The hormonal control of begging and early aggressive behavior: Experiments in black-headed gull chicks

Effect of rapid modulation of circulating plasma testosterone concentration on begging, aggressive behavior and competition for food in black-headed gull (Larus ridibundus) chicks

“…1c). As intended, the elevation by T injection was well within the physiological range of this species (Ros et al, 2002), much lower than the level induced by T-implantation in the earlier study on this species (Groothuis and Ros, 2005;Ros et al, 2002) and restrained within a 100 min interval.…”

“…Moreover, endogenous testosterone, which is secreted by chicks very early during ontogeny (Adkins-Regan et al, 1990;Ottinger and Abdelnabi, 1997;Ros et al, 2002) has been found to positively covary Goodship and Buchanan, 2006) with soliciting behavior for parental food (begging) in passerine species, which was confirmed by an experimental study (Goodship and Buchanan, 2007), with clear benefits for chick survival until fledging (Goodship and Buchanan, 2006). In sharp contrast, postnatal exposure to testosterone suppresses begging in black-headed gull (Larus ridibundus) chicks (Groothuis and Meeuwissen, 1992;Groothuis and Ros, 2005). In this species testosterone facilitates chick aggression, like in booby chicks (Ferree et al, 2004).…”

“…In addition, chicks of colonial species often have to face harsh competition by adult and young conspecifics from other families aiming at seizing the resources brought to the nest by the parents, and actively participate in the defense of the nesting territory by means of threatening and aggressive displays (e.g. Groothuis, 1989;Groothuis and Ros, 2005;Ros et al, 2002).…”

Examining a pathway for hormone mediated maternal effects – Yolk testosterone affects androgen receptor expression and endogenous testosterone production in young chicks (Gallus gallus domesticus)

“…We expected our treatment to induce higher levels of plasma testosterone, and/ or higher levels of AR mRNA expression. This prediction is based on previous findings that yolk T increased competitiveness in this species [43], and aggression or begging behavior in other bird species [12,18,23,36,41,50] which may be under the control of postnatal testosterone. However, the prediction is weakened by the contradictory finding in the literature on early postnatal androgen levels and AR mRNA expression as mentioned above.…”

Cuckoos, cowbirds and hosts: adaptations, trade-offs and constraints

“…This should include further research on the interplay between hormones and begging behaviour. While two studies have shown that brood parasites do not deposit more testosterone into their eggs than their hosts (Hauber & Pilz 2003;Torök et al 2004), Groothuis & Ros (2005) showed that testosterone reduces begging, and so there is still ample scope to test whether hormones play a part in the superior competitive ability of non-evicting brood parasites. It might also be useful to use comparative approaches to generalize how different parasitic species exploit their hosts in terms of begging behaviour.…”