiveness of nest box projects and have highlighted significant management costs associated with some projects. We document the functionality of 303 nest boxes installed across five different community‐led projects in southern Australia for periods of 10–25 years. As expected, we found that nest boxes lost functionality over time. However, 60% remained functional to support the Brush‐tailed Phascogale (Phascogale tapoatafa) and the Sugar Glider (Petaurus breviceps) after almost 20 years. Years installed, method of nest box attachment and tree species influenced whether boxes remained functional. Nest box construction material changed over time so could not be assessed specifically. When inspected in a single year, the Brush‐tailed Phascogale occupied 9% of functional boxes and another 48% contained their nests. The Sugar Glider occupied 15% of functional boxes and another 22% contained their nests. These values suggest the nest box installations were highly effective for these species, although more detailed study is needed to understand what contribution these installations have made to support the local populations. Maintenance of most nest boxes occurred twice a year in the first five years after installation, but many received no maintenance for periods of three years, and some 10–15 years, before our census. Our findings suggest that infrequent maintenance by community groups can sustain nest box projects over periods of several decades. Research into employing nest boxes as a management tool in Australia is still in its infancy. Further studies are needed to resolve factors that limit their effectiveness.     

Field studies of seahorse population density,structure and habitat use in a semi-closed north-eastern Mediterranean marine area (Stratoni,North Aegean Sea)

The present study was carried out in the marine area of Stratoni, Greece, where two seahorse species are present (Hippocampus hippocampus and Hippocampus guttulatus). Two surveys were conducted (September 2016 and May 2019) to gather information regarding seahorse species' abundance, distribution and habitat characteristics. Four different seahorse natural and artificial habitat types were identified. The results revealed that the presence of H. hippocampus was relatively high, especially at sites with artificial structures, whereas the presence of H. guttulatus was rare. Data collected can provide baseline information for future population assessments.     

More long‐unburnt forest will benefit mammals in Australian sub‐alpine forests and woodlands

The composition of mammalian communities in Australia's Eucalyptus forests and woodlands is known to be affected by fire. However, there are few published studies that compare mammal assemblages in recently burnt and long‐unburnt forests because there are few areas with long‐term fire history data. Understanding the value of long‐unburnt forest is important because it is becoming rare in fire‐prone regions of the world, such as south‐eastern Australia, partly because of the widespread use of prescribed burning. We deployed wildlife cameras for 28 trap‐nights at each of 81 sites that ranged from 0.5 to at least 96 years since the last fire. We recorded a total of 15 native mammal species. At least one mammal species was recorded at 80 of the 81 sites. Significantly more species were detected at long‐unburnt sites (>96 years since fire) than sites 0.5–12 years since the last fire. Species composition varied significantly between sites 0.5–12 years and >96 years since the last fire but did not vary between sites 0.5–2 years and 6–12 years since the last fire. Although there was not one category of time since fire (i.e. 0.5–2 years, 6–12 years and >96 years) in which all 15 native mammal species were recorded, long‐unburnt sites were significantly more important for the occurrence of seven mammal species; intermediate and recently burnt sites were significantly more important for one species. Our results suggested that, while a diversity of fire ages is important for conserving mammalian diversity, long‐unburnt forests and woodlands (which comprised only 8% of our study area) are disproportionately important for mammal conservation. Our results add to a growing body of the literature from south‐eastern Australia, suggesting that remaining long‐unburnt forest should be afforded protection from fire and more forest should be transitioned to long unburnt.     

Habitat preferences and habitat restoration options for small‐bodied and juvenile fish species in the northern Murray–Darling Basin

Degradation of instream habitats in the northern Murray–Darling Basin has occurred through numerous stressors, including siltation, clearing of bankside vegetation, intrusion of livestock and impacts of pest species. A better understanding of habitat preferences of native fish species could help guide future instream habitat restoration actions. The habitat choices of seven native fish species, juvenile Murray Cod (Maccullochella peelii), juvenile Golden Perch (Macquaria ambigua ambigua), juvenile Silver Perch (Bidyanus bidyanus), adult Murray–Darling Rainbowfish (Melanotaenia fluviatilis), adult Olive Perchlet (Ambassis agassizii), adult Un‐specked Hardyhead (Craterocephalus stercusmuscarum fulvus) and adult carp gudgeons (Hypseleotris spp.) were tested in preference troughs to help inform potential habitat restoration actions in the Condamine catchment. Each species was given a choice between pair combinations of open sandy habitat, submerged macrophytes, emergent plants and rocky rubble. Habitat preferences varied between species. Murray Cod, Golden Perch, carp gudgeons and Olive Perchlets preferred structure over open sandy habitat, whilst juvenile Silver Perch, Un‐specked Hardyhead and Murray–Darling Rainbowfish did not avoid open sandy habitats. Juvenile Murray Cod preferred rocky rubble habitat over all other habitat choices. Use of complex rock piles to provide nursery habitat for Murray Cod populations is a potential restoration option. Introduction of rock could also benefit Golden Perch and carp gudgeons. Use of emergent plants, submerged macrophytes and rocky rubble for habitat restoration all appear to have merit for one or more species of small‐bodied fishes or juvenile stages of larger sized fishes. Rocky rubble or floating attached macrophytes could be viable restoration options in areas too turbid to establish submerged macrophytes. These habitat interventions would complement existing actions such as re‐snagging and provision of fish passage to assist with sustainable management of native fish populations.     

通过红色名录评估研究中国哺乳动物受威胁现状及其原因

依据中国哺乳类野生种群与生境现状, 我们利用IUCN Red List Categories and Criteria (Version 3.1), Guidelines for Using the IUCN Red List Categories and Criteria和Guidelines for Application of IUCN Red List Criteria at Regional and National Levels (Version 4.0), 评价了中国所有已知的673种哺乳动物的濒危状况。本次评估了71种《IUCN濒危物种红色名录(2015)》没有评估的哺乳动物, 还评估了60种《IUCN濒危物种红色名录(2015)》误认为中国没有分布的哺乳动物。发现中国有3种哺乳动物“野外灭绝”, 3种“区域灭绝”。受威胁中国哺乳动物共计178种, 约占评估物种总数的26.4%, 高于IUCN濒危物种红色名录的物种平均受威胁率(21.8%)。中国哺乳动物1/4的特有种属于受威胁物种。受威胁比例最高的目是灵长目、食肉目与鲸偶蹄目。多数省区的受威胁哺乳动物物种占本省区哺乳动物总数的20-30%。中国哺乳动物种类多分布在中国第二级地理阶梯。生活在高海拔地区的哺乳动物虽然种类少, 但是受威胁哺乳动物的种类比例高。过度利用、生境丧失和人类干扰名列受威胁哺乳动物致危因子的前3位。自从1989年《中华人民共和国野生动物保护法》实施以来, 一些中国濒危哺乳动物的生存状况得到了改善。然而, 鉴于中国哺乳动物区系的独特性和多样性, 以及中国地形地貌的复杂性, 如何拯救这些濒危物种仍是中国生物多样性保护的一项艰巨任务。     

A GIS‐based decision‐making approach for prioritizing seabird management following predator eradication

Given that 29% of seabird species are threatened with extinction, protecting seabird colonies on offshore islands is a global conservation priority. Seabirds are vulnerable to non‐native predator invasions, which reduce or eliminate colonies. Accordingly, conservation efforts have focused on predator eradication. However, affected populations are often left to passively recover following eradications. Although seabirds are highly mobile, their life history traits such as philopatry can limit passive recolonization of newly predator‐free habitat. In such cases, seabird colonies can potentially be re‐instated with active restoration via chick translocations or social attraction methods, which can be risky and expensive. We used biogeographic and species‐specific behavioral data in the Hauraki Gulf, New Zealand, a global hotspot of seabird diversity and predator eradications, to illustrate the use of geographic information systems multi‐criteria decision analysis to prioritize islands for active seabird restoration. We identified nine islands with low observed passive recovery of seabirds posteradication over a 50‐year timeframe, and classified these as sites where active seabird management could be prioritized. Such spatially explicit tools are flexible, allowing for managers to choose case‐specific criteria such as time, funding, and goals constrained for their conservation needs. Furthermore, this flexibility can also be applied to threatened species management by customizing the decision criteria for individual species' capacity to passively recolonize islands. On islands with complex restoration challenges, decision tools that help island restoration practitioners decide whether active seabird management should be paired with eradication can optimize restoration outcomes and ecosystem recovery.     

Influence of within‐patch habitat quality on high‐Andean Polylepis bird abundance

Habitat restoration strategies for fragmented high Andean forest landscapes must consider the influence of within‐patch habitat quality on bird abundance. I examined vegetation and bird abundance at three locations within a highly fragmented Polylepis forest landscape in the Cordillera Vilcanota, southern Peru. Across the landscape, there was significant variation in the vegetation structure of Polylepis forest patches of different size categories, especially in terms of tree girth, tree height, tree density, and canopy vegetation structure. Principal Component Analysis extracted five factors of habitat quality, which together accounted for 74.2% of the variability within 15 habitat variables. Polylepis bird species differed in their responses to habitat quality but, overall, variation in Polylepis bird abundance was not fully captured by the range of habitat quality variables. Tall, dense vegetation cover was clearly important for 11 conservation‐important species, a high density of large trees was important for 10 species and primary forest ground cover was important for eight species. Habitat quality exhibited no significant influence on the abundance of only one species –Asthenes urubambensis. The abundance of seven species was associated with lower elevation forest, but only one species was associated with higher elevation forest. Management of habitat quality in large and medium remnant forest patches throughout the Cordillera Vilcanota, particularly in the 3800–4200 m elevation range, will be a cornerstone in ensuring the persistence of the majority of conservation‐important bird species populations.     

Patterns of habitat utilization of small rodents in an area of Araucaria forest in Southern Brazil

Abstract We investigated patterns of spatial distribution and microhabitat selection of rodents in a patch (26 ha) of mixed ombrophilous forest (or Araucaria forest), dominated by the Araucaria ‘pine’Araucaria angustifolia, in the National Park of Aparados da Serra, RS, in southern Brazil. We conducted monthly trapping sessions lasting 6 days (from June 2000 to June 2001) using a square grid of 121 trap stations, separated by 15 m (2.25 ha). We measured 10 microhabitat variables that could influence species distribution. These variables were related to the occurrence of mammals by using canonical correspondence analysis (CCA) and stepwise multiple regression. The distribution patterns of the three most common rodents differed significantly (χ² = 38.6; P < 0.002), with Delomys dorsalis being more clumped than the other two species. Both CCA and multiple regression analysis showed a significant effect of microhabitat variables on species occurrence. The multiple regression parameters for Oligoryzomys nigripes were R² = 0.142, P < 0.05, for Akodon montensis were R² = 0.222, P < 0.01, and for D. dorsalis R² = 0.323, P < 0.001. Variables that significantly influenced species distribution were vegetation density at 1 m height and length of fallen logs for O. nigripes, canopy cover for A. montensis, and vegetation density at 2 m height, quantity of leaves of Araucaria trees (negative relationship), tree density (except Araucaria trees), and number of potential shelters, for D. dorsalis. The results indicated that D. dorsalis is the most habitat specialist among the rodent species and that there are no apparent competitive interactions.     

基于Dobson算法的中国受威胁陆栖哺乳类优先保护识别与保护现状分析

优先保护区识别对受威胁物种的多样性保护具有重要价值。基于GIS空间分析、管理及预测能力,以中国受威胁陆栖哺乳动物为对象,建立受威胁物种的分布二值网格系统;利用Dobson算法对研究区3810个网格单元进行筛除,确定全国范围下受威胁物种的优先保护区域;结合中国主要的自然保护地分布数据（国家公园和自然保护区）,采用保护空缺方法分析优先保护区内受威胁动物的保护现状。研究发现,29个50km×50km的网格单元就包含了全部的受威胁陆栖哺乳物种,其中位于喜马拉雅山东南区等地的10个网格区域覆盖有80%以上的物种,其所处的10组县级行政区内被主要自然保护地保护的土地面积占25.9%,物种数占83.6%,存在一定的保护空缺。本文采用Dobson排除算法,以小面积规则网格为基本单元,顾及到了实验结果的客观性,有助于提高优先保护区的识别效率。     

Diversity and habitat association of small mammals in Aridtsy forest,Awi Zone,Ethiopia

Here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from August 2011 to February 2012 incorporating both wet and dry seasons in Aridtsy forest, Awi Zone, Ethiopia. Using Sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals(live traps) and 89 rodents of six species(snap traps) were trapped in 2352 and 1200 trap nights, respectively. The trapped small mammals included seven rodents and one insectivore: Lophuromys flavopuntatus(30.6%), Arvicanthis dembeensis(25.8%), Stenocephalemys albipes(20%), Mastomys natalensis(11.6%), Pelomys harringtoni(6.4%), Acomys cahirinus(4.3%), Lemniscomys zebra(0.2%) and the greater red musk shrew(Crocidura flavescens, 1.1%). Analysis showed statistically significant variations in the abundance and habitat preferences of small mammals between habitats during wet and dry seasons.