Petr Procházka

Institute of Vertebrate Biology

Aim Assessing the extent of large-scale migratory connectivity is crucial for understanding the evolution of migratory systems and effective species conservation. It has been, however, difficult to elucidate the annual whereabouts of migratory populations of small animals across the annual cycle. Here, we use the reed warbler (Acrocephalus scirpac...

Migratory birds often move significantly within their nonbreeding range before returning to breed. It remains unresolved under which circumstances individuals relocate, whether movement patterns are consistent between populations and to which degree the individuals benefit from the intratropical movement (ITM). We tracked adult great reed warblers...

Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturisation of light‐level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement...

Annual cycle events may be interlinked, influence following annual cycle stages, and may alter performance of individuals. Such links, called carry-over effects, can explain individual variation in timing or reproductive success in migratory species. Identifying the key links affecting fitness may reveal the mechanisms of species population dynamic...

Geographic distribution models of environmental stable isotopes (so called "isoscapes") are widely employed in animal ecology, wildlife forensics and conservation. However, the application of isoscapes is limited to elements and regions for which the spatial patterns have been estimated. Here, we focused on the ubiquitous yet less commonly used sta...

In some populations of the host of brood parasites, more than two parasite eggs may be laid in a single nest. This phenomenon is known as multiple parasitism, representing a cost to both the host and parasite. In this study, we analysed a long-term dataset (2007–2021) focusing on multiple parasitism of the common cuckoo (Cuculus canorus) parasitizi...

Climatic conditions affect animals but range‐wide impacts at the population level remain largely unknown, especially in migratory species. However, studying climate–population relationships is still challenging in small migrants due to a lack of efficient and cost‐effective geographic tracking method. Spatial distribution patterns of environmental...

The Iberian and North African populations of reed warblers have been recently described as a separate taxon, ambiguus, forming a sister clade to the Sahelian subspecies minor of African Reed Warbler Acrocephalus baeticatus. While the breeding range of ambiguus has been identified, the migration strategy of its populations remained unknown. We deplo...

Mitochondrial DNA sequences and microsatellites were used to assess the influence of Pleistocene glaciations on the genetic structure and demography of the Savi's Warbler, a long-distance migratory passerine that occurs exclusively in reed beds. Phylogenetic and coalescent analyses indicated that Savi's Warblers split from its sister species c. 8 m...

Space-based tracking technology using low-cost miniature tags is now delivering data on fine-scale animal movement at near-global scale. Linked with remotely sensed environmental data, this offers a biological lens on habitat integrity and connectivity for conservation and human health; a global network of animal sentinels of environmental change.

Obligate avian brood parasites usually require longer and/or more parental care than host progeny and thus may have a detrimental effect on survival of host parents. Many hosts of brood parasites are long-distance migrants, spending significant proportions of annual cycles at different sites around the world, which makes correct timing of particula...

Tissue samples are frequently collected to study various aspects of avian biology, but in many cases these samples are not used in their entirety and are stored by the collector. The already collected samples provide a largely overlooked opportunity because they can be used by different researchers in different biological fields. Broad reuse of sam...

Individual identification is crucial for studying animal ecology and evolution. In birds this is often achieved by capturing and tagging. However, these methods are insufficient for identifying individuals/species that are secretive or difficult to catch. Here, we employ an automatic analytical approach to predict the identity of bird females based...

Understanding egg-laying behaviour of brood parasites in space and time can improve our knowledge of interactions between hosts and parasites. However, no studies have combined information on the laying activity of an obligate brood parasite with detailed information on the distribution of host nests within an area and time period. Here, we used mo...

Interactions between avian brood parasites, their hosts and their parasites provide an ideal model system for studying coevolutionary processes across multiple hierarchical levels. Despite this, how brood parasitism affects the ecology and transmission of bird ectoparasites is not well known. Here, we examined the mite fauna of great reed warbler A...

Survival is a major life history trait known to be age- and/or sex-specific in many bird species. Regardless of age and sex, the survival of resident birds can be reduced by high mortality during harsh winters. In this study, we used mark-recapture data collected during 2014–2018 to assess return rates and apparent survival in relation to age, sex...

Identification of individuals greatly contributes to understanding animal ecology and evolution, and in many cases can only be achieved using expensive and invasive techniques. Advances in computing technology offer alternative cost-effective techniques which are less invasive and can discriminate between individuals based on visual and/or acoustic...

How blood parasite infections influence the migration of hosts remains a lively debated issue as past studies found negative, positive, or no response to infections. This particularly applies to small birds, for which monitoring of detailed migration behavior over a whole annual cycle has been technically unachievable so far. Here, we investigate h...

The Retrapping Adults for Survival (RAS) scheme is one of the programmes used to monitor demography of avian populations-it relies on ringing and recapturing of adult birds of selected species on their breeding grounds to estimate their inter-annual survival. Within the Czech RAS scheme, we studied White-spotted Bluethroats (Luscinia svecica cyanec...

An animal's gut microbiota (GM) is shaped by a range of environmental factors affecting the bacterial sources invading the host. At the same time, animal hosts are equipped with intrinsic mechanisms enabling regulation of GM. However, there is limited knowledge on the relative importance of these forces. To assess the significance of host-intrinsic...

The co-evolutionary arms race between brood parasites and their hosts involves stepwise adaptive changes on the side of the parasites as well as hosts. In response to avian brood parasitism, host females may eject a parasitic egg, bury the parasitized clutch or desert it. After nest desertion, females commonly re-nest and may move further to avoid...

Hosts have evolved a multiplicity of defensive responses against avian brood parasites. One of them is mobbing behaviour which often includes direct contact attacks. These aggressive strikes may not only distract the parasites but may also be fatal to them, as documented by cases of dead brood parasite females found near host nests. Here, we presen...

Sex allocation theory posits that parents should adjust offspring sex ratio based on the costs and benefits associated with the production of either sex in a given context. Maternal condition should influence sex ratios when it has sex‐specific impacts on offspring fitness (Trivers–Willard hypothesis) or when rearing costs differ between sons and d...

Several hypotheses have been proposed to explain the mechanisms responsible for maintenance of host-specific gentes in the common cuckoo (Cuculus canorus). Some of them expect that when adult cuckoos return to lay their eggs to their natal site (natal philopatry hypothesis) or habitat in which they were reared (habitat-imprinting hypothesis), there...

Nestlings of the obligate brood-parasitic common cuckoo, Cuculus canorus, use diverse signals to manipulate host parents into feeding them. Begging calls, one of the most prominent parenteoffspring communication signals, have been suggested to differ between cuckoos parasitizing different host species but the call characteristics involved differ be...

Aim: Knowledge of broad-scale biogeographical patterns of animal migration is important for understanding ecological drivers of migratory behaviours. Here, we present a flyway-scale assessment of the spatial structure and seasonal dynamics of the Afro-Palaearctic bird migration system and explore how phenology of the environment guides long-distanc...

Dozens of studies have documented that brood parasites are well adapted to a brood parasitic lifestyle but not all parasitism events are successful. Co‐evolution between brood parasites and their hosts is a dynamic process so it is reasonable to expect that a female brood parasite may commit errors during egg deposition by laying her eggs outside t...

Each year, billions of songbirds cross large ecological barriers during their migration. Understanding how they perform this incredible task is crucial to predict how global change may threaten the safety of such journeys. Earlier studies based on radar suggested that most songbirds cross deserts in intermittent flights at high altitude, stopping i...

Mitochondrial DNA sequences and microsatellites were used to assess the influence of Pleistocene glaciations on the genetic structure and demography of the Savi's Warbler, a long-distance migratory passerine that occurs exclusively in reed beds. Phylogenetic and coalescent analyses indicated that Savi's Warblers split from its sister species c. 8 m...

The functional relevance of microbiota is a key aspect for understanding host–microbiota interactions. Mammalian skin harbours a complex consortium of beneficial microorganisms known to provide health and immune-boosting advantages. As yet, however, little is known about functional microbial communities on avian feathers, including their co-evoluti...

Song dialects, as a special case of geographic variation in vocalization, are useful tools in the study of a number of topics ranging from cultural evolution to the emergence of reproductive barriers, and thus continue to be the focus of many bird‐song studies. The Yellowhammer Emberiza citrinella is a common Palaearctic bird with a long breeding s...

In many taxa, the most common form of sex-biased migration timing is protandry-the earlier arrival of males at breeding areas. Here we test this concept across the annual cycle of long-distance migratory birds. Using more than 350 migration tracks of small-bodied trans-Saharan migrants, we quantify differences in male and female migration schedules...

Growth is a key life history trait that is closely related to individual fitness. In altricial birds, growth is restricted to a relatively short period, and depends primarily on the amount or quality of food and hence on parental care. Obligate brood parasites do not care for their own offspring but impose this burden on other species (hosts). As m...

The Common Cuckoo (hereafter Cuckoo) shows two adult plumage morphs—adult male plumage is grey and adult females are either grey or, less frequently, rufous. The situation is less clear in juveniles, as both sexes exhibit variable proportions of grey and rufous colour. We thus describe the patterns related to sex-specific plumage colour variation i...

Parent-absent vocalisation is produced by nestlings of several bird families when the parents are away from the nest. An analogous behaviour, host-absent vocalisation, has been found in some species of avian brood parasites and there are several explanations why this behaviour could have evolved. Using playback experiments, we examined whether poly...

The Paddyfield Warbler Acrocephalus agricola has recently expanded its breeding range westwards to the western coast of the Black Sea. Although its non-breeding range is known (southern Iran to northern Myanmar), current knowledge on how individual birds migrate and how their routes evolve alongside range expansion processes is very limited. Data f...

Nonbreeding sites of the tracked great reed warblers with the quartiles in longitude and latitude

In many bird species, return rates tend to be greatest in the vicinity of their hatching site, thus natal philopatry is an important trait in avian demography. In the present study, we examined how conditions in natal nests affect return rates and dispersal distances of a long-distance migratory passerine. From 2008 to 2016, we studied a colour-rin...

Understanding why populations of some migratory species show a directional change over time, i.e. increase or decrease, while others do not, remains a challenge for ecological research. One possible explanation is that species with smaller non-breeding ranges may have more pronounced directional population trends, and their populations are thus mor...

In some systems, brood parasites may be attracted by vocal or visual signals connected with host breeding. We studied a Great Reed Warbler (Acrocephalus arundinaceus) population where annually 30–50% of nests are parasitized by the Common Cuckoo (Cuculus canorus). We observed host males and quantified their song-related behaviors, including time sp...

Vertebrate gut microbiota (GM) is comprised of a taxonomically diverse consortium of symbiotic and commensal microorganisms that have a pronounced effect on host physiology, immune system function and health status. Despite much research on interactions between hosts and their GM, the factors affecting inter- and intra-specific GM variation in wild...

The Yellowhammer Emberiza citrinella has several song types that differ in their ending. A research project from the Czech Republic has been analyzing this song variability on a large scale across Europe and New Zealand. The aim of the present work is to examine the situation in Switzerland, for which the first author has recorded the songs of 42 i...

Common cuckoos Cuculus canorus are obligate brood parasites that lay their eggs in the nests of other (host) species. To increase the likelihood of successful parasitism, common cuckoos lay eggs with thicker and structurally stronger eggshells than those of their hosts and non-parasitic relatives. Although hatching from thicker eggshells requires g...

Background Understanding the mechanisms and selective forces leading to adaptive radiations and origin of biodiversity is a major goal of evolutionary biology. Acrocephalus warblers are small passerines that underwent an adaptive radiation in the last approximately 10 million years that gave rise to 37 extant species, many of which still hybridize...

Nestlings of brood parasites exhibit more intensive begging than offspring of their hosts to gain sufficient amount of food or competitive advantage over host nestlings. This begging behaviour should be costly because exuberant acoustic begging may more likely attract nest predators. However, to date, nobody has explored the survival of nests with...

Females of avian brood parasites have evolved various tactics to succeed in their reproductive strategy. Many of these adaptations, for example speed and timing of egg laying or egg mimicry, have been investigated in detail. However, one peculiar habit of parasitic females is still not fully understood—egg removal by adult parasitic females before...

The use of active chemical defence against predators is relatively rare in birds. Among others, it has been reported for some members of family Cuculidae whose chicks, when threatened, expel dark foul-smelling liquid from their cloaca. Apart from the brood parasitic great spotted cuckoo Clamator glandarius, however, this phenomenon has not yet been...

Over decades it has been unclear how individual migratory songbirds cross large ecological barriers such as seas or deserts. By deploying light-level geolocators on four songbird species weighing only about 12 g, we found that these otherwise mainly nocturnal migrants seem to regularly extend their nocturnal flights into the day when crossing the S...