Seed dispersal characteristics to polar regions by means of visitors

Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region. However, no comprehensive, continent-wide evaluation of the risks to Antarctica posed by such species has been undertaken. Here we do so by sampling, identifying, and mapping the vascular plant propagules carried by all categories of visitors to Antarctica during the International Polar Year's first season (2007-2008) and assessing propagule establishment likelihood based on their identity and origins and on spatial variation in Antarctica's climate. For an evaluation of the situation in 2100, we use modeled climates based on the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios Scenario A1B [Nakicenovic N, Swart R, eds (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, UK)]. Visitors carrying seeds average 9.5 seeds per person, although as vectors, scientists carry greater propagule loads than tourists. Annual tourist numbers (~33,054) are higher than those of scientists (~7,085), thus tempering these differences in propagule load. Alien species establishment is currently most likely for the Western Antarctic Peninsula. Recent founder populations of several alien species in this area corroborate these findings. With climate change, risks will grow in the Antarctic Peninsula, Ross Sea, and East Antarctic coastal regions. Our evidence-based assessment demonstrates which parts of Antarctica are at growing risk from alien species that may become invasive and provides the means to mitigate this threat now and into the future as the continent's climate changes.

(Table 1) Characteristics of breeding male Adélie penguins (Pygoscelis adeliae) treated with varying degrees of corticosterone, Adélie land, Antarctica

Breeding individuals enter an emergency life-history stage when their body reserves reach a minimum threshold. Consequently, they redirect current activity toward survival, leading to egg abandonment in birds. Corticosterone (CORT) is known to promote this stage. How and to what extent CORT triggers egg abandonment when breeding is associated with prolonged fasting, however, requires further investigation. We manipulated free-living male Adelie penguins with CORT-pellets before their laying period. We then examined their behavioral response with respect to nest abandonment in parallel with their prolactin levels (regulating parental care), and the subsequent effects of treatment on breeding success in relieved birds. Exogenous CORT triggered nest abandonment in 60% of the treated penguins -14 days after treatment and induced a concomitant decline in prolactin levels. Interestingly, prolactin levels in treated penguins that did not abandon their nest were higher at the point of implantation and also after being relieved by females, when compared with abandoning penguins. Among successful birds, the treatment did not affect the number of chicks, nor the brood mass. Our results show the involvement of CORT in the decision-making process regarding egg abandonment in Adelie penguins when incubation is associated with a natural long fast. However, we suggest that CORT alone is not sufficient to trigger nest abandonment but that 1) prolactin levels need to reach a low threshold value, and 2) a rise in proteolysis (i.e. utilization of protein as main energy substrate) seems also to be required.

Ten generations of corn breeding /

Cover title.

Reprocessing of irradiated fission reactor fuel and breeding material : a literature search /

May 1, 1959.

Reprocessing of irradiated fission reactor fuel and breeding material : a literature search /

"January 1960."

Reprocessing of irradiated fission reactor fuel and breeding material : a literature search /

"October 1961."

Fuel breeding : a literature search /

"August 1959."

The Horse : its treatment in health and disease with a complete guide to breeding, training and management /

Mode of access: Internet.

Determination of breeding sites of nematodes in a municipal drinking water facility /

"Grant No. R804292010."

Horse-breeding, being the general principles of heredity applied to the business of breeding horses, with instructions for the management of stallions, brood mares and young foals, and the selection of breeding stock,

Mode of access: Internet.

Martine's hand-book of etiquette and guide to true politeness : a complete manual for those who desire to understand the rules of good breeding, the customs of good society, and to avoid incorrect and vulgar habits : containing clear and comprehensive directions for correct manners, dress, and conversation, instructions for good behavior at dinner parties and the table : together with the etiquette of the ball and assembly room, evening parties, deportment in the street and when traveling, and the usage to be observed when visiting or receiving calls : to which is added the etiquette of courtship, marriage, domestic duties, and fifty-six rules to be observed in general society /

"Almost every gentleman has wine at his table whenever he has invited guests"-- p. [74].

Sheep, their management and breeding. The various breeds, methods of rearing, fattening and marketing; diseases and ailments, with remedies, etc.

Mode of access: Internet.

Cavies: their varieties, breeding and management.

Mode of access: Internet.

Reprocessing of irradiated fission reactor fuel and breeding materials : an annotated bibliography of selected report literature /

"Chemistry--Separation process for plutonium and uranium."

Reprocessing of irradiated fission reactor fuel and breeding materials : an annotated bibliography of selected report literature /

"Chemistry--Separation process for plutonium and uranium."