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

2021 ◽  
Author(s):  
Francisco Ruiz-Raya
Keyword(s):  
Potential Role ◽  
Physiological State ◽  
Host Responses ◽  
Future Research ◽  
Egg Rejection ◽  
Fitness Costs ◽  
Brood Parasites ◽  
Proximate Mechanisms ◽  
Proximate Factors

Abstract 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.

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 Mimicry-dependent lateralization in the visual inspection of foreign eggs by American robins

2019 ◽  
Vol 15 (7) ◽  
pp. 20190351 ◽  
Author(s):  
Hannah M. Scharf ◽  
Katharine Stenstrom ◽  
Miri Dainson ◽  
Thomas J. Benson ◽  
Esteban Fernandez-Juricic ◽  
...  
Keyword(s):  
Visual Processing ◽  
Species Recognition ◽  
Molothrus Ater ◽  
Population Level ◽  
Brain Lateralization ◽  
Turdus Migratorius ◽  
Brain Hemispheres ◽  
Brood Parasites ◽  
Visual Hemifield ◽  
American Robins

Brain lateralization, or the specialization of function in the left versus right brain hemispheres, has been found in a variety of lineages in contexts ranging from foraging to social and sexual behaviours, including the recognition of conspecific social partners. Here we studied whether the recognition and rejection of avian brood parasitic eggs, another context for species recognition, may also involve lateralized visual processing. We focused on American robins ( Turdus migratorius ), an egg-rejecter host to occasional brood parasitism by brown-headed cowbirds ( Molothrus ater ) and tested if robins preferentially used one visual hemifield over the other to inspect mimetic versus non-mimetic model eggs. At the population level, robins showed a significantly lateralized absolute eyedness index (EI) when viewing mimetic model eggs, but individuals varied in left versus right visual hemifield preference. By contrast, absolute EI was significantly lower when viewing non-mimetic eggs. We also found that robins with more lateralized eye usage rejected model eggs at higher rates. We suggest that the inspection and recognition of foreign eggs represent a specialized and lateralized context of species recognition in this and perhaps in other egg-rejecter hosts of brood parasites.

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 Brainstem development requires galactosylceramidase and is critical for pathogenesis in a model of Krabbe disease

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadav I. Weinstock ◽  
Conlan Kreher ◽  
Jacob Favret ◽  
Duc Nguyen ◽  
Ernesto R. Bongarzone ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cell ◽  
Critical Period ◽  
Developmental Period ◽  
Krabbe Disease ◽  
Hematopoietic Stem ◽  
T Box ◽  
Early Brain Development ◽  
A Cell ◽  
Critical Developmental Period

Abstract Krabbe disease (KD) is caused by a deficiency of galactosylceramidase (GALC), which induces demyelination and neurodegeneration due to accumulation of cytotoxic psychosine. Hematopoietic stem cell transplantation (HSCT) improves clinical outcomes in KD patients only if delivered pre-symptomatically. Here, we hypothesize that the restricted temporal efficacy of HSCT reflects a requirement for GALC in early brain development. Using a novel Galc floxed allele, we induce ubiquitous GALC ablation (Galc-iKO) at various postnatal timepoints and identify a critical period of vulnerability to GALC ablation between P4-6 in mice. Early Galc-iKO induction causes a worse KD phenotype, higher psychosine levels in the rodent brainstem and spinal cord, and a significantly shorter life-span of the mice. Intriguingly, GALC expression peaks during this critical developmental period in mice. Further analysis of this mouse model reveals a cell autonomous role for GALC in the development and maturation of immature T-box-brain-1 positive brainstem neurons. These data identify a perinatal developmental period, in which neuronal GALC expression influences brainstem development that is critical for KD pathogenesis.

Genetic Perspectives on the Neurochemistry of Human Aggression and Violence

2014 ◽  
Author(s):  
Joshua W. Buckholtz ◽  
Andreas Meyer-Lindenberg
Keyword(s):  
Personality Disorder ◽  
Antisocial Personality Disorder ◽  
Borderline Personality ◽  
Developmental Period ◽  
Impulsive Aggression ◽  
Genetic Mechanisms ◽  
Serotonin Signaling ◽  
Genetically Determined ◽  
Critical Developmental Period ◽  
Cardinal Symptom

Violence is a devastating social phenomenon that is costly both to affected individuals and to society at large. Pathological aggression, especially reactive/impulsive aggression, is a cardinal symptom common to several psychiatric disorders—including antisocial personality disorder, borderline personality disorder, and psychopathy—that are associated with risk for violence. Thus, understanding the factors that predispose people to impulsive violence represents a crucial goal for psychology, neuroscience, and psychiatry. Although we are far from a full understanding of the etiopathophysiology of violence, impulsive aggression is heritable, suggesting that genetic mechanisms may be important for determining individual variation in susceptibility. This chapter synthesizes available preclinical and human data to propose a compelling neurogenetic mechanism for violence, specifically arguing that a genetically determined excess in serotonin signaling during a critical developmental period leads to dysregulation within a key corticolimbic circuit for emotional arousal and regulation, inhibitory control, and social cognition.

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