scholarly journals A SINGLE ANCIENT ORIGIN OF BROOD PARASITISM IN AFRICAN FINCHES: IMPLICATIONS FOR HOST-PARASITE COEVOLUTION

Evolution ◽  
2001 ◽  
Vol 55 (12) ◽  
pp. 2550-2567 ◽  
Author(s):  
Michael D. Sorenson ◽  
Robert B. Payne
Keyword(s):  
Brood Parasitism ◽  
Host Parasite

AVIAN BROOD PARASITISM AND ECTOPARASITE RICHNESS-SCALE-DEPENDENT DIVERSITY INTERACTIONS IN A THREE-LEVEL HOST-PARASITE SYSTEM

Evolution ◽  
2012 ◽  
Vol 67 (4) ◽  
pp. 959-968 ◽  
Author(s):  
Zoltán Vas ◽  
Tibor I. Fuisz ◽  
Péter Fehérvári ◽  
Jenő Reiczigel ◽  
Lajos Rózsa
Keyword(s):  
Brood Parasitism ◽  
Avian Brood Parasitism ◽  
Host Parasite

scholarly journals Hosts elevate either within-clutch consistency or between-clutch distinctiveness of egg phenotypes in defence against brood parasites

2021 ◽  
Vol 288 (1953) ◽  
pp. 20210326
Author(s):  
Eleanor M. Caves ◽  
Tanmay Dixit ◽  
John F. R. Colebrook-Robjent ◽  
Lazaro Hamusikili ◽  
Martin Stevens ◽  
...  
Keyword(s):  
Individual Variation ◽  
Brood Parasitism ◽  
Negative Relationship ◽  
Empirical Support ◽  
Phenotypic Traits ◽  
Arms Races ◽  
Brood Parasites ◽  
Egg Colour ◽  
Host Parasite

In host–parasite arms races, hosts can evolve signatures of identity to enhance the detection of parasite mimics. In theory, signatures are most effective when within-individual variation is low (‘consistency’), and between-individual variation is high (‘distinctiveness’). However, empirical support for positive covariation in signature consistency and distinctiveness across species is mixed. Here, we attempt to resolve this puzzle by partitioning distinctiveness according to how it is achieved: (i) greater variation within each trait, contributing to elevated ‘ absolute distinctiveness’ or (ii) combining phenotypic traits in unpredictable combinations (‘ combinatorial distinctiveness’). We tested how consistency covaries with each type of distinctiveness by measuring variation in egg colour and pattern in two African bird families (Cisticolidae and Ploceidae) that experience mimetic brood parasitism. Contrary to predictions, parasitized species, but not unparasitized species, exhibited a negative relationship between consistency and combinatorial distinctiveness. Moreover, regardless of parasitism status, consistency was negatively correlated with absolute distinctiveness across species. Together, these results suggest that (i) selection from parasites acts on how traits combine rather than absolute variation in traits, (ii) consistency and distinctiveness are alternative rather than complementary elements of signatures and (iii) mechanistic constraints may explain the negative relationship between consistency and absolute distinctiveness across species.

scholarly journals Brood parasitism on Meadow Pipits Anthus pratensis by Common Cuckoos Cuculus canorus in two mountain areas in Norway

2019 ◽  
Vol 42 ◽  
pp. 7-14
Author(s):  
Jan Rolf Berstad ◽  
Bård Stokke ◽  
Arne Moksnes
Keyword(s):  
Brood Parasitism ◽  
Cuculus Canorus ◽  
Long Distance ◽  
Mountain Areas ◽  
Anthus Pratensis ◽  
Meadow Pipit ◽  
Southern Norway ◽  
Host Parasite ◽  
Term Monitoring

In the period 2001–2014 we studied Common Cuckoo Cuculus canorus brood parasitism on Meadow Pipits Anthus pratensis in two mountain areas; one located in the eastern and one in the western part of southern Norway. In the total material of 211 Meadow Pipit nests, 14 (6.6%) were parasitized by the cuckoo. The parasitism rate showed considerable variation both in time and space, with highest rate in one of the areas in 2005 (35.3%). Cuckoo eggs were quite similar in appearance to host eggs. In spite of this, 30% of the cuckoo eggs were rejected by desertion. No host ejection of parasite eggs was observed. Nest predation rates were rather low. Due to climate change, it has been hypothesized that the cuckoo, a long-distance migrant, may arrive too late to successfully utilize the Meadow Pipit because the latter is better able to advance the breeding season due to a shorter migration distance. Our data lend support to the mismatch hypothesis, but the low sample size regarding cases of parasitism does not allow us to make any firm conclusions. Long-term monitoring of host-parasite interactions in specific populations is important to further disclose the mechanisms responsible for the decline in the Norwegian cuckoo population.

scholarly journals Persistence of host defence behaviour in the absence of avian brood parasitism

2011 ◽  
Vol 7 (5) ◽  
pp. 670-673 ◽  
Author(s):  
Brian D. Peer ◽  
Michael J. Kuehn ◽  
Stephen I. Rothstein ◽  
Robert C. Fleischer
Keyword(s):  
Brood Parasitism ◽  
New World ◽  
Molothrus Ater ◽  
Egg Rejection ◽  
Brood Parasite ◽  
Bombycilla Cedrorum ◽  
Defence Behaviour ◽  
Cedar Waxwing ◽  
Host Parasite

The fate of host defensive behaviour in the absence of selection from brood parasitism is critical to long-term host–parasite coevolution. We investigated whether New World Bohemian waxwings Bombycilla garrulus that are allopatric from brown-headed cowbird Molothrus ater and common cuckoo Cuculus canorus parasitism have retained egg rejection behaviour. We found that egg rejection was expressed by 100 per cent of Bohemian waxwings. Our phylogeny revealed that Bohemian and Japanese waxwings Bombycilla japonica were sister taxa, and this clade was sister to the cedar waxwing Bombycilla cedrorum . In addition, there was support for a split between Old and New World Bohemian waxwings. Our molecular clock estimates suggest that egg rejection may have been retained for 2.8–3.0 Myr since New World Bohemian waxwings inherited it from their common ancestor with the rejecter cedar waxwings. These results support the ‘single trajectory’ model of host–brood parasite coevolution that once hosts evolve defences, they are retained, forcing parasites to become more specialized over time.

The Pathogenesis of Experimental Mycotic Encephalitis

1969 ◽  
Vol 27 ◽  
pp. 356-357
Author(s):  
James A. Swenberg ◽  
Adalbert Koestner ◽  
R.P. Tewari
Keyword(s):  
Electron Microscopy ◽  
Pathogenetic Mechanisms ◽  
Host Parasite

Previous investigations of pathogenetic mechanisms in mycotic encephalitis have been restricted to light microscopic and mycologic approaches. In this study, electron microscopy was utilized to determine the mode of vascular penetration and the cellular and subcellular host-parasite interrelationships in brains of mice infected with Oidiodendron kalrai. This newly isolated fungus was selected because of its ability to consistently produce encephalitis with gross and microscopic lesions similar to those observed in naturally occuring mycoses.

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 50-51
Author(s):  
D. Johnson ◽  
P. Moriearty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Light Microscopy ◽  
Surface Structure ◽  
Extensive Study ◽  
Scanning Microscopy ◽  
Host Parasite ◽  
Conventional Electron Microscopy ◽  
Scanning Electron

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

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