Parent-offspring conflict and the coordination of siblings in gulls.

• Published in: Proceedings of the Royal Society of London. Series B: Biological Sciences
• Main Authors: Mathevon, Nicolas, Charrier, Isabelle
• Other Authors: Neurobiologie de l'apprentissage, de la mémoire et de la communication (NAMC), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Ecologie et Neuro-Ethologie Sensorielle (ENES), Université Jean Monnet - Saint-Étienne (UJM)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: MESH: Animal Communication; MESH: Animals; MESH: Maternal Behavior; MESH: Models; Biological; MESH: Observation; MESH: Sibling Relations; Newborn; MESH: Birds; MESH: Competitive Behavior; MESH: Feeding Behavior; MESH: France; MESH: Litter Size; [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology; [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior; [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences; Black-headed Gull; Larus ridibundus
• Online Access: https://hal.science/hal-02555962; https://doi.org/10.1098/rsbl.2003.0117

International audience Offspring solicit food from their parents by begging behaviours. Studies on birds suggest that these displays are 'honest signals of need' and adults provide food according to the begging level. However, siblings may compete for parental resources and the begging intensity is expected to change with brood size. Here, we show that in the black-headed gull (Larus ridibundus) an increase of the numbers of siblings can result in a decrease of individual begging cost through nestlings' synchronized signalling. This is in accordance with some mathematical models. As parents respond to the total solicitation emerging from the nest, the probability to get food increases with the number of chicks begging together. The more siblings there are, the more they coordinate their begging while decreasing the number of individual begging bouts. Intra-brood synchronization of begging enables chicks to reduce their effort and hence exerting an important role in parental-offspring negotiation.