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"Cuckoos"
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Evolution of defences against cuckoo : a comparison of four populations in Fennoscandia
The brood parasitic common cuckoo Cuculus canorus has a history of coevolution that involves numerous passerine hosts, but today only a subset is known to be regularly parasitised in any area. In some hosts, there is significant variation in the occurrence of parasitism between populations, but still individuals in non-parasitised populations show strong antiparasite defences. In the present study we compared the strength of egg rejection of four distant Fennoscandian brambling Fringilla montifringilla populations experiencing different levels of cuckoo parasitism (0-6%). Egg rejection ability was in general very well developed and we did not find any population differences in the relationship between egg rejection probability and similarity between host and experimental parasitic eggs. Furthermore, bramblings very rarely made errors in rejection, indicating that selection against rejection behaviour is likely to be very weak. The brambling-cuckoo system therefore differs from other well studied systems which are characterised by pronounced spatial and temporal variation in the host's level of defence. This result is unlikely to reflect independent replication of the same evolutionary trajectory because the weak breeding site tenacity of bramblings should result in an extreme amount of gene flow within the distribution area and thus strongly impede localised responses to selection. Instead, lack of geographic variation has more likely arisen because bramblings respond to selection as one evolutionary unit, and because the average parasitism pressures have been high enough in the past to cause regional fixation of rejection alleles and evolution of clutch characteristics that facilitate cost free egg recognition.
Journal Article
A home for Bird
Vernon the toad takes the silent Bird on a journey in hopes of finding Bird's home.
Book
The cuckoos / Robert B. Payne ; with a molecular genetic analysis of cuckoo phylogeny by Michael D. Sorenson and Robert B. Payne ; color plates by Karen Klitz ; black and white illustrations by John Megahan
\"In The Cuckoos, Robert B. Payne presents a new evolutionary history of the cuckoo family based on molecular genetics, and uses the family tree to explore the origins and diversity of their behaviour. He traces details of the cuckoos' biology to their original sources, includes descriptions of previously unpublished field observations, and reveals new comparisons of songs showing previously overlooked cuckoo species. Illustrated with specially commissioned colour plates and numerous maps, halftones, and line drawings, The Cuckoos provides the most comprehensive and up-to-date account of this family available.\"--Jacket.
eBook
Brood parasitism of a Hooded Warbler in Pennsylvania/Parasitismo de puesta en el nido de un chipe Setophaga citrina por un cuco Coccyzus sp. en Pennsylvania
Brood parasitism of Hooded Warblers (Setophaga citrina) by Brown-headed Cowbirds (Molothrus ater) has been well documented, but brood parasitism of this host by other bird species has not been recorded. Hooded Warblers are known to abandon nests with parasitic eggs early in the egg-laying phase, but are not known to remove parasitic eggs from their nests or to replace these foreign eggs with their own. In June 2017, a Hooded Warbler nest in northeastern Pennsylvania was observed to contain a cuckoo (Coccyzus sp.) egg. Within a span of 6 days, the cuckoo egg was gone and a third Hooded Warbler egg was observed in its place. Received 25 September 2018. Accepted 2 April 2019.
Journal Article
An Improved Cuckoo Search Algorithm for Maximum Power Point Tracking of Photovoltaic Systems under Partial Shading Conditions
The problem of partial shading has serious effects on the performance of photovoltaic (PV) systems. Adding a bypass diode in shunt to each PV module avoids hot-spot phenomena, but causes multi-peaks in the power–voltage (P–V) characteristics of the PV array, which cause traditional maximum power point tracking (MPPT) techniques to become trapped in local peaks. This problem has forced researchers to search for smart techniques to track global peaks and prevent the possibility of convergence at local peaks. Swarm optimization techniques have been used to fill this shortcoming; unfortunately, however, these techniques suffer from unacceptably long convergence time. Cuckoo search (CS) is one of the fastest and most reliable optimization techniques, making it an ideal option to be used as an MPPT of PV systems under dynamic partial shading conditions. The standard CS algorithm has a long conversion time, high failure rate, and high oscillations at steady state; this paper aims to overcome these problems and to fill this research gap by improving the performance of the CS. The results obtained from this technique are compared to five swarm optimization techniques. The comparison study shows the superiority of the improved CS strategy introduced in this paper over the other swarm optimization techniques.
Journal Article
Dynamic, multi‐scale analyses indicate site‐ and landscape‐level forest cover drive Yellow‐billed and Black‐billed Cuckoo interannual turnover
Studies of habitat use in breeding birds often assume species have relatively stable breeding distributions. Some species, however, display considerable year‐to‐year variability, complicating efforts to determine suitable or preferred habitats. After returning to their breeding range, Black‐billed Cuckoos (Coccyzus erythropthalmus) and Yellow‐billed Cuckoos (C. americanus) are thought to range widely before nesting, resulting in high rates of interannual breeding‐site turnover, potentially contributing to conflicting habitat associations found in past studies. However, difficulty detecting these rare and declining species could lead to overinflated estimates of interannual turnover. Using broadcast surveys to increase detection probability, we collected detection/non‐detection data in 2019 and 2020 at 41 publicly owned sites in Illinois and performed a dynamic, multi‐scale occupancy analysis for each species to separate detection probability from potential interannual turnover and determine landscape and small‐scale variables driving habitat use and occupancy dynamics. We found strong support for interannual turnover for both species based on poor performance of non‐dynamic models and variation in estimated annual occupancy (20% and 21% increase between years for Black‐billed and Yellow‐billed Cuckoos, respectively). Black‐billed Cuckoos persisted at sites with less forest in the surrounding landscape and used areas with denser understory vegetation. Yellow‐billed Cuckoos colonized sites with greater canopy cover, avoided developed landscapes, and used areas with a shorter subcanopy layer. The dynamic nature of habitat use in these two cuckoo species suggests the importance of coordinating management and conservation across a broader spatial scale. Managing for larger patches of dense shrubs in less forested landscapes would benefit Black‐billed Cuckoos while Yellow‐billed cuckoos would benefit from management creating forested areas with open understories in less‐developed landscapes. Both Black‐billed and Yellow‐billed Cuckoos showed significant site‐level turnover between years. Black‐billed Cuckoos were associated with greater vertical vegetation cover within sites and persisted at sites with less forest cover in the surrounding landscape, while Yellow‐billed Cuckoos used areas with shorter or absent subcanopy layers within less‐developed landscapes. Sites with greater canopy cover were more likely to be colonized by Yellow‐billed Cuckoos.
Journal Article
Continuous Variation Rather than Specialization in the Egg Phenotypes of Cuckoos
The evolution of brood parasitism has long attracted considerable attention among behavioural ecologists, especially in the common cuckoo system. Common cuckoos (Cuculus canorus) are obligatory brood parasites, laying eggs in nests of passerines and specializing on specific host species. Specialized races of cuckoos are genetically distinct. Often in a given area, cuckoos encounter multiple hosts showing substantial variation in egg morphology. Exploiting different hosts should lead to egg-phenotype specialization in cuckoos to match egg phenotypes of the hosts. Here we test this assumption using a wild population of two sympatrically occurring host species: the great reed warbler (Acrocephalus arundinaceus) and reed warbler (A. scirpaceus). Using colour spectrophotometry, egg shell dynamometry and egg size measurements, we studied egg morphologies of cuckoos parasitizing these two hosts. In spite of observing clear differences between host egg phenotypes, we found no clear differences in cuckoo egg morphologies. Interestingly, although chromatically cuckoo eggs were more similar to reed warbler eggs, after taking into account achromatic differences, cuckoo eggs seemed to be equally similar to both host species. We hypothesize that such pattern may represent an initial stage of an averaging strategy of cuckoos, that - instead of specializing for specific hosts or exploiting only one host - adapt to multiple hosts.
Journal Article
Mutation adaptive cuckoo search hybridized naked mole rat algorithm for industrial engineering problems
Cuckoo Search (CS) is a popular algorithm used to solve numerous challenging problems. In the present work, a novel variant of CS is presented to eliminate its shortcomings. The proposed algorithm is hybridized with the naked mole rat algorithm (NMRA) to enhance the exploitative behavior of CS, and is called Mutated Adaptive Cuckoo Search Algorithm (MaCN). This new algorithm has self-adaptive properties and its key feature is to divide the solutions into multiple sections, which are often called sub-swarms. In addition, a bare-bones search mechanism is also added to enhance exploration. The use of adaptive inertia weights helps optimize the switching probability, an important CS parameter that helps to achieve a balanced operation. The proposed MaCN algorithm is tested on CEC 2005 and CEC 2014 benchmark problems. Comparative studies showed that MaCN delivers promising results in solving CEC competition benchmark problems compared to JADE, success history-based adaptive DE (SHADE), LSHADE-SPACMA and self-adaptive DE (SaDE), among others. In addition to numerical benchmarks, MaCN is used to solve the industrial engineering frame structure and a comparison with hybridization of particle swarm with passive congregation (PSOPC), shuffled frog leaping algorithm hybrid with invasive weed optimization (SFLAIWO), particle swarm ant colony optimization (PSOACO), early strategy with DE (ES-DE), and others show its superiority. In addition, the Wilcoxon rankum and the Freidmann test statistically prove the significance of the proposed MaCN algorithm. MaCN was found to score first rank for the benchmarks. The application of the MaCN algorithm to solve the design problems of the suggests that the best new results are obtained for all test cases.
Journal Article