THE INTRODUCED SACRED IBIS, PREDATOR OF
SEABIRDS AND OTHER FRAGILE SPECIES
Pierre Yésou, Dr. Suzanne Bastian, Prof. Philippe Clergeau,
Denis Lacourpaille & Sébastien Reeber
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Sacred Ibis Threskiornis aethiopicus natural area: sub-saharan Africa
Black-faced ibis
Sacred ibis
Australian white ibis
common and not threatened in Africa
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
introduced in various
continents
2001 > 10 bp
mostly from zoos
Europe: enquiry 2006
1991
1700 bp
Main population in
western France
1989
2000
400 bp
>110 bp
1997 >10 bp
also Taiwan, Florida, …
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Sacred ibis in W France: a success story
1974: introduction in a zoo in S Brittany, easy breeding, free flying birds
move to agricultural land, wetlands, seashore
1991-1994: first breeding outside the zoo (70 km away)
2006: 1700 pairs and over 5000 birds in the wild in W France
Largely explained by:
6000
• species plasticity
(adaptiveness)
5000
• lack of predators
3000
• use of refuse dumps
increasing survival
during cold winters
2000
Nb birds
Nb pairs
4000
1997: no more
breeding in zoo
1000
0
1975
1980
1985
1990
Clergeau P. & Yésou P. (2006). Biological Invasions 8: 1381-1388.
1995
2000
2005
2010
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Introduced Sacred ibises have no positive impact on the environment
Ibises often breed in mixed colonies together with various heron species and the
emblematic Spoonbill. Contrary to one claim, breeding ibises do not attract
Spoonbills: detailed study showed that most Spoonbills breed either earlier than
ibises or apart from them.
Ibises feed on introduced American crayfish, as many other species do (from
kingfisher to various herons, also otter). However, this predation has no effect on
the density of this highly invasive species: mostly adult crayfish are predated
while juvenile age class drives the species dynamics.
Marion L. (2013). CR Biologie 336 : 207-220.
Clergeau P. et al. (2010). Oryx 44 : 533-538.
Photo MNHN
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
… while they pose various problems
Very diversified prey items: invertebrates (including larvae of
dragonflies), amphibians (incl. newts), fish, eggs and chick of birds …
These preys already have to cope with impoverished habitats
(deterioration of wetlands), they now have to face a new predator
Direct impact on sensible species in protected areas:
large predation on colonies or marsh terns, also predation on
seabirds, herons, waders, etc.
Common Toad
(C. Laverdet)
Also feed on rubish dumps + open air poultry farming:
potential sanitary impact (parasites, viruses)
[ Situation in Australia showed a potential risk of
airplane collision: minor risk in the French context ]
Williams A.J. & Ward V.L. (2006). Waterbirds 29 : 321-327.
Near a McDonald restaurant (G. Olioso)
Clergeau P. et al. (2010) . Rev. Ecol. (Terre Vie) 65 : 331-342.
Bastian S. et al. (2010). European Wildlife Diseases Ass. Conf. Book of abstracts : 103.
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Sacred ibis management in W France: a step by step progress (Chi va piano…)
2004: predation becoming obvious, managers of protected areas express their
concerns to Regional Administration, which informs the Ministry of Environment.
2005: an assessment is conducted by national scientific bodies (INRA and ONCFS)
on behalf of the Ministry, and the national advisory body for environment (CNPN)
recommends the species to be eradicated.
2006: Ministry asks the administration to organize the eradication at local level
(= prefecture).
2007: culling tests are conducted (2 sites, 3 months).
since 2008: culling is carried out yearly in 3-4 prefectures.
since 2009: prefectoral administration orders that clutches
are sterilized on the main colony (National Nature Reserve
of Grand-Lieu lake).
2014: Ministry asks for increasing efforts in the
eradication process.
Clergeau P. et al.. (2005). Assessment report to the Ministry in charge for the Environment.
http://www.rennes.inra.fr/scribe/document/ibis_v2.pdf
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Culling
- by environment officers only (by exception: civil helpers under the control of officers)
- no limitation to their action, excepted:
- security maximized (professional people, trained to the use of weapons)
- avoid negative impact on other species
- both at feeding sites (groups of birds, easily attracted by forms)
- and in or around breeding colonies
Mock flock of birds attracts wild ones: idea and realisation Denis Lacourpaille
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Sterilization of clutches
• egg picking
• by professional staff of the nature reserve (experienced ornithologist)
• minimized disturbance (less disturbing than ringing activities)
• no negative impact on sensible species (e.g. spoonbills)
• limits: difficult access to colonies + often a second clutch elsewhere
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
5000
Good results…
from 1700 pairs to 300 in 7 years (- 83%)
thanks to the combination of shooting
(mostly affects potential breeding) and
sterilization (which limits recruitment)
At relatively low cost (< 1 full time civil
servant per year)
4000
3000
breeding pairs
birds shot
sterilized clutches
Nb ind, January
2000
1000
35
30
Nb birds killed
per shooting day
2
R = 0,9804
25
0
2006 2007 2008 2009 2010 2011 2012 2013
20
…but difficulties ahead: shooting
efficiency decreases in parallel to bird
number
it will be more difficult (and
costly) to shot the remaining ibises.
15
10
5
0
2008
2009
2010
2011
2012
2013
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
How did the situation evolve
since the 2006 enquiry ?
2001 > 10 bp
2013: no breeding
Main population in
western France
X
1991: 1700 bp
2013: 300 bp
1989: 400 bp
2000: >110 bp
2013 : ?? no action
2013 : 3 birds, no breeding
Never bred
1997 >10 bp
2013: ??
Main population
in Italy ?
«Le specie aliene invasive, una grave minaccia per i sistemi insulari: esperienze di gestione a confronto»
«Invasive alien species, a major threat to insular ecosystems: comparing management options and experiences»
Portoferraio, 31 marzo/march – 2 aprile/april 2014
Thanks to all those who have been involved in the project: administration,
research, eradication process, logistics, including amateur ornithologists who
regularly provide information on the species status.
Do not allow exotic invasive species to spread !
Thank you very much
for your attention
Courtesy Jean-Sébastien Guitton