Characterization of Pallid Sturgeon (Scaphirhynchus albus) Spawning Habitat in the Lower Missouri River

Acipenseriformes (sturgeons and paddlefish) globally have declined throughout their range due to river fragmentation, habitat loss, overfishing, and degradation of water quality. In North America, pallid sturgeon (Scaphirhynchus albus) populations have experienced poor to no recruitment, or substantial levels of hybridization with the closely related shovelnose sturgeon (S. platorynchus). The Lower Missouri River is the only portion of the species’ range where successful reproduction and recruitment of genetically pure pallid sturgeon have been documented. This paper documents spawning habitat and behavior on the Lower Missouri River, which comprises over 1,300 km of unfragmented river habitat. The objective of this study was to determine spawning locations and describe habitat characteristics and environmental conditions (depth, water velocity, substrate, discharge, temperature, and turbidity) on the Lower Missouri River. We measured habitat characteristics for spawning events of ten telemetry-tagged female pallid sturgeon from 2008–2013 that occurred in discrete reaches distributed over hundreds of kilometers. These results show pallid sturgeon select deep and fast areas in or near the navigation channel along outside revetted banks for spawning. These habitats are deeper and faster than nearby river habitats within the surrounding river reach. Spawning patches have a mean depth of 6.6 m and a mean depth-averaged water-column velocity of 1.4 m per second. Substrates in spawning patches consist of coarse bank revetment, gravel, sand, and bedrock. Results indicate habitat used by pallid sturgeon for spawning is more common and widespread in the present-day channelized Lower Missouri River relative to the sparse and disperse coarse substrates available prior to channelization. Understanding the spawning habitats currently utilized on the Lower Missouri River and if they are functioning properly is important for improving habitat remediation measures aimed at increasing reproductive success. Recovery efforts for pallid sturgeon on the Missouri River, if successful, can provide guidance to sturgeon recovery on other river systems; particularly large, regulated, and channelized rivers.     

Linear skin markings in common bottlenose dolphins (Tursiops truncatus) from the Indian River Lagoon,Florida

A previously undescribed skin abnormality, referred to as “linear skin markings” (LSM), has been identified in free-ranging common bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida (IRL). The lesions were identified during photo-identification surveys conducted from 2002 and 2015. LSM presented as distinct, parallel lines running dorso-ventrally on the torso and varied in length and width. The goals of this study were to determine (1) prevalence of the condition in IRL dolphins, (2) age and sex distribution of affected animals, (3) spatial and temporal distribution patterns, (4) duration of the condition, and (5) development of hypotheses regarding the etiology of the condition. Among 1,357 individual dolphins identified during the study period, 96 (7.0%) showed evidence of LSM. Nearly all (98.8%) cases with an established home range occurred in the northern and central regions of the IRL. The majority of cases of known sex were female (85%), of which 100% had given birth to one or more calves. The mean age of animals with LSM when first observed was 7.3 with a range of 1–20 years. The maximum observed duration of LSM was 15 years. Once observed, the condition persisted indefinitely. The etiology of LSM has not been established.     

Plasticity of Least Tern and Piping Plover nesting behaviors in response to sand temperature

Birds that nest on the ground in open areas, such as Piping Plovers (Charadrius melodus) and Interior Least Terns (Sternula antillarum athalassos), are exposed to high temperatures in thermally stressful environments. As a result, some ground-nesting avian species have adapted behavioral strategies to maintain thermal regulation of eggs and themselves. We assessed the impact of sand temperature on shorebird nesting behaviors by installing video cameras and thermocouples at 52 Least Tern and 55 Piping Plover nests on the Missouri River in North Dakota during the 2014–2015 breeding seasons. Daily duration and frequency of shading behaviors exhibited a nonlinear relationship with temperature; therefore, we used segmented regressions to determine at what threshold temperature (mean temperature = 25.7^⸰C for shading behavior daily frequency and mean temperature = 25.1^⸰C for shading behavior daily duration) shorebird adults exhibited a behavioral response to rising sand temperatures. Daily nest attendance of both species decreased with increasing sand temperatures in our system. Frequency and duration of daily shading behaviors were positively correlated with sand temperatures above the temperature threshold. Piping Plovers exhibited more and longer shading behaviors above and below the temperature thresholds (below: frequency = 10.30 ± 1.69 se, duration = 7.29 min ± 2.35 se; above: frequency = 59.27 ± 6.87 se) compared to Least Terns (below: frequency = −1.37 ± 1.98 se, duration = −0.73 min ± 1.51 se; above: frequency = 31.32 ± 7.29 se). The effects of sand temperature on avian ground-nesting behavior will be critical to understand in order to adapt or develop recovery plans in response to climate change.     

锡林河流域不同植被带土壤绿菌门微生物群落的空间分布特征

[目的] 为了探究锡林河流域中游不同植被带土壤绿菌门（Chlorobi）成员的空间分布特征及驱动因子。[方法] 本文选择典型河滨带环境为研究对象,沿河流中心至河流阶地（陆向）方向,在无植被带（BC）、水莎草沼泽（BS）、灯芯草沼泽化草甸（LF）、鹅绒委陵菜草甸（HF）、河流阶地羊草草原（LT）、丘陵坡地大针茅典型草原（HT）中分别采集0-10 cm土壤样品。基于16S rRNA基因高通量测序分析土壤绿菌门微生物群落的组成、丰度及空间分布特征;结合土壤理化因子分析绿菌门微生物群落空间异质性的驱动因子。[结果] 在属水平上共检测到来自绿菌目（Chlorobiales）和Ignavibacteriales目的9个类群。Chlorobiales1、2、6及Ignavibacteriales7、9类群的最高相对丰度低于0.40%;Ignavibacteriales3、4、5、8类群的最高相对丰度介于0.54%-1.06%。Chlorobiales1、2类群在HF、LT和HT的相对丰度显著高于BS（P<0.05）,Chlorobiales1类群的相对丰度与pH和总有机碳含量呈极显著正相关（P<0.01）;Chlorobiales2类群的相对丰度与粉黏粒含量呈极显著正相关（P<0.01）;Ignavibacteriales3、5、7、9和Ignavibacterium4类群在LF的相对丰度显著高于BC（P<0.05）,与含水量呈极显著正相关（P<0.01）;Chlorobiales6和Ignavibacteriales8类群在BS的相对丰度显著高于其他植被带（P<0.05）,与氨态氮含量呈极显著正相关（P<0.01）。变异权重分析表明,土壤含水量解释了绿菌门微生物群落空间变异的65.7%。[结论] 锡林河流域不同植被带土壤绿菌门微生物群落存在明显的空间异质性;土壤含水量是不同植被带绿菌门微生物群落空间异质性的主要驱动因子。     

Physical size,condition, and demography of chamois (Rupicapra rupicapra L.) in the Avoca River region,Canterbury, New Zealand

Abstract

The physical and demographic characteristics of chamois in the Avoca region are evaluated from 306 animals shot and autopsied between 1975 and 1978. These data are compared with published and unpublished information for chamois populations in Westland and Canterbury. Avoca chamois were large-framed, but weighed less than Westland chamois. The weight difference suggests better habitat condition and food resources for Westland animals, but the large skeletal size of Avoca chamois is unexplained.

High rates of juvenile mortality were caused by acute bacterial-pneumonia infections (Pasteurella). These deaths and other losses by natural causes were offset by the good breeding success of adult females so that stable population numbers were maintained.     

Likely future extirpation of another Asian river dolphin: The critically endangered population of the Irrawaddy dolphin in the Mekong River is small and declining

The population of Irrawaddy dolphins that occupies the Mekong River in southern Lao People's Democratic Republic and Cambodia is classified as Critically Endangered by the IUCN. Based on capture‐recapture of photo‐identified individuals, we estimated that the total population numbered 93 ±  SE 3.90 individuals (95% CI 86–101), as of April 2007. The combined photo‐identification and carcass recovery program undertaken from 2001 to 2007 established that the Irrawaddy dolphin population inhabiting the Mekong River has reached a critical point with regards to its continued survival, where immediate research and management actions are required to greatly reduce adult mortality, and establish the cause of newborn mortality. In addition, community consultation is required to initiate, and evaluate, urgently required conservation measures. An ongoing well‐designed combined program of abundance estimation (i.e., photo‐identification) and carcass recovery is required to monitor total population size and mortality rates, to inform and evaluate management initiatives. The conclusions of this paper are likely generic to river dolphin populations, particularly where photo‐identification is possible.     

Late Ordovician brachiopods from eastern North Greenland: equatorial offshore migration of the Red River fauna

Abstract: Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the Børglum River Formation of the Centrum Sø area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna is thus extended to the easternmost extremity of the Laurentian craton. The assemblage compares specifically with the Hiscobeccus brachiopod fauna, based on key taxa such as notably Hiscobeccus gigas (Wang, 1949), and indicates a late Katian age for this part of the succession. For the first time, this typically inland, shallow‐water fauna is found associated with genera like Bimuria, suggesting a transitional marginal facies with outer shelf benthos. The current study describes a Hiscobeccus fauna that lived at the seaward edge of its preferred habitat. Furthermore, an unpublished Hiscobeccus fauna, from the Børglum River Formation of Peary Land, central North Greenland, as well as several occurrences from the Kap Jackson and Cape Calhoun formations in various parts of Washington Land, western North Greenland, are described here. These show a distinct shift from older strata containing H. capax (Conrad, 1842) to younger strata exclusively yielding specimens of H. gigas. As H. gigas occurs in the upper part of the Cape Calhoun Formation in Washington Land, it indicates that the upper boundary of the Cape Calhoun Formation is considerably younger than previous estimates, reaching into the uppermost Katian (middle Cautleyan–Rawtheyan). The Cape Calhoun Formation correlates with the upper member of the Børglum River Formation and further demonstrates that the Hiscobeccus fauna was widespread in Laurentian marginal settings of North Greenland. Even though the Hiscobeccus fauna was pan‐continental during the late Katian (Richmondian), it possesses a strong provincial signal during the later Ordovician. The new occurrences indicate that this fauna extended to the north‐eastern margin of the Laurentian Craton. It lived in close association with cosmopolitan faunal elements that may have been the earliest sign of the succeeding invasion of migrants from Baltica that arrived later during the Hirnantian. The offshore migration of this atypical Hiscobeccus fauna likely demonstrates the path of warm‐water currents as the Centrum Sø locality was located at the equator during the Late Ordovician.     

Spatial population structure of the Neotropical tiger catfish Pseudoplatystoma metaense: skull and otolith shape variation

Using geometric morphometrics, the skull and otolith of tiger catfish Pseudoplatystoma metaense were analysed to identify population structure in tributaries of the Apure River (i.e. the Sarare, Caparo, Guanare, Portuguesa and San Carlos Rivers) in the Orinoco basin, Venezuela. The analyses show uniformity in skull and otolith shapes of P. metaense within and among four tributaries, with only the Caparo River showing significant differences. Within the Apure basin, the stock of P. metaense was differentiated through spawning, refuge and nursery areas. This study concludes that populations of P. metaense from each major tributary in the Orinoco basin should be considered as part of a metapopulation system for management purposes. Human disturbances in the catchment have directly reduced the spawning areas available to this species, decreased the total biomass and changed the spatial distribution of spawning areas.     

黑龙江省野生东北虎调查管理信息系统的构建

文章以黑龙江省野生东北虎（Panthera tigris altaica）野外调查数据为基础,利用地理信息系统技术、计算机技术与野生动物资源调查管理技术,构建了黑龙江省野生东北虎调查管理信息系统。主要运用面向对象程序设计语言C#和ArcGIS Engine嵌入式组件技术以及SQL Server数据库技术,设计并构建东北虎调查管理系统,实现了对野生东北虎调查数据的图形可视化操作管理。同时,结合研究区域内的自然因素和人文因素对调查资源进行动态的空间分析,及时准确地反映出东北虎的种群数量和空间变化规律,并制作出相应的分类专题图及野外分布信息统计图表等。该管理信息系统将有助于野生东北虎种群及栖息地调查数据与资料的科学管理,对于推动我国野生东北虎就地保护和科学管理具有重要意义。