Variation in prey resources influences the diet and behaviour of predators. When prey become limiting, predators may travel farther to find preferred food or adjust to existing local resources. When predators are habitat limited, local resource abundance impacts foraging success. We analysed the diet of Myotis lucifugus (little brown bats) from Nova Scotia (eastern Canada) to the Northwest Territories (north-western Canada). This distribution includes extremes of season length and temperature and encompasses colonies on rural monoculture farms, and in urban and unmodified areas. We recognized nearly 600 distinct species of prey, of which ≈30% could be identified using reference sequence libraries. We found a higher than expected use of lepidopterans, which comprised a range of dietary richness from ≈35% early in the summer to ≈55% by late summer. Diptera were the second largest prey group consumed, representing ≈45% of dietary diversity early in the summer. We observed extreme local dietary variability and variation among seasons and years. Based on the species of insects that were consumed, we observed that two locations support prey species with extremely low pollution and acidification tolerances, suggesting that these are areas without environmental contamination. We conclude that there is significant local population variability in little brown bat diet that is likely driven by seasonal and geographical changes in insect diversity, and that this prey may be a good indicator of environment quality.

Abstract. We show that free-ranging Laughing Kookaburras (Dacelo novaeguineae), the largest kingfishers, are heterothermic. Their minimum recorded body temperature (T b ) was 28.6• C, and the maximum daily T b range was 9.1• C, which makes kookaburras only the second coraciiform species and the only member of the Alcedinidae known to be heterothermic. The amplitude of nocturnal body temperature variation for wild, freeliving kookaburras during winter was substantially greater than the mean of 2.6• C measured previously for captive kookaburras. Calculated metabolic savings from nocturnal heterothermia were up to 5.6 ± 0.9 kJ per night. There was little effect of ambient temperature on any of the calculated T b -dependent variables for the kookaburras, although ambient temperature did influence the time that activity commenced for these diurnal birds. Kookaburras used endogenous metabolic heat production to rewarm from low T b , rather than relying on passive rewarming. Rewarming rates (0.05 ± 0.01• C min −1 ) were consistent with those of other avian species. Captivity can have major effects on thermoregulation for birds, and therefore the importance of field studies of wild, free-living individuals is paramount for understanding the biology of avian temperature regulation.Key words: Alcedinidae, Coraciiformes, heterothermia, temperature telemetry, torpor. Temperatura Corporal y Patrones de Actividad de Individuos Silvestres de Dacelo novaeguineae: El Martín Pescador de Mayor Tamaño es HeterotérmicoResumen. Mostramos que Dacelo novaeguineae, el martín pescador de mayor tamaño corporal, es heterotérmico. La temperatura corporal mínima (T b ) registrada para esta especie fue de 28.6• C y el rango máximo de variación diaria fue de 9.1• C, lo que hace a esta especie la segunda especie conocida como heterotérmica dentro de los coraciiformes y laúnica dentro de la familia Alcedinidae. La amplitud de la variación de la temperatura corporal nocturna para individuos silvestres de D. novaeguineae durante el invierno fue substancialmente mayor que la media de 2.6• C medida anteriormente en individuos de la misma especie en cautiverio. El ahorro metabólico resultante de la heterotermia nocturna fue de hasta 5.6 ± 0.9 kJ por noche. Hubo poca influencia de la temperatura ambiental sobre cualquier variable dependiente de la T b de D. novaeguineae, aunque la temperatura ambiental influyó sobre el horario en que comenzó la actividad en estas aves diurnas. Los individuos de D. novaeguineae utilizaron la producción de calor metabólico endógeno para aumentar la T b baja, en vez de depender de un recalentamiento pasivo. Las tasas de recalentamiento (0.05 ± 0.01• C min −1 ) fueron consistentes con las reportadas para otras especies de aves. El cautiverio puede tener efectos importantes sobre la termorregulación en las aves, por lo que los estudios de campo con individuos silvestres son de extrema importancia para entender la biología de la regulación de la temperatura en las aves.

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Abstract. We describe a method of discovering suitable parameters for simulating and animating the swarming behaviour of non-biting midges (Diptera: Chironomidae). A characteristic of animal aggregations that can be emulated by software is the emergence of complex behaviours from simple rules. Here the well-characterized swarming behaviour of non-biting midges is used to create a rule-based behaviour model for them. To test the effectiveness of this model in creating the emergent qualities of real swarms, success criteria are derived from quantitative swarm data. We propose using a genetic algorithm to automate the identification of parameter settings that optimize the effectiveness of the model.