scholarly journals Discrimination and ejection of eggs and nestlings by the fan-tailed gerygone from New Caledonia

2021 ◽  
Author(s):  
Alfredo Attisano ◽  
Nozomu J Sato ◽  
Keita Tanaka ◽  
Yuji Okahisa ◽  
Keisuke Ueda ◽  
...  
Keyword(s):  
Breeding Season ◽  
Brood Parasitism ◽  
Visual Cues ◽  
Size Range ◽  
New Caledonia ◽  
Host Defence ◽  
Combined Approach ◽  
Rare Type ◽  
Egg Ejection ◽  
Nestling Period

Abstract Nestling ejection is a rare type of host defence against brood parasitism compared to egg ejection. Theoretically, host defences at both egg and nestling stages could be based on similar underlying discrimination mechanisms but, due to the rarity of nestling ejector hosts, few studies have actually tested this hypothesis. We investigated egg and nestling discrimination by the fan-tailed gerygone Gerygone flavolateralis, a host that seemingly accepts non-mimetic eggs of its parasite, the shining bronze-cuckoo Chalcites lucidus, but ejects mimetic parasite nestlings. We introduced artificial eggs or nestlings and foreign gerygone nestlings in gerygone nests and compared begging calls of parasite and host nestlings. We found that the gerygone ejected artificial eggs only if their size was smaller than the parasite or host eggs. Ejection of artificial nestlings did not depend on whether their colour matched that of the brood. The frequency of ejection increased during the course of the breeding season mirroring the increase in ejection frequency of parasite nestlings by the host. Cross-fostered gerygone nestlings were frequently ejected when lacking natal down and when introduced in the nest before hatching of the foster brood, but only occasionally when they did not match the colour of the foster brood. Begging calls differed significantly between parasite and host nestlings throughout the nestling period. Our results suggest that the fan-tailed gerygone accepts eggs within the size range of gerygone or cuckoo eggs and that nestling discrimination is based on auditory and visual cues other than skin colour. This highlights the importance of using a combined approach to study discrimination mechanisms of hosts.

Picturing Scripts: A Combined Narrative, Social Semiotic and Cognitive Approach to Visual Narrativity

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Cindie Maagaard
Keyword(s):  
Cognitive Processes ◽  
Visual Cues ◽  
Analytical Framework ◽  
Visual Images ◽  
Contextual Knowledge ◽  
Combined Approach ◽  
Future Tense ◽  
Cognitive Approach ◽  
The One ◽  
Cognitive Perspectives

Abstract This article explores visual narrativity through the case of prospective, or future-tense, narratives realized through visual images. Addressing the challenges of representing narrative elements of temporality, events and experience in a single, static image, it proposes an analytical framework combining social semiotic, contextual and cognitive perspectives. In doing so, it argues that a combined approach enhances our ability to understand the interplay between on the one hand the image-internal visual cues of temporality and modality that activate the viewer’s imagination and narrative inferences, and on the other, the processes by which such inferences are made, including the influence of the viewer’s contextual knowledge and cognitive processes in guiding them. The article uses architectural renderings as material for analysis, because they are exemplary of how visual images invite viewers to imagine the kinds of activities and experiences that can unfold in a future setting and thus make inferences about temporality, event and experience beyond the image’s isolated moment.

scholarly journals Impact of brood parasitism and predation on nest survival of the fan‐tailed gerygone in New Caledonia

2020 ◽  
Vol 51 (7) ◽  
Author(s):  
Alfredo Attisano ◽  
Lara B. Groß ◽  
Nozomu J. Sato ◽  
Yuji Okahisa ◽  
Keita D. Tanaka ◽  
...  
Keyword(s):  
Brood Parasitism ◽  
New Caledonia ◽  
Nest Survival

scholarly journals Breeding Biology of Gray-Crowned Tyrannulet in the Monte Desert, Argentina

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Eduardo T. Mezquida ◽  
Luis Marone
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Nesting Success ◽  
Nest Failure ◽  
East Central ◽  
Male And Female ◽  
Monte Desert ◽  
Present Information ◽  
Nestling Period ◽  
Wet Tropics

Abstract We present information from 75 nests of Gray-crowned Tyrannulet (Serpophaga griseiceps) found in open Prosopis woodlands of the central Monte desert between 1995 and 1997 and compare it with information corresponding to other species of the genus. Breeding occurred from October to January. Nests are small open cups. Both parents participated in nest building, which lasted 4–7 days. In the Prosopis woodland, 98% of the nests were built in chañar (Geoffroea decorticans), which also is commonly used as a nest plant by S. subcristata in east-central Argentina. Mean clutch size did not vary among years nor within the breeding season, and it was similar to that observed in other Serpophaga. Both male and female shared the 13–15 day incubation period. Hatching was asynchronous. Nestling period lasted 13–14 days, during which both parents reared the chicks. Nesting success (26%) appeared to be less than that previously reported for Nearctic open-nesters (50–60%), and Neotropical open-nesters in dry (50%) and wet tropics (35%). Egg and nestling predation were the main cause of nest failure.

scholarly journals Creamy-Bellied Thrush Defenses Against Shiny Cowbird Brood Parasitism

The Condor ◽  
2005 ◽  
Vol 107 (4) ◽  
pp. 788-796 ◽  
Author(s):  
Andrea A. Astie ◽  
Juan C. Reboreda
Keyword(s):  
Brood Parasitism ◽  
Hatching Success ◽  
Simultaneous Presentation ◽  
Control Model ◽  
Nest Attendance ◽  
Chick Survival ◽  
Molothrus Bonariensis ◽  
Egg Ejection ◽  
Cowbird Parasitism ◽  
Recognition Errors

AbstractWe studied Creamy-bellied Thrush (Turdus amaurochalinus) defenses against brood parasitism by Shiny Cowbirds (Molothrus bonariensis). Shiny Cowbirds decrease the reproductive success of Creamy-bellied Thrushes, and having historical habitats and ranges that overlap, we expected that thrushes possess antiparasitic defenses. We analyzed nest attendance during prelaying, laying and incubation; responses to the presentation of a model of a female cowbird or a control species close to the nest; nest abandonment associated with parasitism; and responses to experimental parasitism with white or spotted cowbird eggs (with or without the simultaneous presentation of a female cowbird model). Nest attendance was 58%–68% during prelaying and 83%–90% during laying and incubation. Thrushes had a shorter latency in returning near the nest and visited nests more frequently when we presented the cowbird model than the control model. The frequency of abandonment of parasitized nests was low and was not temporally associated with parasitism. Thrushes ejected white eggs more frequently than spotted eggs when parasitism was associated with the presentation of the cowbird model, but there were no differences when the model was absent. Our results indicate that Creamy-bellied Thrushes recognize cowbirds as a threat and eject white but not spotted cowbird eggs. We postulate that the low impact of cowbird parasitism on thrush hatching success and chick survival and the likelihood of recognition errors when parasite eggs resemble host eggs may have prevented the evolution of egg ejection in this host.

Egg ejection cost can limit defence strategies against brood parasitism

Ethology ◽  
2018 ◽  
Vol 124 (10) ◽  
pp. 719-723 ◽  
Author(s):  
Carlos Biagolini-Jr ◽  
Paulo Victor Resende dos Santos
Keyword(s):  
Brood Parasitism ◽  
Egg Ejection ◽  
Defence Strategies

Experiments on egg discrimination in two North American corvids: further evidence for retention of egg ejection

2004 ◽  
Vol 82 (9) ◽  
pp. 1399-1407 ◽  
Author(s):  
Todd J Underwood ◽  
Spencer G Sealy ◽  
Celia M McLaren
Keyword(s):  
Brood Parasitism ◽  
Alternative Hypothesis ◽  
Egg Discrimination ◽  
Corvus Brachyrhynchos ◽  
Detection Model ◽  
Egg Ejection ◽  
Significant Difference ◽  
History Of ◽  
Pica Nuttalli ◽  
High Level

In the absence of brood parasitism in North America, black-billed magpies, Pica hudsonia (Sabine, 1822), and yellow-billed magpies, Pica nuttalli (Audubon, 1837), may have retained egg-discrimination behaviour that evolved in Eurasian magpies, Pica pica (L., 1758), in response to parasitism by Old World cuckoos. We further examined this hypothesis by testing the egg-discrimination abilities of black-billed magpies and the American crow, Corvus brachyrhynchos Brehm, 1822, which has no history of brood parasitism. In addition, we tested an alternative hypothesis that black-billed magpies evolved or retained egg discrimination to counter conspecific parasitism by testing their ability to eject foreign conspecific eggs and by using a signal detection model to estimate the level of conspecific parasitism required for ejection to be favoured. Black-billed magpies ejected all non-mimetic eggs and 62% of mimetic eggs. Significantly more mimetic eggs were ejected during the incubation stage than during the laying stage. Magpies ejected significantly more non-mimetic eggs than mimetic eggs overall, but there was no difference in ejection frequency during incubation. American crows ejected 21% of non-mimetic eggs and 8% of mimetic eggs. There was no significant difference in ejection frequency of the two egg types. Black-billed magpies ejected 11% of conspecific eggs and a relatively high level of conspecific parasitism (22%–49%) would be required to select for conspecific ejection, which provides little support for conspecific parasitism as a current selection pressure for maintaining egg discrimination. Thus, black-billed magpies appear to have retained egg rejection in the absence of parasitism through speciation from Eurasian magpies.

scholarly journals Early Onset of Incubation by Wood Ducks

The Condor ◽  
2004 ◽  
Vol 106 (1) ◽  
pp. 182-186 ◽  
Author(s):  
Gary R. Hepp
Keyword(s):  
Breeding Season ◽  
Brood Parasitism ◽  
Early Onset ◽  
Egg Laying ◽  
Aix Sponsa ◽  
The Third ◽  
Wood Ducks ◽  
Incubation Periods

AbstractI examined onset of incubation in Wood Ducks (Aix sponsa) and evaluated the hypotheses that early onset improves hatchability, reduces brood parasitism, and shortens incubation periods. Most (21 of 22) females began incubating at night, a median of 4 days before egg laying ended. Nocturnal incubation bouts began 18 min before sunset, ended 15 min before sunrise, lasted 732 min each night, and totaled 47.2 hr before egg-laying ended (means). Nocturnal incubation did not begin earlier in the egg-laying period as the breeding season progressed, as would be expected if it improved hatchability of first-laid eggs. Early onset of incubation did not reduce brood parasitism. Females ended nocturnal incubation 35 min before egg laying began, the number of nights of incubation was not related to the number of parasitic eggs laid, and most (83%) nests were parasitized. In support of the third hypothesis, egg-laying females spending more nights incubating had somewhat shorter incubation periods.Inicio Temprano del Período de Incubación por Parte de Aix sponsaResumen. Examiné el inicio del período de incubación en patos de la especie Aix sponsa y evalué las hipótesis de que el comienzo temprano mejora la probabilidad de eclosión, reduce el parasitismo de la nidada y acorta el período de incubación. La mayoría (21 de 22) de las hembras comenzaron a incubar durante la noche, 4 días (mediana) antes que la puesta de huevos terminara. En promedio, la incubación nocturna comenzó 18 min antes del anochecer, terminó 15 min antes del amanecer, duró 732 min cada noche y totalizó 47.2 hr antes que la puesta de huevos terminara. La incubación nocturna no comenzó más temprano durante el período de puesta de huevos a medida que la estación reproductiva avanzó, como se esperaría si ésta mejorase la probabilidad de eclosión de los primeros huevos puestos. El inicio temprano de la incubación no redujo el parasitismo de la nidada. Las hembras terminaron la incubación nocturna 35 min antes que la puesta de huevos comenzara, el número de noches de incubación no se relacionó con el número de huevos de aves parásitas puestos y la mayoría (83%) de los nidos fueron parasitados. En apoyo a la tercera hipótesis, encontramos que las hembras que pusieron huevos y que pasaron más noches incubando tuvieron períodos de incubación un poco más cortos.

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