scholarly journals Host eyes, brains and their brood parasites

2021 ◽  
Author(s):  
Anders Møller ◽  
Johannes Erritzøe
Keyword(s):  
Body Size ◽  
Optic Tectum ◽  
Cognitive Abilities ◽  
Relative Size ◽  
Interspecific Variation ◽  
Brood Parasite ◽  
Common Cuckoo ◽  
Visual Ability ◽  
Brood Parasites ◽  
The Common

1. Brood parasites interact with their hosts for exploitation of host parental abilities and the associated resources. This results in coevolutionary interactions of hosts and parasites. 2. A prime example of such a common specialist brood parasite is the common cuckoo Cuculus canorus and its host races. Hosts use their cognitive abilities to identify parasites and vice versa for their ability to discriminate among potential hosts. 3. We predicted that parasites with relatively large brains for their body size should be more successful at avoiding their hosts, and that hosts with small brains for their body size should more often be exploited by parasites. We also predicted that hosts with relatively large eyes for their body size would have superior discriminatory abilities allowing for superior discrimination against brood parasites. Finally, we predicted that visual ability of specific cuckoo hosts would have evolved exaggerated visual ability as estimated from the relative size of their optic tectum would have resulted in such hosts being more successful as reflected by their higher rate of parasitism. 4. Interspecific variation in size of brain, eye, optic tectum, telencephalon and cerebellum were consistent with these predictions.

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 Fast and furious: host aggression modulates behaviour of brood parasites

2020 ◽  
Author(s):  
Václav Jelínek ◽  
Michal Šulc ◽  
Gabriela Štětková ◽  
Marcel Honza
Keyword(s):  
Brood Parasitism ◽  
Egg Laying ◽  
Nest Defence ◽  
Great Reed Warbler ◽  
Acrocephalus Arundinaceus ◽  
Brood Parasite ◽  
Cuculus Canorus ◽  
Common Cuckoo ◽  
Brood Parasites ◽  
The Common

ABSTRACTAvian brood parasites pose a serious threat for hosts, substantially reducing their fitness which selects for the evolution of host defences. A classic example of a host frontline defence is mobbing which frequently includes contact attacking of brood parasites. Here, we investigated how the nest defence of a very aggressive great reed warbler (Acrocephalus arundinaceus) host influences the speed of egg-laying and egg-removing behaviour of its brood parasite – the common cuckoo (Cuculus canorus). We video-recorded 168 brood parasitic events at 102 active host nests and found that cuckoos avoided host mobbing in only 62% of cases. If hosts spotted the cuckoo at their nests, they almost always attacked it (in 91 of 104 cases), however, such attacks only rarely and temporarily prevented cuckoos from parasitizing (11 additional cases). When attacked, cuckoos parasitized host nests significantly faster and left them immediately. However, when not attacked, cuckoos frequently stayed at or near the nest suggesting that host aggression, rather than the risk of being spotted, influences the speed of brood parasitism in this species. Further, we found that cuckoos performed egg-removing behaviour in all parasitic events without regard to host aggression. As a result, cuckoos removed at least one egg during all brood parasitism events except those when an egg slipped from their beaks and fell back into the nest (in 9 of 73 cases). This indicates that egg-removing behaviour is not costly for the common cuckoo and is an essential part of its parasitism strategy, widening understanding of this currently unexplained behaviour.

scholarly journals Differences in eggshell pigmentation pattern between Common Moorhen Gallinula chloropus and Eurasian Coot Fulica atra eggs

2020 ◽  
Vol 28 (1) ◽  
pp. 176-180
Author(s):  
Valentin Adrian Kiss ◽  
Liviu Răzvan Pripon ◽  
Attila Marton
Keyword(s):  
Reproductive Output ◽  
Brood Parasite ◽  
Closely Related Species ◽  
Pigmentation Pattern ◽  
Brood Parasites ◽  
Wide Range ◽  
Fulica Atra ◽  
Eggshell Pigmentation ◽  
The Common ◽  
Discernible Difference

AbstractFacultative avian brood parasites increase their reproductive output by laying eggs in the nests of conspecifics or closely related species. The Common Moorhen Gallinula chloropus is a well-known facultative brood parasite that nests in wetlands, which are utilised also by a wide range of waterfowl, including the Eurasian Coot Fulica atra. The two species breed in similar habitats and have a similar egg pigmentation pattern; thus, the Coot can be a suitable host of brood-parasitic Moorhen. To study whether there is any discernible difference between the spotting pattern of Coot and Moorhen eggs, we compared the density of different sized spots on eggs of the two species. Our results show that Coot eggs have a significantly higher density of small speckles then Moorhen eggs, while the latter species has eggs with more conspicuous larger spots. Therefore, Coots can possibly rely on these differences in eggshell pattern to recognize and eject the brood parasitic Moorhen eggs.

scholarly journals Killing behaviour of adult brood parasites

2020 ◽  
Author(s):  
Michal Šulc ◽  
Gabriela Štětková ◽  
Václav Jelínek ◽  
Beata Czyż ◽  
Andrzej Dyrcz ◽  
...  
Keyword(s):  
Host Species ◽  
Egg Laying ◽  
Common Cuckoo ◽  
Brood Parasites ◽  
Parasitic Species ◽  
Video Recordings ◽  
The Common

Avian brood parasites such as cuckoos or cowbirds lay their eggs in the nests of other (host) species. To fool their hosts, parasites evolved striking adaptations such as very fast egg-laying or eggs that mimic host eggs. Here, we present video-recordings where the common cuckoo females kill nestlings in host nests. This interesting behaviour has been also observed in other brood parasitic species and we speculate about its significance.

scholarly journals Killing behaviour of adult brood parasites

Behaviour ◽  
2020 ◽  
Vol 157 (12-13) ◽  
pp. 1099-1111 ◽  
Author(s):  
M. Šulc ◽  
G. Štětková ◽  
V. Jelínek ◽  
B. Czyż ◽  
A. Dyrcz ◽  
...  
Keyword(s):  
Video Recording ◽  
Camera Traps ◽  
Cuculus Canorus ◽  
Common Cuckoo ◽  
Brood Parasites ◽  
The Common

Abstract Decades of studies have revealed the striking adaptations of avian brood parasites for their unique reproductive lifestyle. Several have reported that adult brood parasites sometimes kill host nestlings, although the reasons for this behaviour remain unclear. Using continuous video-recording and camera traps, we observed the same behaviour in the common cuckoo Cuculus canorus, showing that both host and parasite nestlings can be killed. The latter has never previously been observed in cuckoos. Here, we review this phenomenon and discuss possible explanations.

scholarly journals Personality of hosts and their brood parasites

2021 ◽  
Author(s):  
Anders Pape Møller ◽  
Xingfeng Si
Keyword(s):  
Brood Parasitism ◽  
Tonic Immobility ◽  
Escape Behavior ◽  
Common Cuckoo ◽  
Escape Behaviour ◽  
Brood Parasites ◽  
Specific Behaviour ◽  
Contact Calls ◽  
The Common ◽  
Comparative Phylogenetic Analysis

Abstract Brood parasites such as the common cuckoo Cuculus canorus exploit the parental abilities of their hosts, Hosts avoid brood parasitism and predation by showing specific behaviour such as loss of feathers, emission of fear screams and contact calls, displaying wriggle behavior to avoid hosts or potential prey, pecking at hosts and prey and expressing tonic immobility (showing behaviour like feigning death or rapid escape from predators and brood parasites). These aspects of escape behavior are consistent for individuals but also among sites, seasons and years. Escape behaviour expressed in response to a broad range of cuckoo hosts and prey are consistently used against capture by humans, but also hosts and brood parasites and predators and their prey. An interspecific comparative phylogenetic analysis of escape behavior by hosts and their brood parasites and prey and their predators revealed evidence of consistent behaviour when encountering potential parasites or predators. We hypothesize that personality axes such as those ranging from fearfulness to being bold, and from neophobic to curiosity response in brood parasites constitute important components of defense against brood parasitism that reduces the overall risk of parasitism.

scholarly journals The Evolution of Predator Resemblance in Avian Brood Parasites

2021 ◽  
Vol 9 ◽  
Author(s):  
Jennifer E. York
Keyword(s):  
Cognitive Processes ◽  
Signal Detection Theory ◽  
Natural Variation ◽  
Host Responses ◽  
Brood Parasite ◽  
Brood Parasites ◽  
Physiological Processes ◽  
Prey Behavior ◽  
The Common ◽  
Independent Effects

Predators have profound effects on prey behavior and some adult brood parasites use predator resemblance to exploit the antipredator defenses of their hosts. Clarifying host perception of such stimuli is important for understanding the adaptive significance of adult brood parasite characteristics, and the mechanisms by which they misdirect hosts. Here I review the literature to explore the adaptive basis of predator resemblance in avian brood parasites, and natural variation in host responses to these stimuli. I also provide a framework for the information ecology of predator resemblance, which is based on the principles of signal detection theory and draws from empirical evidence from the common cuckoo, Cuculus canorus, as the most widely studied system. In this species, visual and acoustic hawk-like stimuli are effective in manipulating host defenses. Overall, contrasts across host responses suggest that different modalities of information can have independent effects on hosts, and that predator resemblance takes advantage of multiple sensory and cognitive processes. Host perception of these stimuli and the degree to which they are processed in an integrated manner, and the physiological processes underlying regulation of the responses, present new avenues for brood parasitism research.

scholarly journals Experimental evidence for chick discrimination without recognition in a brood parasite host

2006 ◽  
Vol 274 (1608) ◽  
pp. 373-381 ◽  
Author(s):  
Tomáš Grim
Keyword(s):  
Host Response ◽  
Brood Parasite ◽  
Cuculus Canorus ◽  
Common Cuckoo ◽  
Arms Races ◽  
Acrocephalus Scirpaceus ◽  
Cuckoo Chick ◽  
The Common ◽  
Recognition Errors ◽  
Host Parasite

Recognition is considered a critical basis for discriminatory behaviours in animals. Theoretically, recognition and discrimination of parasitic chicks are not predicted to evolve in hosts of brood parasitic birds that evict nest-mates. Yet, an earlier study showed that host reed warblers ( Acrocephalus scirpaceus ) of an evicting parasite, the common cuckoo ( Cuculus canorus ), can avoid the costs of prolonged care for unrelated young by deserting the cuckoo chick before it fledges. Desertion was not based on specific recognition of the parasite because hosts accept any chick cross-fostered into their nests. Thus, the mechanism of this adaptive host response remains enigmatic. Here, I show experimentally that the cue triggering this ‘discrimination without recognition’ behaviour is the duration of parental care. Neither the intensity of brood care nor the presence of a single-chick in the nest could explain desertions. Hosts responded similarly to foreign chicks, whether heterospecific or experimental conspecifics. The proposed mechanism of discrimination strikingly differs from those found in other parasite–host systems because hosts do not need an internal recognition template of the parasite's appearance to effectively discriminate. Thus, host defences against parasitic chicks may be based upon mechanisms qualitatively different from those operating against parasitic eggs. I also demonstrate that this discriminatory mechanism is non-costly in terms of recognition errors. Comparative data strongly suggest that parasites cannot counter-evolve any adaptation to mitigate effects of this host defence. These findings have crucial implications for the process and end-result of host–parasite arms races and our understanding of the cognitive basis of discriminatory mechanisms in general.

scholarly journals Rearing a virulent common cuckoo is not extra costly for its only cavity-nesting host

2018 ◽  
Vol 285 (1889) ◽  
pp. 20181710 ◽  
Author(s):  
Peter Samaš ◽  
Jarkko Rutila ◽  
Marcel Honza ◽  
Michal Kysučan ◽  
Tomáš Grim
Keyword(s):  
Breeding Cycle ◽  
Brood Parasite ◽  
Common Cuckoo ◽  
Central Importance ◽  
Level Indicator ◽  
Brood Parasites ◽  
Cavity Nesting ◽  
Feeding Effort ◽  
Low Levels ◽  
Cost Parameters

Virulent brood parasites refrain from arduous parental care, often kill host progeny and inflict rearing costs upon their hosts. Quantifying the magnitude of such costs across the whole period of care (from incubation through to parasite fledgling independence) is essential for understanding the selection pressures on hosts to evolve antiparasitic defences. Despite the central importance of such costs for our understanding of coevolutionary dynamics, they have not yet been comprehensively quantified in any host of any avian brood parasite. We quantified parasite-rearing costs in common redstarts Phoenicurus phoenicurus raising either parasitic common cuckoo Cuculus canorus or their own chicks throughout the complete breeding cycle, and used multiple cost parameters for each breeding stage: incubation, brooding and feeding effort; length of parental/host care; parent/host body condition; and heterophil/lymphocyte ratio (stress-level indicator). Contrary to traditional assumptions, rearing the parasite per se was not associated with overall higher physiological or physical costs to hosts above the natural levels imposed by efforts to rear their own progeny. The low parasite-rearing costs imposed on hosts may, in part, explain the low levels of known host counter-defences in this unusually frequently parasitized cuckoo host.

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