Franz Hoelzl

Genome size varies greatly across the tree of life and transposable elements are an important contributor to this variation. Among vertebrates, amphibians display the greatest variation in genome size, making them ideal models to explore the causes and consequences of genome size variation. However, high-quality genome assemblies for amphibians hav...

Telomere dynamics in hibernating species are known to reflect seasonal changes in somatic maintenance. Throughout hibernation, the periodic states of rewarming, known as inter-bout euthermia or arousals, are associated with high metabolic costs including shortening of telomeres. In the active season, if high energetic resources are available, telom...

Genome size varies greatly across the tree of life and transposable elements are an important contributor to this variation. Among vertebrates, amphibians display the greatest variation in genome size, making them ideal models to explore the causes and consequences of genome size variation. However, high-quality genome assemblies for amphibians hav...

Background Torpor is an energy saving strategy achieved by substantial reductions of metabolic rate and body temperature that enables animals to survive periods of low resource availability. During hibernation (multiday torpor), the frequency of periodic rewarming—characterised by high levels of oxidative stress—is associated with shortening of tel...

Background Telomere length provides a physiological proxy for accumulated stress in animals. While there is a growing consensus over how telomere dynamics and their patterns are linked to life history variation and individual experience, knowledge on the impact of exposure to different stressors at a large spatial scale on telomere length is still...

Increasing evidence at the cellular level is helping to provide proximate explanations for the balance between investment in growth, reproduction and somatic maintenance in wild populations. Studies of telomere dynamics have informed researchers about the loss and gain of telomere length both on a seasonal scale and across the lifespan of individua...

Life history theory predicts a trade‐off between growth rates and lifespan, which is reflected by telomere length, a biomarker of somatic state. We investigated the correlation between telomere length and early life growth of wild boar piglets, Sus scrofa, kept under semi‐natural conditions with high food availability to examine our hypothesis that...

Purpose Alveolar echinococcosis is a severe helminthic disease in humans caused by larvae of the fox tapeworm Echinococcus multilocularis. Austria is considered an endemic area with hotspots having up to 45% prevalence (Bagó et al. in Proceedings of the Zoo and Wildlife Health Conference 2019, Berlin, p. 91, 2019). At our facility, we have register...

We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species of rodents hibernating at either 3 or 14°C. Our data show that hibernators kept at the warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals hibernating at the colder temperature. We sugge...

Diseases of the gastrointestinal tract due to changes in the bacterial flora have been described with increasing incidence in the European brown hare. Despite extensive demographic and phylogeographic research, little is known about the composition of its gut microbiota and how it might vary based on potential environmental or host factors. We anal...

Entire populations of edible dormice (Glis glis) can skip reproduction in years without mast seeding of deciduous trees (particularly beech or oak seed), because juveniles require high caloric seeds for growth and fattening prior to hibernation. We hypothesized that, in mast failure years, female dormice may be forced to spend larger amounts of tim...

The mating system represents one key element of a species’ life history. Although some life history traits of the edible dormouse (Glis glis) have been investigated thoroughly, little information is available about the mating system of this arboreal, nocturnal, hibernating rodent. Molecular studies have suggested that polygynandry and high prevalen...

Measuring Tb during the active season can provide information about the timing of reproduction and the use of short bouts of torpor and may be used as a proxy for the locomotor activity of animals (i.e., maximum Tb). This kind of information is especially important to understand life-history strategies and energetic costs and demands in hibernating...

Background Numerous species, especially among rodents, are strongly affected by the availability of pulsed resources. The intermittent production of large seed crops in northern hemisphere tree species (e.g., beech Fagus spec.,oak Quercus spec., pine trees Pinus spec.) are prime examples of these resource pulses. Adult edible dormice are highly dep...

Telomere shortening is thought to be an important biomarker for life history traits such as lifespan and aging, and can be indicative of genome integrity, survival probability and the risk of cancer development. In humans and other animals, telomeres almost always shorten with age, with more rapid telomere attrition in short-lived species. Here, we...

We studied the impact of hibernation and food supply on relative telomere length (RTL), an indicator for aging and somatic maintenance, in free-living edible dormice. Small hibernators such as dormice have ∼50% higher maximum longevity than non-hibernators. Increased longevity could theoretically be due to prolonged torpor directly slowing cellular...

The rate of telomere loss is increasingly being used as a marker of biological aging, organismal senescence, and survival probability. These protective ends of chromosomes act to protect coding DNA during replication and by buffering against degradation from reactive oxygen species (ROS). In many organisms, telomere loss has been linked to increase...

INTRODUCTION: To study hibernation patterns in free living rodents, it is necessary to capture, surgically implant temperature loggers, ensure a timely release of the wild animals to their territory, meet animal welfare criteria and accomplish subsequent recaptures. We here present our experience from a field study in wild edible dormice (EDM) (Gli...

Edible dormice are arboreal rodents adapted to yearly fluctuations in seed production of European beech, a major food source for this species. In years of low beech seed abundance, dormice skip reproduction and non-reproductive dormice fed ad libitum in captivity can display summer dormancy in addition to winter hibernation. To test whether summer...

Telomeres, the caps of eukaryotic chromosomes, control chromosome stability and cellular senescence, but aging and exposure to chronic stress are suspected to cause attrition of telomere length. We investigated the effect of social isolation on telomere length in the highly social and intelligent African Grey parrot (Psittacus erithacus erithacus)....

In order to test whether rooks (Corvus frugilegus) represent good indicators for the potential circulation of antibiotics in their native habitat, two populations with different migratory behavior were tested for the presence of beta-lactamase producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA). In all, 54 and 102 sa...

The floodplain forest in the Donau-Auen National Park has been used for forestry and agriculture for centuries. These utilizations and several river regulation measures cause dramatic habitat changes. Nevertheless, the alluvial forests east of Vienna are still one of the most important breeding areas for the River Warbler in Austria and Central Eur...