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Migration timing and routes in the Estonian hybridising Greater Spotted Eagle Aquila clanga population Ăœlo Väli and Urmas Sellis

Estonian University of Life Sciences / Eagle Club, Estonia


Distribution ranges Lesser Spotted Eagle Aquila pomarina

Breeding

Greater Spotted Eagle Aquila clanga

Stopover Stopover

Wintering

Conservation actions! Where? When?


Questions • What migration routes, stopovers and wintering sites use Greater Spotted Eagles from a single breeding population (Estonia)?


Questions • What migration routes, stopovers and wintering sites use Greater Spotted Eagles from a single breeding population (Estonia)? • When do they migrate? • What about Lesser Spotted Eagles and hybrids (F1, backcrosses)?


Co-workers thus far 6 Greaters Aquila clanga – 2 adult males – 2 adult females – 2 juvenile males

3 Lessers Aquila pomarina – 2 adult males – 1 adult female

4 hybrids – 2 juvenile F1 (A. clanga x A. pomarina) – 2 ad backcrosses (F1 hybrid x A. pomarina)

• Species and gender of all Greaters and hybrids verified by genetic analysis (Väli et al. 2010, J. Avian Biol.)

• Migration routes available: http://birdmap.5dvision.ee/


Equipment • ‘Microwave’ transmitters – GPS locations, speed, altitude, direction – Transmission via Argos satellites – Solar powered – 45 g (1.4 – 2.8% of body mass)


Juku, male Autumn 2005

Last signal 07th Dec 2005

•

Departure 15th Oct

•

Arrival to wintering area 31st Oct


Mart, male “Autumn” 2006

Departure 15th October

Wintering in Central Europe!

Arrival to southernmost wintering site on 14th March!


Mart, male

Mart, male

“Autumn” 2006

Spring 2007


Ann, female Autumn 2006

Departure 4th August

Several stopover sites up to 400 km from the nest

Start of southward migration 15th Oct Last signal 24th Oct 2006


Destination 1 – Western Balkans

Juku, Autumn 2005

Mart & Ann, Autumn 2006

Mart, Spring 2007


Destination 2 - Anatolia

Iti (female), since Autumn 2009 Departures 25.09 – 07.10 Duration 15 – 52 days

Iti (female), Spring 2012


Destination 3 - Iberia


T천nn, the most famous Greater Spotted Eagle

2009 Spring

2010 Spring

2008 autumn

2009 autumn

2010 Autumn

1st cy

2nd cy

3rd cy


2011 Spring

2012 Spring

2013 Spring

2012 Autumn

2011 Autumn

2012 Autumn

2013 Autumn

Tõnn’s brothers?, 2012 Autumn

4th cy

5th cy

6th cy


Spain, 2009

Estonia, 2009 Estonia, 2008

Sweden, 2010

Spain, 2010

Spain 2010

Denmark, 2011

Spain, 2012


Migration of Estonian Lesser Spotted Eagles

Väli, Ăœ. & Sellis, U. Submitted. Migration patterns of the Osprey and the Lesser Spotted Eagle on the Eastern European - East African flyway


Where do the hybrids go? Luule, female, F1 hybrid (A. clanga x A. pomarina)


Where do the hybrids go? Luule, female, F1 hybrid (A. clanga x A. pomarina)

Autumn 2011 1st cy Departure 27th Sept

Spring 2012 2nd cy

Autumn 2012 2nd cy Departure 18th Sept


Where do the hybrids go?

Teele (female, F1 x A. pomarina) Sander (male, F1 x A. pomarina) Autumn 2006 Autumn 2012 Departure 1st Oct

Departure 10th Sept


Conclusions • Estonian Greater Spotted Eagles have at least three distinct wintering areas (“don’tput-all-eggs-in-one-basket-strategy”) • F1 hybrid  Southern Europe, F1 x Lesser Spotted Eagle  NE Africa • Variable timing but hybrids tend to leave breeding grounds earlier (as do Lessers)


Acknowledgements


Breeding density in Europe Lesser Spotted Eagle

Moderate decline IUCN: Least concern

Greater Spotted Eagle

Large decline IUCN: Vulnerable BirdLife International 2004: Birds in Europe


The Greater Spotted Eagle in Estonia Greater pair

Greater single

Greater x Lesser

F1 hybrid x Lesser

F1 x F1

14

No. of territories

12 10 8 6 4 2 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Increase of knowledge ď Š

Year

Decline of population ď Œ

Population estimations: 1998: 15-30 (incl. mixed pairs), stable? 2003: 20-30 stable 2008: 10-20 decreasing 2013: 5-10 decreasing


The Greater Spotted Eagle Aquila clanga

Medium-large raptor

Long-lived (gen. time 11y)

Nests in wet forest, nest re-used

Forages in open habitats (floodplain meadows) on small mammals, birds, amphibians

Hybridises with the Lesser Spotted Eagle Aquila pomarina


The Greater Spotted Eagle Aquila clanga • World population - some 3000 breeding territories??? IUCN: vulnerable • In Estonia 5-10 territories Protection category I (strictest conservation)

Incl. mixed pairs hybridising with A. pomarina


The Lesser Spotted Eagle Aquila pomarina • Some 20 000 breeding territories in the world??? IUCN: least concern • 600-700 territories in Estonia Protection category I


Hybrids


Hybrids are viable

V채li 2010 Ardea


Hybrids are fertile

V채li 2010 Ardea


Hybridisation in Europe Greater

Lesser

No. of pairs with Greaters or hybrids / No. of studied pairs in total Greater pair

Greater x Lesser

F1 x Greater

F1 x Lesser

Only Lessers

V채li et al. 2010, Biol. J. Linn. Soc.

Migration Strategies in a Hybridising Population of Spotted Eagles Aquila clanga × pomarina  

Презентация на конференции «Орлы Палеарктики: изучение и охрана»

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