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.