Results of gender determination for 2017 divers are online & in 2017 breeding areas in Siberia and Svalbard are utilised

This year the genetic gender determination for divers tagged in march 2017 showed a little more balanced result with 5 females and 3 males but again still more females than males. As before information on the sex of each individual is given in short bird profiles next to the tracking map.

Furthermore, since beginning of July divers are back in their breeding areas! Most of the birds tagged in 2017 headed to breeding areas in Siberia but two birds flew to the south of Svalbard, thus within this study a new potential breeding spot can be added to the used sites in Siberia, Greenland and Norway.

Diver capture season 2017 completed successfully

During this year’s capture season 8 more red-throated divers were tagged successfully and the objective of the project is achieved. From now on, the tracks of newly tagged birds can be followed online. The first diver already left its wintering area in the North Sea. During the next weeks it will be exciting to watch their migration towards the breeding grounds.

Please note – there will now be three map views to choose from. One with tracks of birds tagged in 2015, one with tracks of birds tagged in 2016 and one with tracks of the new birds.

British Ornithologists’ Union 2017 Annual Conference, University of Warwick, UK (2017) ”From avian tracking to population process”

This year’s BOU conference ”From avian tracking to population process” took place from the 28th to the 30th of March 2017 at the University of Warwick (UK) and some results of the DIVER project were presented.

The conference covered topics of movement ecology and their consequences for a suite of population processes. The objective of the conference was to bring together ornithologists and ecologists from academic and conservation organisations, to explore how the tracking of individuals can help to address key questions about population processes and their implications for conservation and management.

The two posters featuring the DIVER project displayed data of tracked red-throated divers, where one focused on site fidelity and temporal consistency during migration, moult and wintering, while the other had its focus on mobility and space utilisation during the annual cycle.

Kleinschmidt, B., Dorsch, M., Žydelis, R., Heinänen, S., Morkūnas, J., Burger, C., Nehls, G. & Quillfeldt, P.: Site fidelity and temporal consistency of red-throated divers (Gavia stellata) during migration, moult & wintering
British Ornithologists’ Union 2017 Annual Conference, University of Warwick, UK (2017)

 

Žydelis, R., Dorsch, M., Heinänen, S., Kleinschmidt, B., Morkūnas, J., Quillfeldt, P. & Nehls, G.
High mobility of Red-throated Divers revealed by satellite telemetry
British Ornithologists’ Union 2017 Annual Conference, University of Warwick, UK (2017)

Further downloads.

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International workshop on Red-throated Divers, 24-25 November 2016, Hamburg

As part of the DIVER project an international workshop on Red-throated Divers was held at BSH premises in Hamburg on 24-25 November 2016. The workshop was a great success with more than 40 diver researchers from different countries, representatives of German regulators and offshore wind energy industry attending the meeting.

During the 2 day meeting interim project results of the DIVER project were presented and discussed as well as presentations of international diver experts from Germany, Denmark, Sweden, the Netherlands, Lithuania, UK and USA. Main focus of the workshop presentations and discussions was on the effect of offshore wind farms to divers, but also different aspects of diver biology, such as diver diet and migration patterns.

The workshop agenda as well as most of the presentations (published with the permission of the authors) can be found below.

 

Thursday, 24 November 2016

Stefan Garthe (Germany): Introduction and current state of knowledge on divers in German waters

Presentation_Garthe

Thomas Merck (Germany): Welcome words of BfN

Jesper Kyed Larsen (Denmark): Divers and wind farms – a point of view from wind energy industry side

Presentation_Larsen

Sue O’Brien (UK): Evidence needs for offshore wind farm development in the UK

Presentation_O’Brien

Georg Nehls (Germany): Introduction to the DIVER project

Presentation_Nehls

Ramūnas Žydelis (Denmark): High mobility of Red-throated Divers revealed by satellite telemetry

Presentation_Zydelis_mobility

Volker Dierschke (Germany): Divers and wind farms – review of available information and perspectives for German marine areas

Presentation_Dierschke

Monika Dorsch (Germany): Red-throated Diver winter movements in areas with offshore wind farms

Presentation_Dorsch

Stefan Heinänen (Denmark): Red-throated Diver habitat use in the German North Sea based on aerial survey data

Presentation_Heinänen

Ramūnas Žydelis (Denmark): Red-throated Diver habitat use in the German North Sea based on telemetry data

Presentation_Zydelis_model

 

Friday, 25 November 2016

Petra Quillfeldt (Germany): Introduction to telemetry methods

Presentation_Quillfeldt

Carrie Gray (USA): Red-throated Loon telemetry project in the US

Presentation_Gray

Ramūnas Žydelis (Lithuania): Red-throated Diver telemetry study in Lithuania

Presentation_Zydelis_LT

Ib Krag Petersen (Denmark): Geolocation study of Red-throated Divers in Iceland, Shetland and Orkney

Presentation_Petersen

Joel Schmutz (USA) (presented by Carrie Gray): Red-throated Loon telemetry study in Alaska

Presentation_Schmutz

Mats Eriksson (Sweden): Levels and trends in the Swedish population of Red-throated Diver in Sweden

Presentation_Eriksson

Birgit Kleinschmidt (Germany): Ecological diet analyses of Red-throated Divers wintering in the German North Sea based on molecular methods

Presentation_Kleinschmidt

Mardik Leopold (Netherlands): Foraging ecology of Red-throated Divers

Presentation_Leopold

Richard Caldow (UK) (presented by Sue O’Brien): Red-throated divers in the UK: site-based protection at sea and assessment of effects of marine activities in protected sites

Andy Webb (UK): Operational effects of Lincs and LID wind farms on red-throated divers in the Greater Wash

Presentation_Webb

First results of large-scale digital aerial surveys

As part of the DIVER project, data from two large-scale digital aerial surveys performed in April and May 2016 covering the core diver wintering and staging area in the German North Sea were analysed. These surveys were conducted within our partner project HELBIRD of the “Forschungs- und Technologiezentrum Westküste” (FTZ, Büsum, Germany).

A total of 1,427 (April 2016) and 1,122 (May 2016) divers could be detected on the recorded video material from these surveys. Originating from a coverage of 6.55% of the study area, a simple extrapolation of these numbers leads to estimates of approximately 21,700 and 17,100 divers, respectively, in the surveyed areas for these two months. Identification rate of divers was high for both surveys with more than 97% of divers being identified to the species level. Almost all divers identified were Red-throated Divers. These numbers indicate that diver abundance and especially that of Red-throated Divers is considerably underestimated in the standard data forms of the Natura 2000 areas in this region: there 3,580 divers (3,300 Red-throated Divers) are listed as a maximum estimate for the SPA “Eastern German Bight” and 10,500 divers (10,000 Red-throated Divers) for the larger SCI “Sylter Außenriff”.

Diver distributions from these two aerial surveys demonstrate that divers clearly avoid areas of offshore wind farms in the surveyed area. This confirms results of the satellite telemetry analyses conducted within the DIVER project, which also indicate that divers avoid offshore wind farms.

Spatial modelling which will be conducted on these aerial survey data at a later stage will allow for more precise estimates of diver abundance and distribution patterns.

Seetaucher_20160410_eng

Seetaucher_20160501_eng

Results of gender determination for 2016 divers available

As in the year before, the genetic gender determination for divers tagged in 2016 resulted in much more females caught than males. Information on the sex of each individual is given in short bird profiles next to the tracking map. The reasons for why there are so few males captured are unknown. Could be that males mainly use different areas in late winter or show different timing than females.

Divers start to move again

First Red-throated Divers tagged in 2015 and 2016 have left their breeding areas. It will be exciting to track whether birds will use the same migration routes and stop-over sites as last year or on spring migration, respectively. Will all birds return to the capture area the German North Sea in the course of the winter season?

 

Diver tracking map is updated!

Please check out diver tracking map. 18 new birds captured and tagged in spring 2016 are online now. First birds are already leaving the North Sea, so the next weeks will be interesting where all birds will end up during breeding season. Please note – there are two map views to choose now. One with tracks of birds tagged in 2015, one with tracks of new birds.