Do common ravens yell because they want to attract others?

  title={Do common ravens yell because they want to attract others?},
  author={Bernd Heinrich and John M. Marzluff},
  journal={Behavioral Ecology and Sociobiology},
SummaryThe formation of groups at food bonanzas results from a variety of mechanism, which include recruitment by signalling and information parasitism. Recruitment is distinguished from information parasitism on functional grounds: attraction of a crowd is termed recruitment if the signaler's fitness is enhanced by the attraction of others but termed parasitism if the signaler's fitness is reduced by the attraction of others. We here show, however, that in Common Ravens, Corvus corax, the… 

Can information sharing explain recruitment to food from communal roosts

It is concluded that both information and grouping benefits are likely to underlie communal roosting behavior in my focal system and contrary to assertions in the literature, the opportunity to share foraging information can be sufficient to drive the evolution and maintenance of recruitment to food from communal roops.

Rich Pickings Near Large Communal Roosts Favor ‘Gang’ Foraging by Juvenile Common Ravens, Corvus corax

This work adapts a general model of juvenile common raven foraging behavior to show formally how the trade off between search efficiency and social opportunity can account for the existence of the alternative social foraging tactics that have been observed in this species.

Who wants food? Individual characteristics in raven yells

Food calling in wild ravens ( Corvus corax ) revisited: Who is addressed?

Numerous birds and mammals use vocal signals to advertise feeding opportunities but often such signals vary with individual and contextual factors. Non-breeding ravens call at food that is difficult

Scrounging Tactics in Free‐Ranging Ravens, Corvus corax

Social foraging allows individuals to scrounge, i.e. to exploit the food others have made available. The conditions promoting scrounging as an alternative foraging tactic have yet received limited

Craving Ravens: Individual ‘haa’ Call Rates at Feeding Sites as Cues to Personality and Levels of Fission-Fusion Dynamics?

Investigation of the occurrence of ‘haa’ calling and individual call rates in a group of individually marked free-ranging ravens found that these findings give rise to the assumption that raven societies are based on differential social relationships on an individual level.

Decision time modulates social foraging success in wild common ravens, Corvus corax

Investigating which factors underline kleptoparasitism avoidance is a promising scenario to test specific predictions derived from these hypotheses and concludes that individuals benefit from applying cognition to such decision‐making, independently of age class.

The Evolution of Food Calls: Vocal Behaviour of Sooty Mangabeys in the Presence of Food

It is found that grunt rates were significantly higher when subjects were foraging in the group’s periphery and with small audiences, in line with the cooperative recruitment hypothesis, and this evolutionary transition may only occur in species that feed on clumped, high-quality resources where social feeding is competitive, a condition not met in sooty mangabeys.

Audience effects in chimpanzee food calls and their potential for recruiting others

The findings support the recruitment function of food calls and suggest that high-ranking males call to attract estrous females to food patches to obtain mating opportunities.



Winter foraging at carcasses by three sympatric corvids, with emphasis on recruitment by the raven, Corvus corax

  • B. Heinrich
  • Environmental Science
    Behavioral Ecology and Sociobiology
  • 2004
It is concluded that the feeding crowds of ravens consist primarily of juvenile non-breeding vagrants who (unlike some resident adults) roost communally and who vigorously recruit each other in part to neutralize the aggressiveness of resident adults defending prized food bonanzas.

Individuals in an osprey colony discriminate between high and low quality information

  • E. Greene
  • Environmental Science, Biology
  • 1987
It is reported that colonial ospreys (Pandion haliaetus, L.) not only transfer information about foraging locations, but that they discriminate among fish species brought back by other colony members, and respond only to schooling prey species.

Aspects of the ecology of the common raven in Harney Basin, Oregon

Common Ravens (Corvus corax L.) have been implicated as significant predators on the eggs of waterfowl and shorebirds on Malheur National Wildlife Refuge. Malheur Refuge, located in southeastern

Colonial Nesting and Social Feeding as Strategies for Exploiting Food Resources in the Great Blue Heron (Ardea Herodias)

The results support the idea that colonial nesting and social feeding are adaptations concerned with finding food, but there are also other factors involved in the evolution of sociality in ardeids and other birds.

Roost Attendance and Aggression in Black Vultures

-In a 5-yr study of a partially marked population of Black Vultures (Coragyps atratus) in North Carolina, turnover among marked birds in a large winter roost averaged 34% each night. Roost attendance

Roles of Endothermy and Size in Inter- and Intraspecific Competition for Elephant Dung in an African Dung Beetle, Scarabaeus laevistriatus

The capacity for facultative endothermy during terrestrial activity in S. laevistriatus appears to be related to the intense competition for dung that they experience, which requires that they sustain near maximal rates of activity, and maintain body temperature near the level obligatorily produced during flight.

Cliff Swallow Colonies as Information Centers

Colonies of cliff swallows appear to be information centers in which colony residents acquire information on the location of food sources and individuals often follow, and are followed by, their neighbors within the colony.