Alfred Trnka

University of Trnava · Department of Biology

A total of 1,621 wild birds representing 34 species were examined for chewing lice in reed beds in southwestern Slovakia during the pre-breeding migration 2008–2009 and 2016–2019. A total of 377 (23.3%) birds representing 15 species were parasitized by 26 species of chewing lice of 12 genera. Dominant genera were Penenirmus (with dominance 32.6%) a...

Feeding wild birds is one of the most popular forms of interaction between wild animals and humans. This relatively simple method can be applied in the educational process in primary schools through active learning in the field, which serves to improve the pro-environmental attitudes of pupils. The aim of the research was to verify the effect of wi...

Double brooding, the laying of a second clutch after successfully fledging young from a first nest in a season, is a common reproductive strategy among short-lived birds to increase annual breeding success. Nevertheless, there is widespread intra- and interspecific variation in the probability of producing a second clutch. Given that the frequency...

Interactions between avian brood parasites, such as common cuckoos (Cuculus canorus), and their hosts are one of the best-studied examples of the coevolutionary arms race. Different stages of this arms race can be seen in different races of common cuckoos and their hosts across their range. However, little is known whether selected populations of t...

Larval trombiculid (chigger) mites are common ectoparasites of terrestrial vertebrates including humans, causing itching and skin inflammation known as trombiculiasis. Investigation of their diversity, distribution and seasonal abundance is therefore important from a veterinary and public health point of view. Although researchers have paid increas...

A total of 1185 passerine birds representing five species were examined for chewing lice in reed beds in southwestern Slovakia in spring (April) 2008, 2009 and 2016. Additional collecting focused only on chewing lice from Panurus biarmicus (Linnaeus, 1758) (Passeriformes: Panuridae) was carried out in spring (April), summer (July) and autumn (Octob...

Tento projekt bol financovaný grantovou agentúrou VEGA (číslo grantu 1/0207/08) Borélie. Velké množstvo času bolo venované na výskum možnej úlohy divožijúcich vtákov pri šírení Lymskej Boreliózy v prírode. Lymská Borelióza je multisystémové a viacstupňové ochorenie vyvolané štyrmi druhmi spirochét (Borrelia burgdorferi, Borrelia afzelii, Borrelia g...

Influenza A viruses are negative strand RNA viruses with segmented genome belonging to the Ortomyxoviridae family. They are further classified into subtypes according to the surface glycoproteins: hemagglutinin (HA) and neuraminidase (NA) (H1-H16 and N1-N9). Ecological studies have established that all influenza A viruses in nature are derived from...

Using direct observations of Common Cuckoo Cuculus canorus behaviour at 53 nests of three Acrocephalus host species, we recorded no vocal activity by females shortly before, during, or after egg-laying, which suggests that female bubbling calls during parasitism are not used as commonly as previously thought.

The book maps the occurrence of bird species in the Úlanská mokraď (wetland) Special protected area (SPA), which is located in the western part of the Slovak Republic, mainly in the Trnava region, only a small part of it (in the Senec district) is part of the Bratislava region. Bird occurrence, focusing primarily on nesting occurrence, was evaluate...

This checklist includes taxa of chewing lice from published records, old collections, and recently collected material from birds and mammals in Slovakia. Data from established collections correspond to five different periods: (1) 1925–1939, collection of Karel Pfleger; (2) 1946–1978, collection of František Balát; (3) 1974–1985, collection of Vladi...

There is increasing evidence of social information transfer about predation risk in foraging animal groups. However, little is known about whether individuals also acquire such information from non-members of their own group. We experimentally manipulated the perceived threat and heterospecific cues about low predation risk in the house sparrow, Pa...

Ecology and epidemiology of murine gammaherpesvirus 68 (MHV-68) have been intensively studied since the isolation of the virus from murid rodents in 1976. This virus was detected in various mammalian species that share the biotope with rodent reservoirs of MHV-68. However, a survey of MHV-68 in birds has not so far been performed. Therefore, the ai...

Birds are one of the best-studied animal groups in Europe. Despite this, there are several bird species, including the Little Bittern (Ixobrychus minutus), of which the breeding biology is still little known. Here, I examine the sex of offspring in relation to hatching order, the degree of hatching asynchrony and some other aspects of nesting biolo...

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...

Artificial fishponds are assumed to be suitable alternative habitat for many waterbirds including fish-eating predators such as herons. However, fish farming may lead to contrasting consequences for birds breeding in these biotopes and act as an ecological trap. I examined nestling diet and reproductive success of the least studied heron species in...

One species of the louse genus Philopterus Nitzsch, 1818 is redescribed and illustrated: Philopterus acrocephalus Carriker, 1949 ex Acrocephalus luscinius (Quoy & Gaimard, 1830), A. melanopogon (Temminck, 1823), A. scirpaceus (Hermann, 1804), A. schoenobaenus (Linnaeus, 1758), Iduna aedon rufescens Stegmann, 1929, I. rama (Sykes, 1832), Locustella...

Research on brood parasitism has focused primarily on specific host anti-parasite behaviours and parasite counter-adaptations, and little is known about other aspects of their behaviours such as consistent behavioural differences between individuals. Therefore, we examined consistency in behaviour of nestlings of common cuckoos ( Cuculus canorus )...

Animals often show correlated suites of consistent behavioural traits, i.e., personality or behavioural syndromes. Does this conflict with potential phenotypic plasticity which should be adaptive for animals facing various contexts and situations? This fundamental question has been tested predominantly in studies which were done in non-breeding con...

Capsule: Using dummy experiments at nests of Great Reed Warblers Acrocephalus arundinaceus, we found no evidence to support the hypothesis that the contrasting black and white plumage colouration in Magpies Pica pica has evolved to reduce mobbing defensive attacks by potential prey species. We suggest instead that it might have evolved in the conte...

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...

The roles and importance of avian-produced odorous secretions have been largely underestimated. This is mainly due to the supposed absence of a sense of smell in birds, and few studies have been carried out on the ecological relevance of olfactory cues in birds. Despite this, some notable breakthroughs related to avian chemical-mediated interaction...

Returning to a breeding site and decision where to breed belong to the key life-history traits, especially in migratory birds. Yet, we still lack knowledge about the drivers of adult return rates and breeding dispersal distances in populations under pressure of brood parasitism. We explored these issues in a trans-Saharan migratory passerine, the g...

The similarity of common cuckoos Cuculus canorus to raptors is accepted as a classic example of predator mimicry. However, cuckoo females are polymorphic: grey females are similar to sparrowhawks Accipiter nisus, while rufous females were assumed to mimic kestrels Falco tinnunculus. Previous evidence based on dummy experiments with grey females con...

Capsule The Little Bittern is highly suitable as Common Moorhen host in terms of accepting and incubating parasitic eggs, however, the survival of Common Moorhen chicks remains disputable.

The aim of the “Ornithological Handbook” is to boost the development of ornithology in a country where no similar book was ever published – in Slovakia. Thus, the book is intended specifically for Slovak amateur and professional ornithologists and birdwatchers – therefore it is only in Slovak language (no English summary included). In 300 pp. this...

Fitness costs associated with brood parasitism have led host species to evolve several lines of defence. The first two lines of defence, aggression against adult parasites and egg rejection, are present at varying levels in almost all hosts. However, it remains unclear how these two fundamental defences covary at host individual level, with previou...

Location of study plots in the study area. Each dot represents one study plot. Yellow dots represent study plots located in cut reed patches, green dots represent study plots located in adjacent uncut reed patches and brown dots represent study plots located in unmanaged reedbed. Supplementary material 1

There is growing evidence that birds are able to discriminate different types of nest intruders and adjust their nest defence behaviour according to intruder dangerousness and distance from the nest (the dynamic risk assessment hypothesis). Here, we tested whether birds’ decisions about nest defence may additionally be affected by an increasing fam...

Egg rejection belongs to a widely used host tactic to prevent the costs incurred by avian brood parasitism. However, the genetic basis of this behaviour and the effect of host age on the probability of rejecting the parasitic egg remain largely unknown. Here, we used a set of 15 polymorphic microsatellite loci, including a previously detected candi...

Reed passerine birds are strict habitat specialists inhabiting reedbed habitats. In Europe, many of these species are threatened due to loss and degradation of natural reedbeds. Another important factor that can negatively affect the abundance of reed passerines is commercial reed harvesting. Previous studies have shown negative impacts of large-sc...

Current research on behavioural consistency showed that various types of animal behaviour are highly repeatable in the context of mate choice, exploration and parental care, including nest protection. However, the repeatability of aggressive nest defence has not yet been studied in hosts of brood parasites, although host aggression against adult pa...

Background Plumage polymorphism may evolve during coevolution between brood parasites and their hosts if rare morph(s), by contravening host search image, evade host recognition systems better than common variant(s). Females of the parasitic common cuckoo (Cuculus canorus) are a classic example of discrete color polymorphism: gray females supposedl...

Theory of parental care in biparental species predicts that a decrease in 1 mate's parental effort should trigger a partial increase of care by the other mate. Previous studies investigating compensatory behavior used nestling provisioning as the measure of parental effort. However, nest defense is also a costly component of parental care because d...

Landscape-scale agricultural intensification has caused severe declines in biodiversity. Hedges and forest remnants may mitigate biodiversity loss by enhancing landscape heterogeneity and providing habitat to a wide range of species, including birds. However, nest predation, the major cause of reproductive failure of birds, has been shown to be hig...

Reproductive success of brood parasites varies considerably both among and within host species, mainly due to differences in host egg-rejection rates and survival of parasitic chicks. Here, we investigated the breeding success of the cuckoo (Cuculus canorus) in one of its major hosts, the great reed warbler (Acrocephalus arundinaceus), with respect...

Offspring sex in birds is maternally determined, thus females are expected to vary brood sex ratio adaptively in response to various environmental and/or genetic conditions preferring one sex to the other sex. However, recent studies provide controversial evidence showing mixed support for adaptive sex manipulation theory. One problem may lie in th...

Background: Co-evolutionary struggles between dangerous enemies (e.g., brood parasites) and their victims (hosts) lead to the emergence of sophisticated adaptations and counter-adaptations. Salient host tricks to reduce parasitism costs include, as front line defence, adult enemy discrimination. In contrast to the well studied egg stage, investiga...

The close resemblance between the common cuckoo, Cuculus canorus, and the Eurasian sparrowhawk, Accipiter nisus, is often viewed as Batesian mimicry evolved by the cuckoo in response to the aggression of its host. However, the effectiveness of such mimicry is poorly known. We examined cuckoo-hawk discrimination ability in the great reed warbler, Ac...

Increasing evidence suggests that birds minimize the risk of nest predation by preferentially settling in territories with low predator encounter rate. However, little is known about whether they are also able to assess the actual risk of nest predation at the time of habitat occupancy and choose their breeding territories accordingly. Here, we tes...

We documented and experimentally tested the use of snake skins in construction of nests in a Great Reed Warbler Acrocephalus arundinaceus population in southwestern Slovakia. There was no difference in predation rates of artificial nests that did or did not contain sloughs. We suggest that snake skins in Great Reed Warbler nests may serve as a post...

Prevalence of the infectious respiratory agens, avian influenza virus (AIV), Mycobacterium avium (M. avium), and Mycobacterium avium subspecies paratuberculosis (MAP), was studied in migratory marsh-dwelling passerines captured in the Parížske močiare wetlands in Western Slovakia during 2008. Surveillance of 650 birds revealed a lower prevalence of...

There is increasing evidence that hosts within a population may not be parasitized by common cuckoos Cuculus canorus with equal probability. Such non-randomness has been documented, for example, for host nest sites and host quality. In this study we demonstrate association between successful cuckoo parasitism and host social mating system. We found...

We studied the rate of predation on artificial and natural nests of Great Reed Warbler Acrocephalus arundinaceus in two contrasting vegetation types, reed Phragmites australis and reed mace Typha angustifolia beds. Reed provided thinner and taller stems to attach a nest to than reed mace, and reed mace provided more cover in late spring, but not in...

Egg predation is a common feature influencing the reproductive success of open nesting birds. Evolutionary pressure therefore favours building cryptic, inconspicuous nests. However, these antipredatory pressures may be in conflict with thermoregulatory constraints, which select for dry nest material maintaining optimum temperature inside a nest cup...

Abstract In birds with biparental care, males and females often conflict over how much care to provide to their offspring and it may be substantially influenced by increased level of polygamy. In accordance with sexual conflict theory, males of socially polygynous bird species provide much less care to their nestlings than do males of most socially...

P. 2010: Infanticide or interference: Does the great reed warbler selectively destroy eggs? — Ann. Zool. Fennici 47: 272–277. Infanticide, the killing of offspring by adult conspecifics, has been demonstrated in many insect, mammal and bird species. In contrast to selective pressures influencing infanticide in other species, egg destruction in bird...

Capsule Dummy birds placed on artificial nests increase nest survival, and their use should be considered in future studies of nest predation.

A growing body of literature suggests that infanticide is common in a variety of animals. However, most reports are concerned with infanticide by males and these evidences are often indirect or questionable. Here we describe the first videotaped non-parental infanticide by a female common pochard (Aythya ferina) which killed one conspecific ducklin...

Three hundred and thirty-one Reed Warblers Acrocephalus scirpaceus (Hermann) were examined for chewing lice (Phthiraptera). Twenty-eight (8.5%) were parasitized with Menacanthus curuccae (Schrank, 1776). Mean intensity of infestation was 4.3 lice. Hence, the name Menacanthus eisenachensis Balát, 1981, currently applied to Menacanthus lice parasitiz...

The prevalence of Borrelia, Mycobacteria and avian influenza virus (AIV) infections, together with the distribution of different AIV subtypes, was studied in migratory waterfowl and terrestrial birds trapped in three localities in Slovakia during 2006. Samples obtained from waterfowl captured in the Senianske Ponds area of Eastern Slovakia showed t...

The prevalence of avian influenza virus (AIV), together with the distribution of different AIV subtypes, was studied in migratory waterfowl and terrestrial birds caught in western Slovakia during summer 2007. Both oropharyngeal and cloacal swabs were collected. Screening of samples revealed that 18% of oropharyngeal and 18% of cloacal samples were...

Post-breeding habitats of nine passerine species were studied in the permanently flooded reed beds of ponds near the village Pusté Úlany (SW Slovakia) in 2002. Structural features of reed beds and the abundance of all birds studied were sampled at two sites and eight study plots. The reed bed structure and abundance of four passerines differed cons...

Predation can act as a selective pressure on birds, which may be expected therefore to change habitat use in the presence of predators. To examine this, experiments were performed using Marsh Harrier Circus aeruginosus silhouettes. The effect of predators on movement patterns and capture efficiency of mist nets were investigated in two unrelated pa...

Capture rates of eight reed passerine birds in relation to time of day were studied in the late breeding periods of 1999-2004 in National Nature Reserve Parížske močiare marsh (SW Slovakia). Based on 3700 captures, significant differences in mean capture times were found among species in both morning and evening. Capture rates of birds differed sig...

In wild bearded tits (Panurus biarmicus) and hawfinches (Coccothraustes coccothraustes) trapped in the Czech Republic and Slovakia from 1999 to 2003, characteristic yellow thin-walled subalar cutaneous cysts filled with friable material containing mites Harpirhynchus nidulans were found. The biggest cysts were 14 mm and 20 mm in size in bearded tit...

Material examined. SW Slovakia, Trnavská pahorkati-na hills, city of Trnava, ponds (7671 = grid reference number of the Databank of Slovak fauna), 145 m a.s.l., 5.V.2002, 1 ad. ex., leg. et det. J. Matula et A. Trnka. Known distribution. The species has a C Palearctic range. It breeds from Baltic eastwards across Russia to C Siberia and south to so...

The diet of the reed bunting was studied at Trnava ponds (W Slovakia) using the stomach content analysis method. Over the period October - February, one hundred and twenty six samples of stomach contents (7,069 plant seeds) were obtained and analysed to determine their qualitative and quantitative composition, frequency and dominance in addition to...

Trnka A. 2005: Lokálne pohyby a denné teritóriá trsťových druhov spevavcov v pohniezdnom období. Sylvia 41: 94–102. V pohniezdnom období 2001–2003 boli na dvoch lokalitách juhozápadného Slovenska metó-dou odchytu vtákov do sietí študované lokálne pohyby a denné teritóriá siedmich druhov spe-vavcov. Zistené boli nápadné pohyby vtákov po obvode rybní...