Research press release


Scientific Reports

Animal behaviour: Meerkats trust experienced guards more



Ramona Rauberたちの研究グループは、2016年と2017年の春にミーアキャットの研究を行い、さまざまな見張り役が発した穏やかな鳴き声の録音を、3~23匹の採餌個体の群れ(9グループ)に聴かせた。そして、それぞれの録音が再生された5分間に採餌行動中のミーアキャットが周囲を見渡す警戒行動を取った割合を計算した。その結果、見張り役を頻繁に行ったことのある個体の穏やかな鳴き声を聞いた採餌中のミーアキャットが周囲を見渡す時間が、見張りをほとんどしたことのない個体の鳴き声を聞いた場合より短くなった。一方、社会的順位、年齢、性別は、採餌中のミーアキャットが示す警戒行動に影響を及ぼさないようだった。


Foraging meerkats are less watchful when individuals with more experience as guards issue calming calls, according to a study in Scientific Reports.

When groups of several meerkats forage for food, typically one individual (seldom more) scans the surroundings and regularly calls out to the others. This is known as sentinel behaviour. By calling, sentinels provide the foragers with information about the identity of the sentinel and the current risk of predation. Although it is known that foraging individuals show differing responses to calls from different sentinels, previous studies have not been able to determine the effects that sentinel age, their relationship to the other individuals in the group, and experience have on the foragers’ responses to their calls.

During the springs of 2016 and 2017, Ramona Rauber and colleagues played sentinel calming calls recorded from different meerkats to 9 groups of 3 to 23 foraging individuals. The researchers calculated the percentage of watchful behaviour (scanning of surroundings) shown by the foraging meerkats during the five minutes each recording was played. The authors found that foraging meerkats spent less time looking around when they heard calming calls of sentinels who more frequently stood guard compared to sentinels who rarely did so. Dominance status, age and sex seemed to have no effect on the watchfulness behaviour shown by the foraging meerkats.

The findings imply that there is a mechanism that enables meerkats to keep track of how experienced an individual is at guarding the group. The authors suggest that the meerkats may do this by recognizing the different calls and remembering how often they have heard this call before.

doi: 10.1038/s41598-018-29678-y


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