For small animals like the mouse, predators are a constant concern (Image Credit: Jess, CC BY-NC 2.0)
Maximising survival by shifting the daily timing of activity (2019) van der Vinne et al., Ecology Letters, https://doi.org/10.1111/ele.13404
All animals need to eat food to survive and maintain their energy balance, but unlike us they can’t just order a pizza and have the food brought to them. They must always forage for food themselves, and every time that they do they expose themselves to predators. Small mammals like mice balance this trade-off by foraging for food at night, when their risk of predation is lowest.
One interesting strategy that mice can employ is to switch their foraging from the nighttime to the day, if they cannot get enough resources during the night or if their nighttime predation risk increases. The authors of today’s paper wanted to develop a model to predict under what conditions these temporal switches would occur, a model which they then tested with mice in the field.
The thought of an orca playing with its food – a cute seal – can be a grim one. But is it useful to project our ideas of morality and emotion onto other species? (Image Credit: Christopher Michel, CC BY 2.0, Image Cropped)
Guest post by Mary Shuttleworth
Scene: A lone seal on a piece of ice, surrounded by an expanse of deep and frosted blue. The scene would be romantic, except the water is rippling. Every now and then dark fins with streaks of white emerge, jostling the ice. It is an orca, and it is in training. Members of its family, or pod, are nearby, watching it as it practices how to take down its prey. The seal is in distress, stress resonating throughout its body. If they have noticed, the orcas take no notice. They are learning how to hunt. More than that, it appears that they could even be playing.
Species such as this Carribean reef shark have higher extinction risks than most fish. But how effective are our management efforts? (Image Credit: Albert kok, CC BY-SA 2.0, Image Cropped)
Reef accessibility impairs the protection of sharks (2018) Juhel et al., Journal of Applied Ecology 55
The importance of sharks goes well beyond what Jaws did to Hollywood, or one week in the USA each July. In any reef ecosystem, sharks perform a key functional role, exerting top-down pressure, stabilising food webs, and improving general ecosystem functioning. They’re also ‘charismatic’ species, meaning they’re easier to raise funding for, and bring money in through tourism. Yet pressure from fishing suggests that reef shark populations may be under threat, and with high body sizes and long lifespans, their populations are more sensitive than most to overfishing, making extinction risks higher.
Yet the lack of data on shark populations means that the effectiveness of the few existing management programs is largely untested. This paper looks at Marine Protected Areas (MPAs), areas in which national or international bodies prevent fishing or even entry, to see whether or not they are an effective conservation method for shark populations.