scholarly journals HABITAT SELECTION BY EXOTIC DAMA GAZELLES (NANGER DAMA RUFICOLLIS) IN TEXAS

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Elizabeth Cary Mungall ◽  
Susan M. Cooper
Keyword(s):  
Habitat Selection ◽  
Adult Males ◽  
Soil Series ◽  
Edwards Plateau ◽  
Supplemental Feed ◽  
West Texas ◽  
Core Areas ◽  
Hot Weather ◽  
Steep Terrain ◽  
One Year

Abstract Habitat selection information is important for both breeding on Texas ranches and repatriation in Africa. This is especially true for the critically endangered dama gazelle (Nanger dama). Exotic dama gazelles of the eastern subspecies (N. dama ruficollis) wearing GPS-radio collars were tracked for one year on two Texas ranches. Three adult and two subadult males were collared from a large (8,996 ha) pasture in west Texas. Next, collars went on all males plus all females released into a 202 ha Edwards Plateau pasture (seven adult females, one maturing male, and one to three adult males). On both sites, the gazelles favored the less steep terrain of the Ector soil series. Adult male core areas averaged 440 ha in west Texas (vegetation sparse) and 57 ha on the Edwards Plateau (dense food stands). These relationships allowed for estimation of the number of adult males that could be stocked in the larger pasture while still allowing room for the males to spread out. No special affinity for water sources was found, although dama gazelles do drink during hot weather when water is available. There was no consistent seasonal distributional change noted. On both Texas sites, the gazelles survive on natural browse. Where there are feeders, competition from larger animals kept gazelles out. For breeding or restoring populations, flat-to-gently rolling terrain with ample browse is best. Shade and water are important, and any supplemental feed requires access. There also needs to be enough favored habitat to accommodate the adult males without dangerous conflict.

scholarly journals Forecasting the Volatility of Crude Oil: The Role of Uncertainty and Spillovers

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4173
Author(s):  
Rangan Gupta ◽  
Christian Pierdzioch
Keyword(s):  
Crude Oil ◽  
Predictive Value ◽  
Realized Variance ◽  
International Spillovers ◽  
Forecasting Models ◽  
West Texas ◽  
Out Of Sample ◽  
One Year ◽  
Lasso Estimator

We use a dataset for the group of G7 countries and China to study the out-of-sample predictive value of uncertainty and its international spillovers for the realized variance of crude oil (West Texas Intermediate and Brent) over the sample period from 1996Q1 to 2020Q4. Using the Lasso estimator, we found evidence that uncertainty and international spillovers had predictive value for the realized variance at intermediate (two quarters) and long (one year) forecasting horizons in several of the forecasting models that we studied. This result holds also for upside (good) and downside (bad) variance, and irrespective of whether we used a recursive or a rolling estimation window. Our results have important implications for investors and policymakers.

scholarly journals Social cues facilitate habitat selection: American redstarts establish breeding territories in response to song

2006 ◽  
Vol 2 (3) ◽  
pp. 337-340 ◽  
Author(s):  
Beth A Hahn ◽  
Emily D Silverman
Keyword(s):  
Habitat Selection ◽  
Local Population ◽  
Breeding Habitat ◽  
Conspecific Attraction ◽  
Adult Males ◽  
Settlement Cues ◽  
Migratory Songbirds ◽  
American Redstarts ◽  
Spring Arrival ◽  
Northern Temperate Forests

For migratory songbirds nesting in northern temperate forests, a short breeding season demands that males rapidly establish territories. Because critical insect and vegetation resources are unavailable during spring arrival, we suggest that conspecifics serve as settlement cues for males new to a local population. To test conspecific attraction, we conducted playback experiments with American redstarts Setophaga ruticilla . Experimental results demonstrate that song playbacks strongly attract conspecifics, recruiting an average of 4.2 additional males per plot; adult males new to our sites increased, while yearling males failed to respond. Yearlings arrived 6 to 10 days later than adults, raising the possibility that yearlings responded to songs of early arriving adults rather than to playbacks. Our work indicates that conspecific attraction is an important mechanism for breeding habitat selection in an established population of a migratory forest songbird, but the effect is moderated by age, reproductive experience and arrival timing.

Mating success of alternative male phenotypes and evidence for frequency-dependent selection in Chinook salmon, Oncorhynchus tshawytscha

2010 ◽  
Vol 67 (12) ◽  
pp. 1933-1941 ◽  
Author(s):  
Barry A. Berejikian ◽  
Donald M. Van Doornik ◽  
Rob C. Endicott ◽  
Timothy L. Hoffnagle ◽  
Eugene P. Tezak ◽  
...  
Keyword(s):  
Mating Success ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
Adult Males ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Male Density ◽  
The Family ◽  
Breeding Groups ◽  
One Year

As with other species, frequency-dependent selection during reproduction has long been proposed as an important mechanism in maintaining alternative male reproductive phenotypes in Pacific salmon ( Oncorhynchus spp.). Jack salmon mature one year earlier than the youngest females in a population and are much smaller than older “adult” males. We tested the hypothesis that mating success of both phenotypes is consistent with the frequency-dependent selection model. By holding male density constant and varying the frequency of adults and jacks in eight separate breeding groups, we found that adult male access to females, participation in spawning events, and adult-to-fry reproductive success increased with their decreasing frequency in a breeding group. Jacks exhibited the same pattern (increasing success with decreasing frequency), although the relationships were not as strong as for adults. Overall, jack and adult males mated with a similar number of females, but jacks sired only 20% of all offspring. Observational data suggested that adult males benefited from sperm precedence associated with their ability to court females and enter the nest first at the time of spawning. Our work provides the first experimental evidence of frequency-dependent selection during mating in the family Salmonidae.

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Atlantic Sturgeon ◽  
Lawrence Estuary ◽  
Early Juvenile ◽  
Salt Wedge ◽  
Sandy Substrate ◽  
Core Areas ◽  
St Lawrence Estuary ◽  
Selection Of

<em>Abstract</em>.—Space use and habitat selection of early juvenile Atlantic sturgeon <em>Acipenser oxyrinchus</em> have been little studied and remain largely unknown throughout the species’ range. In 2000–2002, survey trawling, ultrasonic telemetry, benthos sampling, and hydrodynamic modeling were used to determine the summer movement patterns, home range size, and habitat use and selection of early juvenile Atlantic sturgeon in the St. Lawrence estuary. Sonic-tagged Atlantic sturgeon, assumed to be age 2 based on their size, used a global area estimated at 76 km2 that included two main core areas. Individual summer home range sizes varied from 1 to 8 km2, but core areas were generally smaller than 1 km2. The mean daily distance traveled ranged from 0.4 to 13.5 km/d and was significantly related to sturgeon size. Fish were located mostly in freshwater relatively close to the salt wedge boundary and far from the shore, intertidal zones, and islands. They mostly used the 6–10-m depth range relatively close to a channel, in areas with low bottom current velocities, and over silt–clay substrates. Salinity and distance from the salt wedge were the two most important variables explaining their habitat selection. Age-0 Atlantic sturgeon used similar depth ranges, bottom salinities, and current velocities, but occupied mainly sandy substrate. Management implications of these results are discussed in relation to the impact of dredging and sediment disposal operations in the St. Lawrence estuary.

scholarly journals Habitat Selection and Vegetational Characteristics of Antelope Fawn Bedsites in West Texas

1983 ◽  
Vol 36 (1) ◽  
pp. 110 ◽  
Author(s):  
Ronald D. Tucker ◽  
Gerald W. Garner
Keyword(s):  
Habitat Selection ◽  
West Texas

scholarly journals Common Habits, Adverse Events, and Opinions Regarding Pre-Workout Supplement Use Among Regular Consumers

Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 855 ◽  
Author(s):  
Andrew R. Jagim ◽  
Clayton L. Camic ◽  
Patrick S. Harty
Keyword(s):  
Side Effects ◽  
Adult Males ◽  
Skin Reactions ◽  
Electronic Survey ◽  
Supplement Use ◽  
Upper Limits ◽  
Heart Abnormalities ◽  
One Year ◽  
Serving Sizes ◽  
Serving Size

The purpose of the present study was to examine characteristics of multi-ingredient pre-workout supplement (MIPS) users, their common patterns/habits of MIPS ingestion, and their associated feelings about the effectiveness and safety of this class of supplements. An online electronic survey was distributed through social media to assess self-reported supplementation practices and preferences among adult males and females who reported regular MIPS use. A total of 1045 individuals responded, with 872 of these individuals (males: n = 636, 72.9%; females: n = 233, 26.7%; mean ± SD; age = 27.7 ± 7.9 years; training age = 8.2 ± 7.3 years) completing the survey. The majority of respondents reported the length of current or past MIPS consumption as greater than one year (n = 630, 72.2%), with ingestion frequencies primarily of four (n = 210, 24.1%) or five (n = 212, 24.3%) days per week of training. In addition, the three most popular goals for ingesting MIPS were increased energy and focus (n = 776, 89.0%), muscular endurance (n = 325, 37.3%), and blood flow or “pump” (n = 322, 37.0%). Although most users reported ingesting one serving size with each use, 14% reported ingesting two or more, and 18% indicated they ingest MIPS more than once per day. Importantly, over half (54%) of the respondents reported experiencing side-effects following MIPS use, including skin reactions, heart abnormalities, and nausea. Females were more likely than males to experience these side effects, despite being less likely to consume two or more serving sizes per dose. Our findings also indicated that MIPS users should consume no more than the recommended serving size of a given supplement, as the potentially significant variability in the caffeine content of MIPS products is compounded as more doses are consumed. Furthermore, MIPS users should minimize the ingestion of other supplements which contain high levels of niacin and caffeine, as the concurrent consumption of such products may put users above the tolerable upper limits for these substances.

Territoriality and dominance in male Columbian ground squirrels (Spermophilus columbianus)

1978 ◽  
Vol 56 (11) ◽  
pp. 2402-2412 ◽  
Author(s):  
J. O. Murie ◽  
M. A. Harris
Keyword(s):  
Aggressive Behavior ◽  
Ground Squirrels ◽  
Adult Males ◽  
Length Of Residence ◽  
Visual Contact ◽  
Habitat Features ◽  
Spermophilus Columbianus ◽  
Core Areas ◽  
Columbian Ground Squirrels ◽  
Spacing System

We describe the spacing system and associated aggressive behavior of male Columbian ground squirrels in southwestern Alberta for the 2 months following emergence from hibernation. Adult males (> 2 years old) were classified as dominant if they chased other males more than they were chased by them within their core areas and subordinate if the reverse was true. For dominant males, the proportion of interactions in which they were chased was much less within their core areas than outside them, and defended boundaries between some pairs of adjacent males were apparent from locations of chases and chase reversals. We consider these males to maintain spatiotemporal territories. For subordinate males, the proportion of interactions in which they were chased was similar inside and outside their core areas; they were subordinate in most interactions with any territorial male. Status (dominant–territorial or subordinate) was related to age. Most 2- and 3-year-old males were subordinate; all males of 4 years or older were territorial. Among different groups of male Columbian ground squirrels, variation in expression of the spacing system may depend on habitat features that affect visual contact among squirrels and age and length of residence of the males in the area.

The role of gonadal steroids in feedback regulation of gonadotropin secretion at different stages of primate development

1987 ◽  
Vol 114 (2) ◽  
pp. 257-268 ◽  
Author(s):  
J. S. D. Winter ◽  
L. Ellsworth ◽  
G. Fuller ◽  
W. C. Hobson ◽  
F. I. Reyes ◽  
...  
Keyword(s):  
Feedback Inhibition ◽  
Feedback Regulation ◽  
Serum Testosterone ◽  
Significant Rise ◽  
Sexually Dimorphic ◽  
Adult Males ◽  
Gonadotropin Secretion ◽  
Central Inhibition ◽  
Serum Gonadotropin ◽  
One Year

Abstract. The serum gonadotropin response to castration was assessed in 8 foetal, 2 neonatal, 30 juvenile, and 2 adult rhesus monkeys (M. mulatta). In the 30 castrated juvenile monkeys and 8 sham-operated controls, concentrations of oestrone, oestradiol, androstenedione, dihydrotestosterone, testosterone and 17OH-progesterone were measured in 10 ml serum pools before, one month after, and one year after the surgical procedure. Castration during foetal life (83–137 days gestation) was followed within 48–72 h by a significant rise in serum FSH levels in males, but had no effect on the already high levels in females. Similarly, castration of males during the first post-natal month raised serum FSH and LH into the adult castrate range; however, after 3 months of age serum gonadotropin levels again declined to the normal juvenile range in spite of the open feedback loop. Orchiectomy of pre-pubertal juvenile monkeys (age 3 months–28/12 years) had no immediate effect on serum gonadotropins, but was followed by a delayed rise in FSH (at age 23/12–43/12 years) and LH (at age 27/12–44/12 years) to adult castrate levels. Orchiectomy of older prepubertal (by serum testosterone) or adult males resulted within a few days in a progressive and sustained rise in serum FSH and a more gradual rise in LH. Prepubertal gonadotropin regulation appeared to be sexually dimorphic, since ovariectomy in juvenile females (age 3 months–15/12 years) was followed by generally elevated, if somewhat erratic, serum FSH values, with a secondary rise in both FSH and LH levels at 2–21/12 years. In both sexes, prepubertal castration caused a significant and sustained decline in serum concentrations of oestradiol; castrated males also showed a decline in serum testosterone levels. Although prepubertal castration also caused in both sexes a slight decline in serum oestrone, and ovariectomy a decline in serum androstenedione and dihydrotestosterone, these effects were not sustained one year later, and values were not significantly different from sham-operated controls. Taken together, these data lend support to a model of primate sexual maturation in which the primary regulator of gonadotropin secretion in both sexes during the prolonged juvenile phase is central inhibition of the hypothalamic GnRH regulator. However, during foetal and neonatal life, and again following the onset of puberty, the major modulator of gonadotropin secretion becomes sex steroid-mediated feedback inhibition.

scholarly journals Human shields mediate sexual conflict in a top predator

2016 ◽  
Vol 283 (1833) ◽  
pp. 20160906 ◽  
Author(s):  
S. M. J. G. Steyaert ◽  
M. Leclerc ◽  
F. Pelletier ◽  
J. Kindberg ◽  
S. Brunberg ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Sexual Conflict ◽  
Resource Selection ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Offspring Survival ◽  
Adult Males ◽  
Predator Prey ◽  
Cascading Effects ◽  
Survival And Reproduction

Selecting the right habitat in a risky landscape is crucial for an individual's survival and reproduction. In predator–prey systems, prey often can anticipate the habitat use of their main predator and may use protective associates (i.e. typically an apex predator) as shields against predation. Although never tested, such mechanisms should also evolve in systems in which sexual conflict affects offspring survival. Here, we assessed the relationship between offspring survival and habitat selection, as well as the use of protective associates, in a system in which sexually selected infanticide (SSI), rather than interspecific predation, affects offspring survival. We used the Scandinavian brown bear ( Ursus arctos ) population with SSI in a human-dominated landscape as our model system. Bears, especially adult males, generally avoid humans in our study system. We used resource selection functions to contrast habitat selection of GPS-collared mothers that were successful (i.e. surviving litters, n = 19) and unsuccessful (i.e. complete litter loss, n = 11) in keeping their young during the mating season (2005–2012). Habitat selection was indeed a predictor of litter survival. Successful mothers were more likely to use humans as protective associates, whereas unsuccessful mothers avoided humans. Our results suggest that principles of predator–prey and fear ecology theory (e.g. non-consumptive and cascading effects) can also be applied to the context of sexual conflict.

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