consumed fish

An excel table of all fish individuals consumed by the four cormorants during the three experimental runs including fish species, total length, mass and start/end of consumption per fish species and cormorant

faeces_molecular_prey_detection

The excel table "faeces_molecular_prey_detection" shows the results of the molecular screening of cormorant faeces produced in the feeding trial

Data from: The influence of meal size on prey DNA detectability in piscivorous birds

Molecular methods allow non-invasive assessment of vertebrate predator-prey systems at high taxonomic resolution by examining dietary samples such as faeces and pellets. To facilitate the interpretation of field-derived data, feeding trials, investigating the impacts of biological, methodological, and environmental factors on prey DNA detection have been conducted. The effect of meal size, however, has not yet been explicitly considered for vertebrate consumers. Moreover, different non-invasively obtained sample types remain to be compared in such experiments. Here, we present a feeding trial on abundant piscivorous birds, Great Cormorants (Phalacrocorax carbo), to assess meal size effects on post-feeding prey DNA detection success. Faeces and pellets were sampled twice a day after the feed of large (350-540 g), medium (190-345 g), and small (15-170 g) fish meals contributing either a large (>79%) or small (<38%) share to the daily consumption. Samples were examined for prey DNA and fish hard parts. Molecular analysis of faeces revealed that both large meal size and share had a significantly positive effect on prey DNA detection rate post-feeding. Furthermore, large meals were detectable for a significantly longer time span with a detection limit at ~76 h and a 50% detection probability at ~32 h post-feeding. In pellets, molecular methods reliably identified the meal consumed the previous day, which was not possible via morphological analysis or when examining individual faeces. The less reliable prey DNA detection of small meals or meal shares in faeces signifies the importance of large numbers of dietary samples to obtain reliable trophic data

Data from: Molecular prey identification in Central European piscivores

Diet analysis is an important aspect when investigating the ecology of fish-eating animals and essential for assessing their functional role in food webs across aquatic and terrestrial ecosystems. The identification of fish remains in dietary samples, however, can be time-consuming and unsatisfying using conventional morphological analysis of prey remains. Here, we present a two-step multiplex PCR system, comprised of six assays, allowing for rapid, sensitive and specific detection of fish DNA in dietary samples. This approach encompasses 78 fish and lamprey species native to Central European freshwaters and enables the identification of 31 species, six genera, two families, two orders and two fish family clusters. All targeted taxa were successfully amplified from 25 template molecules, and each assay was specific when tested against a wide range of invertebrates and vertebrates inhabiting aquatic environments. The applicability of the multiplex PCR system was evaluated in a feeding trial, wherein it outperformed morphological prey analysis regarding species-specific prey identification in faeces of Eurasian otters. Additionally, a wide spectrum of fish species was detected in field-collected faecal samples and regurgitated pellets of Common Kingfishers and Great Cormorants, demonstrating the broad applicability of the approach. In conclusion, this multiplex PCR system provides an efficient, easy to use and cost-effective tool for assessing the trophic ecology of piscivores in Central Europe. Furthermore, the multiplex PCRs and the primers described therein will be applicable wherever DNA of the targeted fish species needs to be detected at high sensitivity and specificity

Eurasian otter feeding trial

This are data from a fish feeding trial on Eurasian Otters. The animals were fed a different fish species every day; 5 otter spraints were collected per evening; these were analyzed molecularely for fish DNA and morphologically for fishbones

16S alignment of sequences for genbank

This BioEdit file provides an alignment of the 16S sequences uploaded to genbank for this publication. Please note, that for GenBank publication sequences were cropped to achieve clear and identical sequences from forward and reverse direction reads

COI alignment of sequences for genbank

This BioEdit file provides an alignment of the COI sequences uploaded to genbank for this publication. Please note, that for GenBank publication sequences were cropped to achieve clear and identical sequences from forward and reverse direction reads

kingfisher and cormorant molecular screening

The data show the results of a molecular screening (multiplex PCR) of field collected feces of the Common Kingfisher and the Great Cormorant, as well as regurgitated pellets of the latter. readme is included in the fil