1 / 44

Practical risks of introgression Theoretical risks of introgression Evidence of introgression

Do Falco hybrids in falconry present an ‘ unacceptably high risk of unnatural genetic introgression to native wild falcon populations?’ Matthew Gage and Christian de Coune (m.gage@uea.ac.uk).

fluz
Download Presentation

Practical risks of introgression Theoretical risks of introgression Evidence of introgression

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Do Falcohybrids in falconry present an ‘unacceptably high risk of unnatural genetic introgression to native wild falcon populations?’Matthew Gage and Christian de Coune(m.gage@uea.ac.uk)

  2. Fox, N. C. and S. Sherrod, 1997. The use of Exotic and Hybrid Raptors in Falconry: Information arising from the International Committee on Hybrids. Hawk Board (Third Edition 2004, 65pp).

  3. Do hybrids pose an ‘unacceptably high risk of unnatural genetic introgression to native wild falcon populations?’ • Practical risks of introgression • Theoretical risks of introgression • Evidence of introgression • Challenges and solutions

  4. 1. Practical risks of introgression • Falconry is an ancient hunting partnership between man and bird, based upon a fundamental principle that the bird is trained to depend upon, and return to, its falconer • How many falcons are permanently lost? • How many of these survive?

  5. How many falcons are permanently lost? METHODS • Online survey to IAF affiliated falconry Clubs BY Christian de Coune in 2008 • Simple question: • Numbers of falcons FLOWN this season (2007-8) • Numbers of falcons LOST in 1997 to 2006

  6. RESULTS • Data returned from 1074 falconers, 40 countries • N=1167 total Falco ‘frequencies’ per annum • Therefore an average 1.08 falcons flown per falconer • Use the lost data (97-06) to predict how many of the flown (07-08) will become lost • On average, 5% of falcons flown are lost • =if you fly one falcon per season, you will lose a bird once every 20 years

  7. RESULTS: PURE AND HYBRID USAGE • 70% of falconers fly pure species • 17% fly saker-hybrids • 13% fly non-saker hybrids • 30% fly hybrids (N=1074 falconers reported to the survey)

  8. RESULTS: Hybrid falcons are permanently lost SIGNIFICANTLY LESS OFTEN than pure species (Chi2= 4.97, 1 df, P=0.026)

  9. SURVEY CONCLUSIONS • Online survey allowed some data to be gained on a global sample of IAF-affiliated falconers • OVERALL falcon loss is quite RARE - average 5% of falcons flown • Hybrid loss is SIGNIFICANTLY RARER – 3% of hybrids flown • = if you fly one falcon, you will permanently lose one pure falcon every ~20 years, OR one hybrid every ~33 years

  10. 1. Practical risks of introgression • Falconry is an ancient hunting partnership between man and bird, based upon a fundamental principle that the bird is trained to depend upon, and return to, its falconer • How many falcons are permanently lost? • How many of these survive?

  11. 2001-2003 seasons • 141 falcons successfully hacked (= ‘soft’ release) • 75 wild chicks fledged from wild nests • Compare survival rates AFTER successful fledging in common environment = 33% = 5%

  12. 1. Practical risks of introgression • Falconry is an ancient hunting partnership between man and bird, based upon a fundamental principle that the bird is trained to depend upon, and return to, its falconer • How many falcons are permanently lost? • How many of these survive?

  13. Do hybrids pose an ‘unacceptably high risk of unnatural genetic introgression to native wild falcon populations?’ • Practical risks of introgression • Theoretical risks of introgression • Evidence of introgression • Challenges and solutions

  14. Evolutionary biology provides the evidence! Species that are: Mobile Sympatric Inter-fertile ......have co-existed for millennia without introgression and hybrid proliferation Theoretical risks of introgressionA. Superior hybrid alleles??

  15. Theoretical risks of introgressionB. Genetic swamping?? For hybrid introgression to be successful: • two opposite-sex hybrids • must survive • in the same vicinity • at the same time • defend a territory • produce fertile offspring • THAT THEMSELVES COMPLETE THE SAME CYCLE

  16. ~400 wild cats ~2,000,000 feral cats ~8,000,000 pet cats

  17. ~95% of all Atlantic salmon on Earth are farmed

  18. Do hybrids pose an ‘unacceptably high risk of unnatural genetic introgression to native wild falcon populations?’ • Practical risks of introgression • Theoretical risks of introgression • Evidence of introgression • Challenges and Solutions

  19. 3. Evidence of introgressionA. Molecular signatures Modern molecular markers, such as microsatellites, allow measures of genetic mixing between populations and species

  20. Large study examining 244 hierofalcon specimens (cherrug, rusticolus, jugger, biarmicus) • Compared contemporary (n=60) and pre-1970 historic (n=22) specimens • No clear evidence of anthropogenic hybridizations (compared with natural rates)

  21. 3. Evidence of introgressionB. Breeding successes John Morris and Ronald Stevens (1971) Successful cross-breeding of a peregrine tiercel and a Saker falcon. Captive Breeding of Diurnal Birds of Prey 1: 5-7.

  22. 3. Evidence of introgressionB. Breeding successes 1. 1995 – Peregrine/Prairie male with Peregrine female (Washington DC, USA) 2. 1996 – Gyr/Peregrine male with Peregrine female (Colorado, USA) 3 + 4. 1996 + 1997 - Gyr/Peregrine male with Peregrine female (Thűringen, Germany) 5 + 6. 1998 + 1999 - Gyr/Peregrine male with Peregrine female (Bohuslän, Sweden) 7. 2001 - Gyr/Peregrine male with Peregrine female (Nordrhein- Westfalen, Germany) 8. 2003 – Peregrine/Saker male with female Saker (Slovakia) 9. 2004 - Gyr/Peregrine male with Peregrine female (Sächsische Schweiz, Germany) 10. 2004 – Hybrid male with Peregrine female (Franconia, Germany) 11. 2005 – Gyr+Saker/Peregrine male with female Peregrine (Sussex, UK) 12. 2007 - Gyr/Peregrine male with Peregrine female (East Germany)

  23. 2 km

  24. Do hybrids pose an ‘unacceptably high risk of unnatural genetic introgression to native wild falcon populations?’ • Practical risks of introgression: Currently negligible • Theoretical risks of introgression: Currently negligible • Evidence of introgression: Currently negligible • Challenges and Solutions

  25. What constitutes a hybrid? • Are offspring from F. pelegrinoides and F. peregrinushybrids? • But ‘Distances between pelegrinoides and peregrinus are below 0.6%-0.7% nucleotide substitutions indicating a rather recent divergence of both groups. Distances found in ‘good’ species within the Falconidae and Accipitridae are usually higher than 1.5% (Seibold et al. 1996) ‘ (Wink et al 1998)

  26. There is more genetic variation across the red-necked falcon, Falco chicquera than across all 19 (?) species / subspecies of peregrines

  27. ‘Unnaturalised’ landscapes & inconsistent precedents

  28. 4. CHALLENGES AND SOLUTIONS 1. Minimise hybrid loss and survival further 2. Make any issue more transparent

  29. 4. CHALLENGES AND SOLUTIONS BREEDERS’ RESPONSIBILITIES? • Allopatric hybrid crosses? • Wild-hacking of hybrids? • Releasing hybrids?

  30. 4. CHALLENGES AND SOLUTIONS FALCONERS’ RESPONSIBILITIES? • Mark and Bank registration scheme, with a (global) marking scheme to identify hybrids? • Liabilities for irresponsible hybrid / non-indigenous loss?

More Related