Index and currency in this story: (TSX:GSPTSE, TSX:CADUSD)The Canadian Press TORONTO — Canada’s main stock index was down moderately in late morning trading, with most sectors heading lower. The S&P/TSX composite index was down 30.96 points at 16,437.75 in late morning trading. The energy sector was up but other sectors fell slightly.In New York, the Dow Jones industrial average was up 2.26 points at 27,200.28. The S&P 500 index was down 0.11 points at 3,013.07, while the Nasdaq composite was up 13.62 points at 8,287.23.The Canadian dollar traded at 76.10 cents US, compared with Tuesday’s average of 75.94 cents US.The September crude contract was up 19 cents at US$58.24 per barrel and the September natural gas contract was up 10.4 cents to US$2.24 per mmBTU.The August gold contract was up $8.40 at US$1,428.80 an ounce and the September copper contract was down a cent at US$2.67 a pound.
Linking extreme interannual changes in prey availability to foraging behaviour and breeding investment in a marine predator, the macaroni penguin
Understanding the mechanisms that link prey availability to predator behaviour and population change is central to projecting how a species may respond to future environmental pressures. We documented the behavioural responses and breeding investment of macaroni penguins Eudyptes chrysolophus across five breeding seasons where local prey density changed by five-fold; from very low to highly abundant. When prey availability was low, foraging trips were significantly longer and extended overnight. Birds also foraged farther from the colony, potentially in order to reach more distant foraging grounds and allow for increased search times. These extended foraging trips were also linked to a marked decrease in fledgling weights, most likely associated with reduced rates of provisioning. Furthermore, by comparing our results with previous work on this population, it appears that lowered first-year survival rates associated, at least partially, with fledging masses were also evident for this cohort. This study integrates a unique set of prey density, predator behaviour and predator breeding investment data to highlight a possible behavioural mechanism linking perturbations in prey availability to population demography.