scholarly journals Pronounced Fidelity and Selection for Average Conditions of Calving Area Suggestive of Spatial Memory in a Highly Migratory Ungulate

2020 ◽  
Vol 8 ◽  
Author(s):  
Matthew D. Cameron ◽  
Kyle Joly ◽  
Greg A. Breed ◽  
Christa P. H. Mulder ◽  
Knut Kielland
Keyword(s):  
Spatial Memory ◽  
Resource Selection ◽  
Rangifer Tarandus ◽  
Human Impacts ◽  
Environmental Stochasticity ◽  
Life History Stage ◽  
High Quality ◽  
Western Arctic ◽  
Underlying Mechanisms ◽  
Study Species

A distinguishing characteristic of many migratory animals is their annual return to distinct calving (birthing) areas in the spring, yet the navigational mechanisms employed during migration that result in this pattern are poorly understood. Effective conservation of these species requires reliable delineation of such areas, quantifying the factors that influence their selection, and understanding the underlying mechanisms resulting in use of calving areas. We used barren-ground caribou (Rangifer tarandus granti) as a study species and identified calving sites of the Western Arctic Herd in Alaska using GPS collar data from 2010–2017. We assessed variability in calving areas by comparing spatial delineations across all combinations of years. To understand calving area selection at a landscape scale, we performed a resource selection analysis comparing calving sites to available locations across the herd’s range and incorporated time-varying, remotely sensed metrics of vegetation quality and quantity. We found that whereas calving areas varied from year to year, this annual variation was centered on an area of recurring attraction consistent with previous studies covering the last six decades. Calving sites were characterized by high-quality forage at the average time of calving, but not peak calving that year, and by a narrow range of distinct physiographic factors. Each year, calving sites were located on areas of above-average conditions based on our predictive model. Our findings indicate that the pattern of spring migration for pregnant females was to migrate to areas that consistently provide high-quality forage when averaged across years, and then upon arriving at this calving ground, refine selection using their perception of annually varying conditions that are driven by environmental stochasticity. We suggest that the well-documented and widespread pattern of fidelity to calving grounds by caribou is supportive of a navigational mechanism based on spatial memory at a broad scale to optimize foraging and energy acquisition at a critical life-history stage. The extent to which migrants depend on memory to reach their spring destinations has implications for the adaptability of populations to changing climate and human impacts.

scholarly journals Aerial survey and telemetry data analysis of a peripheral caribou calving area in northwestern Alaska

Rangifer ◽  
2019 ◽  
Vol 39 (1) ◽  
pp. 43-58
Author(s):  
Alexander K. Prichard ◽  
Ryan L. Klimstra ◽  
Brian T. Person ◽  
Lincoln S. Parrett
Keyword(s):  
Industrial Development ◽  
Rangifer Tarandus ◽  
Aerial Survey ◽  
The Arctic ◽  
Primary Data ◽  
Data Sets ◽  
Telemetry Data ◽  
Western Arctic ◽  
Data Source

With industrial development expanding in the Arctic, there is increasing interest in quantifying the impacts of development projects on barren ground caribou (Rangifer tarandus granti). The primary data source to assess caribou distribution and predict impacts in remote areas of Alaska has shifted in recent decades from aerial survey data to telemetry data, but these techniques have different strengths and weaknesses. The ranges of two caribou herds, the Western Arctic Herd and the Teshekpuk Herd, overlap in northwest Alaska between Wainwright and Atqasuk, Alaska. Based on long-term telemetry data sets, this region was thought to be outside of the core calving ranges of both herds. Calving has long been reported to occur in this general area, but early reports assumed caribou were from the Western Arctic Herd and only one systematic aerial survey of caribou density and distribution during calving has been conducted in this area in recent decades. Following interest in industrial development in this area, we conducted aerial strip-transect surveys during early to mid-June 2013–2015 to directly assess the density and distribution of caribou in the area and we used existing telemetry data to compare our results to the seasonal distribution of both herds. Total caribou densities varied between 0.36 and 1.06 caribou/km² among years, and calf densities varied 0.04 and 0.25 calves/km² among years. Contrary to assumptions by early researchers in the area, telemetry data indicated that caribou in this area during early to mid-June were from the Teshekpuk Herd. The use of telemetry data alone underestimated the importance of this area for calving, but the combination of aerial surveys and telemetry data provided complementary information on caribou use of this area showing the importance of collecting the appropriate types of data for assessing potential impacts of development on caribou.

scholarly journals Caribou of the Central Arctic Region of Alaska in relation to adjacent caribou herds

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 65
Author(s):  
D. R. Carruthers ◽  
R. D. Jakimchuk
Keyword(s):  
Rangifer Tarandus ◽  
Arctic Region ◽  
Early Spring ◽  
Summer Period ◽  
Western Arctic ◽  
Unusual Increase

There was an unusual increase in numbers of caribou (Rangifer tarandus granti) in the Central Arctic region of Alaska from 1981 to 1985. In fall and winter numbers were up to five times greater than at the onset of calving in June. Numbers appeared to double during the month of June each year, then remain relatively stable over the summer period with a further increase in the fall. Ingress of caribou from outside the region in fall was observed in all years and egress in the early spring is postulated. We conclude that a small resident herd inhabits the region year round with numbers increasing through ingress of caribou from the Western Arctic herd possibly beginning as early as June. Increases or decreases in the size of adjacent herds probably will affect the numbers of caribou occupying the Central Arctic region.

scholarly journals Emergent weak home-range behaviour without spatial memory

2016 ◽  
Vol 3 (6) ◽  
pp. 160214 ◽  
Author(s):  
Tomoko Sakiyama ◽  
Yukio-Pegio Gunji
Keyword(s):  
Home Range ◽  
Spatial Memory ◽  
Resource Selection ◽  
Memory Capacity ◽  
Cognitive Capacity ◽  
Agent Based Model ◽  
Local Conditions ◽  
Selection Rules ◽  
Agent Based ◽  
Living Things

Space-use problems have been well investigated. Spatial memory capacity is assumed in many home-range algorithms; however, actual living things do not always exploit spatial memory, and living entities can exhibit adaptive and flexible behaviour using simple cognitive capacity. We have developed an agent-based model wherein the agent uses only detected local regions and compares global efficiencies for a habitat search within its local conditions based on memorized information. Here, memorized information was acquired by scanning locally perceived environments rather than remembering resource locations. When memorized information matched to its current environments, the agent changed resource selection rules. As a result, the agent revisited previous resource sites while exploring new sites, which was demonstrating a weak home-range property.

scholarly journals Paediatrician’s guide to epigenetics

2019 ◽  
Vol 104 (3) ◽  
pp. 297-301 ◽  
Author(s):  
Lauren Byrne ◽  
Amanda Jane Drake
Keyword(s):  
Life Events ◽  
Early Life ◽  
Normal Development ◽  
Disease Risk ◽  
Regulation Of Gene Expression ◽  
High Quality ◽  
High Quality Research ◽  
Growth Development ◽  
Underlying Mechanisms ◽  
Early Life Events

Epigenetic regulation of gene expression is critical for normal development. Dysregulation of the epigenome can lead to the development and progression of a number of diseases relevant to paediatricians, including disorders of genomic imprinting and malignancies. It has long been recognised that early life events have implications for future disease risk, and epigenetic modifications may play a role in this, although further high-quality research is needed to better understand the underlying mechanisms. Research in the field of epigenetics will contribute to a greater understanding of growth, development and disease; however, paediatricians need to be able to interpret such research critically, in order to use the potential advances brought about through epigenetic studies while appreciating their limitations.

Variation in the seasonal selection of resources by woodland caribou in northern British Columbia

2008 ◽  
Vol 86 (8) ◽  
pp. 812-825 ◽  
Author(s):  
D. D. Gustine ◽  
K. L. Parker
Keyword(s):  
Conservation Planning ◽  
Resource Selection ◽  
Rangifer Tarandus ◽  
Rank Correlation ◽  
Late Winter ◽  
Theoretic Approach ◽  
Woodland Caribou ◽  
Predictive Capacity ◽  
Spearman’S Rank Correlation ◽  
Selection Strategies

Conservation planning for species of concern or importance can be aided by resource selection functions (RSFs) that identify important areas or attributes. Models that can be interpreted biologically and provide reasonable predictive capacity may best be based on data from individuals grouped into seasonal selection strategies for particular geographical areas or similarities in topographical and vegetative associations. We used logistic regression, the information–theoretic approach, satellite imagery, and locational data (n = 31 females; 16 803 locations) from global positioning system (GPS) collared woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) to model resource selection by animals during calving, summer, fall, breeding, winter, and late-winter seasons. Higher variation in resource use corresponded to times when caribou and their young were most susceptible to predation or when food resources were limited. Even with multiple selection strategies, caribou followed a general progression from higher to lower elevation habitats from calving and summer to late winter. Caribou selected against or completely avoided the burned–disturbed vegetation class in every season except summer. We incorporated RSFs with a raster geographic information system to create selection landscapes. We validated selection landscapes using withheld GPS data (n = 6077), 50 known calving sites, and Spearman’s rank correlation coefficient. Selection models and final selection landscapes performed well in validating use locations of woodland caribou in all seasons (all P < 0.003) and in predicting known calving sites (P < 0.001). When seasonal selection strategies are identified and models are coupled with validation, RSFs are effective tools to assist in conservation planning.

scholarly journals Movement pathways and habitat selection by woodland caribou during spring migration

Rangifer ◽  
2005 ◽  
Vol 25 (4) ◽  
pp. 143 ◽  
Author(s):  
D. Joanne Saher ◽  
Fiona K.A. Schmiegelow
Keyword(s):  
Habitat Selection ◽  
Land Use Planning ◽  
Resource Selection ◽  
Rangifer Tarandus ◽  
Linear Models ◽  
Woodland Caribou ◽  
Winter Habitat ◽  
System Data ◽  
Primary Focus ◽  
Migratory Movements

Woodland caribou (Rangifer tarandus caribou) are a threatened species throughout Canada. Special management is therefore required to ensure habitat needs are met, particularly because much of their current distribution is heavily influenced by resource extraction activities. Although winter habitat is thought to be limiting and is the primary focus of conservation efforts, maintaining connectivity between summer and winter ranges has received little attention. We used global positioning system data from an interprovincial, woodland caribou herd to define migratory movements on a relatively pristine range. Non-linear models indicated that caribou movement during migration was punctuated; caribou traveled for some distance (movement phase) followed by a pause (resting/foraging phase). We then developed resource selection functions (RSFs), using case-controlled logistic regression, to describe resting/foraging sites and movement sites, at the landscape scale. The RSFs indicated that caribou traveled through areas that were less rugged and closer to water than random and that resting/foraging sites were associated with older forests that have a greater component of pine, and are further from water than were random available locations. This approach to analyzing animal location data allowed us to identify two patterns of habitat selection (travel and foraging/resting) for caribou during the migratory period. Resultant models are important tools for land use planning to ensure that connectivity between caribou summer and winter ranges is maintained.

scholarly journals High-quality assembly of sweet basil genome

2018 ◽  
Author(s):  
Nativ Dudai ◽  
Marie-Jeanne Carp ◽  
Renana Milavski ◽  
David Chaimovitsh ◽  
Alona Shachter ◽  
...  
Keyword(s):  
Reference Genome ◽  
Single Copy ◽  
High Quality ◽  
Sweet Basil ◽  
Independent Analysis ◽  
Aroma Production ◽  
Culinary Uses ◽  
Underlying Mechanisms ◽  
Sequencing Platforms

AbstractSweet basil, sometimes called the King of Herbs, is well known for its culinary uses, especially in the Italian sauce ‘Pesto’. It is also used in traditional medicine, as a source for essential oils and as an ornamental plant. So far, basil was bred by classical and traditional methods due to lack of a reference genome that will allow optimized application of the most up-to-date sequencing techniques. Here, we report on the first completion of the sweet basil genome of the cultivar ‘Perrie’, a fresh-cut Genovese-type basil, using several next generation sequencing platforms followed by genome assembly with NRGENE’s DeNovoMAGIC assembly tool. We determined that the genome size of sweet basil is 2.13 Gbp and assembled it into 12,212 scaffolds. The high-quality of the assembly is reflected in that more than 90% of the assembly size is composed of only 107 scaffolds. An independent analysis of single copy orthologues genes showed a 93% completeness which reveal also that 74% of them were duplicated, indicating that the sweet basil is a tetraploid organism. A reference genome of sweet basil will enable to develop precise molecular markers for various agricultural important traits such as disease resistance and tolerance to various environmental conditions. We will gain a better understanding of the underlying mechanisms of various metabolic processes such as aroma production and pigment accumulation. Finally, it will save time and money for basil breeders and scientists and ensure higher throughput and robustness in future studies.

scholarly journals Insulin-like growth factor 1 and growth seasonality in reindeer (Rangifer tarandus) - comparisons with temperate and tropical cervids

Rangifer ◽  
1993 ◽  
Vol 13 (3) ◽  
pp. 91 ◽  
Author(s):  
J. M. Suttie ◽  
R. G. White ◽  
T. R. Manley ◽  
B. H. Breier ◽  
P. D. Gluckman ◽  
...  
Keyword(s):  
Growth Rates ◽  
Rangifer Tarandus ◽  
Plasma Concentrations ◽  
Growth Spurt ◽  
Seasonal Growth ◽  
High Quality ◽  
Rapid Weight Gain ◽  
Vernal Equinox ◽  
Ad Libitum ◽  
Autumn And Winter

Growth in temperate and arctic deer is seasonal, with higher growth rates in spring and summer while growth rates are low or negative in autumn and winter. We have measured IGF1 concentrations in the plasma of reindeer calves exposed to a manipulated photoperiod, indoors, of either 16 hours light followed by 8 hours dark each day (16L:8D) (n = 3) or 8L:16D (n = 3) from about the autumnal to the vernal equinox, to determine whether the seasonal growth spurt normally seen in spring is associated with changes in the circulating level of IGF1. A high quality concentrate diet was available ad libitum. The animals were weighed, and bled every 2 weeks and plasma samples assayed for IGF1 by radioimmunoassay. 6-8 weeks after the start of the study those calves exposed to 16L.-8D showed a significant increase in plasma IGF1 concentration which was maintained until the close of the experiment, 24 weeks after the start. In contrast IGF1 plasma concentrations in those calves exposed to a daylength of 8L:16D did not significantly alter during the study. The elevated IFG1 in the 16L:8D group was associated with rapid weight gain compared with the 8L:16D group. We have shown that the seasonal growth spurt is preceded by an elevation in plasma IFG1 concentration. Further, this elevation in IGF1 is daylength dependent. For comparison IGF1 and growth rate seasonal profiles from temperate and tropical deer are included. This comparison reveals that seasonal increases in IGF1 take place only in animals with a seasonal growth spurt. Thus IGF1 plasma level elevations seem most closely associated with the resumption of rapid growth in spring following the winter.

scholarly journals Mycobiomes of Young Beech Trees Are Distinguished by Organ Rather Than by Habitat, and Community Analyses Suggest Competitive Interactions Among Twig Fungi

2021 ◽  
Vol 12 ◽  
Author(s):  
Abu Bakar Siddique ◽  
Paolo Biella ◽  
Martin Unterseher ◽  
Benedicte Riber Albrectsen
Keyword(s):  
High Throughput Sequencing ◽  
Competitive Exclusion ◽  
Keystone Species ◽  
Interaction Network ◽  
Diversity Indices ◽  
Competitive Interactions ◽  
High Quality ◽  
Network Analyses ◽  
Plant Organ ◽  
Study Species

Beech trees (Fagus sylvatica) are prominent keystone species of great economic and environmental value for central Europe, hosting a diverse mycobiome. The composition of endophyte communities may depend on tree health, plant organ or tissue, and growth habitat. To evaluate mycobiome communalities at local scales, buds, and twigs were sampled from two young healthy mountain beech stands in Bavaria, Germany, four kilometers apart. With Illumina high-throughput sequencing, we found 113 fungal taxa from 0.7 million high-quality reads that mainly consisted of Ascomycota (52%) and Basidiomycota (26%) taxa. Significant correlations between richness and diversity indices were observed (p &lt; 0.05), and mycobiomes did not differ between habitats in the current study. Species richness and diversity were higher in twigs compared to spring buds, and the assemblages in twigs shared most similarities. Interaction network analyses revealed that twig-bound fungi shared similar numbers of (interaction) links with others, dominated by negative co-occurrences, suggesting that competitive exclusion may be the predominant ecological interaction in the highly connected twig mycobiome. Combining community and network analyses strengthened the evidence that plant organs may filter endophytic communities directly through colonization access and indirectly by facilitating competitive interactions between the fungi.

scholarly journals Cardiovascular involvement in patients with 2019 novel coronavirus disease

2021 ◽  
Vol 9 (3) ◽  
pp. 152-160
Author(s):  
Chenze Li ◽  
Dao Wen Wang ◽  
Chunxia Zhao
Keyword(s):  
Cardiovascular Diseases ◽  
Severe Acute Respiratory Syndrome ◽  
Respiratory Symptoms ◽  
Clinical Characteristics ◽  
First Line ◽  
High Quality ◽  
Cardiovascular Involvement ◽  
Underlying Mechanisms ◽  
Novel Coronavirus ◽  
Quality Reports

Abstract 2019 novel coronavirus disease (COVID-19) is caused by the infection of severe acute respiratory syndrome novel coronavirus (SARS-CoV-2). It is characterized by substantial respiratory symptoms and complicated with widespread other organ injuries. Cardiovascular impairment is one of the notable extrapulmonary manifestations, in terms of the deterioration of pre-existing cardiovascular diseases and newly onset acute events. We hereby review the high-quality reports about cardiovascular involvement in COVID-19 and summarize the main clinical characteristics of cardiac relevance for the all the first line clinical physicians. Additionally, the possible underlying mechanisms and the rationale for the application of specific medications, such as renin-angiotensin-aldosterone system inhibitors and hydroxychloroquine are also discussed.

Sign in / Sign up

Export Citation Format

Share Document