Spatial and temporal distribution of Antarctic fur seals (Arctocephalus gazella) on the breeding grounds at Bird Island, South Georgia

first_imgThe number of Antarctic fur seals (Arctocephalus gazella) in the area of the Scotia Sea has been increasing. Observation of their distribution on the breeding grounds are important to help design and interpret censuses. These seals are highly polygynous. In the study area at Bird Island, South Georgia, females give birth and are mated in densely packed colonies located along the shore close to the tideline. Males establish territories in this area, but are also found further inland. This study examined the density-dependent processes regulating the instantaneous size of the male breeding population; the distribution of males in relation to space and the number of females available to be mated and the effect of gregarious behaviour of females on male dispersion. Males were only territorial on the beaches in the areas where most females gave birth and subsequently had their post-partum oestrus. There was an apparent lower (19–20 m2) and upper (40 m2) limit to territory size. Males were excluded from the beach areas when the average density on the beaches was greater than 5 males per 200 m2. An asymptotic density of 10–11 males per 200 m2 was reached on the beaches and 4–5 males per 200 m2 elsewhere. These two asymptotic densities may represent the upper and lower limits of density for a territorial system of dispersion. A model of the temporal changes in female numbers suggested that the total number of females occupying an area of beach during the mating period was approximately twice the number at the peak of the season. There was no indication that males compensated for low female density by increasing territory size. Females and pups became more dispersed after the end of the mating period. It is suggested that one function of gregariousness in females is as a mechanism for mate selection. This study also has implications for methods used to measure population size.last_img read more

Reproductive endocrinology of macaroni (Eudyptes chrysolophus) and gentoo (Pygoscelis papua) penguins: II. Plasma levels of gonadal steroids and LH in immature birds in relation to deferred sexual maturity

first_imgPlasma levels of LH, testosterone, estradiol, and progesterone were measured, during the breeding season, in adult and immature macaroni (Eudyptes chrysolophus) and gentoo (Pygoscelis papua) penguins, at Bird Island, South Georgia (54°S, 38°W), in relation to deferred sexual maturity. Macaroni penguins do not breed until 6–8 years of age whereas gentoo penguins first breed at 2 years of age. Plasma LH was elevated in 3- to 5-year-old macaroni penguins, but not in 1- to 2-year-old birds nor 1-year-old gentoos. However, 1 year olds of both species responded to an injection of exogenous LH-RH by increasing LH secretion. Some individual 3-, 4-, and 5-year-old macaroni penguins had circulating testosterone levels within the range of peak values in adults, suggesting that in males, gonads were physiologically mature several years in advance of the age of first breeding. One-year-old macaroni penguins had elevated progesterone levels and basal estradiol levels, but in 2–4 year olds plasma levels of both progesterone and estradiol were low. This does not support the hypothesis that high progesterone levels “block” ovarian maturation in immature penguins. Immature gentoo penguins showed a different pattern of hormone secretion. Plasma testosterone was low in all breeding periods, but estradiol levels increased to a peak during the incubation period, 4 weeks later than peak values occurred in adults. In both species, therefore, deferred sexual maturity was associated with delayed and/or reduced secretion of LH and gonadal steroids.last_img read more

Offspring sex ratio in relation to female size in southern elephant seals, Mirounga leonina

first_imgSouthern elephant seals Mirounga leonina display extreme sexual dimorphism. In addition females show great variation in size and stored resources at parturition. Therefore they present an excellent opportunity for examination of responses of sex ratio to resource availability. We studied the relationships between the size of southern elephant seal females at parturition and the size and sex of their pups at South Georgia over four breeding seasons. We found a large individual variation in maternal post-partum mass (range 296–977 kg, n=151). Larger mothers gave birth to larger pups, irrespective of the sex of their pup. Male pups were on average 14% larger than females at birth and consequently more costly to bring to parturition. Our results suggest that female southern elephant seals must weigh more than 300 kg if they are to breed at all, and more than 380 kg if they are to give birth to a male pup. Above this threshold the proportion of males among offspring rapidly increases with maternal mass, and stabilizes at a level not significantly different from parity. These results show that smaller females of southern elephant seals vary offspring sex ratio in a way that is consistent with theories on adaptive offspring sex ratio. A smaller mother with a male foetus may benefit from terminating her pregnancy and allocating the resources she saves to her own growth. She could then give birth to and raise a larger pup in the subsequent season.last_img read more

Distribution and abundance of the tick Ixodes uriae in a diverse subantarctic seabird community

first_imgAt Bird Island, South Georgia, we surveyed the distribution and abundance of ticks on the vertebrate fauna and found only 1 species Ixodes uriae. We classified all seabird species into 3 groups: (1) seabirds nesting on the surface of the ground solitarily, in dispersed groups of a few nests, or in colonies with well-spaced nests; (2) seabirds nesting on the surface of the ground in dense colonies; and (3) seabirds nesting in dense colonies in burrows or rock crevices. We detected I. uriae only on 3 species of the second group that nested in large, dense, persistent colonies, i.e., black-browed albatross (Diomedea melanophrys), gray-headed albatross (Diomedea chrysostoma), and macaroni penguin (Eudyptes chrysolophus). Ticks were found on the undersides of the feet on albatrosses but not on the undersides of the feet on penguins. We hypothesize that the coarse pebble nests of penguins, combined with the fact that their young walk around more than albatross young, make the environment on the underside of penguin feet more harsh and hostile for ticks than the underside of albatross feet. Despite the great abundance of Antarctic fur seals (Arctocephalus gazella) on the island, we found no ticks on them.last_img read more

Metagenomic analysis of a a southern maritime Antarctic soil

first_imgOur current understanding of Antarctic soils is derived from direct culture on selective media, biodiversity studies based on clone library construction and analysis, quantitative PCR amplification of specific gene sequences and the application of generic microarrays for microbial community analysis. Here, we investigated the biodiversity and functional potential of a soil community at Mars Oasis on Alexander Island in the southern Maritime Antarctic, by applying 454 pyrosequencing technology to a metagenomic library constructed from soil genomic DNA.The results suggest that the commonly cited range of phylotypes used in clone library construction and analysis of 78–730OTUs (de-replicated to 30–140) provides low coverage of the major groups present (s5%). The vast majority of functional genes (>77%) were for structure, carbohydrate metabolism, and DNA/RNA processing and modification. This study suggests that prokaryotic diversity in Antarctic terrestrial environments appears to be limited at the generic level, with Proteobacteria, Actinobacteria being common. Cyanobacteriawere surprisingly under-represented at 3.4%of sequences, although s1% of the genes identified were involved in CO2 fixation. At the sequence level there appeared to be much greater heterogeneity, and this might be due to high divergence within the relatively restricted lineages which have successfully colonized Antarctic terrestrial environments.last_img read more

Eemian interglacial reconstructed from a Greenland folded ice core

first_imgEfforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling (‘NEEM’) ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.last_img read more

Twenty first century changes in Antarctic and Southern Ocean surface climate in CMIP6

first_imgTwo decades into the 21st century there is growing evidence for global impacts of Antarctic and Southern Ocean climate change. Reliable estimates of how the Antarctic climate system would behave under a range of scenarios of future external climate forcing are thus a high priority. Output from new model simulations coordinated as part of the Coupled Model Intercomparison Project Phase 6 (CMIP6) provides an opportunity for a comprehensive analysis of the latest generation of state‐of‐the‐art climate models following a wider range of experiment types and scenarios than previous CMIP phases. Here the main broad‐scale 21st century Antarctic projections provided by the CMIP6 models are shown across four forcing scenarios: SSP1‐2.6, SSP2‐4.5, SSP3‐7.0 and SSP5‐8.5. End‐of‐century Antarctic surface‐air temperature change across these scenarios (relative to 1995–2014) is 1.3, 2.5, 3.7 and 4.8°C. The corresponding proportional precipitation rate changes are 8, 16, 24 and 31%. In addition to these end‐of‐century changes, an assessment of scenario dependence of pathways of absolute and global‐relative 21st century projections is conducted. Potential differences in regional response are of particular relevance to coastal Antarctica, where, for example, ecosystems and ice shelves are highly sensitive to the timing of crossing of key thresholds in both atmospheric and oceanic conditions. Overall, it is found that the projected changes over coastal Antarctica do not scale linearly with global forcing. We identify two factors that appear to contribute: (a) a stronger global‐relative Southern Ocean warming in stabilisation (SSP2‐4.5) and aggressive mitigation (SSP1‐2.6) scenarios as the Southern Ocean continues to warm and (b) projected recovery of Southern Hemisphere stratospheric ozone and its effect on the mid‐latitude westerlies. The major implication is that over coastal Antarctica, the surface warming by 2100 is stronger relative to the global mean surface warming for the low forcing compared to high forcing future scenarios.last_img read more

Bees Blast River Cats

first_img FacebookTwitterLinkedInEmail(Salt Lake City, UT)  —  The Bees reeled off eight runs in the sixth inning as they blasted the River Cats 10-7 at Smith’s Ballpark.Chris Carter homered twice for Salt Lake and Jabari Blash also left the yard in the win.  The Bees trailed 6-0 before erupting in the eighth.The Bees have won two of the first three games in the four-game series.  The finale is tonight at 6:35 p.m. Written by Tags: Baseball/PCL/Salt Lake Bees Robert Lovell April 20, 2018 /Sports News – Local Bees Blast River Catslast_img read more

NCAA Utah College Track Roundup: 5/12

first_imgMay 13, 2018 /Sports News – Local NCAA Utah College Track Roundup: 5/12 FacebookTwitterLinkedInEmailLAWRENCE, Kan.-Saturday at the WAC track and field championships, Grand Canyon’s men and women each decisively won their titles as the Antelope women posted 225.05 points to Utah Valley’s 205 points. The Grand Canyon men posted 254 points and Utah Valley was second with 170 points.Saturday’s events started with New Mexico State’s women winning the 4 x 100 relay in a time of 46.11 seconds, while Utah Valley finished fourth in 47.12 seconds. The Wolverines’ team consisted of Ashley Zulauf, Alena Gillespie, Mykah Ouderkirk and Lexi Shaw.The men’s 4 x 100 relay was won by Grand Canyon in a time of 40.55 seconds. The Utah Valley men placed third and this team was comprised of Tyler Liddiard, Jordan Carder, Cade Owen and Andre Jones.The Wolverines swept the titles in the women’s and men’s 1500-meter runs as the women’s winner was Savannah Neuberger (4:51.15) and Anthony Ocegueda (3:59.39). Additionally, in the women’s 1500-meter run, Shevaun Ames of Utah Valley placed second.Sarah Root of Grand Canyon won the women’s 100-meter hurdles in 13.50 seconds and William Winfield of Grand Canyon won the men’s 1100-meter hurdles title in 14 seconds.In the women’s 100-meter dash, New Mexico State’s Katara Nelson won the title in 11.41 seconds and the men’s 100-meter dash winner was Grand Canyon’s Ryan Girk in 10.11 seconds.The women’s 400-meter dash winner was Chicago State’s Jocindra Glee in 56.44 seconds while the men’s 400-meter dash winner was Isaac Allanarem of Grand Canyon in 47.13 seconds.Utah Valley’s Savannah Neuberger won the women’s 800-meter run as well in a time of 2:17.28. Cal State-Bakersfield’s Curtis Threlkeld had a time of 1:54.52 in the men’s 800-meter run.Utah Valley’s Lexi Shaw was the women’s 400-meter hurdles champion in a time of 1:00.96 while her teammate, Mykah Ouderkirk placed second.Anthony Phelps of Grand Canyon was the men’s 400-meter hurdles champion and Andre Jones of Utah Valley placed second overall.Katara Nelson of New Mexico State won the women’s 200-meter dash crown and Utah Valley’s Alena Gillespie was second. The men’s 200-meter dash title was won by Grand Canyon’s Ryan Girk (20.51 seconds) and Utah Valley’s Jordan Carder placed second.Paige Hildebrand of Grand Canyon won the women’s 3000-meter steeplechase title while McKayla Walker of Utah Valley placed second.The men’s 3000-meter steeplechase crown was won by Utah Valley’s Adrian Jones in 9:13.28 and in the women’s 4 x 400 meter relay, New Mexico State won in a time of 3:43.54. Utah Valley placed second as the team was comprised of Mykah Ouderkirk, Alena Gillespie, Ashley Zulauf and Lexi Shaw.Grand Canyon’s men won the 4 x 400 relay in 3:13.12.In the women’s 5000-meter run, Utah Valley’s Hannah Branch won the title in 17:31.64. Her teammates, McKayla Walker and Savannah Berry, placed third and fourth, respectively.The men’s 5000-meter run was won by Texas-Rio Grande Valley’s Abraham Chirchir in 14:54.45 with Utah Valley’s Kevin Lynch and Geofrey Kemboi placed third and fourth, respectively.The women’s 10,000-meter run was won by Olivia Stein of Seattle U. in 35:51.29 as Utah Valley’s McKayla Walker, Savannah Berry and Hannah Branch placed second through fourth, respectively.Nathan Keown of Missouri-Kansas City won the men’s 10,000-meter run while Tyson Lambert and Kevin Lynch placed third and fourth respectively.Utah Valley’s Kallie Given placed first in the women’s high jump with a leap of 5 feet 6 inches and Scott Marshall of Grand Canyon won the men’s pole vault with a leap of 17-04.50 feet.In the women’s triple jump, New Mexico State’s Hannah Smith won with a leap of 41-07.75 feet and Albert MacArthur of Utah Valley took the triple jump title for the men with a a leap of 52-02.50 feet.The women’s discus title was won by Tarasue Barnett of Grand Canyon with a toss of 199-03 feet and Darcy Allen of Utah Valley placed second.FRESNO, Calif.-Saturday, the Air Force men and San Diego State women asserted themselves as the Mountain West’s best on the third and final day of competition from Fresno State University.Air Force posted 204 points with Utah State placing fourth at 131 points. San Diego State’s women netted 120.50 points and Utah State placed fifth with 71 points.The men’s 100-meter dash was won by Boise State’s Bryce Kirby in 10.64 seconds and Jalen Hunter of Colorado State won the men’s 110-meter hurdles race in a time of 14.22 seconds.New Mexico’s Carlos Salcido won the 200-meter dash for the men in a time of 21.06 seconds and Air Force’s Tyler Koss won the men’s 400-meter dash title in 46.70 seconds.Air Force’s Chip White won the men’s 400-meter hurdles crown in 52.10 seconds while Clay Lambourne of Utah State won the men’s 800-meter run title in 1:47.96 seconds.Josh Kerr of New Mexico won the men’s 1500-meter run title in 3:44.69 while Colorado State’s Cole Rockhold won the 5000-meter run in 13:55.36, upsetting Utah State’s Dillon Maggard, who placed second at 13:55.85.Colorado State’s Jerrell Mock won the men’s 10,000-meter run in 29:24.87 and New Mexico’s men won the 4 x 100 relay in 40.62 seconds.Air Force’s men secured their title with a won in the men’s 4 x 400 relay in 3:10.00.Utah State’s David Hirschmann won the men’s discus with a toss of 181-01 feet.In the men’s high jump, New Mexico’s Brent Dionisio won the title with a leap of 6-11.50 feet.The men’s javelin champion was Utah State’s Sindri Gudmundsson as the Icelandic national had a toss of 256-04 feet. His teammate, Kyle Morris, placed third.In the men’s pole vault, Utah State’s Sam Nelson took the title with a leap of 16-04.75 feet and Colorado State’s Mostafa Hassan won the men’s shot put with a toss of 61-05 feet.The men’s triple jump champion was John Reynolds of Air Force in 51-01 feet.For the women, San Diego State’s Ashley Henderson won the 100-meter dash crown in a time of 11.04 seconds.Nevada-Las Vegas’ Jasmyne Graham won the 100-meter hurdles in a time of 13.10 seconds. Ashley Henderson also won the 200-meter dash for the Aztecs in 22.59 seconds.In the women’s 400-meter dash, San Diego State’s Lisa-Anne Barrow posted a time of 52.11 seconds.Karoline Sauer of Nevada won the women’s 400-meter hurdles crown in 59.21 seconds and Utah State’s Jordan Brandt placed fourth overall.Avi’ Tal-Wilson Pe of Nevada-Las Vegas won the women’s 800-meter run in 2:02.87 as Alexis Fuller of Boise State won the women’s 1500-meter run in 4:20.40 as Tylee Newman of Utah State finished third.Allie Ostrander of Boise State won the women’s 5000-meter run in 15:44.11 and the women’s 10,000-meter run winner was New Mexico’s Ednah Kurgat.San Diego State won the women’s 4 x 100 relay 44.23 seconds as well as the 4 x 400 relay, this one was won in 3:37.39.In the women’s discus, Colorado State’s Maria Muzzio won the title in 175-06 feet and her teammate, Autumn Gardner won the high jump title with a leap of 6 feet.The women’s javelin title was won by Fresno State’s Vanja Spaic with a toss of 168-04 feet and San Jose State’s Destiny Longmire won the crown with a leap of 20-05.75 feet.In the women’s pole vault, Air Force’s Kathryn Tomczak won the crown with a leap of 13-05.75 feet.Finally, the women’s triple jump champion was Wyoming’s Ja’la Henderson with a leap of 43-10.50 feet.STANFORD, Calif.-Saturday, the Utah Utes’ women’s track and field team competed at the PAC-12 championships and was led by Grayson MurphyIn the women’s 3000-meter steeplechase, Murphy placed second in a time of 10:00.20 while Colorado’s Sage Hurta won the title in this event, posting a time of 9:57.28.The men’s 3000-meter steeplechase was won by Stanford’s Steven Fahy in a time of 8:50.07.In the men’s 10,000-meter run, Stanford’s Jack Keelan took the title in a time of 29:38.44.The men’s javelin title was won by UCLA’s Simon Litzell with a toss of 244-03 feet while the men’s long jump champion is Oregon’s Damarcus Simpson with a leap of 27-04 feet.The men’s shot put title was won by Arizona’s Jordan Geist with a toss of 65-09.75 feet.In the men’s decathlon, Stanford’s Harrison Williams is the champion with 7925 points.In the women’s hepathlon, Washington State’s Alissa Brooks-Johnson won the crown by amassing 5977 points.Stanford’s Vanessa Fraser won the women’s 10,000-meter run title in a time of 33:10.84.In the women’s hammer throw, Arizona State’s Maggie Ewen won the crown with a toss of 244 feet (Ewen also won the shot put crown with a toss of 63.00-75 feet) and in the high jump for the women, USC’s Lyndsey Lopes earned the title with a leap of 5 feet and 10.50 inches.The women’s javelin crown was won by Stanford’s Mackenzie Little with a toss of 180-1 feet and the women’s long jump champion is USC’s Courtney Corrin with a leap of 21-04 feet.California’s Lauren Martinez set a school record with a leap of 14 feet in the women’s pole vault to close out competition for Day 1 of the Pac-12 championships.The meet concludes Sunday. Written by Brad James Tags: Lauren Martinez/Mountain West/Utah/Utah State/Utah Valley/WAClast_img read more

Ibarra’s late goal gives Minnesota 1-1 draw with RSL

first_img Written by FacebookTwitterLinkedInEmailSANDY, Utah (AP) — Miguel Ibarra tied it for Minnesota in the 84th minute in United’s 1-1 draw with Real Salt Lake on Saturday night.Darwin Quintero found Ibarra open in the middle of box and Ibarra turned with a chip shot to beat the goalkeeper. Ibarra scored again three minutes later but had the goal reversed after video review.Damir Kreilach shielded away Minnesota midfielder Fernando Bob on a pass from Sunny and scored on a right-footed roller from beyond the penalty box in the 11th minute for RSL (13-10-6).RSL defender Justen Glad made a key clearance in the 48th minute, hustling back and kicking away Francisco Calvo’s long ball that would have been an easy finish for Minnesota’s Quintero.Minnesota (9-16-3) ended a three-game losing streak. Real Salt Lake had its three-game winning streak snapped. Associated Press September 15, 2018 /Sports News – Local Ibarra’s late goal gives Minnesota 1-1 draw with RSL Tags: MLS/Real Salt Lake/Soccerlast_img read more