Exposure to a mimetic or non-mimetic model avian brood parasite egg does not produce differential glucocorticoid responses in an egg-accepter host species

Scharf, Hannah M.; Āboliņš-Ābols, Mikus; Stenstrom, K. H.; Tolman, Deryk; Schelsky, Wendy M.; Hauber, Márk E.

doi:10.1016/j.ygcen.2021.113723

Cited by 11 publications

(11 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Changes in host physiology in response to brood parasitism may also include variations in glucocorticoid levels (Ruiz-Raya et al, 2018), which can promote anti-parasitic responses (Abolins-Abols and Hauber, 2020). Indeed, it has recently been shown that experimental brood parasitism either with mimetic or non-mimetic eggs does not lead to changes in the physiology of the prothonotary warbler ( Protonotaria citrea ), an egg-accepter host of the brown-headed cowbird ( Molothrus ater ) (Scharf et al, 2021). This reinforces the idea that these physiological adjustments are, at least partially, triggered by egg recognition.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Physiological stress responses to non-mimetic model brood parasite eggs: leukocyte profiles and heat-shock protein Hsp70 levels

Ruiz-Raya

Abaurrea

Vigo

et al. 2022

Preprint

View full text Add to dashboard Cite

Obligate avian brood parasites lay their eggs in the nest of other bird species (hosts). Brood parasitism often imposes severe fitness costs on hosts, which selects for the evolution of effective anti-parasitic defences, such as recognition and rejection of brood parasite eggs. Glucocorticoids have been recently found to mediate host physiological and behavioural adjustments in response to brood parasite eggs; however, it remains unclear whether brood parasitism triggers a general response involving multiple physiological elements. In this study, we experimentally investigated whether a salient brood parasitic stimulus (the presence of a non-mimetic model egg in the nest) causes physiological adjustments in adult Eurasian blackbirds (Turdus merula) at immune (leukocyte profiles) and cellular (heat-shock protein Hsp70 synthesis) level. Also, we explored whether these physiological changes are mediated by variations in corticosterone levels. We found that experimental brood parasitism caused an increase in heterophils and a decrease in lymphocytes, leading to higher H/L ratios in parasitized birds. Nevertheless, we did not find trade-offs between immune function and corticosterone levels. Hsp70 synthesis was not affected by our experimental manipulation. Our findings provide evidence that brood parasite eggs trigger a general stress response in egg-rejecter hosts, including changes in cellular immune profiles.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Brood parasitism stimuli is known to increase corticosterone (CORT) levels in adult hosts during incubation (Ruiz-Raya et al . 2018; but see Scharf et al . 2021) and nestling stages (Antonson et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Physiological stress responses to non-mimetic model brood parasite eggs: leukocyte profiles and heat-shock protein Hsp70 levels

Ruiz-Raya

Abaurrea

Vigo

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…This acceptance threshold can be flexible depending on prior parasitism experience and has been demonstrated to experimentally be shifted in great reed warblers (Hauber et al, 2006). Furthermore, acceptors may still possess the ability to recognize foreign eggs in their clutches, especially hosts with eggs that differ significantly in appearance compared with their parasite's eggs, yet do not remove them due to other factors (e.g., ultimately, due to low parasitism rates or retaliatory behavior from the parasite: Ruiz-Raya & Soler, 2020, or proximately, due to a lack of glucocorticoid responses mounted when viewing foreign eggs in the nest: Scharf et al, 2021). Future research should also seek to narrow the gap in our understanding of the widely documented acceptance behaviors among the hosts of cowbirds in particular, and other avian brood parasites in general.…”

Section: Future Directions In Studying Egg Rejection Behaviorsmentioning

confidence: 99%

The American robin (Turdus migratorius): A focal species for anti‐parasitic egg rejection studies among hosts of the brown‐headed cowbird (Molothrus ater)

Turner

Hauber

2021

Ethology

View full text Add to dashboard Cite

Obligate avian brood parasites lay their eggs in the nest of other species and impose reproductive costs upon their hosts. In response, many hosts have evolved a variety of defenses to avoid or reduce the costs associated with parasitism, including the rejection of parasitic eggs. Here, we review the different sensory and contextual cues involved in egg rejection by the American robin (Turdus migratorius), one of the handful of rejecter host species of the brood parasitic brown-headed cowbird (Molothrus ater) in North America. Robins are an open-cup nesting species whose eggs dramatically differ in appearance from the cowbirds' eggs; therefore, we expect that visual cues would be the primary sensory modality used when rejecting foreign eggs. The results of our comprehensive review confirm that visual cues, including eggshell color and maculation, are strong predictors of robins' egg rejection responses. Egg size, egg shape, and other contextual traits (including clutch composition, maternal status, and sympatry with the parasite) also affect egg rejection in this host species. Future research into this species' egg rejection mechanisms would benefit from comparisons to other strongly and moderately egg rejecter host species of brown-headed cowbirds, as well as from seeking to understand further why so many hosts of this particular parasitic lineage accept foreign eggs. We also discuss the implications of this review for other egg rejecter and non-rejecter hosts of diverse avian brood parasites.

show abstract

“…In addition, it should be noted that the adaptive value of nest desertion is likely determined by life-history traits. As nest abandonment would be adaptive only when the value of current reproduction is low (e.g., lower clutch sizes; Servedio and Hauber 2006 ), prolactin might mediate optimal rejection decisions according to the fitness payoffs of alternative host responses. Prolactin decreases in response to environmental stressors can be downregulated to maintain parental care when current reproduction has important fitness value ( Angelier and Chastel 2009 ; Angelier et al .…”

Section: Beyond Egg Recognition: Endocrine Regulation Of Flexible Host Responsesmentioning

confidence: 99%

Ecophysiology of egg rejection in hosts of avian brood parasites: new insights and perspectives

Ruiz-Raya

2021

Current Zoology

View full text Add to dashboard Cite

Egg rejection is the most effective and widespread defence used by host species to counteract the extreme fitness costs frequently imposed by obligate avian brood parasites. Yet, the proximate mechanisms underlying between- and within-individual variation in host responses remain poorly explored. Emerging evidence suggests that egg rejection is dependent on individual physiological state, and draws attention to the role of hormones as mediators of flexible antiparasitic responses. In this perspective article, I outline recent advances in our understanding of the proximate factors that mediate egg rejection. I also point out some areas where knowledge remains still lacking, especially those related to the development and maintenance of effective cognitive functions, the potential role of oxidative stress, immunological state and developmental stressors. I propose new hypotheses that stimulate future research on behavioural host responses towards brood parasitism.

show abstract

Exposure to a mimetic or non-mimetic model avian brood parasite egg does not produce differential glucocorticoid responses in an egg-accepter host species

Cited by 11 publications

References 58 publications

Physiological stress responses to non-mimetic model brood parasite eggs: leukocyte profiles and heat-shock protein Hsp70 levels

Physiological stress responses to non-mimetic model brood parasite eggs: leukocyte profiles and heat-shock protein Hsp70 levels

The American robin (Turdus migratorius): A focal species for anti‐parasitic egg rejection studies among hosts of the brown‐headed cowbird (Molothrus ater)

Ecophysiology of egg rejection in hosts of avian brood parasites: new insights and perspectives

Contact Info

Product

Resources

About