Posts Tagged ‘Predators’

Bright city lights are keeping ocean predators awake and hungry

By Damon Bolton, UNSW Australia; Alistair Becker; Emma Johnston, UNSW Australia; Graeme Clark, UNSW Australia; Katherine Dafforn, UNSW Australia, and Mariana Mayer-Pinto, UNSW Australia Light pollution is changing the day-night cycle of some fish, dra…

When Facing Predators, Male Monkeys Do Whatever Females Tell Them

In the forests of West Africa, bands of handsome primates called Diana monkeys roam the tree branches. Each group has just one male and several females with their babies. The tradeoff for his apparently cushy living situation is that the male has to c…

Unexpected diversity in socially synchronized rhythms of shorebirds

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring). The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within- and between-species diversity in incubation rhythms. Between species, the median length of one parent’s incubation bout varied from 1–19 h, whereas period length—the time in which a parent’s probability to incubate cycles once between its highest and lowest value—varied from 6–43 h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light–dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms.

The defensive response of the honeybee Apis mellifera [REVIEW]

Morgane Nouvian, Judith Reinhard, and Martin Giurfa
Honeybees (Apis mellifera) are insects living in colonies with a complex social organization. Their nest contains food stores in the form of honey and pollen, as well as the brood, the queen and the …

Cats as “unintelligent design”?

So news aggregator Digg labelled a story by Britt Peterson at Atlantic. Curious are the cultural assumptions around design in nature. Anyway, The animal so many dote on is among the world’s most destructive predators. New Zealand’s recent announcement of a plan to eradicate all invasive predators, including feral cats, sparked an immediate response—and not […]

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