The focus of this research was the spontaneous magnetic alignment responses of animals. We show that snapping turtles (Chelydra serpentina) and crayfish (Cambarus sciotensis) spontaneously align their body axes relative to the magnetic field. In snapping turtles, this response is sensitive to low-level radio frequency fields, consistent with a mechanism involving a light-dependent radical pair mechanism. Findings from the turtle experiments also suggest that the Earth's magnetic field plays an important role in encoding spatial information in novel surroundings, and may help to organize multiple locales into a 'mental map' of familiar space. Given the importance of magnetic input in many aspects of spatial behavior, another important finding was that magnetic alignment of yearling turtles was disrupted by high levels of maternally transferred mercury, an industrial waste product found at high levels in some fresh water ecosystems. In crayfish, we investigated the effects of ectosymbionts (Annelida: Branchiobdellida) on magnetic alignment responses. Interestingly, the response of crayfish to magnetic cues parallels the complex symbiotic interaction between crayfish and their ectosymbiotic worms, which changes from mutualistic to parasitic with increasing worm density. Our working hypothesis was that these changes in spatial behavior may increase or decrease contact to other crayfish, and therefore increase or decrease transmission rates. Next, to address the ontogeny of the SMA, we attempted to replicate an earlier study showing a possible magnetic alignment response in chicken embryos. Although chicken embryos did show non-random alignment, we were not able to find a magnetic effect. Alignment is also an important feature of animal constructions and is very likely to have fitness consequences, which we explored in woodpecker cavity alignments in a meta-analysis of available global data. The latitudinal and continental pattern in 23 species of woodpeckers suggests that an alignment response can have the proximate function to regulate microclimate in the cavity and therefore, presumably, optimize incubation temperatures and increase hatching success. Overall, the presented findings show how experimental and observational studies of spontaneous alignment behavior can provide insight into the ecology and sensory biology of a wide range of animals. / Ph. D.

Made available in DSpace on 2014-06-11T19:23:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-09Bitstream added on 2014-06-13T18:09:37Z : No. of bitstreams: 1 silva_lcc_me_sjrp.pdf: 264964 bytes, checksum: 6d475d5b7734bbff4951cab4446a3a4e (MD5) / O objetivo deste trabalho é avaliar as propriedades funcionais da carne de Ema (Rhea americana) e de Avestruz (Struthio camellus) por meio de um estudo comparativo com a carne de Frango (Gallus domesticus). Para tanto, analisaram-se a solubilidade das proteínas miofibrilares, a capacidade de retenção de água, a capacidade de emulsificação das proteínas totais, a estabilidade da emulsão e as perdas por cocção, por evaporação e por gotejamento. Obtiveram-se os seguintes resultados por meio das análises da composição nutricional do músculo Iliotibialis lateralis das aves: avestruz: 19,59 % de proteínas, 75,53 % de umidades, 1,37 % de lipídeos, 1,13 % de cinzas e 2,38 % de carboidratos; ema: 23,50 % de proteínas, 74,19 % de umidades, 1,11 % de lipídeos, 1,13 % de cinzas e 0,07 % de carboidratos e frango: 18,35 % de proteínas, 73,30 % de umidades, 5,92 % de lipídeos, 1,03 % de cinzas e 1,40 % de carboidratos. Por meio da análise das propriedades funcionais observou-se que as proteínas solúveis no NaCl (PS) e as proteínas extraídas com NaCl das proteínas totais (PT) apresentaram, respectivamente, os seguintes resultados: pH 7.0: avestruz (7,40 % e 38,06 %), ema (8,52 % e 36,11 %) e frango (7,68 % e 41,88 %); pH 5.5: avestruz (5,87 % e 30,18 %), ema (6,53 % e 28,54 %) e frango (5,65 % e 29,97 %) e pH 3.0: avestruz (3,04 % e 15,64%), ema (3,29 % e 13,97 %) e frango (2,85 % e 15,52 %). Na análise da capacidade de retenção de água obteve-se para avestruz (73,19 %), ema (66,25 %) e frango (67,13 %). Com relação à capacidade de emulsificação no pH 7.0 foram obtidos estes resultados: avestruz (21,42 mL óleo/ 100 mg de proteína), ema (18,98 mL óleo/ 100 mg de proteína) e frango (31,87 mL óleo/ 100 mg de proteína). Para a estabilidade da emulsão (pH 7.0) obteve-se: para avestruz (36,33 mL liberado (água e óleo)/ 100 g de emulsão)... / This study aims to assess the functional properties of both Rhea (Rhea americana) and Ostrich meat (Struthio camellus) through a comparive study to chicken meat (Gallus domesticus). For that, myofibrillar proteins solubility, water retention capacity, total proteins emulsifying capacity, emulsion stability and losses due to cooking, evaporation and meat proteins drip loss were analyzed. This results obtained through the nutritional composition analysis of the muscle Iliotibialis lateralis of poultry: to ostrich 19,59 % proteins, 75,53 % humidity, 1,37 % fat, 1,13 % ash and 2,38 % carbohydrate; to rhea 23,50 % proteins, 74,19 % humidity, 1,11 % fat, 1,13 % ash and 0,07 % carbohydrate and to chicken 18,35 % proteins, 73,30 % humidity, 5,92 % fat, 1,03 % ash and 1,40 % carbohydrate. Through the functional properties analysis we observed that the soluble proteins in NaCl (PS) and the extracted proteins with NaCl from total proteins (PT) presented, respectively, the following results: pH 7.0: to ostrich (7,40 % and 38,06 %), rhea (8,52 % and 36,11 %) and chicken (7,68 % and 41,88 %), pH 5.5: to ostrich (5,87 % and 30,18 %), rhea (6,53 % and 28,54 %) and chicken (5,65 % and 29,97 %) and pH 3.0: to ostrich (3,04 % and 15,64 %), rhea (3,29 % and 13,97 %) and chicken (2,85 % and 15,52 %). Analysing water retention capacity we obtained to ostrich (73,19 %), rhea (66,25 %) and chicken (67,13 %). Regarding the emulsifying capacity in pH 7.0 these results were obtained: ostrich (21,42 mL oil/ 100 mg proteins), rhea (18,98 mL oil/ 100 mg proteins) and chicken (31,87 mL oil/ 100 mg proteins). For the emulsion stability (pH 7.0) we obtained: to ostrich (36,33 mL released (water and oil)/ 100 g emulsion), rhea (81,00 mL released (water and oil)/ 100 g emulsion) and chicken (0,66 mL released (water and oil)/ 100 g emulsion). The values found to cooking losses were: ostrich (21,77 g/ 100 g sample)... (Complete abstract click electronic access below)