Some populations of newts (Taricha granulosa) possess large quantities of the neurotoxin tetrodotoxin (TTX) in their skin and eggs. Many populations of garter snake (Thamnophis sirtalis) are resistant to this toxin and can consume large numbers of newts with no negative effects. Despite the wealth of information acquired on the interaction between newts and their predator, garter snakes, very little research has been conducted on possible interactions between newts and other predators. I conducted a suite of experiments examining for the presence of other predators on newts, specifically focusing on predators of their eggs and larvae. I found a single predator, caddisfly larvae were capable of consuming the toxic eggs. Larval caddisflies are extremely abundant at one study site (775,000 caddisfly larvae per pond), and appear to be resistant to the negative effects of ingesting tetrodotoxin. After hatching, larval newts retain substantial quantities of TTX and most are unpalatable to predatory dragonfly naiads. Ovipositing female newts respond to the presence of caddisflies by depositing their eggs at the top of the water column where they are out of the reach of most predatory caddisflies. When caddisflies do consume a newt egg, some of the toxin is retained in their body tissues. Finally, caddisflies consume more newt eggs when those eggs contain less toxin versus eggs that contain large amounts of TTX. This may cause newt eggs that contain low quantities of TTX to more likely to die of predation which could ultimately drive an increase in toxicity of the adult population over time. Collectively, these findings indicate an additional player, caddisfly larvae, is a major predator of newts and could be involved in the evolution of tetrodotoxin toxicity in newts.

The disulfide bond pattern in the galactose-specific lectin 24K from the egg jelly of the Chinook salmon Oncorhynchus tshawytscha was determined, and its previously reported amino acid sequence was confirmed by mass spectrometry. A combination of tryptic digestion, HPLC separation, and chemical, modifications was used to establish the location of seven disulfide bonds and one pair of free cysteines. After proteolysis, peptides containing one or two disulfide bonds were identified by reduction and mass spectral comparison. MALDI mass spectrometry was supported by chemical modification (iodoacetamidylation) and in silico digestion. The assignments of disulfide bonds were further confirmed by mass spectral fragmentation studies including in-source dissociation (ISD) and collision-induced dissociation (CID). Lectins of comparable biochemical functions can be found in amphibian eggs as well. Those eggs are covered with glycoproteinaceous extracellular matrix, which is known as the zonae pellucidae (ZP). The ZP consists of three major glycoproteins referred to as ZPA, ZPB, and ZPC, which contain homologous regions named "ZP domains". The ZP domain is also found in other secretory glycoproteins. Trans -membrane domains present at the C -terminus of ZP glycoproteins are removed at furin-processing sites. However, the details of this processing are unclear because of the lack of information about the precise C -termini of ZP glycoproteins. In this study, the N -termini and C -termini of the glycoprotein gp 37 (ZPB, from gp 37 precursor) and gp 41 (ZPC, from gp 43) from the clawed South African toad ( Xenopus laevis ) were determined by mass spectrometric analysis. Our results suggest that the N -terminus and C -terminus of gp 41 are generated by oviductin-mediated cleavage at GSR 55 and GSR 367 and the C -terminus of gp 37 is generated by furin-mediated cleavage at CNT 457 . These findings shed light on the biochemical processing of gp 43 to gp 41 and gp 37 precursor to gp 37.

Three paleo-environments were studied. The first project concerned the Manson Impact and the effect of the Black Hills on the resulting fall-out from this asteroid strike. Samples of the Crow Creek Member were taken east of the Black Hills in Nebraska and South Dakota and samples from the Red Bird Member were taken from the west, in Wyoming. These samples were examined for chemical weathering, soot, shocked quartz, and fossils. The Crow Creek samples had shocked quartz (indicative of an impact), severe chemical weathering, soot, and evidence of tsunamis. There were few calcareous fossils. The Red Bird showed no signs of chemical weathering, a distinct absence of soot and shocked quartz and an abundance of fossils. These results indicate that the Black Hills were large enough to pose an atmospheric and oceanic barrier to the effects of the Manson Impact. The second project dealt with dinosaur eggs which were found in Montana. The eggs were examined and subjected to Computed Tomography Scans. The egg-shell, matrix, and volcanic ash were studied. The egg-shell was found to be from an undescribed oolithic species, and revealed that a transgressive event transpired after the eggs had fossilized. The matrix revealed that the eggs were laid in a flood-plain. The ash revealed a high amount of tungsten and yielded a high percentage of potassium for future dating. The eggs themselves revealed that intact embryos were within. This project has provided information on dinosaur nesting behavior. In the third project corals were examined to determine the usefulness of sampling different architectural structures for evaluating environmental proxies. Coral was collected at the Verde Reef. The different architectural structures were sampled using SIMS, and LA-ICP-MS to selectively sample the small architectural structures. Oxygen isotope ratios and elemental: calcium ratios were compared among the different structures. It was found that dissepiments intake isotopic oxygen and elements at different rates than other structures. This has an impact in sampling corals for environmental proxies, but, because of the very small amount of mass contained in the dissepiments that bulk analyses would not be significantly affected.

No description available.

No description available.

M. S.

Nests of the Black-crowned Night Heron and the Snowy Egret were examined in five central Utah colonies in 1973 to determine the spatial distribution within the colony. Nest locations of the 1085 nests of the two species were plotted to the nearest foot with an alidade and plane table. Tests of randomness, clump size, association, segregation, and T distribution were utilized. No differences between species were noted for the distance to the nearest and the next nearest nest. The Night Heron nested closer to other Night Herons and more often than did the Snowy Egret which non-significantly selected either species to nest closest. The Snowy Egret nests were 1.7 times higher than the Night Heron nests. Both species nests were aggregated within the colony. The association between the species within the habitat was positive but were segregated within the colony. Nest succession within a colony indicates that the Snowy Egret becomes more selective as time progresses but that the Night Heron remains selective throughout the entire season.

Information was collected on the nesting ecology of the Great Horned Owl, with particular emphasis placed on aspects of its population and distribution, territoriality and predation. The study was conducted for the two years, 1967 and 1968 in the Thorpe and Topliff hills of central western Utah. Nesting densities on the study area were .36 pairs per square mile in 1967 and .40 pairs per square mile in 1968. Nests averaged one mile apart and were distributed in the periphery of the hills, overlooking the desert valleys. Favorite nest sites were cliff niches, but abandoned quarries and junipers were also utilized. Territorial studies of three nesting pairs indicate that these owls maintained hunting areas ranging from 172 acres to 376 acres in coverage. Owls ranged as far as one mile into the adjacent desert valleys, but extended little activity into the mountainous interior. The black-tailed jackrabbit and desert cottontail contribute the bulk of the Horned Owl food, followed by the kangaroo rat. Other mammals, birds and invertebrates are also utilized, but to a lesser extent.

During the spring seasons of 1967 and 1968 ecological studies were made of nesting Ferruginou.s Hawks (Buteo regalis) in a 325 square mile area in west-central Utah. In the springs of 1967 and 1968 a systematic search was conducted throughout the study area for Ferruginous Hawk nests. When active nests were located they were kept under observation throughout the study. The density of nesting pairs in 1967 and 1968 ranged from 7 to 15.4 square miles per pair. An annual seasonal displacement was exhibited, with Ferruginous Hawks being present in the study area only during the nesting season, which lasted from early March until early September. Nest locations implied a preference to inhabit particular areas. The distance separating neighbors in 1967 and 1968 varied from 2.3 miles to .4 miles. More than ninety percent of the pairs observed attended more than one nest; such supernumerary nests averaged 2.5 per pair. The majority of nests were constructed on the ground. More than half of the nests faced south; only about one-tenth faced north. The typical nest was composed of large sticks, lined with bark , grass, and paper, and had an average diameter of 39 inches, a thickness of 17 inches, a pocket diameter of 14 inches, and a pocket depth of 3 inches. Both members of each pair of hawks were active in nest building, which began in early March. In 1967 thirteen nests produced 20 eggs (1.5 eggs per nest) and 8 young (.67 percent), of which 8 (100 percent) fledged (.67 per nest); in 1968 fourteen nests produced 50 eggs (3.57 eggs per nest) and 33 young (2.36 per nest), of which 28 (85 percent) fledged (2 per nest). Territorial behavior was inconsistent. On occasion each nesting pair was seen to actively defend its territory against other predatory birds; whereas on other occasions intruding raptors met no resistance from the resident pair of Ferruginous Hawks. From 26 eyries, 283 prey individuals were identified. Mammals (92 percent) predominated. The Ord's Kangaroo Rat (Dipodomys ordii) was the most numerous prey species (44 percent), with the Blacktail Jackrabbit (Lepus californicus) being the next most common (30 percent). Birds represented 5 percent of the total prey. Several hunting techniques were exhibited by the hawks. Hunting was usually conducted before sunrise and after sunset each day. Recorded mortality was minimal, with only one dead Ferruginous Hawk observed during the study.

No description available.