Two tropical legumes and a temperate legume were studied during the course of this work. These were Leucaena leucocephala (cv. Peru), Canavalia ensiformis(cv. unknown) and Lupinus albus (cv. Vladimir [Kievskji mutant]) respectively. The dried ground leaf obtained from Leucaena leucocephala (LLM), the seeds of Canavalia ensiformis (jack bean; JB) and Lupinus albus (lupin) were the materials used in the study. Liquid chromatographic methods (HPLC) were developed for the analysis of mimosine and 3-hydroxy-4(lH )-pyridone (3,4-DHP) in LLM, Leucaena seed (LS) and chick excreta. Neither mimosine nor 3,4-DHP wftS detected in the serum of chicks fed LLM. Poor and variable recoveries of mimosine and 3,4-DHP were obtained when these were added to serum The analysis of canavanine in JB and the serum of chicks fed JB and canavanine, was also accomplished using HPLC. Canaline was not detected in any of the samples analysed by HPLC although recovery of added canaline to serum, JB and excreta was high. A small amount of what appeared to be canavanine was detected in lupin. Saponins and tannins were found in all the legumes under study. Trypsin inhibitors were detected in all but the lupins Inclusion of LLM in chick diets reduced their performance. Addition of Fe(III), polyethylene glycol (RAM = 4000) and cholesterol to LLM diets improved chick performance almost to that of chicks fed control diets. Cooking LLM alsoimproved chick performance. Addition of enzymes to LLM did not improvechick performance and did not improve the apparent metabolisable energy (AME) of LLM. Dietary inclusion of mimosine or LS, to supply the same amount of mimosine as that from LLM, did not restrict chick performance to the same extent as LLM Inclusion of autoclaved jack bean (JB) in chick diets caused a severe reduction in chick performance. The reduction in performance was not matched byinclusion of canavanine at the same level as that from JB. The inclusion ofextracted JB also reduced chick performance. Germination of the JB, prior to autoclaving and dietary inclusion, did not reduce canavanine levels nor was chick performance improved. Addition of arginine to JB diets improved performance of chicks but additional lysine had no beneficial effect. Lupin diets perm itted chicks to perform much better than LLM or JB diets. Autoclaving made little difference to the AME of lupins although the results were probably confounded by the presence of M aillard reaction products. Addition of enzymes to lupins increased the concentration of lower molecular weight carbohydrates but only had a small beneficial effect on AME of lupins for chicks.

No description available.

During the summers of 2007-2009, I studied the population growth and reproductive and foraging ecology of the Razorbill (Alca torda) at Matinicus Rock (MR), Maine. This medium-sized marine bird in the family Alcidae (auks) was extirpated from the Gulf of Maine in the late 19th century by hunting, collecting, and colony disturbance. Following legislation protecting seabirds and their nesting habitats, the Razorbill has recolonized probable former nesting habitat in the Gulf of Maine during the past several decades. Six small colonies comprise the Maine population, which is listed as threatened and forms the southern extension of the species breeding distribution. In Chapter 1, I present a population model of the MR breeding colony, based on studies of population growth and reproductive success, and supplemented with previously collected data from the National Audubon Society Seabird Restoration Program (Project Puffin), with whom I collaborated. I also describe chick diet (supplemented with Project Puffin data) and draw connections between diet and reproductive success. I found that reproductive success was too low to account for the observed population growth rate, and conclude that the colony is a sink population supported by substantial immigration. Because annual fledging success was positively associated with prey quality, I suggest that substandard chick diet may contribute to the sink population dynamic via diet-driven depressed fledging success. In Chapter 2, I report on the foraging behavior of chick-rearing Razorbills fitted with bird-borne data-loggers at MR in 2008-2009. I describe diving behavior including depth, duration, and profile shape of dives, as well as diel patterns. Diving activity was restricted to daylight hours, and dives were shallowest and most frequent in the evening. Though generally similar to diving behavior reported at four European and Canadian colonies, Razorbills at MR performed three times as many dives per day as at the Gannet Islands, Labrador, and the mean dive depth was greater than three of four previous studies. Deeper and more frequent dives may indicate higher foraging effort and lower prey availability. Reproductive success would suffer if parents cannot buffer chicks against the effects of low prey availability through increased foraging effort or other behavioral modifications. Together, the pieces of our research indicate that prey availability may be negatively affecting reproduction and population growth at MR. Rapid colony growth cannot be explained by local reproductive success, and is likely the result of substantial immigration from other colonies. Chick diet is varied and includes multiple high-quality forage fish species, yet chicks also consume poor-quality prey (larval fish and euphausiids) that may signal periods of very poor prey availability. Frequency and depth of dives made by chick-provisioning adults are also suggestive of parents allocating extra effort to foraging, relative to other colonies.