Feeding ecology of black oystercatcher (Haematopus bachmani) chicks

Thesis (M.S.) University of Alaska Fairbanks, 2016The Black Oystercatcher is an internationally recognized bird species of conservation concern and the focus of multiple monitoring programs due its small global population size, restricted range, vulnerability to human and natural threats in nearshore marine ecosystems, and the important role it plays as a top-level consumer in the intertidal food web. I studied a population of Black Oystercatchers in Kenai Fjords National Park, Alaska in 2013 and 2014, examining variation in chick diet, assessing methods used to monitor diet, and investigating the influence of provisioning on brood survival. To better understand the biases and limitations associated with the quantification of prey remains, I compared diet estimates from prey remains with two other methods: direct observation of adults feeding young, and diet reconstruction by stable isotope analysis. Estimates from collected prey remains over-represented the proportion of limpets in the diet, under-represented the proportion of mussels and barnacles, and failed to detect soft-bodied prey such as worms. I examined age- and habitat-specific variation in chick diet and found no relationship between diet and age of chicks; however, diet differed between gravel beach and rocky island nesting habitats. To determine the importance of diet on brood survival, I modeled daily survival rates of broods as a function of energy intake rate and other ecological factors and found that broods with higher intake rates had higher growth rates and daily survival rates. Given the consequences of reduced energy intake on survival, changes in the abundance and composition of intertidal macroinvertebrates as a result of climate change may have significant impacts on Black Oystercatcher populations. These findings highlight the importance of diet and provisioning to chicks and identify limitations of using prey remains to characterize Black Oystercatcher diet.General Introduction -- Literature Cited -- Chapter 1. Are prey remains reliable indicators of chick diet? -- 1.1 Abstract -- 1.2 Introduction -- 1.3 Methods -- 1.3.1 Prey remains -- 1.3.2 Direct observations -- 1.3.3 Stable isotope analysis -- 1.3.4 Statistical analysis -- 1.4 Results -- 1.4.1 Prey remains -- 1.4.2 Direct observations -- 1.4.3 Stable isotopes -- 1.4.4 Comparison among methods -- 1.5 Discussion -- 1.6 Acknowledgments -- 1.7 Literature Cited -- Chapter 2. Accelerated energy intake increases survival rates of Black Oystercatcher broods -- 2.1 Abstract -- 2.2 Introduction -- 2.3 Methods -- 2.3.1 Study area and field methods -- 2.3.2 Energy analysis -- 2.3.3 Survival analysis -- 2.4 Results -- 2.5 Discussion -- 2.6 Acknowledgments -- 2.7 Literature Cited -- General Conclusions -- Literature Cited

The preparation and characterisation of monomeric and linked metal carbonyl clusters containing the closo-Si2Co4 pseudo-octahedral core

PhSiH3 reacts with [Co₄(CO)₁₂] at 50 °C in hydrocarbon solvents to give [(µ₄-SiPh)₂Co₄(CO)₁₁], 2c, shown by an X-ray crystal structure determination to have a pseudo-octahedral Si₂Co₄ core. Substituted aryl-silanes behaved similarly. Mixtures of PhSiH₃, H₃SiC₆H₄SiH₃ and [Co₄(CO)₁₂] in a ca. 2 1 2 ratio gave the dimeric cluster [{Co₄(µ₄-SiPh)(CO)₁₁Si}₂C₆H₄], 3a, which has the two Si₂Co₄ cores linked by a C₆H₄ group to give a rigid molecule which an X-ray structure analysis shows to be over 23 Å long. Related dimers linked by –(CH₂)₈– groups were isolated from mixtures of PhSiH₃, α ,ω-(H₃Si)₂(CH₂)₈ and [Co₄(CO)₁₂]. Electrochemical studies show the two cluster units in 3a do not interact electronically

Growth and Feed Efficiency of Juvenile Channel Catfish Reared at Different Water Temperatures and Fed Diets Containing Various Levels of Fish Meal

Channel catfish Ictalurus punctatus do not feed well at low temperatures. It is generally thought that a diet containing fish meal enhances feed palatability at low temperatures since fish meal is highly palatable to fish. There is a lack of information on the effects of fish meal levels on the growth performance of channel catfish reared at low temperatures. Therefore, a study was conducted in a recirculating system to examine the effects of fish meal levels on the feed consumption, weight gain, and feed efficiency of juvenile channel catfish reared at various temperatures. Fish with an initial weight of 9.6 ± 0.1 g were stocked in 23-L clear polycarbonate tanks maintained at approximately 17, 21, or 27 °C. The fish were fed with diets containing 0, 4, or 8% menhaden Brevoortia spp. fish meal for 9 weeks. There was a significant interaction between water temperature and fish meal level with respect to weight gain. At 27 °C, fish fed diets containing 4% and 8% fish meal gained significantly more weight than fish fed the all-plantprotein diet. However, the level of fish meal had no significant effect on the weight gain of fish at 17 °C or 21 °C. This suggests that the olfactory and gustatory responses of channel catfish to fish meal (up to 8% in the diet) may not be as sensitive at low temperatures as at optimum temperatures. The results also indicate that more than 4% fish meal in the diet is not beneficial for the optimum growth and feed efficiency of channel catfish fingerlings raised at 27 °C

Growth and Feed Efficiency of Juvenile Channel Catfish Reared at Different Water Temperatures and Fed Diets Containing Various Levels of Fish Meal

Channel catfish Ictalurus punctatus do not feed well at low temperatures. It is generally thought that a diet containing fish meal enhances feed palatability at low temperatures since fish meal is highly palatable to fish. There is a lack of information on the effects of fish meal levels on the growth performance of channel catfish reared at low temperatures. Therefore, a study was conducted in a recirculating system to examine the effects of fish meal levels on the feed consumption, weight gain, and feed efficiency of juvenile channel catfish reared at various temperatures. Fish with an initial weight of 9.6 ± 0.1 g were stocked in 23-L clear polycarbonate tanks maintained at approximately 17, 21, or 27 °C. The fish were fed with diets containing 0, 4, or 8% menhaden Brevoortia spp. fish meal for 9 weeks. There was a significant interaction between water temperature and fish meal level with respect to weight gain. At 27 °C, fish fed diets containing 4% and 8% fish meal gained significantly more weight than fish fed the all-plantprotein diet. However, the level of fish meal had no significant effect on the weight gain of fish at 17 °C or 21 °C. This suggests that the olfactory and gustatory responses of channel catfish to fish meal (up to 8% in the diet) may not be as sensitive at low temperatures as at optimum temperatures. The results also indicate that more than 4% fish meal in the diet is not beneficial for the optimum growth and feed efficiency of channel catfish fingerlings raised at 27 °C

Crustal Accretion in the Gulf of California: An Intermediaterate Spreading Axis

An important objective of Deep Sea Drilling Project (DSDP) Leg 65 was to study crustal accretion at an ocean ridge axis with an intermediate-spreading rate for comparison with previously studied sections displaying slowand fast-spreading rates. The southern Gulf of California was selected for this purpose because the basement displays high seismic velocities (comparable to those observed for Cretaceous basement in the western North Atlantic) and high ambient sedimentation rates, which facilitated penetration of zero-age basement. Four sites were drilled, forming an axial transect immediately south of the Tamayo Fracture Zone (Figs. 1 and 2) and providing a series of characteristic sections into the crust. This chapter attempts to provide a brief synthesis of the results from Leg 65, focusing particularly on the lithology, geochemistry, and paleomagnetic properties of the cored basement material. From these data, we present an interpretation of the processes of magmatic evolution and crustal accretion occurring at the Gulf of California spreading axis

A classification of spherically symmetric spacetimes

A complete classification of locally spherically symmetric four-dimensional Lorentzian spacetimes is given in terms of their local conformal symmetries. The general solution is given in terms of canonical metric types and the associated conformal Lie algebras. The analysis is based upon the local conformal decomposition into 2+2 reducible spacetimes and the Petrov type. A variety of physically meaningful example spacetimes are discussed

Angular clustering of galaxies at 3.6 microns from the Spitzer Wide-area Infrared Extragalactic (SWIRE) Survey

We present the first analysis of large-scale clustering from the Spitzer Wide-area Infrared Extragalactic legacy survey (SWIRE). We compute the angular correlation function of galaxies selected to have 3.6 m fluxes brighter than 32 Jy in three fields totaling 2 deg2 in area. In each field we detect clustering with a high level of significance. The amplitude and slope of the correlation function is consistent between the three fields and is modeled as w() ¼ A1 with A ¼ (0:6 0:3) ; 10 3; ¼ 2:03 0:10. With a fixed slope of ¼ 1:8, we obtain an amplitude of A ¼ (1:7 0:1) ; 10 3. Assuming an equivalent depth of K 18:7 mag we find that our errors are smaller but our results are consistent with existing clustering measurements in K-band surveys and with stable clustering models. We estimate our median redshift z ’ 0:75, and this allows us to obtain an estimate of the three-dimensional correlation function (r), for which we find r0 ¼ 4:4 0:1 h 1 Mpc