552 research outputs found
Interpopulational variation in costs of reproduction related to pregnancy in a viviparous lizard
Interpopulational variation in reproductive costs may affect variation in life
history traits including reproductive investment (i.e. clutch mass relative to either
maternal body mass or length). While the relationships between reproductive investment
and costs of reproduction, especially costs to mobility, have been well studied in
squamate reptiles, how these costs relate to investment and explain patterns within
and between populations is not always straightforward. In the present study, we
examined the relationship between reproductive investment and costs of reproduction
(gravid and postpartum sprint speeds and maternal postpartum body condition)
in two populations of a viviparous skink, Pseudemoia entrecasteauxii living in different
habitat types. We found that costs of reproduction (i.e. impact on gravid and
postpartum sprint speeds) depended on the interaction between relative reproductive
burden (RRB) and population. There was no link between relative clutch mass (RCM)
and maternal sprint speeds. Maternal postpartum body condition was not related to
either RRB or RCM for either population. Gravid females living in the open habitat
population showed significantly slower sprint speed compared with the same females
immediately postparturition, and other gravid females living in a closed habitat population.
Such females are likely to experience a higher cost of reproduction in terms of
changes in sprint speed as well as exposure to predators and may show a behavioural
shift to crypsis in order to compensate for locomotor impairment and to reduce the
risk of predation. We suggest that factors which relate to costs of reproduction (i.e.
sprint speeds) are complex and may involve multiple factors such as reproductive
investment and habitat characteristics
Psalms for Organ, Volume 01: Chios
Pages 27-29 in Psalms for Organ, Volume 1
The Nuclear Science References (NSR) Database and Web Retrieval System
The Nuclear Science References (NSR) database together with its associated
Web interface, is the world's only comprehensive source of easily accessible
low- and intermediate-energy nuclear physics bibliographic information for more
than 200,000 articles since the beginning of nuclear science. The
weekly-updated NSR database provides essential support for nuclear data
evaluation, compilation and research activities. The principles of the database
and Web application development and maintenance are described. Examples of
nuclear structure, reaction and decay applications are specifically included.
The complete NSR database is freely available at the websites of the National
Nuclear Data Center http://www.nndc.bnl.gov/nsr and the International Atomic
Energy Agency http://www-nds.iaea.org/nsr.Comment: 16 pages, 5 figure
Shedding some light on Thismia rodwayi F. Muell. (fairy lanterns) in Tasmania: distribution, habitat and conservation status
Thismia rodwayi is a seldom-seen, subterranean plant that occurs in Tasmania, the eastern states of the Australian mainland and New Zealand. Surveys for the species were prompted by a new record from Archers Sugarloaf near Meander in Tasmania's central north. Several new populations of the species were subsequently discovered in wet eucalypt forests dominated by Eucalyptus obliqua, E. regnans, E. delegatensis or E. viminalis, with an understorey dominated by Pomaderris apetala, Bedfordia salicina and/or Olearia argophylla. The species is now known from the Meander, Glen Huon, Little Denison River, Mount Field, Mount Wellington and Ben Lomond areas. Analysis of current information suggests that the listing of T. rodwayi under Schedule 5 (Rare) of the Tasmanian Threatened Species Protection Act 1995 is appropriate
Does mate guarding prevent rival mating in snow skinks? A test using AFLP
We report on likely mixed paternity in a natural population of snow skinks (Niveoscincus mirolepidoms) from alpine Tasmania, Australia. This species is nonterritorial and males guard females after copulation, Suggesting that guarding behavior has evolved to prevent rival mating of still-receptive females. To what degree does this mate-guarding prevent rival copulations? We sampled gravid females at random in the wild and looked for within-clutch mixed paternity among their offspring using amplified fragment length polymorphism (AFLP). Incorpating all visualized fragments, offspring band-sharing based on maternal bands was 0.94 (+/- 0.05, SD), whereas for paternal fragments it was 0.54 (+/- 0.46, SD). We then tested paternal band-sharing scores for all young of pairs against the mean score of the maternally inherited fragments to assess whether paternal genetic variation was larger than for a known single parent, hence, suggesting multiple sires. To reduce the risk of unequal sampling of polymorphic maternal and paternal fragments, We based Our statistical tests on heterozygous bands only. Offspring band sharing based on maternal heterozygous fragments was on average 0.68 ( +/- 0.22, SD), versus 0.35 (+/- 0.33, SD) based on paternally inherited fragments. in six of eight clutches (75%), at least one pair of voting in a clutch had paternal scores outside of the confidence interval for a single parent (i.e., the mother). Thus, mixed paternity seems to be widespread in this Population, despite prolonged postcopulatory mate-guarding by males
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