Oldrich Tomasek

Blood sampling is a challenging procedure in many captive animals. Although manual restraint or anesthesia are usually possible, they entail intense stress and a high risk of injuries or organ failure. Blood sampling using medicinal leeches (Hirudo medicinalis) represents a promising non-invasive alternative to venipuncture; however, leech blood meal was to date used only for qualitative analyses such as genetic or serological screenings. Hence, the aim of this study was to evaluate the suitability of the leech blood sampling method for quantification of hematological and biochemical parameters. Medicinal leeches were manually applied on 67 zoo animals of eleven species, and control blood samples were obtained by venipuncture of the jugular vein. The leeches drew up to 20 ml of blood in 20 to 55 min. Although most hematological and biochemical parameters were significantly altered in leech-derived samples, their values showed strong (r = 0.62–0.79; 10/24 parameters) to very strong (...

Tropical bird species are characterized by a comparatively slow pace of life, being predictably different from their temperate zone counterparts in their investments in growth, survival and reproduction. In birds, the development of functional plumage is often considered energetically demanding investment, with consequences on individual fitness and survival. However, current knowledge of interspecific variation in feather growth patterns is mostly based on species of the northern temperate zone. We evaluated patterns in tail feather growth rates (FGR) and feather quality (stress-induced fault bar occurrence; FBO), using 1518 individuals of 167 species and 39 passerine families inhabiting Afrotropical and northern temperate zones. We detected a clear difference in feather traits between species breeding in the temperate and tropical zones, with the latter having significantly slower FGR and three times higher FBO. Moreover, trans-Saharan latitudinal migrants resembled temperate zone...

Macrophysiological research is vital to our understanding of mechanisms underpinning global life history variation and adaptation under diverse environments. Birds represent an important model taxon in this regard, yet our knowledge is limited to only a few physiological traits, mostly studied in temperate and Neotropical species. Here, we examined latitudinal and elevational variation in an emerging biomarker of physiological pace of life, blood glucose concentration, collected from 61 European temperate and 99 Afrotropical passerine species. Our data suggest that the slow physiological pace-of-life syndrome, indicated by lower baseline glucose level and stronger stress response, evolves convergently in lowland tropical birds across continents and is shaped by their low fecundity. In contrast, elevational variation in blood glucose levels implied a unique montane pace-of-life syndrome combining slow-paced life histories with fast-paced physiology. The observed patterns suggest an u...

Variation in intensity and targets of sexual selection on multiple traits has been suggested to play a major role in promoting phenotypic differentiation between populations, although the divergence in selection may depend on year, local conditions or age. In this study, we quantified sexual selection for two putative sexual signals across two Central and East European barn swallow (Hirundo rustica rustica) populations from Czech Republic and Romania over multiple years. We then related these differences in selection to variation in sexual characters among barn swallow populations. Our results show that tail length and ventral coloration vary between populations, sexes, and age classes (first‐time breeders vs. experienced birds). We found that selection on tail length was stronger in first‐time breeders than in experienced birds and in males than in females in the Romanian population, while these differences between age groups and sexes were weak in Czech birds. We suggest that the ...

High mortality of nestling cockatiels (<i>Nymphicus hollandicus</i>) was observed in one breeding flock in Slovakia. The nestling mortality affected 50% of all breeding pairs. In general, all the nestlings in affected nests died. Death occurred suddenly in 4- to 6-day-old birds, most of which had full crops. No feather disorders were diagnosed in this flock. Two dead nestlings were tested by nested PCR for the presence of avian polyomavirus (APV) and <i>Chlamydophila psittaci</i> and by single-round PCR for the presence of beak and feather disease virus (BFDV). After the breeding season ended, a breeding pair of cockatiels together with their young one and a fledgling budgerigar (<i>Melopsittacus undulatus</i>) were examined. No clinical alterations were observed in these birds. Haemorrhages in the proventriculus and irregular foci of yellow liver discoloration were found during necropsy in the young cockatiel and the fledgling budgerigar. Microsc...

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 intraspecific GM variation in wild populations are still poorly known. We analysed data on faecal microbiota composition in 51 passerine species (319 individuals) using Illumina MiSeq sequencing of bacterial 16S rRNA (V3-V4 variable region). Despite pronounced interindividual variation, GM composition exhibited significant differences at the interspecific level, accounting for approximately 20%-30% of total GM variation. We also observed a significant correlation between GM composition divergence and host's phylogenetic divergence, with strength of correlation higher than that of GM vs. ecological or life history traits and geographic variation. The effect of host's phylogeny on GM composition was significant, even after statistical control for these confounding factors. Hence, our data do not support codiversification of GM and passerine phylogeny solely as a by-product of their ecological divergence. Furthermore, our findings do not support that GM vs. host's phylogeny codiversification is driven primarily through trans-generational GM transfer as the GM vs. phylogeny correlation does not increase with higher sequence similarity used when delimiting operational taxonomic units. Instead, we hypothesize that the GM vs. phylogeny correlation may arise as a consequence of interspecific divergence of genes that directly or indirectly modulate composition of GM.

Life span and aging are substantially modified by natural selection. Across species, higher extrinsic (environmentally related) mortality (and hence shorter life expectancy) selects for the evolution of more rapid aging. However, among populations within species, high extrinsic mortality can lead to extended life span and slower aging as a consequence of condition-dependent survival. Using within-species contrasts of eight natural populations of Nothobranchius fishes in common garden experiments, we demonstrate that populations originating from dry regions (with short life expectancy) had shorter intrinsic life spans and a greater increase in mortality with age, more pronounced cellular and physiological deterioration (oxidative damage, tumor load), and a faster decline in fertility than populations from wetter regions. This parallel intraspecific divergence in life span and aging was not associated with divergence in early life history (rapid growth, maturation) or pace-of-life syndrome (high metabolic rates, active behavior). Variability across four study species suggests that a combination of different aging and life-history traits conformed with or contradicted the predictions for each species. These findings demonstrate that variation in life span and functional decline among natural populations are linked, genetically underpinned, and can evolve relatively rapidly.

Inbreeding depression, or the reduction in fitness due to mating between close relatives, is a key issue in biology today. Inbreeding negatively affects many fitness-related traits, including survival and reproductive success. Despite this, very few studies have quantified the effects of inbreeding on vertebrate gamete traits under controlled breeding conditions using a full-sib mating approach. Here, we provide comprehensive evidence for the negative effect of inbreeding on sperm traits in a bird, the zebra finch Taeniopygia guttata. We compared sperm characteristics of both inbred (pedigree F = 0.25) and outbred (pedigree F = 0) individuals from two captive populations, one domesticated and one recently wild-derived, raised under standardized conditions. As normal spermatozoa morphology did not differ consistently between inbred and outbred individuals, our study confirms the hypothesis that sperm morphology is not particularly susceptible to inbreeding depression. Inbreeding did,...

Toll-like receptors (TLRs) are a cornerstone of vertebrate innate immunity. In this study, we identified orthologues of TLR4, TLR5 and TLR7 (representing both bacterial- and viral-sensing TLRs) in the grey partridge (Perdix perdix), a European Galliform game bird species. The phylogeny of all three TLR genes follows the known phylogeny of Galloanserae birds, placing grey partridge TLRs (PePeTLRs) in close proximity to their turkey and pheasant orthologues. The predicted proteins encoded by the PePeTLR genes were 843, 862-863 and 1,047 amino acids long, respectively, and clearly showed all TLR structural features. To verify functionality in these genes we mapped their tissue-expression profiles, revealing generally high PePeTLR4 and PePeTLR5 expression in the thymus and absence of PePeTLR4 and PePeTLR7 expression in the brain. Using 454 next-generation sequencing, we then assessed genetic variation within these genes for a wild grey partridge population in the Czech Republic, EU. We identified 11 nucleotide substitutions in PePeTLR4, eight in PePeTLR5 and six in PePeTLR7, resulting in four, four and three amino acid replacements, respectively. Given their locations and chemical features, most of these non-synonymous substitutions probably have a minor functional impact. As the intraspecific genetic variation of the three TLR genes was low, we assume that either negative selection or a bottleneck may have reduced TLR population variability in this species.

Major histocompatibility complex (MHC)-dependent mating preferences have been observed across vertebrate taxa and these preferences are expected to promote offspring disease resistance and ultimately, viability. However, little empirical evidence linking MHC-dependent mate choice and fitness is available, particularly in wild populations. Here, we explore the adaptive potential of previously observed patterns of MHC-dependent mate choice in a wild population of Atlantic salmon ( Salmo salar ) in Québec, Canada, by examining the relationship between MHC genetic variation and adult reproductive success and offspring survival over 3 years of study. While Atlantic salmon choose their mates in order to increase MHC diversity in offspring, adult reproductive success was in fact maximized between pairs exhibiting an intermediate level of MHC dissimilarity. Moreover, patterns of offspring survival between years 0+ and 1+, and 1+ and 2+ and population genetic structure at the MHC locus relat...

Direct comparisons are important when assessing the value of DNA extraction methods for diagnostic virology as the inhibitors present and the efficiency of extraction vary with the target infectious agent as well as the species and the site from which the clinical sample was obtained. Three DNA extraction methods were compared for routine polymerase chain reaction (PCR) detection of beak and feather disease virus (BFDV) in whole blood and feather samples and of avian polyomavirus (APV) in feather samples. Boiling in Chelex 100 Resin was found to be the most sensitive method for detection of BFDV or APV DNA in both feather and blood samples. In combination with nested PCR it enabled detection of BFDV DNA in 13/13 positive whole blood samples and in 22/23 positive feather samples. It also enabled detection of APV in 31/31 samples detected as positive in this study. NucleoSpin kits enabled detection of BFDV DNA in only 9/13 blood samples and in 18/23 feather samples. The lower rate of BFDV DNA detection when using NucleoSpin kits was not a result of inhibition of PCR in most cases. The NucleoSpin Tissue Kit enabled detection of APV DNA in 29/31 feather samples. Inhibition of DNA amplification was observed when using the DNAzol Direct kit. Therefore, of the methods evaluated here, Chelex 100 Resin treatment of samples was the best option for routine testing for BFDV and APV DNA in clinical samples.

Eight captive-bred horned parakeets (Eunymphicus cornutus) and four captive-bred Major Mitchell cockatoos (Cacatua leadbeateri) from the same aviary tested positive for psittacine circovirus (PsCV) DNA in whole blood by nested-polymerase chain reaction (PCR). The chronic form of disease with feather fragility and loss was observed in three horned parakeets. Infection in other individuals was subclinical. Immunosuppression, either hematologically or as susceptibility to secondary infections, was not observed. Treatment consisted of the administration of beta-(1,3/1,6)-D-glucan from oyster mushroom (Pleurotus ostreatus). Excluding two accidentally dead parakeets, four out of the original six horned parakeets, and all Major Mitchell cockatoos were negative for PsCV DNA in whole blood in 7-9 mo after the treatment was started. Even though the absence of PsCV DNA in blood does not signify elimination of the virus from the whole organism, these preliminary results indicate a possible effect of beta-glucan in the treatment of PsCV infection. To the author's knowledge, this is the first report of PsCV in horned parakeets.

Physiological and biochemical traits hold great promise for demographic research as potential proxies (biomarkers) of various biotic and environmental variables that determine individual fitness and ultimately demographic rates. Integrating such biomarkers into demographic models can thus provide insights into drivers of population dynamics or increase predictive power of the models by refining estimation of vital rates. Biomarkers also represent promising means to characterise population structure and dynamics on much shorter time-scales compared to classical demographic approaches. Functional traits further emerge as direct targets of conservation efforts directed towards conserving functional diversity. Yet, biomarkers and functional traits remain underutilised in demography and population ecology, indicating that their benefits still await wider recognition. This chapter briefly reviews the most prominent physiological and biochemical traits (e.g. metabolic rates, hormones, oxid...

Sex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and a...

Diverging populations often shift patterns of signal use—a process that can contribute to reproductive isolation and speciation. Yet it is not clear why most traits gain or lose signal value during divergence. One reason this could occur is because changes in the relationship between signals and relevant physiological parameters degrade the reliability of a signal, or even change its underlying information content. Here we test the hypothesis that the relationship between signal trait elaboration and a central component of organismal health—oxidative stress—differs across closely related populations that have diverged in signal use and preferences. In the recently diverged barn swallow subspecies complex (Hirundo rustica, Family: Hirundinidae), different populations use different traits as sexual signals. Two of these traits, ventral breast plumage color, and tail streamer length, differ markedly between North American H. r. erythrogaster and European H. r. rustica. Despite this divergence, variation in ventral plumage color was similarly associated with measures of oxidative damage across both populations. However, the directionality of these relationships differed between the sexes: darker male barn swallows had higher levels of plasma oxidative damage than their lighter counterparts, while the opposite relationship was seen in females. In contrast, relationships between tail streamer length and measures of oxidative stress were not consistent across populations. Some analyses indicated that in European H. r. rustica, where males bearing elongated streamers are preferred as mates, longer-streamered males were more oxidatively stressed; however, the opposite pattern was suggested in North American H. r. erythrogaster. Tail streamer length was not associated with measures of oxidative stress in females of either population. Differences in the physiological state of stronger signalers across populations and between the sexes may be related to costs or constraints on signal elaboration (e.g., biochemical pathways associated with melanogenesis), or reflect differences in how signal-mediated social interactions influence oxidative stress. Overall, our results suggest that while some phenotypic traits appear to be capable of conveying similar physiological information regardless of their use as signals, divergence in other phenotypic traits may be associated with shifts in their information content.

ABSTRACT The aim of this study was to evaluate the efficiency of releasing commercially reared individuals of the grey partridge (Perdix perdix) as a method for species recovery. This study compares the mortality risk of grey partridges depending on origin, sex and body condition, controlling for age, infection risk and release method. In total, 110 locally caught wild individuals and 75 commercially reared game-farm partridges were released and radio tracked within the same study area in the Czech Republic between 2009 and 2011. To exclude a possible effect of age on survival, only individuals in the second calendar year of life were chosen for the analysis. Commercially reared partridges had significantly higher mortality risk than wild ones. None of the commercially reared birds survived in the wild until the end of the nesting period, and none produced a fledged brood. Females from game farms showed significantly better survival than males and preferred to mate with wild males, whereas wild females avoided mating with commercially reared males. Predation was the main cause of mortality, and proportion of birds killed by raptors and mammals did not differ between wild and commercially reared birds. These results highlight the uselessness of releasing adult commercially reared partridges in an effort to establish viable populations of this species in the wild and stress the need for a change from intensive rearing methods aimed predominantly at quantity towards a more conservation breeding-oriented approach aimed at quality.

Eight captive-bred horned parakeets (Eunymphicus cornutus) and four captive-bred Major Mitchell cockatoos (Cacatua leadbeateri) from the same aviary tested positive for psittacine circovirus (PsCV) DNA in whole blood by nested–polymerase chain reaction (PCR). The chronic form of disease with feather fragility and loss was observed in three horned parakeets. Infection in other individuals was subclinical. Immunosuppression, either hematologically or as susceptibility to secondary infections, was not observed. Treatment consisted of the administration of β-(1,3/1,6)-d-glucan from oyster mushroom (Pleurotus ostreatus). Excluding two accidentally dead parakeets, four out of the original six horned parakeets, and all Major Mitchell cockatoos were negative for PsCV DNA in whole blood in 7–9 mo after the treatment was started. Even though the absence of PsCV DNA in blood does not signify elimination of the virus from the whole organism, these preliminary results indicate a possible effect of β-glucan in the treatment of PsCV infection. To the author's knowledge, this is the first report of PsCV in horned parakeets.