02134nas a2200229 4500008004100000245008100041210006900122260001200191300001000203490000600213520143100219100002101650700002001671700001701691700003201708700001601740700002401756700002001780700002201800700002301822856005901845 2018 eng d00aSocial context modulates digestive efficiency in greylag geese (Anser anser)0 aSocial context modulates digestive efficiency in greylag geese A c11/2018 a164980 v83 a

In group-living animals, social context is known to modulate physiology, behaviour and reproductive output as well as foraging and nutritional strategies. Here we investigate the digestive efficiency of 38 individuals belonging to different social categories of a semi-feral and individually marked flock of greylag geese (Anser anser). During 9 consecutive days in winter 2017, when the ground was fully covered with snow (i.e. no grass or other natural forage available) and the accessible food was standardized, 184 individual droppings were collected and analysed to estimate the apparent digestibility of organic matter (ADOM). Lignin was used as an indigestible internal marker in the food and droppings. The digestive efficiency was higher in pairs with offspring as compared to pairs without offspring or unpaired birds. Furthermore, individuals with high ADOM were more likely to breed successfully in the following season than those with low ADOM. Our findings demonstrate that social status modulates digestive efficiency, probably via a chain of physiological mechanisms including a dampened stress response in individuals enjoying stable social relationships with and social support by their family members (i.e. their own pair-partner and offspring). Our findings underline the importance of the social network in modulating physiology, such as digestive efficiency, and ultimately reproductive success.

1 aFrigerio, Didone1 aKotrschal, Kurt1 aFabro, Carla1 aPuehringer-Sturmayr, Verena1 aIaiza, Lara1 aHemetsberger, Josef1 aMason, Federico1 aSarnataro, Chiara1 aFilacorda, Stefano uhttps://www.nature.com/articles/s41598-018-34337-3.pdf01977nas a2200145 4500008004100000245008900041210006900130300001600199490000700215520150100222100002001723700002301743700002001766856004501786 2000 eng d00aStimulus enhancement in greylag geese: socially mediated learning of an operant task0 aStimulus enhancement in greylag geese socially mediated learning a1119–11250 v593 a

We recently observed the spreading of a novel tradition in a flock of semiferal greylag geese, Anser anser:
an increasing number of individuals began to bite and chew the stems of butterbur, Petasites hybridus.
Because this behaviour spread particularly fast within families, social learning seemed to be involved. We
therefore designed an experiment with hand-reared goslings, which were socially imprinted on humans,
to investigate whether and how the observation of an experienced tutor affects the acquisition of a novel
skill. Goslings had to open the gliding lid of a box to get at a food reward. To each of seven hand-reared
observers a human tutor demonstrated where and how to open the lid, whereas seven controls remained
untutored. All observers learned to perform the task but only one of the controls succeeded. The observers
explored more often at the position shown by the tutor than elsewhere and seemingly learned by trial
and error. In contrast, control birds explored primarily at positions that did not allow them to open the
box. These results indicate that in greylag goslings the observation of an experienced model facilitates the
learning of an operant task. We conclude that stimulus enhancement followed by operant conditioning
were the mechanisms involved, which may have accounted for the fast spread of the stem-chewing
tradition between family members.

1 aFritz, Johannes1 aBisenberger, Agnes1 aKotrschal, Kurt uhttps://fegeco.myspecies.info/node/41641