Walter Hodl

Walter Hodl
University of Vienna | UniWien · Department of Integrative Zoology

PhD

About

230
Publications
43,359
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
5,141
Citations
Additional affiliations
October 1978 - present
University of Vienna
Position
  • Professor (Associate)
Description
  • My main research focuses on communciation and behavioural ecology of frogs.
October 1978 - present
University of Vienna
Position
  • Professor (Associate)
Description
  • Even though I am officially retired I continue teaching and research as I did in the past. Former visiting professor at Univ. Sao Paulo, Univ. Joao Pessoa, Univ. Sao Luis, Salzburg.

Publications

Publications (230)
Article
Full-text available
Carotenoids play an import role as one of the most prevalent pigments in animals. Carotenoid-based coloration accounts for striking sexually and naturally selected colour adaptations. Several anurans (frogs and toads) change body coloration either slowly and permanently between life stages (ontogenetic colour change), or rapidly and temporarily wit...
Article
Full-text available
Territoriality has been widely described across many animal taxa, where the acquisition and defence of a territory are critical for the fitness of an individual. Extensive evidence suggests that androgens are involved in the modulation of territorial behaviours in male vertebrates. Short-term increase of androgen following a territorial encounter a...
Preprint
Full-text available
Territorial behaviour has been widely described across many animal taxa, where the acquisition and defence of a territory are critical for the fitness of an individual. Extensive evidence suggests that androgens (e.g. testosterone) are involved in the modulation of territorial behaviour in male vertebrates. Short-term increase of androgen following...
Article
No PDF available ABSTRACT The males of the brilliant-thighed poison frog, Allobates femoralis, are known to present stereotypic phonotactic responses to the playback of conspecific and synthetic calls. Fixed site attachment and a long calling period render this terrestrial and diurnal pan-Amazonian frog a rewarding species for bioacoustics. Several...
Article
Full-text available
Most male frogs produce calls to attract females and repel rivals. The transmission of these calls can be affected by many acoustic and environmental characteristics, which can influence the detection and decoding of the signal by the receiver. Calling-perch height has a strong influence on sound propagation and acoustic spacing with neighboring ma...
Article
Full-text available
Prolonged and complex courtship behaviors, involving tactile, acoustic, and visual signals, are common in Neotropical poison frogs (Dendrobatidae). Courtship is an important precursor to mating, but courtship components vary across species. In Brilliant-Thighed Poison Frogs (Allobates femoralis [Boulenger 1883]), males guide females to oviposition...
Article
Full-text available
Sound radiation patterns have ecological implications in the effective communication between conspecifics, like optimization of the sound propagation, increase the likelihood to reach mates and to mitigate effects of sound scattering by environmental factors like vegetation. The territorial frog Allobates femoralis advertises its territory against...
Article
ABSTRACT: Adult males of the African treefrog species Leptopelis flavomaculatus occur in either brown or green color morphs. In this study, we investigated whether the two color morphs of breeding males of L. flavomaculatus differ in traits other than color. We examined call differences (dominant frequencies and call durations), call-site selection...
Article
Full-text available
Some territorial animals recognize familiar neighbours and are less aggressive to established neighbours than they are to strangers. This form of social recognition produces a ‘dear enemy’ effect, which may allow animals to reduce the costs of territory defence. The dear enemy effect is thought to reflect either the decreased threat posed by neighb...
Article
Full-text available
In the majority of anuran species, acoustic signals are the dominant mode of inter- and intrasexual communication. Male calls are always accompanied by the movement of a more or less conspicuous vocal sac - A potential visual cue. Reed frogs possess a striking vocal sac with a colorful patch of gland tissue clearly visible once the vocal sac is inf...
Article
Some amphibians use chemical signals in addition to optical and acoustical signals to transmit information. Males of mantellid frogs from Madagascar and hyperoliid frogs from Africa emit complex, species‐ and sex‐specific bouquets of volatiles from their femoral or gular glands. We report here on the identification, synthesis, and determination of...
Chapter
Full-text available
The herpetological research activities of the University of Vienna in the Neotropics have been increasing drastically during the last 40 years. The path for modern Austrian contributions was cleared by the soil-zoologist Friedrich Schaller, appointed to the Vienna University in 1967. His wide-ranging knowledge and commitment to organismal biology m...
Article
Full-text available
These authors contributed equally to this work Summary statement Three-striped poison frogs (Ameerega trivittata) can navigate home via a direct path from areas exceeding the range of their routine movements. Abstract Most animals move in dense habitats where distant landmarks are limited, but how they find their way around remains poorly understoo...
Article
Full-text available
Animals relying on uncertain, ephemeral and patchy resources have to regularly update their information about profitable sites. For many tropical amphibians, widespread, scattered breeding pools constitute such fluctuating resources. Among tropical amphibians, poison frogs (Dendrobatidae) exhibit some of the most complex spatial and parental behavi...
Data
Movement speed during tadpole transport Histogram showing the range of movement speed during tadpole transport from one tracking location to the next one (m/h).
Data
Tagged male tadpole carrier The tag consists of a silicon tube around the waist, with an additional silicone strap between the hind legs, a small diode (beneath the white sealing) and a dipole antenna made of flexible coated wire.
Data
Movement precision during tadpole transport Summarized data of the average angular deviation, average distance from the straight-line path and SC for the tadpole transport of frogs which encountered only available pools during tadpole transport (A) and frogs which encountered non-available pools (N), minimum, maximum, 1st and 3rd quartile, median a...
Data
Movement precision during homing Summarized data of the average angular deviation, average distance from the straight-line path and SC for the homing trajectories of frogs which encountered only available pools during tadpole transport (A) and frogs which encountered non-available pools (N), minimum, maximum, 1st and 3rd quartile, median and mean.
Data
Homing trajectories Trajectory map showing movement patterns of frogs homing back to their territory after tadpole transport. Red asterisks represent the territory centers of tracked carriers and colored lines show different tracking events. Squares represent the cross-array of thirteen artificial tadpole deposition sites, blue squares representing...
Data
Summarized results of homing trajectories Each row represents a specific tracking event. Columns show the tracked distance during homing, straight line distance (from the last deposition site to the territory center), duration of homing, whether homing took more than one day (overnight = 1), average speed and the straightness coefficient.
Data
Movement speed during homing Histogram showing the range of movement speed during homing from one tracking location to the next one (m/h).
Data
Model results—Influence of weather on movement speed File contains Table S1 on model selection, Table S2 showing all model-averaged coefficients and the discussion of the model results.
Data
Summarized results of tadpole transport trajectories Each row represents a specific tracking event. Columns show the frog ID, number of tadpoles, tracked distance, total time of the tracked path (h), average speed (m/h) across the entire TTs, number of deposition sites visited (in parentheses the number of available (a) and non-available (n) deposi...
Article
Full-text available
Acoustic ranging allows identifying the distance of a sound source and mediates inter-individual spacing and aggression in territorial species. Birds and mammals are known to use more complex cues than only sound pressure level (SPL), which can be influenced by the signaller and signal transmission in non-predictable ways and thus is not reliable b...
Article
Full-text available
The contents of the gular glands of the male African reed frog Hyperolius cinnamomeoventris consist of a mixture of aliphatic macrolides and sesquiterpenes. While the known macrolide gephyromantolide A was readily identified, the structure of another major component was suggested to be a tetradecen-13-olide. The synthesis of the two candidate compo...
Data
Experimental procedures, mass spectra of macrolides, alternative fragmentation pathway, enantiomer separation by GC–MS, 1H and 13C NMR spectra.
Article
Full-text available
In anurans, males have larger laryngeal structures than females and produce conspicuous species-specific calls in various social contexts. Knowledge of female vocalisations is not well established and we start by summarising available spectral and behavioural information on calls in females. We then present novel data on female and male calls in St...
Article
Full-text available
During acoustic communication, an audible message is transmitted from a sender to a receiver, often producing changes in behavior. In a system where evolutionary changes of the sender do not result in a concomitant adjustment in the receiver, communication and species recognition could fail. However, the possibility of an evolutionary decoupling be...
Data
Ancestral character reconstruction of note number of the A. femoralis complex. (PDF)
Data
Information of DNA sequences used in the phylogenetic analysis. (XLSX)
Data
Distribution of study populations of Allobates femoralis throughout the Amazon basin. (PDF)
Data
Detailed description of the study methods. (PDF)
Data
Summary of changes in call note number. (PDF)
Article
Full-text available
The ability to associate environmental cues with valuable resources strongly increases the chances of finding them again, and thus memory often guides animal movement. For example, many temperate region amphibians show strong breeding site fidelity and will return to the same areas even after the ponds have been destroyed. In contrast, many tropica...
Article
Full-text available
Physical gestures are prominent features of many species’ multimodal displays, yet how evolution incorporates body and leg movements into animal signaling repertoires is unclear. Androgenic hormones modulate the production of reproductive signals and sexual motor skills in many vertebrates; therefore, one possibility is that selection for physical...
Article
Full-text available
Detour behaviour, an individual's ability to reach its goal by taking an indirect route, has been used to test spatial cognitive abilities across a variety of taxa. Although many amphibians show a strong homing ability, there is currently little evidence of amphibian spatial cognitive flexibility. We tested whether a territorial frog, Allobates fem...
Article
Full-text available
Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variat...
Article
Full-text available
Parental care systems are shaped by costs and benefits to each sex of investing into current versus future progeny. Flexible compensatory parental care is mainly known in biparental species, particularly where parental desertion or reduction of care by 1 parent is common. The other parent can then compensate this loss by either switching parental r...
Article
Full-text available
Spreading reproduction across time or space can optimize fitness by minimizing the risks for offspring survival in varying and unpredictable environments. Poison frogs (Dendrobatidae) are characterized by complex spatial and reproductive behaviour, such as territoriality, prolonged courtship and parental care. The partitioning of larvae from terres...
Article
Full-text available
“Ecosystem engineering” describes habitat alteration by an organism that affects another organism; such nontrophic interactions between organisms are a current focus in ecological research. Our study quantifies the actual impact an ecosystem engineer can have on another species by using a previously identified model system—peccaries and rainforest...
Article
Full-text available
Adult individuals of several anuran species exhibit conspicuous visual displays during intraspecific communication. While signal properties in adults have been subject to an increasing number of studies, little is known about the variation of visual signals in juveniles and during ontogenetic changes. Foot-flagging signals of the Bornean frogs Stau...
Article
Full-text available
The distribution of many vertebrate species in the Amazon basin is delimited by large rivers, which are frequently regarded as geographic barriers related with speciation and are therefore of high conservation value. Rapid development in the region includes plans to dam one of its thirteen major rivers, the Xingu. Environmental impact assessment is...
Article
Full-text available
Female mate choice promotes the development of male secondary sexual traits such as nuptial colouration, whereas scramble competition favours male traits which enhance their ability for access to females. In the explosively breeding moor frog (Rana arvalis), males express a conspicuous blue colouration during a short reproductive period characteris...
Article
Full-text available
Among vertebrates, comparable spatial learning abilities have been found in birds, mammals, turtles and fishes, but virtually nothing is known about such abilities in amphibians. Overall, amphibians are the most sedentary vertebrates, but poison frogs (Dendrobatidae) routinely shuttle tadpoles from terrestrial territories to dispersed aquatic depos...
Article
Full-text available
Although in anurans the predominant mode of intra- and intersexual communication is vocalization, modalities used in addition to or instead of acoustic signals range from seismic and visual to chemical. In some cases, signals of more than one modality are produced through or by the anuran vocal sac. However, its role beyond acoustics has been negle...
Article
Full-text available
Undeniably, acoustic signals are the predominant mode of communication in frogs and toads. Acoustically active species are found throughout the vast diversity of anuran families. However, additional or alternative signal modalities have gained increasing attention. In several anurans, seismic, visual and chemical communications have convergently ev...
Article
Full-text available
Here we document the development of thirteen novel microsatellite markers for the reticulated glass frog Hyalinobatrachium valerioi (Centrolenidae). Nine of those markers were polymorphic and contained between 4 and 34 alleles per locus (mean = 20.3) in 138 individuals (91 males, 47 females) from the field site 'La Gamba', Costa Rica. Average obser...
Article
Full-text available
Introduction The ability to relocate home or breeding sites after experimental removal has been observed in several amphibians and the sensory basis of this behavior has been studied in some temperate-region species. However, the actual return trajectories have rarely been quantified in these studies and it remains unknown how different cues guide...