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1.
Nicholas M. Anich Thomas J. Benson James C. Bednarz 《Journal of Field Ornithology》2009,80(2):206-211
ABSTRACT. Although radio telemetry can provide useful information, the possible negative effects of transmitters, including biased results and detrimental effects on the birds, must also be considered. Several investigators have examined the effects of transmitters on larger birds, but few have examined their possible long-term effects, as assessed by return rates, on small passerines. We examined the possible negative effects of transmitters on a small (15.5 g) passerine. We used glue to attach radio transmitters to 40 male Swainson's Warblers ( Limnothlypis swainsonii ) at two study sites in Arkansas in 2005 and 2006. To assess possible effects of transmitters on survival, we compared the following-year return rates of radio-tagged birds to birds that were captured and color banded, but did not receive transmitters. Least squared mean return rates for all birds ranged between 0.46 and 0.57. We found no significant difference in the following-year return rate of radio-tagged and nonradio-tagged birds. In addition, we found no significant differences in return rates between study sites or years, and no significant interactions between any combination of radio transmitter (radio tagged or not), site, and year. Our results indicate that attachment of transmitters did not affect return rates of male Swainson's Warblers and that the glue-on technique is a good option for short-term studies of small passerines. 相似文献
2.
Gary R. Graves; 《Ecology and evolution》2024,14(3):e11099
The core breeding range of Swainson's warbler (Limnothlypis swainsonii) overlaps a zone of exceptionally high tornado frequency in southeastern North America. The importance of tornadoes in creating breeding habitat for this globally rare warbler and other disturbance-dependent species has been largely overlooked. This paper estimates tornado frequency (1950–2021) and forest disturbance in the 240 counties and parishes in which breeding was documented from 1988 to 2014. The frequency of destructive tornadoes (EF1-EF5) varied 6-fold across the breeding range with a peak in the Gulf Coast states. Counties from east Texas to Alabama experienced the lowest median return interval of 5.4 years per 1000 km2, resulting in approximately 2477 ha of forest damage per 1000 km2 per century, based on current forestland cover. Tornadoes were significantly less frequent north and east of the core breeding range, with return intervals increasing to 9.1 years per 1000 km2 for breeding counties on the Atlantic coastal plain, 10.2 years per 1000 km2 in the Ozark Mountains, and 32.3 years per 1000 km2 in the Appalachian Mountains. Breeding counties within 150 km of the coastline from east Texas to North Carolina are also subjected to the highest frequency of hurricanes in the Western Hemisphere. Hurricanes often cause massive forest damage but archived meteorological and forestry data are insufficient to estimate the aggregate extent of forest disturbance in breeding counties. Nevertheless, the combined impact of tornadoes and hurricanes in the pre-Anthropogenic era was likely sufficient to produce a dynamic mosaic of early-successional forest crucial for the breeding ecology of Swainson's warbler. To ensure the long-term survival of this rare warbler, it is advisable to develop habitat management plans that incorporate remote sensing data on early-successional forest generated by catastrophic storms as well as anthropogenic activities. 相似文献
3.
THOMAS J. BENSON NICHOLAS M. ANICH JEREMY D. BROWN JAMES C. BEDNARZ 《The Journal of wildlife management》2010,74(1):81-93
ABSTRACT Numerous factors, including nest predation and brood parasitism, may limit populations of neotropical migratory birds. However, nest predation and brood parasitism are not constant, and temporal, biological, habitat, and landscape factors can affect the likelihood of these events. Understanding these patterns is important for species of conservation concern for which managers seek to provide quality habitat. One such species, the Swainson's warbler (Limnothlypis swainsonii), is a neotropical migrant that breeds primarily in bottomland hardwood forests of the southeastern United States. Little is known of factors influencing reproductive success of this rare, yet locally abundant, species. From 2004 through 2007, we examined factors influencing reproductive success of Swainson's warblers at 2 sites in eastern Arkansas, USA, St. Francis National Forest and White River National Wildlife Refuge. We used 2-stage modeling to assess the relationship between 1) temporal and biological, and 2) habitat and landscape factors and brood parasitism, nest survival, and fledgling production. Brood parasitism was greater in this population (36%) than reported elsewhere (≤ 10%), but decreased throughout the breeding season. Nest survival was comparable to or lower than in other populations of this species and increased throughout the breeding season. The probability of brood parasitism was greater near forest edges. Although nests of Swainson's warblers were often associated with giant cane (Arundinaria gigantea), nest survival had a weak negative association with cane density. For nests that were successful, the best predictor of number of Swainson's warblers fledged was brood-parasitism status: nonparasitized nests fledged 2.75 young, whereas parasitized nests fledged 0.60 Swainson's warblers. Our findings suggest that managing and restoring relatively high-elevation bottomland forests that are located far from agricultural edges should increase Swainson's warbler productivity. 相似文献
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Jessica Kemper Richard M. Cowling David M. Richardson Greg G. Forsyth David H. McKelly 《Austral ecology》2000,25(2):179-186
The South Coast Renosterveld has been fragmented extensively by agriculture. The extent of this fragmentation in terms of overall habitat loss, fragment sizes and fragment numbers has not been described previously, thereby limiting the development of conservation strategies for this vegetation type. Patterns of renosterveld loss in three sectors along a west–east gradient were described using LANDSAT imagery and a Geographical Information System‐based program (FRAGSTATS) for spatial pattern analysis. These patterns were then correlated with rainfall and topography measures, which are indicators of agricultural potential. Over 80% of the South Coast Renosterveld has been cultivated. Fragmentation levels increased significantly from east to west, with 33% of natural vegetation remaining in the east and only 4% in the west. Topographical variables were the strongest predictors of patterns of renosterveld loss, with fragments being largely confined to slopes too steep for ploughing; they therefore face little risk of future cultivation. These results have implications for conservation planning options for the South Coast Renosterveld. There is the potential for large reserves in the east, as well as corridor reserves along major river valleys, but for only small, isolated reserves in the west. 相似文献
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Johann H van Niekerk 《Ostrich》2016,87(3):231-240
This paper explains habitat use by Swainson’s Spurfowl Pternistis swainsonii on maize Zea mays and livestock farms on the Highveld south-east of Johannesburg, South Africa. The purpose is to describe habitat modification methods to manipulate the abundance of Swainson’s Spurfowl on Highveld farms where maize is produced. Field observations were conducted along a 100 km road transect during June 2014–May 2015. A hierarchical habitat analysis with three spatial levels was applied. The location of adult male Swainson’s Spurfowl was used as an indicator of habitat use. Females breed and rear broods in male territories. The micro (2.5-m-radius plot around the birds) and macro (>2.5-m-radius plot) habitats and landscape features were recorded for each sighting. Spurfowl moved within landscapes on a seasonal basis. A micro/macro combination linked with landscape features was a reliable indicator of spurfowl habitat preferences. Micro- and macro-habitats within landscapes can potentially be modified at a single spatial level, or a combination of levels, to manipulate spurfowl abundance on Highveld farms with maize production and livestock. 相似文献
7.
J.M. Hoekstra 《Journal of Insect Conservation》1998,2(3-4):179-185
Orthopteran species are increasingly threatened with extinction in the wild. I review the state of orthopteran conservation in the wild, focusing on unique challenges facing these efforts. To provide a basis for discussion, I first review conservation efforts for Trimerotropis infantilis, the Zayante bandwinged grasshopper, which was the first orthopteran given official protection under the U.S. Endangered Species Act. I then address the principal challenges for orthopteran conservation. Successful conservation of Orthoptera in the wild will require motivation for conservation action, availability of basic biological information, and development of applied management programmes. 相似文献
8.
Two troglobitic fishes of conservation concern that inhabit Missouri are the Ozark and southern cavefishes, Amblyopsis rosae and Typhlichthys subterraneus, respectively. These species inhabit the groundwater of karstified bedrock in the Springfield and Salem plateau regions of the state, respectively. These two areas differ substantially – geographically, geologically, and hydrologically. This paper explores how these differences interact in shaping (1) the habitat in which these two species dwell, (2) the resulting ecological constraints that the fishes face, (3) how their ecologies and populations reflect these constraints, and (4) how conservation and management efforts may need to be tailored to best compliment the unique challenges that each species presents. 相似文献
9.
The study on the population status and human impacts on the endemic and endangered Swayne’s hartebeest (Alcelaphus buselaphus swaynei) was carried out in Nechisar Plains, Nechisar National Park, between 2009 and 2010. Direct and total count methods were applied in the population census. Data collected since 1967 were also examined to indicate trends of Swayne’s hartebeest populations and their translocation status. In eight illegal Guji Oromo settlements, a total of 134 household samples were identified for group discussion and interview. A trend on livestock population was carried out. The total count of Swayne’s hartebeest was 12, 11 and 12 during the 1st, 2nd and 3rd counts, respectively. The population has been decreasing and nowadays only 12 individuals remain. Most respondents had a negative attitude towards conservation areas. The increase in livestock population from 1985 to 1996 was 47.8%. It also increased by 49.9% and 56.5% during 2006 and 2010, respectively. There were 12,531 heads of livestock that depended on the grass plains illegally. Overstocking rate of livestock, illegal resource exploitation and loss of wildlife habitat were the major problems encountered. Active measures have to be implemented to control the human impact and safeguard the future of Swayne’s hartebeest. 相似文献
10.
动物通道是缓解高速公路对其周边野生动物生境隔离的有效措施,通道的位置是影响其使用效率的关键因素,然而现有研究对通道的选址却甚少涉及。以武深高速为例,推荐一种基于物种运动路径识别的通道选址方法,选取影响动物生境选择的环境因子构建评价体系,借助GIS手段对公路周边野生动物生境适宜性进行分析,在此基础上借鉴水文分析原理快速准确地刻画出物种在生境中的潜在活动路径,从而确定了5处高速公路上建设动物通道的理想位置。结果表明,该方法能定量地反映出生境的质量格局对于物种运动的影响,准确定位出物种运动受到阻碍的关键区域,在景观层次上,提出的通道位置能有效地缓解栖息地破碎化造成的生态压力;研究不但能弥补目前研究的不足,同时亦为道路网设计、城市生态规划等相关领域研究提供科学参考。 相似文献
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Roberto Buonomo Jorge Assis Francisco Fernandes Aschwin H. Engelen Laura Airoldi Ester A. Serrão 《Molecular ecology》2017,26(3):766-780
Effective predictive and management approaches for species occurring in a metapopulation structure require good understanding of interpopulation connectivity. In this study, we ask whether population genetic structure of marine species with fragmented distributions can be predicted by stepping‐stone oceanographic transport and habitat continuity, using as model an ecosystem‐structuring brown alga, Cystoseira amentacea var. stricta. To answer this question, we analysed the genetic structure and estimated the connectivity of populations along discontinuous rocky habitat patches in southern Italy, using microsatellite markers at multiple scales. In addition, we modelled the effect of rocky habitat continuity and ocean circulation on gene flow by simulating Lagrangian particle dispersal based on ocean surface currents allowing multigenerational stepping‐stone dynamics. Populations were highly differentiated, at scales from few metres up to thousands of kilometres. The best possible model fit to explain the genetic results combined current direction, rocky habitat extension and distance along the coast among rocky sites. We conclude that a combination of variable suitable habitat and oceanographic transport is a useful predictor of genetic structure. This relationship provides insight into the mechanisms of dispersal and the role of life‐history traits. Our results highlight the importance of spatially explicit modelling of stepping‐stone dynamics and oceanographic directional transport coupled with habitat suitability, to better describe and predict marine population structure and differentiation. This study also suggests the appropriate spatial scales for the conservation, restoration and management of species that are increasingly affected by habitat modifications. 相似文献
13.
A primary means of conserving a species or a habitat in a human‐dominated landscape is through promoting coexistence with humans while minimizing conflict. For this, we should understand how wildlife is impacted by direct and indirect human activities. Such information is rare in areas with high human densities. To investigate how animals respond to altered ecological conditions in human‐dominated landscapes, we focused on a wild herbivore of conservation concern in the Krishnasaar Conservation Area (KrCA) in Nepal. Here, blackbuck Antilope cervicapra, a generalist grazer, lives in refugia located with a growing human population. We studied the impacts of humans on habitat use and behavior of blackbuck. We laid 250 × 250 m grid cells in the entire KrCA and carried out indirect sign surveys with three replications for habitat use assessment. We observed herds of blackbuck for 89 h in different habitat types using scan sampling methods. Our habitat‐use survey showed that habitats under intensive human use were hardly used by blackbuck, even when high‐quality forage was available. Habitat openness was the major predictor of habitat use inside the core area, where levels of human activities were low. We also found a positive correlation between habitat use by blackbuck and livestock. Blackbuck were substantially more vigilant when they were in forest than in grassland, again indicating an influence of risk. Overall, blackbuck appear to be sensitive to the risk associated with both natural and anthropogenic factors. Our findings have direct implications for managing human–wildlife interactions in this landscape, specifically regarding strategies for livestock grazing in habitats highly used by blackbuck and concerning predictions of how changing land use will impact the long‐term persistence of blackbuck. Our work suggests that wild herbivores may be able to persist in landscapes with high human densities so long as there are refuges where human activities are relatively low. 相似文献
14.
A large complement of Australia’s biotic web is dependent on a regular regime of burning, much of which is the result of firing by humans. Many researchers have suggested that moderate and repeated burning by Aborigines is a tool designed to enhance hunting efficiency. We present the first test of this with data on contemporary Martu Aboriginal burning and hunting strategies in the arid spinifex savanna of the Western Desert during the cool-dry season (May–August). Our results show a strong positive effect of mosaic burning on the efficiency of hunting burrowed prey (primarily conducted by women), but not larger mobile prey (primarily conducted by men). We suggest that regular anthropogenic disturbance through burning in Australia’s Western Desert may be important for sustaining biodiversity and habitat mosaics, but these effects may be maintained primarily by women’s hunting of burrowed game. We discuss the implications of these results for understanding variability in hunting strategies, issues of conservation, and land management policy for the region. 相似文献
15.
生物多样性保护的景观规划途径 总被引：96，自引：1，他引：96
景观规划设计在生物多样性保护中起着决定性的作用。基于不同的保护哲学,生物多样性保护的景观规划途径主要可分为两种：一是以物种为核心的景观规划途径,另一种是以景观元素为核心和出发点的规划途径。前者首先确定物种,然后根据物种的生态特性来设计景观格局,后者则以各种尺度的景观元素作为保护对象,根据其空间位置和关系设计景观格局。多种空间战略被认为有利于生物多样性的保护,包括保护核心栖息地、建立缓冲区、构筑廊道、增加景观异质性和引入或恢复栖息地。落实这些空间战略必须首先回答选择什么和在什么地方设计上述景观元素的问题。对此,目前尚没有很好的答案。传统的生物保护战略被动地强调现存濒危物种和景观元素的保护,如果将物种运动和生态过程作为一个能动的景观控制过程来对待,我们将会有一种全新的景观规划途径。其中有三个方面的概念对这种新的景观规划途径有启发意义：即景观的空间构型对生态过程的作用,生物进化空间轨迹与景观格局设计及景观阻力与潜在的生态基础设施的设计。景观生态安全格局正是在这些方向上的一个新的探索。 相似文献
16.
Kenton Neufeld Douglas A. Watkinson Keith Tierney Mark S. Poesch 《Diversity & distributions》2018,24(5):593-604
Aim
Hydrologic alterations are widespread in freshwater ecosystems worldwide and often detrimentally impact fish populations. Habitat suitability models are commonly used to assess these impacts, but these models frequently rely upon observed fish–habitat relationships rather than more mechanistic underpinnings. The aim of this study was to demonstrate how to incorporate swim performance into a measure of habitat connectivity at a fine scale, providing a method for assessing the availability of suitable habitat for stream fishes.Location
We applied this technique to an endangered species, the Western Silvery Minnow Hybognathus argyritis, in the Milk River of southern Alberta, Canada. The Milk River is an augmented system, where a diversion in nearby St. Mary River augments flow by a factor >3 × (from 1–5 m3/s to 15–20 m3/s).Methods
We used laboratory measured swim performance of Western Silvery Minnow to develop a movement cost function that was used in conjunction with a habitat suitability model to assess habitat availability via a recently developed graph‐theoretic metric, equivalent connected area (ECA).Results
Stream augmentation altered not only habitat suitability but also habitat connectivity for this species. During augmentation, suitable habitat area declined by 81.3%. Changes in habitat connectivity were site dependent. Movement costs between habitat patches were lower during augmentation due to current‐assisted dispersal and increased distance to patches during natural flows from dried streambeds. When movement costs were incorporated into ECA, ECA decreased by 78.0% during augmentation.Main conclusions
With changing climate and increasing anthropogenic impacts on aquatic ecosystems, understanding how freshwater fishes relate to their habitat is critical for appropriate management. In many cases, such as the Western Silvery Minnow, mitigating habitat suitability may not be sufficient, as species are unable to reach suitable habitat. The incorporation of swim performance into habitat connectivity assessments, as carried out here, can be easily adapted to other species and situations and can improve the understanding of impacts to stream fishes and increase the effectiveness of mitigation efforts. 相似文献17.
自然保护区体系构建方法研究进展 总被引：3，自引：0，他引：3
面对越来越严重的野生生物的生境丧失和生境破碎化威胁,如何构建科学的自然保护区体系成为自然保护区学领域研究的热点问题.本文在对国内外自然保护区体系构建文献分类整理的情况下,具体介绍了保护空缺分析、保护优先区分析和生态区保护规划分析等自然保护区合理布局方法,以及生境廊道规划设计方法.对各种方法的优缺点和适用条件进行了分析,提出了目前自然保护区体系构建方法研究中存在的问题,并探讨了未来的研究方向,以期对自然保护区体系构建的研究和实践提供一定的参考,促进自然保护区事业的发展. 相似文献
18.
Rieks D. van Klinken Justine V. Murray Javier N. Garcia Anthony R. Clarke 《The Annals of applied biology》2019,175(3):350-362
Control of mobile pests frequently requires area‐wide management (AWM) that spans commercial and non‐commercial habitats. Spatial modelling of habitat suitability can guide investment and implementation of AWM, but current approaches rarely capture population drivers, including local foraging, at an appropriate spatial resolution. To support the development of AWM for the fruit fly pest, Bactrocera tryoni (Tephritidae), we developed a habitat suitability model for the three premier fruit‐growing regions in south‐eastern Australia (~34,780 km2). Expert elicitation and published literature was used to develop a Bayesian network to model the drivers of B. tryoni habitat suitability, as determined by the ability of populations to persist and increase. The effect of uncertainty was tested through sensitivity analysis. The model was then linked with spatially explicit data (at 10 m resolution) to generate risk maps, using moving windows to capture local foraging movement. Habitat suitability was most strongly influenced by host availability within a distance of 200 m. Climate stress, and soil moisture for pupation, was also limiting. Experts were uncertain regarding the relative importance of drivers of host availability (host preference, host density, fruit seasonality), but this did not greatly affect model outputs. Independent trapping data supported model predictions, but their value was limited as traps were placed almost exclusively in optimal or suitable habitat. Amenability to AWM, when assessed as the ratio of suitable or optimal habitat that was under non‐horticultural versus horticultural land‐uses, differed by region (0.15–1.17). However, risk‐mapping did identify where ratios were locally most favourable (lowest). Also, predominantly local dispersal by B. tryoni suggests AWM for pest suppression could be applied at a landscape‐scale. Results show that a relatively simple model could capture the multi‐scale drivers of population dynamics and the complexity of landscapes sufficiently to guide AWM of a mobile pest. 相似文献
19.
Alina Gabriela Monroy-Gamboa;Víctor Sánchez-Cordero;Sahotra Sarkar; 《Conservation Science and Practice》2024,6(3):e13099
Anthropogenic loss of biodiversity continues to increase worldwide, and existing conservation area networks (CANs) are inadequate for its adequate representation and persistence. To identify a set of new nominal conservation areas in Oaxaca, a Mesoamerican biodiversity hotspot in Mexico, for terrestrial vertebrate species, we used a multi-criteria systematic conservation planning approach. Besides minimizing the area incorporated into the nominal CAN, we incorporated 25 socioeconomic variables using multi-attribute value theory. We constructed a portfolio of nominal CAN solutions for four different scenarios all of which satisfied a 10% representation target for the modeled suitable habitat of each vertebrate species: (1) existing protected area-based (PA) solution; (2) voluntary conservation area-based (VCA) solution; (3) PA-VCA solution; and (4) R-C solution (rarity-complementary algorithm). The PA-VCA and PA solutions were the most expensive in terms of area that had to be included in the nominal CANs (13,352 km2 and 12,587 km2, respectively). In all our multi-criteria analyses, highest costs were associated with maximizing the number of airports, amount of tourism, and length of available highways in a nominal CAN. We have thus established a portfolio of multi-criteria solutions to the problem of creating an adequate CAN for the representation of terrestrial vertebrate species. 相似文献
20.
景观中有某些潜在的空间格局,被称为生态安全格局,他们由景观中的某些关键性的局部,位置和空间联系所构成,ＳＰ对维护或控制某种生态过程中有着异常重要的意义。ＳＰ的组分对过程来说具有主动,空间联系和高效的优势,因而对生物保护和景观改变具有重要的意义。生物的空间运动和栖息地的维护需要克服景观阻力来完成,所以,阻力面（流动表面）反映了生物扩散和维持的动态,ＳＰ可以根据流动表面的空间特性来判别。一个典型的生物 相似文献