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Conservation in Mauritius and Rodrigues: Challenges and Achievements from Two Ecologically Devastated Oceanic Islands


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Mauritius and Rodrigues are among the last places on earth to have been reached by humans and yet are also among the most ecologically devastated, thus illustrating our great propensity to destroy the environment. Today, conservation approaches and techniques continue to be innovated, developed, and tested on the two islands, which consequently represent a kind of “conservation laboratory” for the tropics. Despite some notable successes, conservation problems on the islands persist and are being exacerbated by a low and declining commitment of the government to the conservation of biodiversity. In spite of the commitment of many government officers and bodies to addressing conservation challenges, their efforts are often curtailed by interference intense enough to make the officers yield to the whims of politicians and end up backing decisions that are detrimental to conservation.
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Conservation in Mauritius and
Rodrigues: Challenges and
Achievements from Two
Ecologically Devastated
Oceanic Islands
F.B. Vincent Florens
Department of Biosciences , University of Mauritius , Réduit , Mauritius;
Université de la Réunion , La Réunion , France
servation problems on the islands persist and are being
exacerbated, on the one hand by a low and declining
commitment of the government to the conservation of
biodiversity, and on the other by an overwhelmingly
prominent conservation non-governmental organiza-
tion (NGO) that appears to be increasingly drifting
away from biodiversity conservation and towards self-
preservation. There is a growing need to shift the focus
of local conservation efforts away from the current
expensive, predominantly species-centric approach
towards a more all-encompassing and economically
more sustainable ecosystem approach. Some of the
missing ingredients for this outcome seem to include
involving alternative NGOs to carry out conservation
work, an increased capacity of the authorities to take
evidence-based decisions, and a reduction of the
powers of politicians, who, facilitated by the country s
laws, often interfere and pressure conservation profes-
sionals and scientists to produce outcomes that are often
contrary to the country s stated conservation policies.
Mauritius and Rodrigues are among the last places on
earth to have been reached by humans and yet are also
among the most ecologically devastated, thus illustrat-
ing our great propensity to destroy the environment.
The resulting situation, with several species on the
brink of extinction, has attracted extensive conserva-
tion efforts, mostly from abroad. Some species near
extinction, whose situation appeared hopeless, have
recovered and represent conservation success stories.
Today, conservation approaches and techniques con-
tinue to be innovated, developed, and tested on the two
islands, which consequently represent a kind of “con-
servation laboratory” for the tropics. In some ways, the
islands could be seen as representing what awaits the
rest of the tropical world as the latter catches up in
terms of human overpopulation, habitat destruction,
and with fragmentation and alien species invasion
being accelerated. Despite some notable successes, con-
Conservation Biology: Voices from the Tropics, First Edition. Navjot S. Sodhi, Luke Gibson, and Peter H. Raven.
© 2013 John Wiley & Sons, Ltd. Published 2013 by John Wiley & Sons, Ltd.
Africa: Conservation in Mauritius and Rodrigues 41
and why, leaving little ambiguity about the heavy-
handed role humans played directly and indirectly in
rapidly driving so many species to extinction ( Cheke
and Hume, 2008 ; Rijsdijk et al ., 2011 ).
Except for certain recent conservation successes, the
two islands can be regarded as textbook examples of
what should not be done if we are to preserve biodiver-
sity and ecosystem functioning and, ultimately, our-
selves. Natural habitats on both islands were destroyed
for settlement or agriculture, the rate of destruction
jumping to catastrophic levels in the nineteenth
century, mainly as sugar cane plantations were estab-
lished widely on Mauritius. This development contin-
ued thereafter, leaving a confetti of fragments of native
habitat sprinkled mostly over the steeper slopes and
other areas least suitable for agriculture (Figures 6.1 ,
6.2 ). Many extant native species that survived this
environmental transformation, particularly plants,
remain threatened due to extinction debt ( Tilman et al .,
1994 ; Vellend et al ., 2006 ). The rarest species in the
world is from Mauritius: the palm Hyophorbe amaricau-
lis , down to a single individual. All propagation
attempts over at least 50 years have failed (e.g., Sarasan,
2010 ), making it a top contestant to become the symbol
of the living dead. Many other species, particularly
Mauritius (1865 km 2 ) and Rodrigues (109 km
2 ), two
volcanic oceanic islands formed 8–10 million years ago
in the Mascarene Archipelago in the southwest Indian
Ocean, had one of the worst possible starts in relation
to biodiversity conservation. Within merely 370 or so
years of human presence, these formerly pristine
islands, teeming with endemic and often evolutionarily
remarkable species, were transformed into two of the
worst impacted places on earth ecologically ( Cheke and
Hume, 2008 ). Mauritius is most famous among con-
servation biologists for having provided the world with
the very symbol of human-induced species extinction,
the remarkable dodo ( Raphus cucullatus ) ( Turvey and
Cheke, 2008 ). Rodrigues had its own large fl ightless
bird, the solitaire ( Pezophaps solitaria ), which was also
quickly driven extinct by humans. But these two species
are only the tip of the iceberg of extinction on each
island. Parrots, owls, rails, giant tortoises and lizards,
fruit bats, snails, and many other animal and plant
species disappeared rapidly after humans fi rst set foot
on the islands (Table 6.1 ). The two islands are unusual
in that their original biota was relatively well known
from an early stage of human presence, owing to their
late discovery. Thus, helped by some relatively complete
fossil records (e.g., Rijsdijk et al ., 2009 ), Mauritius and
Rodrigues provide us with one of the best records of
what was initially present and what was lost, when,
Table 6.1 Native and endemic terrestrial species diversity in selected groups in Mauritius (Mau) and Rodrigues (Rod),
with respective total number of extinctions. Percentages are given in brackets
Native Total Endemic Total Extinct Endemic Extinct
Mau Rod Mau Rod Mau Rod Mau Rod
691 150 273 (39.5%) 47 (31.3%) 61 (8.8%) 17 (11.3%) 30 (11.0%) 10 (21.3%)
521 * (20.0%) 0 2 (40.0%) 1 (50.0%) 0 0
Land birds
28 14 19 (67.9%) 13 (92.9%) 16 (57.1%) 11 (78.6%) 12 (63.2%) 11 (84.6%)
** 17 8 16 (94.1%) 8 (100.0%) 5 (29.4%) 8 (100.0%) 5 (31.3%) 8 (100.0%)
Butterfl ies
30 10 5 (16.7%) 0 4 (13.3%) 1 (10.0%) 1 (20.0%) 0
125 30 81 (64.8%) 16 (53.3%) 43 (34.4%) 7 (23.3%) 36 (44.4)% 5 (31.3%)
1 Baider et al . 2010 ;
2 Cheke and Hume 2008 ,
3 Hume 2011 ;
4 Williams 2007 ;
5 Griffi ths and Florens 2006 ;
* Goodman et al . 2008
** one species of gecko survives on Rodrigues but it was fi rst recorded after 1884 and is believed to be
Figure 6.1 The percentage of native habitats (in black) remaining at different dates on Mauritius. Only remnants dominated
in their canopy by native species are shown. Those dominated in the canopy by invasive alien plants but with some native
relicts accounted for another 3.4% in 1997. The situation on Rodrigues is even worse.
Adapted from Vaughan and Wiehe ( 1937 ) and Page and D ’ Argent ( 1997 ).
Figure 6.2 Current habitat destruction on Mauritius. (a) The last remnant of mainland coastal native forest in the
Mascarenes being cleared at Roches Noires, Northeast Mauritius, for developing an “environmentally friendly” integrated
resort scheme, demonstrating major loopholes in the local environmental impact assessment process (May 2008). (b) Pile of
uprooted native and endemic plants on Ilot Gabriel Nature Reserve, North Mauritius shortly after the islet was leased to the
friend of a minister. Offi cially only dead wood was cleared (August 2008). (c) Illegal wetland back-fi lling in northern Mauritius
(March 2008). Most coastal wetlands in Mauritius now suffer from severe disturbances like fragmentation and fi lling
( Laurance et al., 2012 ) (d) One of the illegal clearings for deer hunting within the dense forest of the Nature Reserve of
Cabinet (note shooting platform indicated by the arrow). Those responsible were not fi ned, despite being identifi ed (August 2006).
Photos © F.B.V. Florens
(c) (d)
Africa: Conservation in Mauritius and Rodrigues 43
endemic to one or the other island are threatened
( Cheke and Hume, 2008 ).
Such a grim situation laid a perfect stage for attracting
substantial conservation efforts, mainly from abroad
from institutions like the Peregrine Fund and the Jersey
Wildlife Preservation Trust ( Jones, 2008 ). These efforts
led to spectacular conservation successes starting in
the 1970s with the Mauritius Kestrel ( Falco punctatus ),
then known from only four individuals and more
recently boasting over 800 wild birds ( Jones, 2008 ).
Recoveries of the Pink Pigeon ( Columba mayeri ) and
Echo Parakeet ( Psittacula eques ) on Mauritius were
achieved through intensive management, including
captive breeding, and represent some of the other great
conservation achievements that followed in the 1980s
and 1990s ( Jones and Swinnerton, 1997 ; Swinnerton
et al ., 2004 ). In parallel with these species-centric
approaches, habitat restoration has been attempted,
mainly through the control of invasive alien species on
important offshore islets such as Round Island, which
holds the highest density of threatened vertebrate
species in the world, or Ile aux Aigrettes, home to the
last relicts of the coastal dry forests of the Mascarenes
( Parnell et al ., 1989 ).
Habitat restoration has also been undertaken on
Mauritius and Rodrigues mainland, where so-called
“conservation management areas” (CMAs) have been
set up and managed ( Cheke and Hume, 2008 ). CMAs
(totaling < 1% of remaining mainland native habitats)
are typically located within well-preserved remnants of
native vegetation. Ranging from 0.3–19.3 hectares in
size, CMAs are usually regularly cleared of invasive
introduced plants and are fenced against large alien
mammals like deer, feral pigs, and goats (Figures 6.3 a,
b). The successful eradication of alien species, includ-
ing rats, goats, and rabbits, from several islets, resulted
in dramatic recovery of the native vegetation and
fauna (e.g., North et al ., 1994 ). On the mainland, the
control of invasive alien plants like the strawberry
guava ( Psidium cattleianum ) in the CMAs on Mauritius
or the rose apple ( Syzygium jambos ) on Rodrigues had
marked benefi cial effects on both native plants ( Baider
and Florens, 2006, 2011 ; Monty, Florens and Baider,
2013 ) and animals ( Florens and Baider, 2007 ; Florens
et al ., 2010 ; Hugel, 2012a ). However, it has been
noted more recently that this restoration activity is
plants, have each shrunk down to a continuously
decreasing handful of individuals. For example, the
Mauritian endemic Badula ovalifolia , an understory tree
discovered in 1821, is today known from only three
adults and one sapling with nearly half of its adult
population lost since 1997 ( Florens, Baider and Bosser,
2008 ). But apart from the extremely small and frag-
mented populations left over from habitat destruction,
the native biota also faces growing pressures from
many invasive alien animals (particularly predators),
and plant species that often reach extreme densities in
even the best preserved habitat remnants ( Strahm,
1993 ; Florens, 2008 ).
Overexploitation has also contributed to the overall
decay of biodiversity on both islands. Easily hunted
animals like the four species of giant tortoises (two on
each island) were swiftly driven extinct ( Cheke, 1987 ).
Populations of economically useful plants were also
decimated. The best examples are some palm species
with edible hearts, which went from being extremely
abundant ( Bernardin de Saint Pierre, 1773 ) to the
brink of extinction within two centuries ( Maunder
et al ., 2002 ). In addition to all these major classic
threats, there is a suite of other biological problems
such as agricultural insect pest introduction ( Kaiser,
Hansen and Müller, 2008 ), lost interactions like seed
dispersal by now extinct fauna ( Hansen, 2010 ), and
the hampering of pollination or seed dispersal by alien
species ( Hansen, Olesen and Jones, 2002 ; Hansen and
Müller, 2009 ), all of these piling up pressure against
the survival of native species of the two islands.
Climate change may also worsen matters, although
evidence so far suggests that the pre-human coloniza-
tion biota of Mauritius has been rather resilient to past
climatic stress ( Rijsdijk et al ., 2009, 2011 ; van der Plas
et al ., 2012 ). Climate change over the last 38,000 years
seems to have triggered transitions between vegetation
communities that mainly involved species reassort-
ments or changes in vegetation distribution, with little
evidence for plant species having gone extinct ( de Boer
et al. , 2013a, b ). At any rate, a large portion of the
surviving native species is nowadays under threat of
extinction according to the IUCN Red List criteria.
Among angiosperms, 81.7% and 77.8% of species
should classify as currently threatened in Mauritius
and Rodrigues, respectively ( Baider et al ., 2010 ). The
corresponding fi gures for land mollusks, an often-used
indicator group, stand at 80% and 60% for Mauritius
and Rodrigues, respectively ( Griffi ths and Florens,
2006 ). In addition, all nine extant land bird species
44 Conservation Biology
More recently, a number of translocations of threat-
ened species to safer havens have been successful. For
example, individuals of the Mauritius Fody ( Foudia
rubra ), a species declining in the face of alien predation
and habitat degradation in its last strongholds in the
Mauritian uplands ( Nichols, Woolaver and Jones,
2004 ), were translocated to the lagoon islet of Ile aux
Aigrettes ( Cristinacce et al ., 2008 ), where alien preda-
tors are absent. Other highly restricted vertebrates that
have survived on a single offshore islet have been
reintroduced onto other islets following the eradication
of their alien predators there. For example, individuals
unnecessarily being made both more expensive and
damaging to native biodiversity merely due to a lack of
basic evidence-informed decision ( Florens and Baider,
2013 ). Furthermore, expensive attempts to exclude
large hoofed mammals from the CMAs have generally
been ineffective ( Florens, 2008 ; Baider and Florens,
2011 ) and their presence and impact did not prevent a
strong recovery of the forest community in the CMAs,
particularly on Mauritius, indicating that attempts to
exclude large mammals might not be as important as
is generally assumed compared with alien plant control,
at least locally.
Figure 6.3 Some conservation activities on Mauritius and Rodrigues. (a) Fencing forest remnants to try to exclude large
alien mammals. This measure generally provides weak benefi ts relative to its cost, particularly on Mauritius, but continues to
be implemented. (b) Weeding of invasive alien plants from native forests. This represents by far the most judicious use of the
conservation dollar, but has a low popularity relative to more “exciting” species-centric projects. (c) Supplementary feeding of
pink pigeon on Mauritius. This conservation action has proven invaluable in saving the species when it was on the brink of
extinction, but now helps maintain the species dependence on intensive management of questionable sustainability. (d)
Innovative use of Aldabra tortoises within a valley undergoing reforestation with native species at the Francois Leguat Tortoise
Park, Rodrigues. The animals are used as analogues to replace extinct endemic species and their lost ecological functions.
Photos © (a), (c) F.B.V. Florens; (b) Courtesy of D. Florens; (d) Photo courtesy of François Leguat Reserve
Africa: Conservation in Mauritius and Rodrigues 45
surprisingly large proportion of native species, particu-
larly of plants, that persist ( Baider et al ., 2010 ; Florens
et al ., 2012 ). Furthermore, new native or endemic
plant species still continue to be discovered despite the
fact that only tiny habitat remnants survive ( Le Péchon
et al ., 2011 ; Baider et al ., 2012 ; Baider and Florens,
2013 ). Even in a few cases where populations have
been extirpated from one or the other island, reintro-
duction might still be possible. Some plants extinct on
Rodrigues can be reintroduced from Mauritius. Neigh-
boring Réunion Island might also supply Mauritius
with some species for eventual reintroduction, includ-
ing plants such as Hernandia mascarenensis ( Bosser et
al ., 1976 onwards), the butterfl ies Antanartia borbonica
and Salamis augustina ( Williams, 2007 ; Martiré and
Rochat, 2008 ), the snail Erepta setiliris ( Griffi ths and
Florens, 2006 ), and the bird Circus maillardi ( Jones,
2008 ). As in the case of the introduced tortoises, close
relatives of other extinct endemic species could be con-
sidered as introduction candidates to serve as ana-
logues in natural communities. However, stemming
further losses and extinctions is a much higher
The conservation successes outlined here are hearten-
ing, particularly the recoveries of some charismatic
vertebrates, but the disturbing fact remains that, over
the course of some four decades of sustained and often
intense and costly conservation efforts, only a handful
of species seem to have been saved from virtually
certain extinction. Most of these have been vertebrates
( Jones, 2008 ), although a few plant species have also
recovered much, including Ramosmania heterophylla
(Rubiaceae), a Rodrigues endemic ( Strahm, 1989 ). In
contrast, the vast majority of native species, particu-
larly the less charismatic ones such as at least 750
endemic insect species (e.g., Motala et al ., 2007 ; Hugel,
2009, 2010, 2012b ), continue to decline, as the over-
whelming majority (99%) of native habitats on which
most depend continues to decay into impoverished eco-
systems dominated by alien invasive plants. The
number of species that have been saved for the medium
to long run thus represent a mere drop in the ocean of
endemic and threatened species, a situation that calls
for more decisive and meaningful conservation action.
It is true that several species once thought to be extinct,
having escaped all surveys for sometimes one or even
of the endemic skink Leiolopisma telfairii have been
moved from their last refuge on Round Island to Ile aux
Aigrettes, thus establishing a second population that
will help reduce the risk of extinction ( Thébaud et al .,
2009 ). In other cases, the entire species has gone
extinct, and further action is obviously impossible. This
has been the case with the four giant tortoise species,
which formerly played important ecological functions
as herbivores and seed disseminators ( Hansen, Kaiser
and Müller, 2008 ). In some cases, alien analogues have
been introduced to try to restore the former ecological
interactions. Thus, Aldabra tortoises ( Aldabrachelys
gigantea ) have been introduced to Ile aux Aigrettes
where they now disseminate seeds of endemic ebony
( Griffi ths et al ., 2011 ). This tortoise, along with a
smaller species ( Astrochelys radiata ), have been intro-
duced to Rodrigues to restore ecological function in the
François Leguat Giant Tortoise Reserve, where they
successfully disseminate seeds of native plants and
control invasive alien weeds ( Burney, 2011 ; Figure
6.3 d). However, A. gigantea has more recently also been
shown to enhance the germination of some invasive
alien weeds ( Waibel et al. , 2013 ). Another limitation
with their use as analogue species is that they may not
be able to breed in some sites where they have been
introduced ( Griffi ths et al. , 2012 ).
Mauritius and Rodrigues can thus boast a number
of conservation achievements and continue to play an
important role as a laboratory where new conservation
approaches and techniques are being innovated, tested,
and developed. The outcomes are useful not only locally
but as examples elsewhere, since many places in the
world are or will soon be facing similar problems,
including habitat destruction, overexploitation, dis-
rupted mutualisms, and species invasion. Indeed, to a
substantial extent, Mauritius and Rodrigues already
represent situations that await much of the tropical
world based on current worldwide trends in human
overpopulation (densities of 668 people in Mauritius
and 364 in Rodrigues per km
2 [ CSO, 2010 ]), habitat
destruction and fragmentation, extinction, and inva-
sion by alien species. These multiple threats combine to
produce acute conservation problems but have one
advantage: they incite urgent and concrete conserva-
tion interventions. By attracting such attention, Mau-
ritius and Rodrigues have played useful roles as
conservation laboratories for the world beyond, and so
far many such experiments are working effectively.
Despite the massive habitat loss and other threats,
there is some cause for measured optimism given the
46 Conservation Biology
“conservation successes” over the long run. It is also
true, however, that a conservation NGO, like the one
currently spearheading the conservation of these
species, can itself derive substantial benefi ts with con-
tinued intensive species-centered management; such
activities make the NGO effectively indispensable and
at the same time help guarantee an infl ux of funds
through management fees, which generally increase
with project cost. Incentives to favor species-centered
conservation management, which is the most expen-
sive approach but also the one that builds the greatest
dependence on continued management for the longest
time, can thus be very strong. The virtual monopoly of
non-governmental conservation action, which this
NGO holds on the two islands, exacerbates this problem.
Such a situation can constitute a brake to the promo-
tion of the much more desirable approach of address-
ing conservation from an ecosystem point of view – for
example, by restoring whole habitats as through the
control of invasive alien species. While the need for
such large-scale restoration has recently been recog-
nized for Mauritius and Rodrigues ( NBSAP, 2006 ), it is
still proving diffi cult to implement with less than 10%
of the objective attained at midterm of the National
Biodiversity Strategy and Action Plan (NBSAP), much
of which is concentrated on islets of importance mainly
for a few vertebrate species but which overall comprise
a tiny fraction of the total native or threatened
This situation prevails despite an ongoing Protected
Area Network (PAN) project funded at US$16 million,
mainly by the UNDP. A small fraction of that amount
would suffi ce to exceed the NBSAP ( 2006 ) target of
larger scale habitat restoration at current proven costs
of initial invasive alien plant control ( < US$2,000 per
ha) ( Florens and Baider, 2013 ). Unfortunately, from
the project document ( UNDP-GEF 2009 ), it appears
that much of this record funding for the country,
entrusted mainly to the same NGO and the National
Parks and Conservation Services, is earmarked for con-
sultancies and other activities that might often dupli-
cate existing knowledge, in particular that concerning
weed control costs and effi cacy, leaving relatively little
for on the ground conservation work. On a positive
note, Mauritius has set up a Conservation Fund, and
some progress has been made in restoring wider habitat
areas. However, disproportionally more effort still goes
to expensive and relatively low-impact projects. A
recent example is the translocation attempt made on
one of the populations of an endemic species of reptile
two centuries, have been relocated in the reduced
patches of remaining habitat ( Florens, Florens and
Sevathian, 2001 ; Florens and Baider, 2007 ; Baider and
Florens, 2011 ). But given the evident extinction debt
and the degree to which the two islands natural habi-
tats have been and continue to be impacted (e.g., Figure
6.2 ), it would be naïve to conclude that enough is being
done to stem further extinctions.
A major weakness in the current regional conserva-
tion approach, particularly in Mauritius, where the
bulk of the two islands biodiversity survives, is the
disproportionate importance being given to a case-by-
case species-level approach to conservation, especially
for birds and more recently for reptiles. This species-
specifi c approach often takes away efforts and funds
from a more comprehensive ecosystem approach that
would benefi t many more species simultaneously,
including the very birds and reptiles of central atten-
tion as the habitat as a whole became more functional.
Thus, a close examination at some of the hailed con-
servation successes, such as that of the pink pigeon on
Mauritius, reveals that the continued maintenance of
the birds depends heavily on the ongoing intensive
management of the habitat as a whole, including the
provision of supplementary food, the control of alien
predators, and the management of disease, which is
rife in the “wild” subpopulations ( Bunbury et al .,
2008 ). The use of feeding hoppers, made necessary
because there is still too little restored native forest to
support the recovering bird population – less than 1%
of the native vegetation currently left – has been
observed to facilitate predation on the birds by alien
vertebrates, presumably feral cats (personal observa-
tion, 1996). It is also plausible that the feeding hoppers
may increase risks of transmission of water-borne dis-
eases, despite the fact that only dry grains are dispensed
in the hoppers ( Namah, 2010 ) and that the bird-
concentrating effect that feeding hoppers have is likely
to favor disease transmission as in the recent outbreak
of beak and feather disease among Echo Parakeets
( Kundu et al. , 2012 ). If conservation is “The imple-
mentation of policies/programs for the long-term
retention of natural communities/species under condi-
tions which provide for continuing evolution” ( Primack,
1998 ), then we have not yet succeeded with the pink
pigeon but instead have saved it from extinction only to
succeed in maintaining it as it were “under drip in an
intensive care unit.” The heavy dependence of this and
other species such as the Echo Parakeet on intensive
management seriously questions the viability of these
Africa: Conservation in Mauritius and Rodrigues 47
protect biodiversity on Mauritius and Rodrigues are
fairly robust, their implementation often remains a
remote dream. For example, the endemic Pteropus
niger , the only of three original species of frugivorous
bats that has escaped extinction on Mauritius, has been
legally protected since 1993. After some 20 years, no
nes have been levied, despite the fact that many
animals are illegally killed every year by fruit growers
( Anonymous, 2010 ) and sometimes for sport. The gov-
ernment is even considering relaxing the protection
law ( Anonymous, 2010 ) and adopting a culling
program for this endangered bat species under pressure
from fruit growers ( Florens, 2012a )! A discouraging
sign of the times is that even refraining from culling
populations of this endangered species would start to
be regarded as a conservation victory. Another similar
example of status-quo “conservation victory” concerns
one of the last areas of native forest in southwest Mau-
ritius (at Ferney), which was scheduled to be sliced in
half by a new highway but which in the end was not
( Cheke and Hume, 2008 ). As part of the solution, it
appears imperative that the discretionary powers that
ministers have in law be reduced; there are clearly too
many examples of undue pressure placed on offi cers
and bodies to take actions that are often in confl ict with
the country ’ s offi cial strategies and the international
conventions that it has have adopted. A bill has been
drafted by an international team of legal experts that
should, if enacted, help fi ll this and other gaps. But the
civil society should also take up a more vigorous role in
taking authorities to task on the numerous violations
that are continuing to erode what is left of the unique
biodiversity of the two islands.
Mauritius and Rodrigues islands still hold exceptional
biodiversity of global signifi cance despite massive
habitat destruction, invasion by alien species, and
other threats that have led to many extinctions and to
a biota that is today among the most threatened in the
world. Decisive conservation actions have saved some
species from virtually certain extinction and a suite of
conservation and restoration management actions
continue to be innovated, tested, or improved, often
with encouraging results. However, apart from the
classic threats of habitat destruction and fragmenta-
tion, invasive species and diseases, extinction debt, or
broken down mutualisms that are besetting the islands
( Gongylomorphus fontenayi ) that was under threat on
Flat Island, a nature reserve north of Mauritius that is
highly subject to pressure by the human population.
An exaggeration of the taxonomic status of the reptile
(from population to full endemic species contra pub-
lished works [ Austin, Arnold and Jones, 2009 ]) seems
to have triggered the authorities to contribute substan-
tial funding there while neglecting other much higher
impact conservation work elsewhere, like larger scale
habitat restoration. In light of such situations, it
appears vital to strengthen the capacity of the govern-
mental authorities like the National Parks and Conser-
vation Services, most of whose staff is trained not in
ecology or conservation but in agriculture, to take
more effective and practical conservation decisions.
Breaking the monopoly of the NGO seems vital too.
One other major conservation problem is the weak
and declining commitment of government to conser-
vation of biodiversity (e.g., Figure 6.2 , Caujapé-Castells
et al ., 2010 ; Florens 2012a , b; Florens, 2013 ), which
itself appears to largely refl ect the lack of importance
that ordinary Mauritians attach to conservation, gen-
erally perceived as a luxury. This problem of perception
is more acute on the more urbanized Mauritius than it
is on Rodrigues. Despite the commitment of many gov-
ernment offi cers and bodies to addressing conservation
challenges, their efforts are often curtailed by interfer-
ence intense enough to make the offi cers yield to the
whims of politicians and end up backing decisions that
are detrimental to conservation. One example is the
recent lease of the Ilot Gabriel Nature Reserve to a min-
ister s friend for touristic exploitation, where the pro-
moter not only violated clauses of the lease with
impunity, but benefi ted by a cover-up of the wrongdo-
ings (Figure 6.3 b). A similar situation happened on
another nature reserve (Flat Island). Currently, the gov-
ernment is taking a disturbingly long time to approve
the management plan for the National Park of Islets, a
situation that incidentally favors plans to develop
hotels on biologically important islets. The declining
commitment of the government to conservation is also
apparent in the management of the Conservation
Fund, which is meant to fi nance conservation projects
but which is instead being used largely for the day-to-
day running of the National Parks and Conservation
Service, or even to fi nance litter-picking campaigns
and other expenses only remotely related to conserva-
tion. This misallocation of funds continues to deprive
the National Biodiversity Strategy and Action Plan of
funding. Furthermore, while laws and regulations to
48 Conservation Biology
for Mauritius (Mascarene Islands) and their conservation
status . Phytotaxa , 52 , 21 – 28 .
Baider , C. , Florens , F. B. V. , Baret , S. , Beaver , K. , Matatiken , D. ,
Strasberg , D. and Kueffer , C. ( 2010 ) Status of plant conser-
vation in oceanic islands of the Western Indian Ocean. 4th
Global Botanic Gardens Congress. Dublin, Ireland. http://
Claudia.pdf (accessed March 19, 2013).
Bernardin de Saint Pierre , J.-H. ( 1773 ) Voyage à l Isle de France,
à l Isle de Bourbon, au Cap de Bonne Espérance; etc. par un
offi cier du Roi . Société Typographique , Neuchâtel, France .
Bosser , J. , Cadet , T. , Guého , J. and Marais , W. ( 1976 onwards)
Flore des Mascareignes – La Réunion, Maurice, Rodrigues .
Bunbury , N. , Stidworthy , M. F. , Greenwood , A. G. , Jones , C. G. ,
Sawmy , S. , Cole , R. E. , Edmunds , K. and Bell , D. J. ( 2008 )
Causes of mortality in free-living Mauritian pink pigeons
Columba mayeri , 2002–2006 . Endangered Species Research ,
9 , 213 – 220 .
Burney , D. A. ( 2011 ) Rodrigues island: hope thrives at the
François Leguat Giant Tortoise and Cave Reserve . Madagas-
car Conservation and Development , 6 , 3 – 4 .
Caujapé-Castells , J. , Tye , A. , Crawford , D. J. , Santos-Guerra , A. ,
Sakai , A. , Beaver , K. , Lobin , W. , Florens , F. B. V. , Moura , M. ,
Jardim , R. , Gomes , I. and Kueffer , C. ( 2010 ) Conservation
of oceanic island fl oras: present and future global chal-
lenges . Perspectives in Plant Ecology, Evolution and Systemat-
ics , 12 , 107 – 129 .
Cheke , A. S. ( 1987 ) An ecological history of the Mascarene
Islands, with particular reference to extinctions and intro-
ductions of land vertebrates , in Studies of the Mascarene
Islands Birds (ed. A. W. Diamond ), Cambridge University
Press , Cambridge , pp. 5 – 89 .
Cheke , A. S. and Hume , J. P. ( 2008 ) Lost Land of the Dodo: An
Ecological History of Mauritius, Réunion and Rodrigues . T &
AD Poyser , London .
Cristinacce , A. , Ladkoo , A. , Switz er , R. , Jordan , L. , Ven-
catasamy , V. , de Ravel-Koenig , F. , Jones , C. G. and Bell , D.
( 2008 ) Captive breeding and rearing of critically endan-
gered Mauritius fodies Foudia rubra for reintroduction . Zoo
Biology , 27 , 255 – 268 .
CSO ( 2010 ) Population and Vital Statistics, Republic of Mauritius,
Year 2010 . Central Statistics Offi ce , Port Louis, Mauritius .
de Boer E. J. , Slaikovska , M. , Hooghiemstra , H., Rijsdjik , K. F. ,
Vélez , M. I. , Prins , M. , Baider , C. and Florens , F. B. V. (2013a)
Multi-proxy reconstruction of environmental dynamics and
colonization impacts in the Mauritian uplands . Palaeogeog-
raphy, Palaeoclimatology, Palaeoecology .
de Boer , E. J. , Hooghiemstra , H. , Florens , F. B. V. , Baider , C. ,
Engels , S. , Dakos , V. , Blaauw , M. and Bennett , K. D. ( 2013b )
Rapid succession of plant associations during the glacial-
Holocene transition in Mauritius: an alternative mecha-
nism to tracking climate change in a small oceanic island?
Quaternary Science Reviews , 68 , 114 – 125 .
biodiversity, certain generally little-mentioned threats
appear poised to worsen the situation or at least hinder
progress. The low and declining commitment of gov-
ernment to biodiversity conservation needs to be
addressed and remedied. The country should seek to
implement its laws to protect biodiversity rather than
seeking to relax or ignore them. There is also much
room for improvement in the capacity of practitioners
to adopt a more robust, evidence-based approach to
conservation and restoration action as well as in priori-
tization of tasks, particularly concerning restoration of
habitats. Finally, it appears essential to encourage
NGOs action to move towards more all-encompassing
and sustainable efforts like embracing an ecosystem
approach and community involvement in conservation
in a more meaningful manner, keeping species-centered
action only when it is absolutely necessary.
The National Parks and Conservation Service for pro-
viding permission to carry out research within the
National Parks. Cláudia Baider and Anthony S. Cheke
for their very constructive comments on earlier ver-
sions of the manuscript.
Anonymous ( 2010 ) Fourth National Report on the Convention
on Biological Diversity – Republic of Mauritius . http:// (accessed
March 19, 2013).
Austin , J. J. , Arnold , E. N. and Jones , C. G. ( 2009 ) Interrela-
tionships and history of the slit-eared skinks ( Gongylomorphus,
Scincidae ) of the Mascarene Islands based on mitochondrial
DNA and nuclear gene sequences . Zootaxa , 2153 , 55 – 68 .
Baider , C. and Florens , F. B. V. ( 2006 ) Cur rent decline of the
“Dodo-tree”: a case of broken-down interactions with
extinct species or the result of new interactions with alien
invaders? In Emerging Threats to Tropical Forests (eds W. F.
Laurance and C. A. Peres ). Chicago University Press ,
Chicago, IL , pp. 199 – 214 .
Baider , C. and Florens , F. B. V. ( 2011 ) Control of invasive alien
weeds averts imminent plant extinction . Biological Inva-
sions , 13 , 2641 – 2646 .
Baider , C. and Florens , F. B. V. (2013) Eugenia alletiana (Myrta-
ceae), a new critically endangered endemic species to the
island of Mauritius . Phytotaxa , 94 (1), 1 – 12 .
Baider , C. , Florens , F. B. V. , Rakotoarivelo , F. , Bosser , J. and
Pailler , T. ( 2012 ) Two new records of Jumellea (Orchidaceae)
Africa: Conservation in Mauritius and Rodrigues 49
plant Roussea simplex in Mauritius . Biotropica , 41 ,
202 – 208 .
Hansen , D. M. , Kaiser , C. N. and Müller , C. B. ( 2008 ) Seed
dispersal and establishment of endangered plants on
oceanic islands: the Janzen-Connell model and the use of
ecological analogues . PLoS ONE , 3 , e2111 .
Hansen , D. M. , Olesen , J. M. and Jones , C. G. ( 2002 ) Trees,
birds and bees in Mauritius: exploitative competition
between introduced honey bees and endemic nectarivorous
birds? Journal of Biogeography , 29 , 721 – 734 .
Hugel , S. ( 2009 ) New Landrevinae from Mascarene islands
and little known Landrevinae from Africa and Comoros
(Grylloidea: Landrevinae) . Annales de la Société Ento-
mologique de France , 45 , 193 – 215 .
Hugel , S. ( 2010 ) New and little known predatory katydids
from Mascarene islands (Ensifera: Meconematinae and
Hexacentrinae) . Zootaxa , 2543 , 1 – 30 .
Hugel , S. ( 2012a ) Impact of native forest restoration on
endemic crickets and katydids density in Rodrigues island .
Journal of Insect Conservation , 16 , 473 – 474 .
Hugel , S. ( 2012b ) Trigonidiinae crickets from Rodrigues
island: from widespread pantropical species to critically
endangered endemic species . Zootaxa , 3191 , 41 – 55 .
Hume , J. P. ( 2011 ) Systematics, morphology, and ecology of
pigeons and doves (Aves: Columbidae) of the Mascarene
Islands, with three new species . Zootaxa , 3124 , 1 – 62 .
Jones , C. G. ( 2008 ) Practical conser vation on Mauritius and
Rodrigues. Steps towards the restoration of devastated eco-
systems , in Lost Land of the Dodo (eds A. S. Cheke and J. P.
Hume ), T & AD Poyser , London , pp. 226 – 259 .
Jones , C. G. and Swinnerton , K. ( 1997 ) A summary of con-
servation status and research for the Mauritius kestrel Falco
punctatus , pink pigeon Columba mayeri and echo parakeet
Psittacula eques . Dodo , 33 , 72 – 75 .
Kaiser , C. N. , Hansen , D. M. , Müller , C. B. ( 2008 ) Exotic pest
insects: another perspective on coffee and conservation .
Oryx , 42 , 1 – 4 .
Kundu , S. , Faulkes , C. G. , Greenwood , A. G. , Jones , C. G. ,
Kaiser , P. , Lyne , O. D. , Black , S. A. , Chowrimootoo , A. and
Groombridge , J. J. ( 2012 ) Tracking viral evolution during a
disease outbreak: the rapid and complete selective sweep of
a circovirus in the endangered Echo Parakeet . Journal of
Virology , 86 , 5221 – 5229 .
Laurance , S. G. W. , Baider , C. , Florens , F. B. V. , Ramrekha , S. ,
Sevathian , J-C. and Hammond , D. H. ( 2012 ) Human drivers
of tropical wetland disturbance and their impacts on biodi-
versity . Biological Conservation , 149 , 136 – 142 .
Le Péchon , T. , Baider , C. , Gigord , L. D. B. , Haevermans , A. and
Dubuisson , J.-Y. ( 2011 ) Dombeya sevathianii (Malvaceae): a
new critically endangered species endemic to Mauritius .
Phytotaxa , 24 , 1 – 10 .
Martiré , D. and Rochat , J. ( 2008 ) Les papillons de La Réunion et
leurs chenilles. Biotope, Mèze (Collection Parthénope) , Muséum
national d ’ Histoire naturelle , Paris, France .
Florens , F. B. V. ( 2008 ) Ecologie des forêts tropicales de l ’ île
Maurice et impact des espèces introduites envahissantes .
PhD thesis, Université de La Réunion, Réunion, France.
Florens , F. B. V. ( 2012a ) Going to bat for an endangered
species . Science , 336 , 1102 .
Florens , F. B. V. ( 2012b ) National parks: Mauritius is putting
conservation at risk . Nature , 481 , 29 .
Florens , F. B. V. ( 2013 ) Conservation: Mauritius threatens its
own biodiversity . Nature , 493 , 608 – 609 .
Florens , F. B. V. and Baider , C. ( 2007 ) Relocation of Ompha-
lotropis plicosa (Pfeiffer, 1852), a Mauritius endemic landsnail
believed extinct . Journal of Molluscan Studies , 73 , 205 – 206 .
Florens , F. B. V. and Baider , C. ( 2013 ) Ecological restoration
in a developing island nation: how useful is the science?
Restoration Ecology , 21 ( 1 ), 1 – 5 ; DOI: 10.1111/j.1526-
Florens , F. B. V. , Baider , C. and Bosser , J. M. ( 2008 ) On the
Mauritian origin of Badula ovalifolia (Myrsinaceae), hith-
erto believed extinct, with complementary description . Kew
Bulletin , 63 , 481 – 483 .
Florens , F. B. V. , Florens , D. and Sevathian , J. C. ( 2001 )
“Extinct” species rediscovered in Mauritius . Phelsuma , 9 ,
53 – 54 .
Florens , F. B. V. , Baider , C. , Martin , G. M. N. , and Strasberg , D.
( 2012 ) Surviving 370 years of human impact: what
remains of tree diversity and structure of the lowland wet
forests of oceanic island Mauritius? Biodiversity and Conser-
vation , 21 , 2139 – 2167 .
Florens , F. B. V. , Mauremootoo , J. R. , Fowler , S. V. , Winder , L.
and Baider , C. ( 2010 ) Recovery of indigenous butterfl y
community following control of invasive alien plants in a
tropical island s wet forests . Biodiversity and Conservation ,
19 , 3835 – 3848 .
Goodman , S. M. , Jansen van Vuuren , B. , Ratrimomanarivo , F. ,
Probst , J.-M. and Bowie , R. C. K. ( 2008 ) Specifi c status of
populations in the Mascarene Islands referred to Mormop-
terus acetabulosus (Chiroptera: Molossidae), with description
of a new species . Journal of Mammalogy , 89 , 1316 – 1327 .
Griffi ths , C. J. , Hansen , D. M. , Jones , C. G. , Zuël , N. and Harris ,
S. ( 2011 ) Resurrecting extinct interactions with extant
substitutes . Current Biology , 21 , 1 – 4 .
Griffi ths , C. J. , Zuël , N. Tatayah , V. , Jones , C. G. , Griffi ths , O. and
Harris , S. ( 2012 ) The welfare implications of using exotic
tortoises as ecological replacements . PLoS ONE , 7 , e39395 .
Griffi ths , O. L. and Florens , F. B. V. ( 2006 ) A fi eld guide to the
non-marine molluscs of the Mascarene Islands (Mauritius,
Rodrigues, Réunion) and the northern dependencies of Mauri-
tius . Bioculture Press , Mauritius .
Hansen , D. M. ( 2010 ) On the use of taxon substitutes in rewil-
ding projects on islands , in Islands and Evolution (eds V.
Pérez-Mellado and C. Ramon ), Institut Menorquí d ’ Estudis .
Recerca, Menorca, Spain , pp. 111 – 146 .
Hansen , D. M. and Müller , C. B. ( 2009 ) Invasive ants disrupt
gecko pollination and seed dispersal of the endangered
50 Conservation Biology
Holocene concentration-Lagerstätte on oceanic island Mauri-
tius provides a window into the ecosystem of the dodo ( Raphus
cucullatus ) . Quaternary Science Reviews , 28 , 14 – 24 .
Sarasan , V. ( 2010 ) Importance of in vitro technology to
future conservation programmes worldwide . Kew Bulletin ,
65 , 549 – 554 .
Strahm , W. A. ( 1989 ) Plant Red Data Book for Rodrigues . Koeltz
Scientifi c Books , Konigstein, Germany .
Strahm , W. A. ( 1993 ) The conservation and restoration of the
ora of Mauritius and Rodrigues . PhD thesis, University of
Reading, Reading.
Swinnerton , K. J. , Groombridge , J. J. , Jones , C. G. , Burn , R. W.
and Mungroo , Y. ( 2004 ) Inbreeding depression and founder
diversity among captive and free-living populations of the
endangered pink pigeon Columba mayeri . Animal Conserva-
tion , 7 , 353 – 354 .
Thébaud , C. , Warren , B. H. , Cheke , A. S. and Strasberg , D.
( 2009 ) Mascarene Islands, biology , in Encyclopedia of Islands
(eds R. G. Gillespie and D. A. Clague ), University of Califor-
nia Press , Berkeley, CA , pp. 612 – 619 .
Tilman , D. , May , R. M. , Lehman , C. L. and Nowak , M. A.
( 1994 ) Habitat destruction and the extinction debt . Nature ,
371 , 65 – 66 .
Turvey , S. T. and Cheke , A. S. ( 2008 ) Dead as a dodo: the
fortuitous rise to fame of an extinction icon . Historical
Biology , 20 , 149 – 163 .
UNDP-GEF ( 2009 ) Expanding coverage and strengthening
management effectiveness of the protected area network on
the island of Mauritius . UNDP Project document. PIMS
3749, GEF Project ID 3526. Unpublished report.
van der Plas , G. , de Boer , E. , Hooghiemstra , H. , Florens , F. B.
V. , Baider , C. and van der Plicht , H. ( 2012 ) Mauritius since
the last glacial: environmental and climatic reconstruction
of the last 38,000 years from Kanaka crater . Journal of Qua-
ternary Science , 27 , 159 – 168 .
Vaughan , R. E. and Wiehe , P. O. ( 1937 ) Studies on the vegeta-
tion of Mauritius I. A preliminary survey of the plant com-
munities . Journal of Ecology , 25 , 289 – 343 .
Vellend , M. , Verheyen , K. , Jacquemyn , H. , Kolb , A. , Van
Calster , H. , Peterken , G. and Hermy , M. ( 2006 ) Extinction
debt of forest plants persists for more than a century follow-
ing habitat fragmentation . Ecology , 87 , 542 – 548 .
Waibel , A. , Griffi ths , C. J. , Zuël , N. , Schmid , B. , and Albrecht ,
M. ( 2013 ) Does a giant tortoise taxon substitute enhance
seed germination of exotic fl eshy-fruited plants? Journal of
Plant Ecology , 6 , 57 – 63 .
Williams , J. R. ( 2007 ) Butterfl ies of Mauritius . Bioculture
Press , Mauritius .
Maunder , M. , Page , W. , Mauremootoo , J. R. , Payendee , R. ,
Mungroo , Y. , Maljkovic , A. , Vericel , C. and Lyte , B. ( 2002 )
The decline and conservation management of the threatened
endemic palms of the Mascarene Islands . Oryx , 36 , 56 – 65 .
Monty , M. L. F. , Florens , F. B. V. and Baider , C. ( 2013 ) Invasive
alien plants elicit reduced production of owers and fruits
in various native forest species on the tropical island of
Mauritius (Mascarenes, Indian Ocean) . Tropical Conserva-
tion Science , 6 , 35 – 49 .
Motala , S. M. , Krell , F.-T. , Mungroo , Y. and Donovan , S. E.
( 2007 ) The terrestrial arthropods of Mauritius: a neglected
conservation target . Biodiversity and Conservation , 16 ,
2867 – 2881 .
Namah , J. ( 2010 ) Ecology of birds in managed and non-
managed forests of Mauritius . BSc thesis, University of
Mauritius, Mauritius.
NBSAP ( 2006 ) Mauritius National Biodiversity Strategy and
Action Plan . Port Louis, Mauritius.
Nichols , R. , Woolaver , L. and Jones , C. G. ( 2004 ) Continued
decline and conservation needs of the Endangered Mauritius
olive white-eye Zosterops chloronothos . Oryx , 38 , 291 – 296 .
North , S. G. , Bullock , D. J. and Dulloo , M. E. ( 1994 ) Changes
in the vegetation and reptile populations on Round Island,
Mauritius, following eradication of rabbits . Biological Con-
servation , 67 , 21 – 28 .
Page , W. and D ’ Argent , G. A. ( 1997 ) A vegetation survey of
Mauritius (Indian Ocean) to identify priority rainforest
areas for conservation management. IUCN/MWF report .
Port Louis, Mauritius.
Parnell , J. A. N. , Cronk , Q. , Wyse Jackson , P. and Strahm , W.
( 1989 ) A study of the ecological history, vegetation and
conservation management of Ile aux Aigrettes, Mauritius .
Journal of Tropical Ecology , 5 , 355 – 374 .
Primack , R. B. ( 1998 ) Essentials of Conservation Biology .
Sinauer Associates , Sunderland, MA .
Rijsdijk , K. F. , Zinke , J. , de Louw , P. G. B. , Hume , J. P. , van der
Plicht , H. , Hooghiemstra , H. , Hanneke , J. M. , Meijer , H. J.
M. , Vonhof , H. , Porch , N. , Florens , F. B. V. , Baider , C. , van
Geel , B. , Brinkkemper , J. , Vernimmen , T. and Janoo , A.
( 2011 ) Mid-Holocene (4200 kyr BP) mass mortalities in
Mauritius (Mascarenes): insular vertebrates resilient to cli-
matic extremes but vulnerable to human impact . The
Holocene , 21 , 1179 – 1194 .
Rijsdijk , K. F. , Hume , J. P. , Bunnik , F. , Florens , F. B. V. , Baider ,
C. , Shapiro , B. , van der Plicht , J. , Janoo , A. , Griffi ths , O. L. ,
van den Hoek Ostende , L. W. , Cremer , H. , Vernimmen , T. , de
Louw , P. G. B. , Bholah , A. , Saumtally , S. , Porch , N. , Haile , J. ,
Buckley , M. , Collins , M. and Gittenberger , E. ( 2009 ) Middle-
... Mauritius is located in one of the World's Biodiversity Hotspot (Myers et al. 2000). It hosts ~700 native angiosperm species, 40% of which are endemic (Florens 2013). About 9% of these species have been driven extinct since human colonization in 1638 and some 80% of the surviving ones are estimated to be threatened with extinction . ...
... The latter can reach nearly 30,000 individuals per hectare among plants with diameter at breast height ≥1 cm, making up for over 95% of all stems of woody alien species in native forests of the wetter regions of Mauritius (Florens et al. 2016). However, there are a few hundred hectares where alien plants have been controlled (Florens 2013) and where ecological restoration is ongoing . ...
... Specifically, we checked the survival of all previously known Roussea individuals ( Fig. 1A) which were recorded in 2003 (Hansen & Müller 2009a,b) and 2012 (Pynee et al. 2013), that could be confidently identified individually (totalling 34 individuals). Among these five sites, all are invaded by alien plants, except for Pétrin which has been weeded since the 1990s as it is a conservation management area (Florens 2013). In this medium-term study, we also included the only five Roussea individuals (on Le Pouce) which are known to naturally grow without IAPs in their immediate vicinity (although the site as a whole is invaded), and considered them to belong to the same category of Roussea plants from around which IAPs were removed over 25 years ago. ...
Up to 6,800 plant species endemic to oceanic islands are highly threatened with extinction. Although habitat destruction and fragmentation have greatly contributed to this, it is generally recognised that invasive alien species currently pose the single most important threat to island plants. Most studies exploring the role of novel interspecific interactions in driving declines of island plants, focussed on threats mediated by animals, be it direct (e.g. browsing, seed predation, mutualism disruption) or indirect (e.g. extinction of seed dispersal or pollination mutualists). Relatively few studies have investigated the specific role of plant-plant interactions, particularly in-situ. We studied a threatened island endemic plant in rapid decline to evaluate the short (1-2 years) and medium-term (about 1-2 decades) influence of invasive alien plants (IAPs) on individuals and a variety of proxies of plant fitness. We compared mortality of traceable individuals that were recorded 12-20 years previously between habitats that are invaded with IAPs and habitats where IAPs are absent, or have been removed decades ago. We also carried out an in-situ manipulative experiment using 14 randomly chosen plants from around which IAPs were removed, paired with controls, at two sites. Canopy cover change before and after IAPs’ removal was quantified along with above ground biomass of IAPs removed for use as potential explanatory variables of change in proxies of plant fitness. Ten branches were randomly selected per plant and branch dynamics, leaves’ sizes and reproductive structure production were monitored quarterly for two years. Over the medium term, plant mortality was recorded only in presence of IAPs (X2=4.80, df = 1, p<0.05). Over the short term, at the plant level, IAPs’ removal triggered overall weak to moderate improvements in the number of surviving and new branches as well as change in number of branches at one of the sites. At the leaf and branch levels, we found weak evidence for positive effects of IAPs removal on surviving leaves, flower buds produced and difference in leaf surface area per branch in one site. We therefore provide some experimental evidence of negative effects of alien plants on overall fitness of the threatened species in-situ presumably through competitive interactions. We posit that the effects were found to be weak to moderate due to the short experimental period over which they could develop (1-2 years). Overall, IAPs stand out as the most severe threat from among all documented threats to the species, for being the only one capable of causing mortality of adult plants. Results hence highlight island plants’ vulnerability to IAPs, and how their timely control would improve the survival and fitness of threatened plants, even at the scale of single individuals. Such a strategy could be more often employed. Our study stresses on prioritising IAPs’ control for rescuing long-lived threatened plants that grow in habitats invaded by alien plants (itself a very common situation on oceanic islands) before addressing other subtler, slower-acting threats, like disrupted pollination or seed dispersal mutualisms, florivory or seed predation.
... Subsequent further declines, before an intensive recovery programme, were linked to the use of organochlorine pesticide in agriculture and malaria control in the early second half of the 20th century (Safford & Jones, 1997). Predation by alien vertebrates primarily the ship rat (Rattus rattus), long-tailed macaque (Macaca fascicularis), feral cat (Felis catus) and the Small Indian mongoose (Urva auropunctatus), together with increasing habitat degradation by invasive plants also remain threats (BirdLife, 2023;Florens, 2013). Habitat quality around nesting sites has been shown to have an influence on kestrel breeding success with increasing cover of agricultural land causing reduced prefledging survival (Burgess et al., 2011;Cartwright et al., 2014). ...
... Mauritius is a tropical oceanic island among the latest to be colonised by humans (in 1638) and which was subjected to one of the fastest habitat transformation worldwide, sparing only about 4.4% of its original terrestrial habitats (Hammond et al., 2015), which survive in a fragmented state (Florens, 2013) and threatened by various deleterious impacts including invasive alien animals (Cheke & Hume, 2008) and plants (e.g. Florens et al., 2010, Monty et al. 2013. ...
... Currently, even the best preserved and protected native forest remnants are dominated by one or another invasive alien plant species which typically form a dense forest understorey (Florens et al., 2016). As a result, extinction rates have reached high levels and much of the surviving biota is highly threatened Florens, 2013;Griffiths & Florens, 2006). ...
The Mauritius Kestrel Falco punctatus, once the rarest kestrel worldwide, became an icon of bird conservation after it recovered from four to six individuals in 1974 to some 800 by 2005 following intense conservation management. Its population however then halved within about a decade prompting a re-evaluation of the IUCN status and up listing of the species in 2014 and an increased conservation attention. Drivers of this new decline are unclear and the influence of habitat structure and diet on breeding success may be important contributors but have received relatively little attention, particularly in the way they may interact to influence production of new fledglings. We address this knowledge gap by studying whether breeding success is influenced by habitat structure (in terms of cover of the invasive Ravenala in native habitats, an alien plant causing strong structural shift in the forests that it invades, and extent of cleared area), diet composition and food pass frequency (as a proxy for food intake) and food quality at 28 nests of a reintroduced kestrel population in south east Mauritius during the 2015-2016 breeding season. The kestrel's diet comprised native and alien birds, reptiles, insects, and small alien mammals, with a disproportionately high proportion of Phelsuma gecko. A higher frequency of food provisioning and percentage cover of Ravenala both contributed to higher breeding success. Ravenala may increase gecko density or increase gecko detectability and predation by the kestrel, or both, while changed land use (pasture and sugar cane fields) may increase prey diversity in the form of non-forest prey known to be eaten by Kestrels (e.g. alien agamids, small mammals and birds). These prey related influences on breeding suggest that the Bambou mountain range provides a human-generated novel ecosystem altering food availability and increasing the kestrel's breeding success. However, Ravenala is an invasive alien species harmful to the wider forest biodiversity. Progressive weeding of Ravenala and concurrent re-introduction and augmentation of native palms and Pan-danus species which geckos can use at comparable densities to Ravenala, is recommended. This would likely improve the kestrel's hunting habitat quality and maintain high gecko density or detectability and the vegetation structure required for hunting manoeuvrability and prey availability without the negative consequences of inva-sive Ravenala.
... Examining how ecosystems recover after P. cattleyanum management can reveal if additional barriers to recovery exist that need to be addressed. In some cases, P. cattleyanum management alone can increase species richness and recovery of presumed extinct and critically endangered plant species (Baider and Florens 2011;Florens 2013;Florens et al. 2017). In other cases, seed predation and limited seed dispersal may hinder native forest regeneration following P. cattleyanum management (Mascaro et al. 2008;Nerfa et al. 2022), highlighting the need for additional active restoration actions. ...
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Invasive plant species can drive ecosystem change, particularly on oceanic islands that are vulnerable to plant invasions and subsequent biodiversity loss. While invasive species management is vital for habitat restoration, efficacy of management efforts and the ability of native plants to regenerate varies among studies. The aim of this study was to examine the consequences of managing a thicket-forming woody plant species—Psidium cattleyanum Sabine (strawberry guava)—on subtropical forest regeneration, comparing spatial scales and management periods. We surveyed 15 locations on Norfolk Island, an isolated Pacific Island with a high proportion of endemic and threatened species, by establishing paired managed and unmanaged plots to assess changes in species-area relationships, abundance, richness, and composition of the plant community. Total plant richness was higher in managed plots at the largest scale examined (125 m²). However, there was no significant difference between managed and unmanaged plots in the slopes of species-area relationships when canopy, understory, and seedling strata were combined. Stratum-specific analyses revealed that management-driven changes were most evident in the subcanopy strata, which had significantly higher woody plant abundance and richness in managed plots. Compositional dissimilarity between managed and unmanaged plots was greater in locations with higher moisture levels, suggesting that post-management regeneration is related to environmental conditions. This study suggests that P. cattleyanum suppresses plant recruitment and its removal allows for forest regeneration, indicating that management of dominant invasive woody species facilitates plant recruitment on Norfolk Island if nearby native propagule sources are present.
... Given current trends, Mauritius may be used as a `conservation laboratory` (Florens, 2013a) for many other places in the world by virtue of factors and conditions that negatively impact biodiversity being already prevailing in Mauritius at an advanced level reminiscent of what await most other countries elsewhere,. For example, human population density in Mauritius is 13 times above world average and this exerts high urbanization pressures on natural habitats, including on cave ecosystems, the like which is not yet being felt in most other countries because they currently hold lower human population densities, but their populations are growing, and thus they are approaching the situation already existing today in Mauritius. ...
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Human disturbance to lava tube caves in Mauritius and implications for their native vertebrate biodiversity
... Here, we study the spatiotemporal dynamics of the genetic load and its components, i.e., the masked load (or inbreeding load) and the realised load (or expressed load) (Bertorelle et al. 2022). We design a spatially explicit model in SLiM for a hypothetical threatened species that experiences population fragmentation and decline, based on the well-documented habitat degradation in the island of Mauritius (Mauremootoo et al. 2003a) responsible of pushing several species to the brink of extinction, including the pink pigeon (Nesoenas mayeri) (Jackson 2022), the echo parakeet (Psittacula echo) (Raisin et al. 2012), the Mauritius kestrel (Falco punctatus) (Groombridge et al. 2001), and others (Cheke and Hume 2008;Florens 2013). We model habitat loss and fragmentation based on historic forage coverage data in Mauritius dating back to 1773, and we forecast the impact on the genetic load and neutral genetic diversity 200 years into the future. ...
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Habitat loss and population fragmentation pose severe threats to biodiversity and the survival of many species. Population isolation and the decline in effective population size lead to increased genetic drift and inbreeding. In turn, this reduces neutral diversity, and it also affects the genetic load of deleterious mutations. Here, we analyse the effect of such genomic erosion by designing a spatially explicit, individual based model in SLiM, simulating the effects of the recorded habitat loss in Mauritius over the past ~ 250 years. We show that the loss of neutral diversity (genome-wide heterozygosity) was barely noticeable during the first 100 years of habitat loss. Changes to the genetic load took even more time to register, and they only became apparent circa 200 years after the start of habitat decline. Although a considerable number of deleterious mutations were lost by drift, others increased in frequency. The masked load was thus converted into a realised load, which compromised individual fitness and population viability after much of the native habitat had been lost. Importantly, genomic erosion continued after the metapopulation had stabilised at low numbers. Our study shows that historic habitat loss can pose a sustained threat to populations also in future generations, even without further habitat loss. The UN’s Decade on Ecosystem Restoration needs to lead to transformative change to save species from future extinction, and this requires the urgent restoration of natural habitats.
... Second, the Mauritian landscape was further redesigned under French rule in the eighteenth century (1715-1810) by the introduction of sugar cane cultivation, which reached its peak during the nineteenth century under British hegemony . The massive investment in monocrop agriculture caused drastic deforestation, mainly in the accessible coastal areas (Florens 2013;Norder et al. 2017). Furthermore, the transition from a French to a British administration resulted in a radical transformation of demographics. ...
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The recurring ebb and flow of epidemic diseases profoundly impacted how colonial administrations dealt with death. This article focuses on the role disease played in shaping the “necrogeography” of colonial landscapes, a key point of intersection between funerary and landscape archaeology. Using an extensive corpus of evidence from cemeteries that capture inhumation practices from formerly enslaved and indentured populations, this article provides an assessment of these burial contexts as part of the cultural landscape in Mauritius. Drawing together functional and emotional dimensions, their features and development will be considered against the backdrop of the island’s specific and dynamic disease ecology.
... Diospyros boutoniana is threatened by the spread of invasive alien species and habitat degradation, as well as logging and wood harvesting (for deer ranching expansion and high-end housing); grazing, ranching or farming; human intrusions and disturbance; climate change and severe weather. Climate change in the form of increasing temperatures, decreasing rainfall, and faster intensifications of cyclones among other impacts, are set to shift conditions away from what the species has adapted to, thereby posing an additional threat to its maintenance, particularly within a context of habitat remnants that are highly fragmented (Florens 2013) hence limiting the scope of geographical shifts to track the species climatic envelope. ...
Technical Report
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Diospyros boutoniana is a species endemic to Mauritius; found predominantly in the southwest, and occasionally, southeast and northern mountain ranges between 200–750 m elevation. The extent of occurrence (EOO) is estimated at 762 km2 and the area of occupancy (AOO) at 104 km2. It is known from at least 24 sites based on collections and observations and four locations (sensu IUCN Standards and Petitions Committee 2019) with regard to the most important threats. It is estimated that there are 16,500 mature individuals. However, the population is declining due to habitat loss, habitat degradation and invasive species. The subpopulations are considered severely fragmented as indicated by high genetic structuring with little gene flow between genetic clusters within the species (Linan et al. 2020). The ongoing repeated culling of the Endangered bat species in Mauritius can only weaken the species’ ecological role, thus reduce seed dispersal and regeneration of large fleshy-fruited species like D. boutoniana. Diospyros boutoniana is threatened by the spread of invasive alien species and habitat degradation, as well as logging and wood harvesting (for deer ranching expansion and high-end housing); grazing, ranching or farming; human intrusions and disturbance; climate change and severe weather. Climate change in the form of increasing temperatures, decreasing rainfall, and faster intensifications of cyclones among other impacts, are set to shift conditions away from what the species has adapted to, thereby posing an additional threat to its maintenance, particularly within a context of habitat remnants that are highly fragmented (Florens 2013) hence limiting the scope of geographical shifts to track the species climatic envelope. The Red List assessment for D. boutoniana is Endangered: EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v).
... A key aspect that is hard to address empirically is the spatial context of species interactions 13 , as most remaining Mauritian plants and their frugivores are rare and exhibit greatly reduced areas of cooccurrence 34,54 . A notable exception being the ubiquitous flying fox which is capable of long-distance flights across the fragmented landscape 62,63 , but which nevertheless faces elevated extinction risk 49 . ...
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Insular communities are particularly vulnerable to anthropogenic extinctions and introductions. Changes in composition of island frugivore communities may affect seed dispersal within the native plant community, risking ecological shifts and ultimately co-extinction cascades. Introduced species could potentially mitigate these risks by replacing ecological functions of extinct species, but conclusive evidence is lacking. Here, we investigate changes in plant–frugivore interactions involving frugivorous birds, mammals and reptiles in Mauritius, an oceanic island with an exceptionally well-specified frugivore community and well-described species introduction history. We demonstrate substantial losses of binary interaction partnerships (at the species level) resulting from native species extinctions, but also gains of equal numbers of novel interactions with introduced species, potentially supporting the idea that non-native species might compensate for lost seed dispersal. However, closer investigation of animal seed handling behaviour reveals that most interactions with seed dispersers are replaced by ecologically different interactions with seed predators. Therefore, restoration of seed dispersal functionality in this novel plant–frugivore community is unlikely.
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Large Old World fruit bats (LOWFBs), species of Pteropus, Acerodon, and related genera of large bats in the pteropodid subfamily Pteropodinae, play important roles as agents of dispersal and pollination across the Paleotropics. LOWFBs are also collectively the most threatened group of bats in the world, with 71% of extant species assessed as threatened by the International Union for the Conservation of Nature. As highlighted here, contrary to other bats, the vast majority of LOWFBs face multiple simultaneous threats. Most importantly, biological and ecological traits, in particular life history characteristics, diet, movement, social ecology, and physiology, intensify threats and accelerate species declines. Furthermore, we demonstrate that LOWFBs are to be considered keystone species and express concern about the erosion of this role and the cascading effects expected on native ecosystems. In response to this alarming situation, we advance general recommendations and identify overarching research and conservation actions. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 54 is November 2023. Please see for revised estimates.
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Small island developing states (SIDS) display high biodiversity due to their insular situation but suffer from a disproportionate vulnerability to climate change, economic and environmental shocks. In Mauritius, a SIDS located the Indian Ocean, mangroves ensure essential ecological functions and support coastal communities’ livelihoods, they are however threatened by continuous degradations. In 2020, communities on the southeast of the island experienced compounded overlapping effects of a global pandemic and an ecological crisis, with impacts on livelihoods and well-being. This same area is known for its extent of mangroves. While regulating and provisioning services of mangroves are well documented, this study elucidates some of the lesser-known cultural values attached to mangroves and the ways in which communities depend on them for their well-being. Based on a multi-dimensional ecosystem services framework, an in-person survey was implemented between August and October 2021 in coastal villages on the east-southeast of Mauritius, totalling 281 surveyed households of Mauritians in middle- to low-income categories with livelihoods associated to fishing and/or tourism. The collected data was analysed through distribution analysis, multiple correspondence analysis and logarithmic regression. Our results show that two thirds of respondents depend on mangrove ecosystem services with low (37.2%) to medium and high (26.3%) dependencies. Dependency on mangroves is materialized through cultural services, and as a support for food security and income generation. Socio-economic drivers and multiple crises play a direct and indirect role in mangrove dependency. Study results suggest that precarious households have higher levels of dependency, and are subsequently more vulnerable to mangroves degradation and socio-ecological changes. The impact of changes and socio-economic parameters are therefore essential dimensions to take into account for coastal management and biodiversity conservation policy design in an insular context.
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Research on crop systems and biodiversity conservation in the tropics has mainly been concerned with how low to mid intensity agricultural systems can benefit from adjacent natural habitats by receiving ecosystem services from natural biodiversity. One intensively studied crop in this framework is coffee. Positive effects are relatively easy to quantify by comparing coffee yield and by recording native species diversity. However, a largely overlooked issue is how agricultural areas affect native organisms in adjacent natural habitats, for example through movement of pest species that could impose a risk of degrading these habitats. We give an example from Mauritius, where an introduced coffee pest severely reduces the reproductive success of a threatened endemic plant species. We argue that such effects may be more common than suggested by the literature, especially when crop and native plants are congeneric. In the long term, such negative effects may degrade natural habitats, thereby causing ecosystem services derived from these habitats to decline.
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From this hilltop porch at sunrise, above the limestone landscape of Plaine Corail on the southwestern corner of Rodrigues Island in the middle of the Indian Ocean, I am looking out over a patchwork of small subsistence farms, awakening livestock, a sleepy airport, and a vast reef-bounded lagoon, bigger than the island itself – and something else. Something that warms the cockles of my heart. Something I have been writing and dreaming about for decades, a kind of project that gives me hope for conservation in an otherwise dark hour. Nestled in the midst of all these human landscapes is a truly prehistoric scene, the Francois Leguat Giant Tortoise and Cave Reserve. On this remarkable 19 hectares, Reserve Manager Aurele Anquetil André and his dedicated staff of young Rodriguans have planted over 130,000 native trees and shrubs, some virtually extinct in the wild and many quite rare otherwise, in just five years. Nearly all have survived, and with only limited maintenance despite the huge challenges posed by invasive weeds on all remote Indo - Pacific islands. Giant tortoises, over 1,000 of them, lumber about doing the work. Fenced in and well - fed on the invasive plants that compete with the natives, introduced Aldabra Tortoises (Aldabrachelys gigantea) weighing up to 200 kg crop the invasive plants, and smaller Radiated Tortoises of Madagascar (Geochelone radiata) pull up the weed seedlings. Remarkably – and I had to see this for myself – they don’t touch the native plants, which co - evolved with the extinct tortoise fauna (Cylindraspis spp.) that disappeared in the late eighteenth century after French colonists shipped over 280,000 of them to Reunion and other places for butchery. These plants have defenses against tortoises and browsing birds. Notable in the latter category was the extinct Solitaire (Pezophaps solitaria) a giant pigeon endemic to Rodrigues that was even larger than the Dodo, the famous extinct denizen of Mauritius, Rodrigues’ big neighbor 650 km to the west. Through heterophylly, the adaptation of having tough, finely dissected and presumably less edible leaves near the ground where animals can reach, as well as in some cases certain plant chemicals that the tortoises apparently don’t like, and long flexible stems that tortoises seem not to trample down or chew, these plants are thriving in the midst of a high density of these hungry lumbering reptiles. A tall secure fence keeps them inside the Reserve, and keeps out the free - ranging goats, sheep, and cattle which have converted so much of the rest of this island to Lantana and other unpalatable invasives. Those ungulates, with their advanced teeth, love to eat the native plants, and have nearly driven them to extinction. I have been an advocate for this approach – reintroducing the “megafauna” back to lands where they are extinct, or their closest living relatives or even an ecological surrogate – for several decades. The scientific underpinnings for restoring ecological functions this way are quite sound, and there are plenty of examples of this “rewilding” already working around the world, from Siberia’s “Pleistocene Park” with reintroduced musk oxen, wild horses, and so forth, to American media mogul Ted Turner’s vast ranches in the western US with herds of many thousands of bison, elk, and yes – even a giant tortoise (Bolson’s) reintroduced to its former range from Mexico. You can read about these and others in my recent book1. Some years ago I even proposed something like this for Madagascar – starting with tortoises but under the right circumstances perhaps including living ratite birds, hippos, and crocodiles, in some fenced reserve lands. I doubt that most readers took me seriously then (perhaps even now). Here at the Leguat Reserve, though, rewilding is not a hypothetical proposal, it is a way of life, a major tourist attraction, and a very interesting scientific experiment. Rewilding is working here, and working wonderfully. Tortoises pull the weeds, apply the fertilizer, and germinate the seeds. Regarding the latter, recently published experiments2 show that passing through the slow digestive system of a giant tortoise is just what some of these hard - to - germinate seeds of rare native plants have been waiting for. The authors show conclusively that the highly endangered, large - seeded native ebony tree (Diospyros egrettarum) is germinating and thriving on the remarkable 25-hectare Ile aux Aigrettes Reserve, a small island off Mahebourg, Mauritius, thanks to the Aldabra tortoises reintroduced there by the Mauritian Wildlife Foundation. At the Leguat Reserve on Rodrigues, guides lead thousands of visitors per year through huge spectacular limestone caves that have yielded the fossils of giant tortoises, Solitaires, and the other extinct biota of Rodrigues. Their tour, and the excellent museum on the Reserve, make that wonderful connection between the fossils of a remarkable extinct fauna, and the rare plants and surviving fauna of large handsome fruit bats, rare land snails, nesting White - tailed Tropicbirds, and the surviving cousins of the native giant tortoises now roaming the canyons and plateaus of the Reserve. What am I doing here? To begin with, my wife Lida Pigott Burney and I have in recent years started our own similar rewilding project on the island of Kaua`i, in the Hawaiian Islands. We likewise have a cave system, full of fossils of the extinct animals, as a centerpiece for restorations on worn - out farmland that feature thousands of native plants, some quite rare. Our big fossil herbivores, giant flightless ducks and geese, are all extinct, and alas, tortoises never reached Hawaii. So we laboriously pull the weeds, tons of them, with the help of the school children of Kaua`i and hundreds of volunteers. The current question I and my colleagues are asking is, could giant tortoises give us a hand, serving as ecological surrogates for the lost birds? In any case, the National Geographic Society funded our team, including paleontologists Julian Hume and Lorna Steel from UK, paleo - entomologist Nick Porch and speleologist Greg Middleton from Australia, and Lida and myself as the paleoecologists, to work on the excellent fossil deposits on Rodrigues and compare them to our results from elsewhere. That work is going well, we’re finding plenty. But thanks to these lumbering living reptiles, I’m thinking all over again about the potential to use tortoises, and perhaps substitutes for other extinct megafauna, to try some rewilding at an appropriate place – such as a securely fenced, private reserve in western Madagascar – and such a place exists. Owen Griffiths, the biologist/entrepreneur who created the La Vanille Crocodile Park and Tortoise Reserve on Mauritius (inspiration for Ile aux Aigrettes) and the Leguat Reserve on Rodrigues, is hard at work in Madagascar on his private reserve lands, where he hopes to start rewilding with Aldabra tortoises and other appropriate creatures. Before you dismiss this idea as crazy, you might consider that it was Charles Darwin himself who set all this in motion. He visited Mauritius on the return voyage of the H.M.S. Beagle in 1836, where he heard about the extinct giant tortoises of that island. Many years later, he suggested that the best way to see that the thousands of giant tortoises then living on uninhabited Aldabra Island (their last stand in the Indian Ocean region) didn’t go the way of the extinct giant tortoises of Madagascar, the Mascarenes, and the Seychelles, was to move some to these other islands and establish populations, and that was done on Mauritius. People took him seriously, and the tortoises’ future looks bright. Many of Darwin’s ideas were controversial then, and some still are in some quarters. Rewilding proposals like this are still being argued, but they have the potential to “jump start” evolution when it seems to have gone hopelessly off the track. After visiting the Leguat Reserve, I’m more hopeful than ever that evolution might have a second chance.
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The original diversity of the pigeons and doves (Columbidae: Nesoenas, Columba, Alectroenas) of the Mascarene Islands (Mauritius, Réunion, Rodrigues) has been poorly understood. Only two of perhaps as many as ten species are known from skin specimens, whereas the rest are known from old accounts and subfossil remains only. Most accounts, however, do not distinguish between species, so accurate identification is difficult to determine. The introduction of non-native pigeons has further exacerbated the problem and has led to erroneous interpretation. This paper provides a detailed re-analysis of the Mascarene columbid fauna (excluding the large, terrestrial “didines”, the Dodo Raphus cucullatus and Solitaire Pezophaps solitaria), based partly on newly discovered subfossil remains. Key findings include: a new species of Alectroenas from Rodrigues and new species of Nesoenas and Columba from Mauritius; referral of the problematic species 'Columba' rodericana of Rodrigues to the genus Nesoenas; and documentation of new morphological and historical information concerning the extant Pink Pigeon Nesoenas mayeri and the extinct Mauritius Blue Pigeon Alectroenas nitidissima. The Columbidae comprises the largest avian radiation in the Mascarenes and probably colonised the islands at least four times from Madagascar and SE Asia during low sea level stands.
The predatory katydids of Mauritius, Rodrigues, and Réunion islands are examined. One new Hexacentrinae genus and species, and three new Phisidini species (Meconematinae) are described from Mauritius: Nepheliphila raptor n. g. n. sp., Brachyphisis nattecantor n. sp., Paradecolya expectata n. sp. and Paradecolya briseferi n. sp. The only Phisidini from Rodrigues Brachyphisis spinifera (Butler, 1876) is transferred to Rodriguesiophisis n. gen., n. comb. and the male is described for the first time. Descriptions of the two Phisidini from La Réunion Brachyphisis viettei Chopard, 1957 and Paradecolya inexpectata (Chopard, 1957) are given. The male of B. viettei is described for the first time. The song of all these species but P. briseferi n. sp. is described for the first time. In addition to these endemic species, the widespread Xiphidiopsis lita Hebard, 1922 occurs on all three Mascarene islands.
Work on the endangered birds of Mauritius has been undertaken by the Wildlife Preservation Trusts since 1976. The Mauritius kestrel Falco punctatus has been successfully reintroduced and a population of 420-530 birds was estimated at the end of the 1996-1997 breeding season. The pink pigeon Columba mayeri has also been reintroduced to three sites. In August 1997 there were 330 known free-living birds, more than half of which had been born in the wild. The echo parakeet Psittacula eques is the focus of intensive conservation management and research work. During the 1996/1997 breeding season there were 13 known wild pairs. At the end of the breeding season there were 50-61 birds. The conservation management of all three endemic bird species is briefly described.
First published in 1987, this volume presents the scientific results of an expedition, promoted by the British Ornithologists' Union, to study the endangered birds of the Mascarene Islands in the Indian Ocean. This group of islands is of unique importance to bird conservation and is perhaps best known as the last home of the famous dodo. Thirty endemic species of birds are already extinct and the populations of several others are now so small as to be of doubtful validity. The data presented here will enable the appropriate government departments and conservation bodies to proceed on the basis of a sound knowledge of the needs of the threatened birds, and it is hoped that the survival of at least a proportion of the unique wildlife of this island group can be ensured. Studies of Mascarene Island Birds will also provide the keen amateur ornithologist with a serious interest in conservation with a direct appreciation of field work aimed at protecting rate species in their natural habitat.
The scincid lizard genus Gongylomorphus is endemic to the western Mascarene islands of Mauritius and Réunion in the southwest Indian Ocean, where its range was greatly reduced in the Nineteenth century, probably by an introduced southern Asian wolf snake (Lycodon aulicus capucinus) and perhaps other exotics. A phylogenetic analysis of the single recognised species of Gongylomorphus was conducted using 1473 bp of combined recent mtDNA and nuclear sequence (cytochrome b 714 bp, 12SrRNA 388 bp, c-mos 371 bp) from 40 individual Gongylomorphus and members of 13 scincid genera used as outgroups. The three recognised subspecies form monophyletic lineages that diverge by 7% for mtDNA and 0.8% for c-mos and, as they also differ in morphology, they are raised to species status here. G. fontenayi occurs in relict montane forest in southwest Mauritius and on neighbouring Flat Island; G. bojerii on this and other offshore islands north and southeast of Mauritius; and the sister of this last species, G. borbonicus was found on Reunion where it became extinct by about 1840. Phylogenetic topology suggests the ancestor of Gongylomorphus originated in Madagascar or possibly Africa, ;ising Mauritius from the west and speciating there as long as 3Ma, before a propagule from the G. bojerii lineage invaded Reunion < 2.1Ma to produce G. borbonicus. On and around Mauritius, moderate mtDNA variation exists within and between populations. Extant G. bojerii have two main haplogroups differing by ∼ 1.7%: one on the northern offshore islands (Gunners Quoin, Flat, Gabriel, Round and Serpent islands, and Pigeon House Rock) and the other in the southeast (Ilot Vacoas). But homologous sequence from a recently extinct population on Ile aux Fouquets and subfossil bones from at least one mainland site indicates that members of both haplogroups originally occurred together in the southeast. Although the G. bojerii population on Serpent Island is morphologically distinct, it is genetically undifferentiated from neighbouring populations. In G. fontenayi, a more robust orange-tailed population occurs on Flat Island over 60 km away from the remaining ones in the southwestern mountains of Mauritius but diverges from these by only 1.7% in mtDNA sequence. Subfossil material in the intervening area appears to represent intermediate haplotypes and confirms original continuity. These examples show that relict and limited material can mislead about the distinctness of allopatric populations.