Master theses

We are pleased to list the master theses that have been carried out in this project.

Title: Plant phenological events as an indicator for the beginning of the migration of three Central European amphibian species

Abstract:

Amphibians are among the most endangered vertebrates. One of the reasons for population decline is habitat fragmentation through land use and roads, which limits the seasonal migration of amphibians between their habitats. Amphibian migrations in spring are influenced by meteorological factors such as temperature, and the same applies in a similar way to plant phenology. As climatic conditions vary between years, phenological events such as amphibian migration take place at different times.

The aim of this thesis was to find a possible association between the phenological phases of selected plant species and the beginning of amphibian migration, since possible associations would allow a prediction of amphibian migration by phenological events. In this master thesis amphibian migration and phenological plant phases are compared based on data recorded in Austria between 2008 and 2018. Three amphibian species (Bufo bufo, Rana temporaria, R. dalmatina), five tree species (Aesculus hippocastanum, Betula pendula, Larix decidua, Prunus armeniaca, Salix caprea), one shrub species (Corylus avellana) and one herb (Galanthus nivalis) were studied. A dataset of amphibian sightings was used, which originates from the herpetofaunistic database of the Natural History Museum Vienna and from the two Citizen Science projects naturbeobachtung.at (Austrian Society for Nature Conservation) and Project Roadkill; plant phenological data were obtained from the Citizen Science database PhenoWatch. The data sets were compared and analysed using linear regression modelling.

The results showed strong similarities between the phenology of some plant species (Larix decidua, Salix caprea, Prunus armeniaca) and the beginning of the migration of Rana temporaria. The flowers of Prunus armeniaca and Salix caprea were particularly suitable as indicators of the beginning of the migration of amphibians. These results could provide a simple way for people implementing amphibian conservation measures to make local predictions about the beginning of amphibian migration.

For example, a person has noticed the bloom of the willow in his garden or on his way to work on 2 March and now wants to predict the amphibian migration of the grass frog. With the help of a decision tree and the graphical representation of the models, the person could find out graphically or with a simple calculation that the amphibian migration according to the model is estimated about 20 days later, on 22 March. Prediction through the flowering of the apricot is even easier - the results show that the migration of the grass frog takes place around the same time, usually a few days later.

 

Title: Igel-Roadkill im Wiener Stadtgebiet - Analyse des Einflusses von Landnutzung mittels Citizen Science und anderer öffentlicher Daten.

Abstract:

This master thesis analyses the spatial and temporal distribution of hedgehog roadkills in Vienna. Furthermore, the data quality of the Austrian citizen science project Roadkill will be examined and its ecological significance will be evaluated. In the citizen science project, voluntary participants report dead vertebrate animals on or near roads. A four-stage scheme was developed for the evaluation of the data quality of the data. Criteria of this scheme were the presence of a photo, a description of the dead animal or the place where the dead animal was found as well as an exact taxonomy classification of the animal. About 34% of the data fall into the highest quality level. These data offer the highest information content by providing an exact specification of the animal species including a photo, as well as by describing the place of discovery and the dead animal itself. The high
quality of the data therefore makes it most likely to be validated. First, all roadkill project data from Austria will be examined. Subsequently, all reports, divided into the animal classes, are analysed. The reported data on hedgehog roadkills (Erinaceus europaeus and Erinaceus roumanicus) in Austria will then be filtered. For comparison purposes, further data on hedgehog roadkills in Vienna are used. In addition, a hedgehog roadkill monitoring was carried out in Vienna. All hedgehog roadkill data were combined with high-resolution geographical background data. The conditional probabilities in individual land use categories were then calculated and the results were compared with relevant scientific literature. The spatial analysis showed that traffic areas, built-up areas and green areas increase the
probability of a hedgehog roadkill. During the monitoring a total of three hedgehog roadkills could be mapped. So a professional roadkill monitoring is costly and time-consuming and Citizen Science projects make it possible to generate a lot of data over longer periods at a lower cost.

Title: Linking European hare (Lepus europaeus) vehicle collisions with landscape structure with datasets from citizen scientists and hunters.

Abstract:

The world's expanding road networks and the associated fragmentation of the landscape have numerous negative consequences for wildlife. This is rendered most apparent by accidents involving wildlife, i.e. collisions between animals and vehicles, which can be fatal to animals. One animal that is frequently involved in accidents is the European hare (Lepus europaeus).
This research explores whether (i) roadkill datasets from the citizen science project Roadkill.at correlate with data gathered professionally by hunters concerning accidents involving European hares and (ii) if land cover and landscape structure differ between roadkills reported by hunters or citizen scientists. We considered roadkill data for 2013 and 2014 reported from the province of Lower Austria. The spatial and landscape-related analysis and evaluation of roadkill specimens was carried out with the aid of a geographic information system. In order to carry out a landscape-related evaluation, three different radii around each reported roadkill specimen were analysed, intended to represent the home range of the hare based on the varying reports of home range size of hares and the minimum mapping unit of CORINE land cover data and were analysed with series of Mann-Whitney U tests.
The datasets investigated show that accidents involving European hares are particularly common in areas with large proportions of arable land. While the hunters' dataset reported that hares in areas with significantly higher proportions of arable land and heterogeneous agricultural land were found on roadsides away from settlements, the citizens participating in the citizen science project reported hares in environments with significantly higher proportions of residential and industrial areas and more motorways and main roads.
Comparing the two datasets shows differences in the quantity of reported road-kills, which can influence the results of the studies.

Title: Hotspotanalyse und Resultate von Amphibien- und Reptilien-Roadkills im Nordburgenland anhand von Daten aus dem Citizen Science Projekt Roadkill und CORINE Land Cover.

Abstract:

Every year, more than 100,000 amphibians are killed on the roads of Austria due to traffic collisions on their way to their spawning grounds. Reptiles are also affected by such kills, so-called roadkills. Mapping is associated with a high personnel and financial expense, therefore there are gaps in current knowledge e.g. concerning migration routes of amphibians. So-called hotspots, e.g. road sections on which a high number of individuals are killed by the traffic, are only rarely known. Therefore, to be able to implement targeted and efficient protection measures on traffic routes, the knowledge of a connection between typified land uses such as CORINE land use classes and the occurrence of roadkill can make an important contribution to identifying the threats of those animal groups on certain road sections. Generating hotspots using roadkill data and the KDE + software could make the identification more precise and cost-effective.

The aim of this study was to find possible statistical connections between the occurrence of roadkill and land use classes by means of conditional probability and generalized linear models (GLM) with Poisson distribution. For this purpose, during a period of 19 months, identified roadkill was collected on a 97.5 km route in northern Burgenland and entered into an application. Hotspots were generated using KDE + software. The results of the statistical evaluation were compared with the generated hotspots and checked for plausibility.

A connection between the occurrence of roadkills and land use classes was found only in reptiles. Due to the high dependence of amphibians on their spawning grounds, the identification of Roadkill Hotspots with this method is not recommended. In order to be able to make statements regarding the identification of amphibious hotspots, an intersection of KDE +, CORINE land use classes and water body data should be carried out subsequently.