scholarly journals An Experimental Test of Defenses Against Avian Brood Parasitism in a Recent Host

2021 ◽  
Vol 9 ◽  
Author(s):  
Virginia E. Abernathy ◽  
Laura E. Johnson ◽  
Naomi E. Langmore
Keyword(s):  
Brood Parasite ◽  
Parasitism Rate ◽  
Host Switch ◽  
Brood Parasites ◽  
Egg Ejection ◽  
Parasitism Rates ◽  
Eastern Australia ◽  
Avian Brood Parasitism ◽  
Selection For ◽  
Nest Predator

Theoretical studies predict that hosts of avian brood parasites should evolve defenses against parasitism in a matter of decades. However, opportunities to test these predictions are limited because brood parasites rarely switch to naïve hosts. Here, we capitalize on a recent host switch by the brood-parasitic Pacific Koel (Eudynamys orientalis) in eastern Australia, to investigate how quickly the Red Wattlebird (Anthochaera carunculata), a recent host that has been annexed by the koel within the last 90 years, can learn to recognize and mob adult cuckoos and evolve the ability to eject parasite eggs. Pacific Koel nestlings kill all host young, so there should be strong selection for hosts to evolve defenses. However, low parasitism rates and high egg recognition costs might slow the spread of egg ejection in our study populations, while adult parasite recognition should be able to spread more rapidly, as this defense has been shown to be a learned trait rather than a genetically inherited defense. We tested Red Wattlebirds at two sites where parasitism rate differed. As predicted, we found that the Red Wattlebird showed little or no ability to eject foreign model eggs at either site, whereas two historical hosts showed high levels of egg ejection at both sites. However, Red Wattlebirds responded significantly more aggressively to a koel mount than to mounts of a harmless control and nest predator at the site with the higher parasitism rate and gave significantly more alarm calls overall toward the koel mount. Our results support previous evidence that recognition and mobbing of a brood parasite are learned traits and may be especially beneficial to naïve hosts that have not had enough time or a high enough selection pressure to evolve egg rejection.

scholarly journals Colour, vision and coevolution in avian brood parasitism

2017 ◽  
Vol 372 (1724) ◽  
pp. 20160339 ◽  
Author(s):  
Mary Caswell Stoddard ◽  
Mark E. Hauber
Keyword(s):  
Brood Parasite ◽  
Future Directions ◽  
Animal Coloration ◽  
Host Interactions ◽  
Brood Parasites ◽  
Sensory Modalities ◽  
Integrative Study ◽  
Avian Brood Parasitism ◽  
Host Life ◽  
Perception Function

The coevolutionary interactions between avian brood parasites and their hosts provide a powerful system for investigating the diversity of animal coloration. Specifically, reciprocal selection pressure applied by hosts and brood parasites can give rise to novel forms and functions of animal coloration, which largely differ from those that arise when selection is imposed by predators or mates. In the study of animal colours, avian brood parasite–host dynamics therefore invite special consideration. Rapid advances across disciplines have paved the way for an integrative study of colour and vision in brood parasite–host systems. We now know that visually driven host defences and host life history have selected for a suite of phenotypic adaptations in parasites, including mimicry, crypsis and supernormal stimuli. This sometimes leads to vision-based host counter-adaptations and increased parasite trickery. Here, we review vision-based adaptations that arise in parasite–host interactions, emphasizing that these adaptations can be visual/sensory, cognitive or phenotypic in nature. We highlight recent breakthroughs in chemistry, genomics, neuroscience and computer vision, and we conclude by identifying important future directions. Moving forward, it will be essential to identify the genetic and neural bases of adaptation and to compare vision-based adaptations to those arising in other sensory modalities. This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.

scholarly journals Prolactin mediates behavioural rejection responses to avian brood parasitism

2021 ◽  
Author(s):  
Francisco Ruiz-Raya ◽  
Juan Diego Ibáñez-Álamo ◽  
Charline Parenteau ◽  
Olivier Chastel ◽  
Manuel Soler
Keyword(s):  
Brood Parasitism ◽  
Positive Association ◽  
Prolactin Secretion ◽  
Host Responses ◽  
Plasma Prolactin ◽  
Physiological Mechanisms ◽  
Parental Behaviour ◽  
Brood Parasites ◽  
Egg Ejection ◽  
Avian Brood Parasitism

Adaptations resulting from co-evolutionary interactions between avian brood parasites and their hosts have been extensively studied, yet the physiological mechanisms underlying antiparasitic host defences remain little known. Prolactin, one of the main hormones involved in the regulation of avian parental behaviour, might play a key role in the orchestration of the host responses to avian brood parasitism. Given the positive association between prolactin and parental behaviour during incubation, decreasing prolactin levels are expected to facilitate egg-rejection decisions. We tested this prediction by implanting Eurasian blackbird (Turdus merula) females with an inhibitor of prolactin secretion, bromocriptine mesylate, to experimentally decrease their plasma prolactin levels. Bromocriptine-implanted individuals ejected mimetic model eggs at higher rates, and showed shorter latency to egg ejection, than placebo-treated birds. To our knowledge, this is the first experimental evidence that behavioural host defences against avian brood parasitism are mediated by prolactin.

scholarly journals Threat recognition and response in an avian brood-parasite host from New Caledonia

2020 ◽  
Author(s):  
Alfredo Attisano ◽  
Kasper Hlebowicz ◽  
Roman Gula ◽  
Jörn Theuerkauf
Keyword(s):  
Brood Parasitism ◽  
Nest Predation ◽  
New Caledonia ◽  
Brood Parasite ◽  
Brood Parasites ◽  
New Caledonian Crow ◽  
Caledonian Crow ◽  
Threat Recognition ◽  
Recognition And Response ◽  
Nest Predator

Abstract Nest predation and avian brood parasitism are the main sources of nest failure in many passerine birds. Large predators threaten both brood and parents, whereas brood parasites pose only a danger to eggs or nestlings. The fan-tailed gerygone Gerygone flavolateralis from New Caledonia is subjected to high rates of nest predation by the New Caledonian crow Corvus moneduloides (responsible for about 20–40% of predation) and moderate rates of brood parasitism by the shining bronze-cuckoo Chalcites lucidus (parasitizing about 18% of nests), which also depredates nests that are too advanced for parasitism (13% of nests). To test if fan-tailed gerygones are able to discriminate predators from brood parasites, we presented 3 bird models at active gerygone nests: a brood parasite/small nest predator (shining bronze-cuckoo), a large nest predator (crow), and a small non-native bird (common chaffinch Fringilla coelebs), which is unknown to the gerygone, as a control. We assessed the response of adult gerygones to the presentation of each model by measuring the minimum approach distance, number of alarm calls, number of attacks, and time to first nest visit after the presentation (latency). Adult gerygones often attacked the cuckoo, approached but never attacked the chaffinch and always avoided the crow. Latency was shorter after an attack response and during brooding, but similar among models. We did not find any link between the cuckoo model presentation and later ejection of cuckoo nestlings. We conclude that adult fan-tailed gerygones discriminate between different models and respond accordingly to the level of threat, but do not show awareness of parasitism risk and increase of nestling ejection rates following exposure to the cuckoo model.

scholarly journals The neuroethology of avian brood parasitism

2021 ◽  
Vol 224 (17) ◽  
Author(s):  
Kathleen S. Lynch
Keyword(s):  
Species Recognition ◽  
Developmental Period ◽  
Song Learning ◽  
Growing Up ◽  
Brood Parasite ◽  
Brood Parasites ◽  
Proximate Mechanisms ◽  
Parasite Evolution ◽  
Avian Brood Parasitism ◽  
Critical Developmental Period

ABSTRACT Obligate brood-parasitic birds never build nests, incubate eggs or supply nestlings with food or protection. Instead, they leave their eggs in nests of other species and rely on host parents to raise their offspring, which allows the parasite to continue reproducing throughout the breeding season. Although this may be a clever fitness strategy, it is loaded with a set of dynamic challenges for brood parasites, including recognizing individuals from their own species while growing up constantly surrounded by unrelated individuals, remembering the location of potential host nests for successful reproduction and learning the song of their species while spending time being entirely surrounded by another species during a critical developmental period, a predicament that has been likened to being ‘raised by wolves’. Here, I will describe what we currently know about the neurobiology associated with the challenges of being a brood parasite and what is known about the proximate mechanisms of brood parasite evolution. The neuroethology of five behaviors (mostly social) in brood parasites is discussed, including: (1) parental care (or the lack thereof), (2) species recognition, (3) song learning, (4) spatial memory and (5) pair-bonding and mate choice. This Review highlights how studies of brood parasites can lend a unique perspective to enduring neuroethological questions and describes the ways in which studying brood-parasitic species enhances our understanding of ecologically relevant behaviors.

scholarly journals Host density predicts the probability of parasitism by avian brood parasites

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180204 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Spatial Distribution ◽  
Reproductive Success ◽  
Host Species ◽  
Field Data ◽  
Host Density ◽  
Brood Parasites ◽  
Parasitism Rates ◽  
Analyse Data ◽  
First Time ◽  
Determining Factor

The spatial distribution of hosts can be a determining factor in the reproductive success of parasites. Highly aggregated hosts may offer more opportunities for reproduction but can have better defences than isolated hosts. Here we connect macro- and micro-evolutionary processes to understand the link between host density and parasitism, using avian brood parasites as a model system. We analyse data across more than 200 host species using phylogenetic comparative analyses and quantify parasitism rate and host reproductive success in relation to spatial distribution using field data collected on one host species over 6 years. Our comparative analysis reveals that hosts occurring at intermediate densities are more likely to be parasitized than colonial or widely dispersed hosts. Correspondingly, our intraspecific field data show that individuals living at moderate densities experience higher parasitism rates than individuals at either low or high densities. Moreover, we show for the first time that the effect of host density on host reproductive success varies according to the intensity of parasitism; hosts have greater reproductive success when living at high densities if parasitism rates are high, but fare better at low densities when parasitism rates are low. We provide the first evidence of the trade-off between host density and parasitism at both macro- and micro-evolutionary scales in brood parasites. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

Diversity, distribution and parasitism rates of fleas (Insecta: Siphonaptera) on sigmodontine rodents (Cricetidae) from Argentinian Patagonia

2018 ◽  
Vol 109 (1) ◽  
pp. 72-83 ◽  
Author(s):  
J. Sanchez ◽  
M. Lareschi
Keyword(s):  
Host Species ◽  
Arid Regions ◽  
Epidemiological Studies ◽  
Surveillance Systems ◽  
Parasitism Rate ◽  
Host Environment ◽  
Ecological Aspects ◽  
Parasitism Rates ◽  
Survival And Development ◽  
Causative Agents

AbstractFleas have great medical relevance as vectors of the causative agents of several diseases in animals and humans and rodents are the principal reservoirs for these pathogens. Argentinian Patagonia has the highest diversity of rodent fleas in South America. However, parasitism rates of rodents by fleas, the factors that influence them and the ecological aspects that modulate geographical distributions of flea–host association remain unknown for this region. This is the first study to record the diversity, prevalence, abundance, geographical distributions and host ranges of fleas in Argentinian Patagonia. It also compares parasitism rates among Patagonian ecoregions and host species. We captured 438 rodents belonging to 13 species, which harboured 624 fleas from 11 species and subspecies (P = 46%; mean abundance = 1.44). The high parasitism rates obtained were consistent with previous records for other arid regions, suggesting that Patagonia favours the survival and development of Siphonaptera. Host geographic range and abundance were related to the parasitological indexes: host species with high-density populations had the highest mean flea abundance and prevalence, whereas widely distributed hosts had the highest richness and diversity of flea species. Our results contribute to the knowledge of the flea–host–environment complex. Our analysis of flea distributions and parasitism rate in Central Patagonia may be useful in epidemiological studies of flea-borne diseases and provide a basis for implementing surveillance systems for better risk assessment of emerging zoonoses in the region.

scholarly journals Host Recognition of Brood Parasites: Implications for Methodology in Studies of Enemy Recognition

The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 530-543 ◽  
Author(s):  
Tomáš Grim
Keyword(s):  
Traditional Approach ◽  
Columba Livia ◽  
Host Recognition ◽  
Brood Parasite ◽  
Common Cuckoo ◽  
Brood Parasites ◽  
Accurate Picture ◽  
Rock Pigeon ◽  
The Common ◽  
Enemy Recognition

AbstractVarious studies have shown that experiments on nest defense and enemy recognition (e.g. recognition of adult brood parasites) can be confounded by many factors. However, no study has described a confounding effect of control dummy type. Here, I show experimentally that the choice of control dummy may influence the results of an experiment and lead to erroneous conclusions. I tested recognition abilities of the Blackcap (Sylvia atricapilla), currently a host rarely used by the Common Cuckoo (Cuculus canorus). Blackcaps responded very differently to two kinds of control dummies: they ignored the Eurasian Blackbird (Turdus merula) dummy, but attacked the Rock Pigeon (Columba livia) dummy as frequently as they attacked the Common Cuckoo. The differing results may be explained by the fact that the Rock Pigeon is more similar to the Common Cuckoo than the Eurasian Blackbird is, and consequently elicited more aggressive behavior than the latter. Thus, absence of discrimination in enemy-recognition studies may reflect a methodological artifact resulting from varying abilities of particular hosts to discriminate along a continuum of recognition cues. This result has serious methodological implications for further research on enemy recognition and aggression in general: a control dummy should not be too similar to the dummy brood parasite; otherwise, the chance of detecting existing recognition abilities is low. Further, I argue that coevolution only increases pre-existing aggression in the particular host species. Therefore, increment analysis (assessing changes in host antiparasitic responses during the nesting cycle while controlling for background aggression to control dummies) provides a more accurate picture of hosts' recognition abilities than the traditional approach (when the total level of antiparasitic response is analyzed).

scholarly journals Brood parasitism in eusocial insects (Hymenoptera): role of host geographical range size and phylogeny

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180203 ◽  
Author(s):  
Jukka Suhonen ◽  
Jaakko J. Ilvonen ◽  
Tommi Nyman ◽  
Jouni Sorvari
Keyword(s):  
Brood Parasitism ◽  
Range Size ◽  
Geographical Range ◽  
Social Parasite ◽  
Brood Parasite ◽  
Social Parasites ◽  
Brood Parasites ◽  
Eusocial Insects ◽  
Interspecific Brood Parasitism ◽  
Logistic Regressions

Interspecific brood parasitism is common in many animal systems. Brood parasites enter the nests of other species and divert host resources for producing their own offspring, which can lead to strong antagonistic parasite–host coevolution. Here, we look at commonalities among social insect species that are victims of brood parasites, and use phylogenetic data and information on geographical range size to predict which species are most probably to fall victims to brood parasites in the future. In our analyses, we focus on three eusocial hymenopteran groups and their brood parasites: (i) bumblebees, (ii) Myrmica ants, and (iii) vespine and polistine wasps. In these groups, some, but not all, species are parasitized by obligate workerless inquilines that only produce reproductive-caste descendants. We find phylogenetic signals for geographical range size and the presence of parasites in bumblebees, but not in ants and wasps. Phylogenetic logistic regressions indicate that the probability of being attacked by one or more brood parasite species increases with the size of the geographical range in bumblebees, but the effect is statistically only marginally significant in ants. However, non-phylogenetic logistic regressions suggest that bumblebee species with the largest geographical range sizes may have a lower likelihood of harbouring social parasites than do hosts with medium-sized ranges. Our results provide new insights into the ecology and evolution of host–social parasite systems, and indicate that host phylogeny and geographical range size can be used to predict threats posed by social parasites, as well to design efficient conservation measures for both hosts and their parasites. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

scholarly journals Parasitic cuckoo catfish exploit parental responses to stray offspring

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180412 ◽  
Author(s):  
M. Polačik ◽  
M. Reichard ◽  
C. Smith ◽  
R. Blažek
Keyword(s):  
Brood Parasitism ◽  
Lake Tanganyika ◽  
Buccal Cavity ◽  
Brood Parasite ◽  
Theme Issue ◽  
Brood Parasites ◽  
Parental Response ◽  
Interspecific Brood Parasitism ◽  
Late Developmental Stage ◽  
Parental Responses

Interspecific brood parasitism occurs in several independent lineages of birds and social insects, putatively evolving from intraspecific brood parasitism. The cuckoo catfish, Synodontis multipunctatus , the only known obligatory non-avian brood parasite, exploits mouthbrooding cichlid fishes in Lake Tanganyika, despite the absence of parental care in its evolutionary lineage (family Mochokidae). Cuckoo catfish participate in host spawning events, with their eggs subsequently collected and brooded by parental cichlids, though they can later be selectively rejected by the host. One scenario for the origin of brood parasitism in cuckoo catfish is through predation of cichlid eggs during spawning, eventually resulting in a spatial and temporal match in oviposition by host and parasite. Here we demonstrate experimentally that, uniquely among all known brood parasites, cuckoo catfish have the capacity to re-infect their hosts at a late developmental stage following egg rejection. We show that cuckoo catfish offspring can survive outside the host buccal cavity and re-infect parental hosts at a later incubation phase by exploiting the strong parental instinct of hosts to collect stray offspring. This finding implies an alternative evolutionary origin for cuckoo catfish brood parasitism, with the parental response of host cichlids facilitating its evolution. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

scholarly journals Myxomatosis on the Western Plains of Victoria

1977 ◽  
Vol 79 (2) ◽  
pp. 209-217 ◽  
Author(s):  
F. G. Tighe ◽  
J. W. Edmonds ◽  
I. F. Nolan ◽  
Rosamond C. H. Shepherd ◽  
A. Gocs
Keyword(s):  
Myxoma Virus ◽  
Eastern Australia ◽  
Selection For

SUMMARYMyxomatosis on the Western Plains is an enzootic disease in contrast with the epizootic pattern which is general in eastern Australia. The most unusual aspects are the presence of significant numbers of diseased rabbits throughout the winter and the continuously low percentage of rabbits with antibodies to myxoma virus.Climatic and topographic conditions are unsuited to the production of the high densities of mosquitoes necessary for widespread epizootics. Under these conditions the effects of less efficient methods of myxomatosis transmission are apparent. The unusual epidemiology of myxomatosis has resulted in selection for virulence of the virus similar to that which has occurred under summer epizootic conditions. All field strains are now in the mid range of virulence.

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