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

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.

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Endocrine regulation of egg rejection in an avian brood parasite host

Biology Letters ◽

10.1098/rsbl.2020.0225 ◽

2020 ◽

Vol 16 (6) ◽

pp. 20200225 ◽

Cited By ~ 3

Author(s):

Mikus Abolins-Abols ◽

Mark E. Hauber

Keyword(s):

Stress Response ◽

Stress Physiology ◽

Endocrine Regulation ◽

Egg Rejection ◽

Brood Parasite ◽

Potential Mechanism ◽

Turdus Migratorius ◽

American Robins ◽

Defence Behaviour ◽

Behavioural Adaptations

Parasite–host coevolution can lead to novel behavioural adaptations in hosts to resist parasitism. In avian obligate brood parasite and host systems, many host species have evolved diverse cognitive and behavioural traits to recognize and reject parasitic eggs. Our understanding of the evolution and ecology of these defences hinges on identifying the mechanisms that regulate them. We hypothesized that corticosterone, a hormone linked to stress response, vigilance and the suppression of parental behaviour, stimulates the rejection of foreign eggs by brood parasite hosts. We experimentally reduced circulating glucocorticoid levels with mitotane injections in American robins Turdus migratorius and found that the mitotane-treated birds rejected foreign eggs at a lower frequency compared to the sham-treated subjects. This is the first study to causally identify a potential mechanism of a widespread defence behaviour, and it is consistent with egg rejection being mediated by stress physiology.

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Fate of Grackle (Quiscalus SPP.) Defenses in the Absence of Brood Parasitism: Implications for Long-Term Parasite-Host Coevolution

The Auk ◽

10.1093/auk/121.4.1172 ◽

2004 ◽

Vol 121 (4) ◽

pp. 1172-1186 ◽

Cited By ~ 1

Author(s):

Brian D. Peer ◽

Spencer G. Sealy

Keyword(s):

Host Species ◽

Brood Parasitism ◽

Selection Pressure ◽

Egg Rejection ◽

Allopatric Population ◽

Brood Parasites ◽

Cowbird Parasitism ◽

The Common ◽

Molothrus Aeneus

Abstract We tested grackles (Quiscalus spp.) to determine whether they retain egg rejection behavior in the absence of the selection pressure of brood parasitism. Neither Bronzed Cowbird (Molothrus aeneus) nor Brown-headed Cowbird (M. ater) parasitism was recorded in 797 Great-tailed Grackle (Q. mexicanus) nests. Cross-fostered Bronzed Cowbird nestlings, but not Brown-headed Cowbird nestlings, fledged from Great-tailed Grackle nests, indicating that Brown-headed Cowbird parasitism does not select for rejection in these grackles. Great-tailed Grackle populations sympatric and allopatric with Bronzed Cowbirds rejected 100% of model cowbird eggs. An allopatric population of Boat-tailed Grackle (Q. major), a sister species of the Great-tailed Grackle, also rejected 100% of model eggs. Egg rejection in the Boat-tailed Grackle has apparently been retained in the absence of parasitism for as long as 800,000 years since it split from the Great-tailed Grackle. The Common Grackle (Q. quiscula), which lays the most variable eggs among the grackles, also has the lowest level of egg rejection—which is consistent with the argument that it may have lost most of its rejection behavior in the absence of parasitism. With extreme intraclutch egg-variation, Common Grackles may be more likely to reject their own oddly colored eggs, which would select against rejection behavior in the absence of parasitism. Those results have significant implications for long-term parasite-host coevolution, because they suggest that egg rejection has been retained in most species of Quiscalus in the absence of parasitism. If typical of the world's avifauna, such retention may force brood parasites to specialize on a few host species and to rarely return to using old hosts, which would readily reject their eggs.

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

Ornis Norvegica ◽

10.15845/on.v42i0.2708 ◽

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.

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No immediate or future extra costs of raising a virulent brood parasite chick

Behavioral Ecology ◽

10.1093/beheco/arz043 ◽

2019 ◽

Vol 30 (4) ◽

pp. 1020-1029 ◽

Cited By ~ 4

Author(s):

Peter Samaš ◽

Tomáš Grim ◽

Václav Jelínek ◽

Marek M Abraham ◽

Michal Šulc ◽

...

Keyword(s):

Parental Care ◽

Brood Parasite ◽

Reed Warbler ◽

Return Rates ◽

Levels Of Care ◽

Acrocephalus Scirpaceus ◽

Breeding Attempt ◽

Low Levels ◽

Host Parasite

AbstractParental care is an adaptive behavior increasing the survival of a young. Virulent brood parasites, like the common cuckoo Cuculus canorus, avoid the parental care and leave the care for their nestlings to hosts. Although raising a cuckoo is always costly because it kills host’s progeny, to date it is not known whether raising of a brood parasite itself represents any extra cost affecting host’s fitness, that is, a cost above the baseline levels of care that are expended on raising the host own young anyway. We quantified costs of rearing a cuckoo nestling in the most frequent host, the reed warbler Acrocephalus scirpaceus. We measured changes in the host physical (body mass) and physiological conditions (stress levels quantified via heterophils/lymphocytes ratio) within the 1 breeding attempt (immediate cost) and retrapped some of these adults in the next breeding season to estimate return rates as a measure of their survival (future cost). In contrast to universal claims in the literature, raising a cuckoo nestling did not entail any extra immediate or future costs for hosts above natural costs of care for own offsprings. This counterintuitive result might partly reconcile theoretical expectations in the hosts with surprisingly low levels of counter-defences, including the reed warbler. Unexpectedly low raising costs of parasitism may also help explain a long-term maintenance of some host–parasite systems.

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Evicting cuckoo nestlings from the nest: a new anti-parasitism behaviour

Biology Letters ◽

10.1098/rsbl.2009.0540 ◽

2009 ◽

Vol 6 (1) ◽

pp. 67-69 ◽

Cited By ~ 91

Author(s):

Nozomu J. Sato ◽

Kihoko Tokue ◽

Richard A. Noske ◽

Osamu K. Mikami ◽

Keisuke Ueda

Keyword(s):

Reproductive Success ◽

Host Species ◽

Brood Parasitism ◽

Future Research ◽

Egg Rejection ◽

Brood Parasite ◽

Defence Mechanisms ◽

Evolutionary Pathway ◽

Unique System ◽

Avian Brood Parasitism

As avian brood parasitism usually reduces hosts' reproductive success, hosts often exhibit strong defence mechanisms. While such host defences at the egg stage (especially egg rejection) have been extensively studied, defence mechanisms at the nestling stage have been reported only recently. We found a previously unknown anti-parasitism behaviour in the large-billed Gerygone, which is a host species of the little bronze-cuckoo, a host-evicting brood parasite. The hosts forcibly pulled resisting nestlings out of their nests and dumped them. Although it has been suggested that defence mechanisms at the nestling stage may evolve when host defence at the egg stage is evaded by the parasite, the studied host seems to lack an anti-parasitism strategy at the egg stage. This suggests that the evolutionary pathway may be quite different from those of previously studied cuckoo–host systems. Future research on this unique system may give us new insights into the evolution of avian brood parasitism.

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Conventional oil and natural gas infrastructure increases brown-headed cowbird ( Molothrus ater ) relative abundance and parasitism in mixed-grass prairie

Royal Society Open Science ◽

10.1098/rsos.170036 ◽

2017 ◽

Vol 4 (7) ◽

pp. 170036 ◽

Cited By ~ 7

Author(s):

Jacy Bernath-Plaisted ◽

Heather Nenninger ◽

Nicola Koper

Keyword(s):

Natural Gas ◽

Great Plains ◽

Relative Abundance ◽

Brood Parasitism ◽

Molothrus Ater ◽

Rapid Expansion ◽

Northern Great Plains ◽

Brood Parasite ◽

Parasitism Rates ◽

Oil And Natural Gas

The rapid expansion of oil and natural gas development across the Northern Great Plains has contributed to habitat fragmentation, which may facilitate brood parasitism of ground-nesting grassland songbird nests by brown-headed cowbirds ( Molothrus ater ), an obligate brood parasite, through the introduction of perches and anthropogenic edges. We tested this hypothesis by measuring brown-headed cowbird relative abundance and brood parasitism rates of Savannah sparrow ( Passerculus sandwichensis ) nests in relation to the presence of infrastructure features and proximity to potential perches and edge habitat. The presence of oil and natural gas infrastructure increased brown-headed cowbird relative abundance by a magnitude of four times, which resulted in four times greater brood parasitism rates at infrastructure sites. While the presence of infrastructure and the proximity to roads were influential in predicting brood parasitism rates, the proximity of perch sites was not. This suggests that brood parasitism associated with oil and natural gas infrastructure may result in additional pressures that reduce productivity of this declining grassland songbird.

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