Johan Van Rhijn

Open University of the Netherlands | OU · School of Science

Breeding Pacific Golden-Plovers (Pluvialis fulva) cover 140 longitudinal degrees of Arctic tundra. Having examined 557 museum skins from across this huge distributional range, we conclude that Pacific Golden-Plovers breeding in Alaska are structurally larger than those breeding in Siberia, especially in wing length. Birds from Alaska also have more...

Nuptial ornament diversity was studied in 1814 individual male Ruffs that were caught in their spring staging areas in Friesland, The Netherlands. Ornaments (hereafter called plumages) comprised of a ruff, two head tufts and facial wattles. Individual feathers were found to be plain (white, black or one hue), or patterned with black and only one hu...

In most waders (Charadrii) replacement of old by new feathers during moult of primaries occurs in a fixed order and in such a way that flight capacities are maintained. Moult of the secondaries of the Eurasian Golden Plover Pluvialis apricaria deviates from this general pattern. The sequence of secondary moult is irregular and – in most cases – asy...

The repair jobs that birds have to do to maintain high quality plumage take energy and time, so should be under intense selection. Recently, we have shown that secondary moult in the Eurasian Golden Plover Pluvialis apricaria is incomplete, irregular and asymmetric between wings, and argued that this reflected their ‘relaxed’ migratory habits. On t...

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The evolution of male parental care in vertebrates with internal fertilization must have been preceded by a stage in which males profit by staying with the female after copulation. This paper discusses the results of a series of computer simulations to determine the pay-off to post-copulatory mate guarding under various conditions. Guarding is prom...

http://www.johanvanrhijn.nl/overig-eng/TheRuff.htm

Presents a model on the phylogenetic pathways in the evolution of parental care and social organization in birds. It departs from an ancestral state with pure male parental care which may evolve via "uniparental care' (male cares, but female cares if male deserts) and "double clutching' towards biparental care with similar roles, polyandry and pure...

Processes leading to the establishment of social relationships are the main topic of the present study, which is based on observations of black-headed gulls kept in experimental groups in aviaries. Among these birds various kinds of social relationships were established, such as heterosexual monogamous pair-bonds, polygynous associations, and male-...

Mechanisms for sex-recognition in the Black-headed Gull, Larus ridibundus, were analysed in order to understand the occurrence of homo-sexual male pairs among captive members of this species. No discontinuities between males and females could be detected in either external characteristics or behaviour. Although most individuals select a mate of the...

This paper has tried to answer the question of how the independent and the satellite strategy of the Ruff originated and has been maintained during evolution. It is not intended as a report of a piece of completed research but gives a number of tentative, but testable hypotheses. Data are presented that independent males and satellites are equally...

In species with internal fertilization, but without parental care, an evolution of 'maternal care' is fundamentally different from an evolution of 'paternal care'. Maternal care should be a pure EES. Paternal care should always be superimposed on a mixed ESS to stay (or not to stay) and to establish some kind of a pair-bond with the female from cop...

The present paper makes a plea for the development of methods for clssifying behaviour in a systematic way, by which relevant sources of information are less likely to be neglected than in the conventional intuitive way of classifying behaviour. Film-analysis of the behaviour of the black-headed gull revealed that more details can be distinguished...

In several vertebrate species it has been demonstrated that individuals recognize each other, and in many other species (even invertebrates) the conditions for it seem to be fulfilled. Individual recognition might therefore be a wide-spread phenomenon in the animal kingdom. This has consequences for the settlement of conflicts between animals: indi...

This paper discussed the information content of threat signals. It was an attempt to explain the inconsistencies between the points of view of model-builders using game theory as a tool (represented in a paper by CARYL in 1979 in this journal), and of the (mainly field-) ethologists spending a considerable part of their time observing animals in gr...

The patterning of body-care behaviour in the Herring Gull has been studied by means of: (a) qualitative observations on four individuals, and (b) application of six quantitative analytical methods on the behaviour recordings of the dominant gull (which was least influenced by other individuals). The qualitative observations led to the conclusion th...

In the Ruff two groups of males can be distinguished: independent males and satellite males. This classification is based upon differences in territoriality and behaviour, and is highly correlated with differences in the nuptial plumage. Independent males are mostly dark coloured; their behaviour contains much fighting and related activities. They...