Geology topics

R.H. Wagner

Publications and source records attributed to R.H. Wagner.

3 recordsLinked to original sources

USGS2011

Behavioral and physiological responses to male handicap in chick-rearing black-legged kittiwakes

Parental investment entails a trade-off between the benefits of effort in current offspring and the costs to future reproduction. Long-lived species are predicted to be reluctant to increase parental effort to avoid affecting their survival. We tested this hypothesis in black-legged kittiwakes Rissa tridactyla by clipping flight feathers of experimental males at the beginning of the chick-rearing period. We analyzed the consequences of this handicap on feeding and attendance behavior, body condition, integument coloration, and circulating levels of corticosterone and prolactin in handicapped males and their mates in comparison to unmanipulated controls. Chicks in both groups were compared in terms of aggressive behavior, growth, and mortality. Handicapped males lost more mass, had less bright integuments, and attended the nest less often than controls. Nevertheless, they fed their chicks at the same rate and had similar corticosterone and prolactin levels. Compared with control females, females mated with handicapped males showed a lower provisioning rate and higher nest attendance in the first days after manipulation. Their lower feeding rate probably triggered the increased sibling aggression and mortality observed in experimental broods. Our findings suggest that experimental females adaptively adjusted their effort to their mate's perceived quality or that their provisioning was constrained by their higher nest attendance. Overall, our results suggest that kittiwake males can decrease their condition for the sake of their chicks, which seems to contradict the hypothesis that kittiwakes should be reluctant to increase parental effort to avoid affecting their survival.

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USGS2009

Evidence that pairing with genetically similar mates is maladaptive in a monogamous bird

Background Evidence of multiple genetic criteria of mate choice is accumulating in numerous taxa. In many species, females have been shown to pair with genetically dissimilar mates or with extra-pair partners that are more genetically compatible than their social mates, thereby increasing their offsprings' heterozygosity which often correlates with offspring fitness. While most studies have focused on genetically promiscuous species, few studies have addressed genetically monogamous species, in which mate choice tends to be mutual. Results Here, we used microsatellite markers to assess individual global heterozygosity and genetic similarity of pairs in a socially and genetically monogamous seabird, the black-legged kittiwake Rissa tridactyla . We found that pairs were more genetically dissimilar than expected by chance. We also identified fitness costs of breeding with genetically similar partners: (i) genetic similarity of pairs was negatively correlated with the number of chicks hatched, and (ii) offspring heterozygosity was positively correlated with growth rate and survival. Conclusion These findings provide evidence that breeders in a genetically monogamous species may avoid the fitness costs of reproducing with a genetically similar mate. In such species that lack the opportunity to obtain extra-pair fertilizations, mate choice may therefore be under high selective pressure.

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USGS2009

Can kittiwakes smell? Experimental evidence in a larid species

Birds have long been thought to have a poor sense of smell, although they have the proper anatomical and neurological structures for detecting olfactory cues ( Roper 1999 ). However, in the past decade several bird species have been shown to use smell in various contexts, such as foraging ( Nevitt et al. 1995 ), navigation ( Wallraff 2004 ), selection of nest materials ( Petit et al. 2002 , Gwinner & Berger 2008 ), nest location ( Bonadonna & Bretagnolle 2002 ), predator avoidance ( Amo et al. 2008 , Roth et al. 2008 ) and recognition of conspecifics ( Hagelin et al. 2003 ) or mates ( Bonadonna & Nevitt 2004 , for reviews see Roper 1999 , Hagelin & Jones 2007 , Nevitt 2008 ). The evidence, however, mainly concerns the Procellariiformes (petrels, shearwaters and albatrosses), a group that has long been suspected of using olfaction because of their strong body odour, highly developed olfactory bulb, nocturnal habits and burrow‐nesting ( Nevitt & Bonadonna 2005 , Nevitt 2008 ). Evidence of olfactory ability is scarce in other avian taxa. Exceptions include, for instance, Turkey Vulture Cathartes aura ( Smith & Paselk 1986 ), Brown Kiwi Apteryx australis ( Wenzel 1968 ), Homing Pigeon Columba livia ( Wallraff 2004 ), Blue Tit Cyanistes caeruleus ( Petit et al. 2002 , Amo et al. 2008 ), Domestic Fowl Gallus domesticus ( McKeegan et al. 2005 ), Kakapo Strigops habroptilus ( Hagelin 2004 ), Yellow‐backed Chattering Lory Lorius garrulus flavopalliatus ( Roper 2003 ), African Penguin Spheniscus demersus ( Cunningham et al. 2008 ) and Crested Auklets Aethia cristatella ( Hagelin et al. 2003 ). The Laridae, including Black‐legged Kittiwakes Rissa tridactyla , are diurnal, have relatively small olfactory bulbs ( Bang & Cobb 1968 ) and do not appear to use olfaction to locate food ( Frings et al. 1955 , Lequette et al. 1989 , Verheyden & Jouventin 1994 ). Kittiwakes use vocal cues in mate and parent/offspring recognition ( Wooller 1978 , Mulard & Danchin 2008 ), suggesting that olfaction may be at best secondary in those contexts. However, mates commonly allopreen, potentially exposing them to their mate’s chemical compounds. Moreover, the relative size of the olfactory bulb may be a poor predictor of olfactory abilities ( Hagelin 2004 , Mennerat et al. 2005 ). The aim of this experimental study was to assess whether Black‐legged Kittiwakes are able to detect odours added to the nest.

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