The multifaceted role of the environment in regulating the structure and dynamics of biological communities has long fascinated ecologists and motivated much debate and research. Now, in a time of accelerated global changes due to human impacts, the need to understand how the environment shapes communities has gained new urgency....
Some parasites may modify the behavior of their
hosts. Altered behaviors may: 1) benefit the host in
that they defend against the pathogen, 2) benefit the
pathogen and represent manipulations of the host
response, and 3) benefit neither the host or the
pathogen and simply be a product of the...
Organismal tolerance to abiotic environmental stresses contributes significantly to setting the distribution limits of organisms, as demonstrated by vertical zonation patterns in the marine intertidal zone. In this thesis, the ultimate (evolutionary) and proximate (mechanistic) causes of tolerance to temperature and emersion stresses associated with the intertidal zone were examined...
Description of anuran larvae with the use of staging tables is
a common practice in the study of frog life-histories, but there has
been no previous description or table of Ascaphus larvae. In comparing
Ascaphus larvae to a simplified staging table for anurans it
was found that these larvae vary...
Osmotic and ionic regulation was studied in the Dungeness
crab, Cancer magister, after acute exposure to a range of five
salinities from 25% to 125% sea water (100% = 32%). Blood, urine
and muscle tissue were sampled at 24 and 48 hours after exposure.
Analyses were made of blood and...
The adaptiveness of polygyny in passerines poses a particularly
intriguing problem. The altricial young of this group require extended
parental care, but young of polygynous pairings generally lack the undivided
attention of the male which young of monogamous pairings receive.
Polygynous offspring may thus be undernourished and experience
greater mortality....
Interface habitats are considered valuable natural systems, tightly linked to adjacent habitats through the flow of matter and energy. However, there is limited research on mechanisms of connectivity such as movement of organisms and particulate matter and ways in which anthropogenic disturbance to interface habitats may affect immediate and adjacent...