Some recent studies on cooperation

Brood Parasitism and the Evolution of Cooperative Breeding in Birds (Science)
Brood parasites (like cuckoos) do best when they lay eggs in the nests of cooperative breeders. But cooperative breeders are better at rejecting brood parasites, because having more eyes and ears at the nest also helps keep out brood parasites.

The result of brood parasitism. A reed warbler feeding her "baby" that's actually a cuckoo.

The result of brood parasitism: a reed warbler feeding her “baby” – which is actually a big fat cuckoo.  Talk about a strong maternal instinct. This is also what it looks like when I visit my mom for the holidays. Image from wikimedia.

Evolutionary routes to non-kin cooperative breeding in birds (Proceedings B)
Direct fitness benefits are important in cooperatively breeding birds. Out of 213 cooperatively breeding species, 30% of species form nest with non-kin and another 15% nest primarily with non-kin. Cooperative breeders that require helpers are more likely to have non-kin helpers, than species where cooperative breeding is optional.

Female rhesus macaques discriminate unfamiliar paternal sisters in playback experiments: support for acoustic phenotype matching (Proceedings B)
Most kin discrimination in primates is thought to occur by individuals simply learning who are their maternal kin. Female macaques responded more to calls from their paternal half-sisters than non-kin, regardless of familiarity. This suggests that primates might be able to identify relatives they have never met by the sound of their voice.

Reciprocity and conditional cooperation between great tit parents (Behavioral Ecology)
Parental care requires cooperation between parents; each parent would rather have the other do more work. One way to resolve this conflict is through reciprocity. This experiment showed that songbird parents increased and decreased their feeding rate based on their mate’s feeding rate, independent of offspring begging.

So those these birds seem to “negotiate” over cooperative investments. What about wasps?

Do paper wasps negotiate over helping effort? (Behavioral Ecology)
No, it doesn’t seem that they do.

Just finished preliminary trials on the effects of oxytocin on grooming and food sharing in vampire bats. But I’m hoping to replicate my results in a second study group before I publish anything.

 

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About Gerry Carter

I study the behavioral, sensory, and social ecology of vampire bats. http://socialbat.org.
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