Why fight? Socially dominant jackdaws, Corvus monedula, have low fitness

Zoological Laboratory of the University of Groningen, Netherlands
Animal Behaviour (Impact Factor: 3.07). 01/2004; DOI: 10.1016/j.anbehav.2003.12.020
Source: OAI

ABSTRACT Social dominance is intuitively assumed to be associated with higher fitness, because social dominance implies better access to resources. We found that, in a colony of jackdaws, the dominant males consistently produced fewer fledglings, which had lower chances of survival to 1 year of age. Laying date and clutch size were independent of dominance, but females that mated with dominant males were in poorer condition and laid smaller eggs. Parental survival was independent of social dominance, and the frequency of extrapair fertilizations in jackdaws is negligible. Dominance was a stable trait of individuals, and not a state that all individuals eventually attained. We conclude that, in this colony, dominant jackdaws had lower fitness. To our knowledge, this is the first example of such a pattern in a free-living species. We hypothesize that the high density of our colony resulted in high testosterone titres, which suppressed paternal care of mate and offspring to the extent that it outweighed the benefits of higher resource access.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Fighting is a fundamental determinant of male fitness in species where females prefer socially dominant males as mates or where dominants can prevent subordinates from mating. This in turn can lead to the evolution of honest inter- and intra-sexual cues of male dominance. Fighting as a behaviour comprises both fighting rate (number of fights per unit of time) and fighting performance (success in winning fights), but it is not always clear which of these components are important for female choice and how they link to signals of male quality. To quantify the relative importance of fighting as a cue for females, we recorded detailed behavioural data from male black grouse Tetrao tetrix at leks. We explored the relationship between phenotypic traits (body mass, eye comb size, tail (lyre) length and blue chroma colouration) and fighting performance and rates and how these were related to male mating success. In older males' pairwise fights, winners had lower blue chroma than losers, but there were no differences in other morphological traits. In yearlings, no morphological trait predicted success in pairwise contests. Both fighting rate and performance were positively related to the number of copulations acquired by a male; however, when controlled for lek centrality, fighting performance and not fighting rate was significantly related to mating success. Our results indicate that females may be using components of fighting behaviour as cues for mate choice.
    Behavioral Ecology and Sociobiology 01/2012; 66(12). · 2.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although personality has been defined as a suite of correlated behaviours, most studies of animal personality actually consider correlations between a few traits. We examined the repeatability and correlational structure of five potential personality traits (activity, neophobia, exploratory tendencies, risk-taking behaviour and obstinacy), in female zebra finches. In addition, we assessed to what extent personality influenced social dominance in a feeding context in this gregarious species. All personality traits were found to be highly repeatable within individuals. In addition, except for obstinacy, all of them were related to each other, thus defining a behavioural syndrome. Social dominance was predicted by personality, with proactive individuals being more likely to be dominant. Our results suggest that personality can be considered as a new static factor influencing within-group hierarchies. We finally discuss these results in terms of the consequences for the evolution of personalities and the need to take several traits into account to provide full descriptions of individual personality.
    Animal Behaviour. 01/2011;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Several studies have shown considerably poorer breeding success of Great Tit Parus major populations in northern Finland than in mid- and western Europe. The aim of this study was to find out whether the poor success is linked to physiological condition and loads of blood parasites. This was done by comparing several condition indices, blood parasite prevalences and infection intensity in two populations, northern Finland (66°N) and Latvia (56°N). It was found that Great Tits had smaller clutches and produced fewer fledglings in northern Finland than in Latvia. Great Tits breeding in northern Finland had higher levels of haematocrit and higher concentrations of heterophils, lymphocytes, eosynophils and total globulin, while they had lower albumin/globulin ratios, which indicate higher levels of physiological stress and increased probability of infectious diseases. Surprisingly, Great Tits had lower blood parasite prevalence and the intensity of infection in northern Finland than in Latvia, while parasite vectors were more abundant in northern Finland.
    Journal of Ornithology 01/2013; 154(4):1019-1028. · 1.63 Impact Factor

Full-text (2 Sources)

Available from
May 29, 2014