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Reinventing mutualism between humans and wild fauna: Insights from vultures as ecosystem services providers

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In parallel with economic and social changes, mutualism in human-vulture relations has virtually disappeared worldwide. Here, we describe the mutualis-tic relationship between humans and the globally threatened Egyptian vulture in Socotra, Yemen. By analyzing both the spatial distribution of vultures and the amount of human byproducts they consume, we show that human activ-ities enable the maintenance of the densest population of this rare scavenger, whereas vultures provide a key regulating service by disposing of up to 22.4% of the organic waste annually produced in towns. Globalization is impacting the archipelago, and therefore policies that better integrate societal needs and biodiversity conservation are urgently needed. We propose a win-win solution that relies on the restructuring of the mutualism, shifting from regulating ser-vices toward cultural services. Our study highlights the necessity of reconciling trade-offs between biodiversity conservation and economic development in a framework of global change affecting Middle Eastern countries.
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LETTER
Reinventing mutualism between humans and wild fauna: insights
from vultures as ecosystem services providers
Laura Gangoso1, Rosa Agudo1,Jos´
e Daniel Anad ´
on2, Manuel de la Riva1, Ahmed Saeed Suleyman3,
Richard Porter4,&Jos´
e Antonio Don ´
azar1
1Department of Conservation Biology, Estaci ´
on Biol ´
ogica de Do ˜
nana (CSIC), Avda. Am ´
erico Vespucio s/n, E-41092 Sevilla, Spain
2Department of Ecological Modeling, UFZ–Centre for Environmental Research, D-04301 Leipzig, Germany
3Socotra Archipelago Conservation and Development Programme, P.O. Box 16494, Sana’a, Yemen
4BirdLife International, Wellbrook Court, Girton Road, Cambridge CB3 0NA, UK
Keywords
Conservation dilemma; economic development;
ecosystem services; Egyptian vulture;
human-vulture mutualism; Socotra; urban
biomes; waste management.
Correspondence
Laura Gangoso, Department of Conservation
Biology, Estaci ´
on Biol ´
ogica de Do ˜
nana (CSIC),
Avda. Am ´
erico Vespucio s/n, E-41092 Sevilla,
Spain. Tel: +34 954466700; Fax: +34
954621125. E-mail: laurag@ebd.csic.es
Received
10 May 2012
Accepted
9 August 2012
Editor
Dr. Rudolf de Groot
doi: 10.1111/j.1755-263X.2012.00289.x
Abstract
In parallel with economic and social changes, mutualism in human-vulture
relations has virtually disappeared worldwide. Here, we describe the mutualis-
tic relationship between humans and the globally threatened Egyptian vulture
in Socotra, Yemen. By analyzing both the spatial distribution of vultures and
the amount of human byproducts they consume, we show that human activ-
ities enable the maintenance of the densest population of this rare scavenger,
whereas vultures provide a key regulating service by disposing of up to 22.4%
of the organic waste annually produced in towns. Globalization is impacting
the archipelago, and therefore policies that better integrate societal needs and
biodiversity conservation are urgently needed. We propose a win-win solution
that relies on the restructuring of the mutualism, shifting from regulating ser-
vices toward cultural services. Our study highlights the necessity of reconciling
trade-offs between biodiversity conservation and economic development in a
framework of global change affecting Middle Eastern countries.
Introduction
Ecosystem services are defined as the benefits people ob-
tain from ecosystems (Millennium Ecosystem Assessment
2005). The populations or species responsible for provid-
ing a particular ecosystem service can be described as
service-providing units (Luck et al. 2003). Higher ver-
tebrates and birds in particular are well-known ecosys-
tem service providers (Whelan et al. 2008). Services may
arise via bird-products (meat, guano, clothes, etc.), which
are classified as provisioning services, or via behavior,
mainly foraging behavior, which provides regulating ser-
vices (scavenging of carrion and waste, controlling pest
populations, pollinating and dispersing plants) and sup-
porting services (cycling nutrients and contributing to soil
formation). Finally, the mere presence of birds provides
cultural services (role of birds in art and religion or bird-
watching tourism) (Whelan et al. 2008).
The ecosystem services provided by birds mainly
occur beyond urban boundaries, but can occasionally
take place within highly anthropized (human-altered)
environments. Urban areas represent particular ecosys-
tems that, in general, bring about a drastic modification
of natural conditions at multiple scales (Grimm et al.
2008). Urbanization causes generalized habitat (H)
degradation and biodiversity loss, potentially leading to
the disappearance of natural processes. Urban-related
alterations also include pollution as well as the prolif-
eration of infrastructures (e.g., roads, power lines, etc.)
and alien species. Although most species are displaced
from human-altered environments, some synanthropic
ones may be able to thrive in these a priori hostile
Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc. 1
Reinventing human-vulture mutualism L. Gangoso et al.
Hs (McKinney & Lockwood 1999), and even become
widespread and locally abundant (Marzluff 2001) by
obtaining benefits from either bottom-up (e.g., increase
in food abundance) and/or top-down effects (e.g.,
decrease in predation/persecution). Occasionally, these
species are considered pests and the targets of eradication
campaigns to avoid nuisance and the spread of infec-
tious diseases (e.g., Battersby et al. 2002; Lavine 2011).
However, urban species may also provide key ecosystem
services, although this is often overlooked by ecologists
and natural resource managers (Wenny et al. 2011, but
see Markandya et al. 2008). Therefore, in the case of
threatened species, the identification, comprehension,
and preservation of mutualistic relationships could be
critical from a conservation perspective.
Here, we describe an exceptional case of a mutualis-
tic relationship between humans and one of the most
threatened vulture species worldwide, the Egyptian vul-
ture (Neophron percnopterus), which occurs in the Soco-
tra archipelago, a recognized insular biodiversity hotspot
(UNEP/WCMC 2008). To disentangle human-vulture
mutualism, we first assessed whether vulture abundance
and distribution is influenced by human settlement (HS)
distribution. We then quantified the magnitude of the
regulating service provided by vultures. Because under-
standing the trade-offs among biodiversity conservation,
economic development and societal needs is critical for
developing effective conservation strategies, we finally
propose policy choices to better reconcile vulture con-
servation and socioeconomic development on Socotra Is-
land. This example provides an exceptional opportunity
to gain insight into the study of bird-human relationships
with important implications for the fields of urban ecol-
ogy, ecosystem services, biodiversity conservation, and
environmental economics.
Methods
Study system
The Socotra archipelago is located about 100 km east
of the Horn of Africa and 380 km south of the coast
of Yemen. The archipelago is considered a biodiversity
hotspot and endemicity is high at the species level in
both plant and animal kingdoms (Van Damme & Banfield
2011). There are no indigenous medium or large-bodied
mammals on the archipelago (Cheung & DeVantier
2006), except for domestic herbivores introduced 11,000
years ago (Cerny et al. 2009). Currently, it is esti-
mated that around 9,000 cows (Bos taurus), 300,000 goats
(Capra hircus), and 92,000 sheep (Ovis aries), as well as
1,300 donkeys (Equus asinus) and 1,300 camels (Camelus
dromedarius) are present on the largest island, also called
Socotra (F. Pella & M. Fasola, personal communica-
Figure 1 Socotra has the highest density of Egyptian vultures known
worldwide. These vultures are appreciated and not persecuted by local
people, probably contributing to the success of the vulture-human mutu-
alistic relationship.
tion, 2011). Traditional agricultural, fishing, and livestock
practices have persisted until the present, likely favored
by the geographic isolation of the archipelago and the
existence of strong seasonally reversing monsoon winds
(Van Damme & Banfield 2011). Socotra is home to about
50,000 inhabitants, the majority of which live in two
towns: Hadiboh (32,300 people) and Qalansiyah (10,600
people) (Cheung & DeVantier 2006).
The Egyptian vulture is a medium-sized (about 2 kg)
Old World scavenger (Figure 1) that lives in open land-
scapes in arid and rugged regions. It breeds territo-
rially but congregates in large numbers at communal
roosts and feeding locations (del Hoyo et al. 1994). The
species’ dependence on livestock varies locally, but it can
be strong in places that lack native medium-sized and
large mammals, such as the Canary Islands (Gangoso
et al. 2006). The Egyptian vulture maintains continental
long-distance migratory populations and sedentary insu-
lar demes in Macaronesian, Mediterranean, and Ethiopic
archipelagos. Global populations have been reduced to
30,000–40,000 mature individuals and the species are
considered “Endangered” (BirdLife International 2011).
Socotra has the highest density of Egyptian vultures
known worldwide (0.22 breeding pairs (bp)/km2; Porter
& Suleyman 2012). This value contrasts sharply with
the estimated density for the second densest population
(Iberian Peninsula: 0.052 bp/km2,Cort
´
es Avizanda et al.
2009) or to that observed in other insular populations
such as the Canary Islands (0.02 bp/km2, authors own
data) and Sicily (0.0003 bp/km2,Sar
´
aet al. 2009).
Vulture distribution
To assess what factors are influencing vulture distri-
bution on the island, we performed roadside transects
2Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc.
L. Gangoso et al. Reinventing human-vulture mutualism
Figure 2 Distribution of the main habitat types on Socotra Island (see details in Supporting Information). Road transects, human settlements, and sampled
communal roosts are also shown. Note that human settlements have been enlarged for representation purposes. The excluded area (striped polygon)
indicates the area where no information on human settlements was available due to cloud cover in the satellite images.
(n=11) during an 8-day period, covering a total of
400 km (Figure 2). The relative importance of HSs
and H in explaining the abundance and distribution of
Egyptian vultures was assessed by means of deviance par-
titioning analysis. For the analysis, road transects were
divided into 1-km units (n=370). Each unit was charac-
terized by a group of variables describing HS and nonan-
thropogenic attributes of the H. HS variables included:
distance to Hadiboh (DHAD) and the percentage of area
occupied by HSs in 250, 500, 1,000, 2,500, and 5,000
m radii (designated as HS250, HS500, HS1000, HS2500,
HS5000, respectively). H variables included: distance to
the coast (DCOAST), altitude (ALT), percentage of every
vegetation type within 250, 500, 1,000, and 5,000 m radii
(i.e., shrubland [CS]; succulent shrubland [SS]; semiever-
green woodland [SEW]; open and wooded herb commu-
nity [OH]; mountain and semimountain shrubland and
woodland [MSM]) (Figure 2). In addition, vulture abun-
dance in villages was estimated by conducting bird counts
in HSs. See full methods in Supporting Information.
Quantification of the service
We assessed the contribution of vultures to the regulat-
ing service, that is, the disposal of waste, carrion, and ex-
crement, by analyzing the content of pellets (n=332)
collected from 11 different communal roosts. In addition,
we calculated field metabolic rate and daily food require-
ments of individual vultures (see full methods in Sup-
porting Information).
Results
Vulture distribution
Deviance partitioning analysis showed that the distri-
bution of Egyptian vultures on Socotra was mostly ex-
plained by the presence and density of HSs (Figure 3).
While variables describing (HS) accounted for 81% of the
explained deviance, the pure effect of nonanthropogenic
attributes of the H was responsible for 26%. With regard
to the single variables considered, multivariate general-
ized linear models for HS included a positive response
to both HS density within a small radius (HS250 D2=
19.58; HS1,000 D2=22.28) and the DHAD (D2=26.34;
where D2is the accumulated% of deviance explained by
the model). This result indicated that the highest abun-
dances of Egyptian vultures were located in close prox-
imity or within HSs, a pattern also supported by the
explicative power yielded for every HS variable, which
decreased as the considered radius increased (Figure 4).
Multivariate models for H included only a negative re-
sponse to the DCOAST (D2=6.55); demonstrating that
vegetation/landscape types play a very marginal role in
the distribution patterns of Egyptian vultures.
Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc. 3
Reinventing human-vulture mutualism L. Gangoso et al.
Pure HS Pure H Join HS+H
% of total explained deviance
020406080
Figure 3 Results of the deviance partitioning analysis for the abundance
of the Egyptian vulture on road transects. Explained deviance values (as a
percent of the total explained deviance) are shown as bars.
Quantification of the service
The minimum food requirement of an Egyptian vulture
was calculated as 265 g/day. Considering a total pop-
ulation of 1,900 individuals as suggested by Porter &
Suleyman (2012), Egyptian vultures would consume up
to 503.50 kg of organic matter per day, or 183.78 tons
per year. Our field observations indicated, however, that
the estimated size of the population calculated by Porter
& Suleyman might be quite conservative. We recorded
a total of 996 individuals during the bird counts at vil-
lages [fledglings (0.10%), 1–2 years (12.27%), 2–3 years
(5.12%), 3–4 years (4.23%), 4–5 years (0.20%), and
5 years old (78.12%)]. In addition, we recorded 1,105,
925, and 1,113 individuals (mean =1,047.5) in three
different counts respectively, flying to roosting sites in
Hadiboh. Considering an adult population of 1,000 bp
(Porter & Stone 1996) and using the proportion of age
classes recorded (see above), we estimated a total popu-
lation of at least 2,560 individuals on Socotra Island in
2009. Based on these data, vultures would consume up
to 247.62 tons of organic matter each year. Our anal-
yses showed that most of this organic matter was de-
rived from human activities (93.3% of the matter iden-
tified in the pellets analyzed), in which waste (49.8%)
was the most common component, followed by live-
stock carcasses (37.2%), fish remains (5.9%), and hu-
man feces (0.3%). In contrast, the frequency of wild prey
was much lower (6.7%) with a decreasing importance of
0 5 10 15 20 25
radius (m)
% explained deviance
250 500 1000 2000 5000
Figure 4 Response of the abundance of the Egyptian vulture to variables
describing human settlement density at different radii around road tran-
sects, as assessed by quasi-poisson univariate models (all models P<
0.05, except for a 5,000 m radius).
insects (5.2%), birds (1.0%), rodents (0.1%), and snails
(0.1%). The total amount of solid waste produced on
Socotra in 2005 was estimated at 3,250 tons, in which
1,105 tons corresponded to vegetable and putrescible or-
ganic matter (Loretz & Martin 2006). Using this informa-
tion, we estimated that, at a minimum, between 16.63%
and 22.41% (considering a population of either 1,900 or
2,560 vultures, respectively) of putrescible organic matter
produced in Socotra each year is eliminated by vultures.
It is important to note that we did not exclude the veg-
etable fraction of the organic waste in our calculations, so
the amount of hazardous organic waste of animal origin
that was disposed of by vultures should be even higher.
Discussion
A relict human-vulture mutualism
Our study illustrates a striking example of bird-human
mutualism: humans provide food resources, which fa-
cilitates the maintenance of the densest population of
the rare Egyptian vulture, whereas vultures provide a
regulating service by cleaning up carrion, waste, and hu-
man feces in villages and towns. This kind of relationship
between vultures and humans, although common in the
past (Bannerman 1963; Mundy et al. 1992), has nearly
disappeared recently due to the development of modern
societies and the precipitous decline of many scavenger
populations worldwide (Don´
azar et al. 2002; Pain et al.
4Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc.
L. Gangoso et al. Reinventing human-vulture mutualism
Figure 5 Egyptian vultures feeding tamely in a wady (Arabic word for a
stream bed that only carries surface water intermittently) on the outskirts
of Qalansiyah, where Socotran girls have just deposited waste.
2003; Koenig 2006). We disentangled and quantified for
the first time this mutualistic relationship.
On the one hand, Socotran vultures benefit from hu-
man activities by obtaining food resources that, in turn,
have allowed for the maintenance of the densest pop-
ulation of this rare species worldwide. The remarkable
dependence on humans is demonstrated by the clear
spatial structuring of the Socotran vulture population ac-
cording to HSs and the minor influence H features have
on its distribution. This pattern is particularly evident in
the largest city, Hadiboh, where more than 1,000 birds
were counted. The concentration of vultures in villages
is likely attributable to the accumulation of waste and
slaughterhouse offal, as well as the lack of wild prey in
their natural Hs (Cheung & DeVantier 2006). This hy-
pothesis is supported by the results of this study, which
showed that more than 90% of the items analyzed in
pellets came from human leftovers. This finding differs
markedly from observations for western European pop-
ulations where wild prey comprises between 50% and
75% of the diet of Egyptian vultures (Don´
azar et al. 2010,
Margalida et al. 2012a).
On the other hand, humans benefit from the presence
of Egyptian vultures, as these birds provide a key regulat-
ing service by cleaning up putrescible matter from villages
and rural areas. At present, Socotra lacks a waste collec-
tion system and the dumping of carcasses and garbage in
the open is the predominant form of disposal (Figure 5).
The ecological importance of vultures as agents of carrion
and waste disposal is well recognized, but rarely has it
been quantified (Wenny et al. 2011, but see Markandya
et al. 2008; Margalida et al. 2012b). Our data indicate
that between 17% and 22% of the total putrescible waste
Figure 6 The capital city, Hadiboh, accumulates large quantities of waste.
Villagers butcher many domestic animals and the remains are deposited
for vultures in the streets and in the open. Moreover, every morning
two restaurants provide a barrel of kitchen waste (about 60 kg), which is
consumed by vultures in a few hours time (authors’ own data).
produced in Socotra each year is eliminated by vultures.
Furthermore, it is important to note that this is a very
conservative estimate, given that it was calculated us-
ing the minimum food requirement for an adult vulture
(265 g/day), even though energy demands greatly de-
pend on animal activity and significantly increase dur-
ing the breeding period. In addition, vultures often feed
on human feces, a phenomenon very well described in
ancient European literature (Dewar 1906; Negro et al.
2002), which provides an important service in villages
that usually lack a sewage system. In this way, poten-
tially hazardous organic remains are efficiently elimi-
nated, thus reducing the risk of infectious disease in
humans and the spread of livestock diseases, such as
brucellosis, tuberculosis, and anthrax (Pain et al. 2003;
Koenig 2006; Markandya et al. 2008). The regulating ser-
vice provided by vultures in Socotra is recognized by is-
land inhabitants who refer to Egyptian vultures as soeydu,
which literally means “garbage bin” (Figure 6) (Cheung &
DeVantier 2006).
Confronting the conservation dilemma: ideas
for policy choices
Policy makers in Socotra currently face an impor-
tant development versus conservation dilemma that in-
volves the complex relationship between biodiversity
preservation needs and the demands of poverty allevi-
ation (Adams et al. 2004). Globalization is beginning to
impact the archipelago, entailing drastic changes in tra-
ditional land uses and economic activities, as well as the
modernization of infrastructure and sanitary conditions
in urban areas (Van Damme & Banfield 2011). From both
Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc. 5
Reinventing human-vulture mutualism L. Gangoso et al.
social and economic perspectives, development is desir-
able in Socotra, but it is not cost-free from an environ-
mental perspective and the question arises as to what
extent this imminent growth is compatible with the
maintenance of a healthy (i.e., not constrained by
human-related limiting factors) vulture population and
its associated functions.
Unfortunately, there are precedents showing failures
in the attempt to reconcile these two positions. The
situation on the Canary Islands provides an instruc-
tive example. This archipelago has many biogeographical
similarities with Socotra, but the contemporary history
of insular development is radically different. Until the
second half of the last century, the islands were virtu-
ally undeveloped, but the clear prioritizing of economic
development over biodiversity conservation gave rise to
several negative impacts on the ecosystem, most of them
irreversible, which notably included the disappearance
of numerous endemic taxa such as the Egyptian vul-
ture (presently at risk of extinction, Don´
azar et al. 2002).
Notwithstanding, national and regional governments are
obliged to take active measure in favor of these endan-
gered species. Consequently, recent European conserva-
tion plans have invested a substantial amount of eco-
nomic resources to protect and promote their welfare.
Considering only the LIFE projects public funds, a to-
tal of 19.14 million Euros has been devoted to the re-
covery of Egyptian vulture populations in the last two
decades (European Commission-Environment-LIFE Pro-
gramme 2011).
However, jointly achieving both conservational and
developmental goals is challenging. Here, we propose
a possible solution that would guarantee the conserva-
tion of the Egyptian vulture population by simultane-
ously promoting the sustainable development of the is-
land and relies on the restructuring of the mutualistic
human-vulture relationship by shifting from the regulat-
ing service toward a cultural service on a general scale,
while partially maintaining the regulating service to (1)
guarantee the disposal of carcasses in the open and rural
areas, according to human demand and (2) assure food
resources to maintain a dense vulture population.
The Socotra’s outstanding biodiversity and landscapes
and particularly, the unique ecological and behavioral
traits of Socotran Egyptian vultures (especially its amaz-
ing tameness) may act as a driving force of a nature-based
tourism. The promotion of an environmentally responsi-
ble and socially sensitive bird-related ecotourism would
drive a natural change in the way people value the species
and, consequently, a shift from a waste disposer toward a
natural treasure and an income-generating asset, which
will, in turn, offer local inhabitants new livelihood op-
portunities. In this sense, the Egyptian vulture would be
considered as a cultural service provider and hence con-
verted into a ‘flagship-species,” that is, “a species used as
the focus of a broader conservation marketing campaign
based on its possession of one or more traits that appeal
to the target audience” (Verissimo et al. 2011).
The feasibility of obtaining both conservational and
developmental goals has often been questioned and
branded as unrealistic, due to incompatibilities and the
intrinsic cost of one goal or the other that may hinder the
final outcome (Adams et al. 2004). Our approach con-
stitutes, however, a remarkable exception since no di-
rect losses are expected regarding both biodiversity and
the environment, and conservation would not increase
poverty in any way.
At the local scale, the policy need is to reconcile the in-
terests of different stakeholders in the management of the
natural resources. It is worth noting that when operating
in ecologically sensitive areas, such as this insular ecosys-
tem, all actions should be based on sound planning. To
accomplish this proposal, it would be advisable to take
into account the following conservational and develop-
mental considerations:
1. Maintenance of traditional extensive grazing prac-
tices that guarantee available food resources for the
subject species, which also includes management
plans aimed at controlling potential future negative
impacts associated with these practices, for exam-
ple, overgrazing and trampling (Gangoso et al. 2006;
Platcher & Hampicke 2010).
2. Sustainable economic development, based on back-
ground knowledge (e.g., Don´
azar et al. 2002; Hille
& Collar 2011), that avoids potential future limit-
ing factors for biodiversity, and in particular for the
vulture population, such as H loss and nonnatural
mortality due to poisoning, pollution, or direct and
indirect persecution.
3. Avoidance of unsustainable tourist industries that
imply massive H destruction, proliferation of inad-
equate infrastructures, and promotion of irrespon-
sible activities (e.g., off-road rallies) such as those
already occurring in other archipelagoes, including
Cape Verde and the Canary Islands.
4. Enhancement of the proposed strategy by instilling
new values in the local inhabitants through envi-
ronmental education and soliciting popular partici-
pation in H management.
In conclusion, the challenge for Socotra is to find an
ecologically, socially, and economically sustainable path
for future insular growth that reconciles trade-offs be-
tween conservation and development. The recognition of
the species’ roles within the ecosystem and the a priori
identification of the underlying trade-offs will assist in
6Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc.
L. Gangoso et al. Reinventing human-vulture mutualism
the design of future management plans. This is crucially
relevant in the Socotra archipelago, one of only four UN-
ESCO Natural World Heritage Sites in the Arab world, at
a time when Yemen and a number of other Middle East-
ern countries are undergoing political reforms as a result
of the current uprisings and the rapidly changing political
landscape (Van Damme 2011).
Acknowledgments
We thank Mauro Fasola, Francesca Pella, and Fabio
Atorre for logistical support in Socotra and for the data
provided. Javier Juste and Fernando Hiraldo made use-
ful comments on earlier versions of the manuscript. The
research was funded by the projects CGL2004-00270
and CGL2009-12753-C02-02. During the writing of this
manuscript, LG was supported by the FP7-REGPOT 2010-
1 EcoGenes Project (Grant No. 264125). The Regional So-
cotran and National Yemeni Governments approved the
research protocols.
Supporting Information
Additional Supporting Information may be found in the
online version of this article:
Methods
Please note: Wiley-Blackwell is not responsible for the
content or functionality of any supporting materials sup-
plied by the authors. Any queries (other than missing ma-
terial) should be directed to the corresponding author for
the article.
References
Adams, W.M., Aveling, R., Brockington, D. et al. (2004).
Biodiversity conservation and the eradication of poverty.
Science,306, 1146–1149.
Bannerman, D.A. (1963) Birds of the Atlantic Islands.Vol. I. A
history of the birds of the Canary Islands and of the salvages.
Oliver & Boyd, Edinburgh and London, UK.
Battersby, S.A., Pearsons, R. & Webster, J.P. (2002). Urban rat
infestations and the risk to public health. J. Environ. Health
Res.,1, 4–12.
BirdLife International. (2011). Species factsheet:
Neophronpercnopterus. Available from: http://www.birdlife.
org (visited Dec. 19, 2011).
Cerny, V., Pereira, L., Kujanova, M. et al. (2009) Out of
Arabia-the settlement of island Soqotra as revealed by
mitochondrial and Y chromosome genetic diversity. Am. J.
Phys. Anthropol.,138, 439–447.
Cheung, C. & DeVantier, L. (2006). Socotra —a natural history
of the islands and their people. Odyssey Books and Guides,
Airphoto International Ltd., Hong Kong.
Cort´
es-Avizanda, A., Ceballos, O. & Don´
azar, J.A. (2009).
Long-term trends in population size and breeding success
in the Egyptian vulture (Neophron percnopterus)inNorthern
Spain. J. Raptor Res., 43, 43–49.
del Hoyo, J., Elliott, A. & Sargatal, J. (1994). Handbook of the
birds of the World,Vol II: New World vultures to Guinea Fowls.
Lynx Editions, Barcelona, Spain.
Dewar, D. (1906). Bombay Ducks. John Lane, London, 277 pp.
Don´
azar, J.A., Palacios, C.J., Gangoso, L., Ceballos, O.,
Gonz´
alez, M.J. & Hiraldo, F. (2002). Conservation status
and limiting factors in the endangered population of
Egyptian vulture (Neophron percnopterus) in the Canary
Islands. Biol. Conserv.,107, 89–97.
Don´
azar, J.A., Cort´
es-Avizanda, A. & Carrete, M. (2010).
Dietary shifts in two vultures after the demise of
supplementary feeding station: consequences of the EU
sanitary legislation. Eur. J. Wildl. Res.,56, 613–621.
European Commission-Environment-LIFE Programme.
(2011). Available from: http://ec.europa.eu/environment/
life/ (visited Dec. 1, 2011).
Gangoso, L., Don´
azar, J.A., Scholz, S., Palacios, C.J. & Hiraldo,
F. (2006). Contradictions in conservation of island
ecosystems: plants, introduced herbivores and avian
scavengers in the Canary Islands. Biodivers. Conserv.,15,
2231–2248.
Grimm, N.B., Faeth, S.H., Golubiewski, N.E. et al. (2008).
Global change and the ecology of cities. Science,319,
756–760.
Hille, S.M. & Collar, N.J. (2011). Status assessment of raptors
in Cape Verde confirms a major crisis for scavengers. Oryx,
45, 217–224.
Koenig, R. (2006). Vulture research soars as the scavengers’
numbers decline. Science,312, 1591–1592.
Lavine, A. (2011). The urban wildlife we don’t want: Coyote
Management Planning and Regulatory Control Measures.
Available from: http://dx.doi.org/10.2139/ssrn.1862801
(visited Apr. 30, 2012).
Loretz, R. & Martin, F. (2006). SWM Masterplan for Socotra,
Yemen. NDS-U Thesis, University of Applied Sciences,
Northwestern Switzerland.
Luck, G.W., Daily, G.C. & Ehrlich, P.R. (2003). Population
diversity and ecosystem services. Trends Ecol. Evol.,18,
331–336.
Margalida, A., Carrete, M. & S´
anchez-Zapata, J.A. (2012a).
Good news for European vultures. Science,335, 284.
Margalida, A., Ben´
ıtez, J.R., S´
anchez-Zapata, J.A., ´
Avila, E.,
Arenas, R. & Don´
azar, J.A. (2012b). Long-term
relationship between diet breadth and breeding success in a
declining population of Egyptian Vultures. Neophron
percnopterus. Ibis,154, 184–188.
Markandya, A., Taylor, T., Longo, A., Murty, M.N.,
Murty, S. & Dhavala, K. (2008). Counting the cost of
vulture decline—an appraisal of the human health
and other benefits of vultures in India. Ecol. Econ.,67,
194–204.
Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc. 7
Reinventing human-vulture mutualism L. Gangoso et al.
Marzluff, J.M. (2001). Worldwide urbanization and its effects
on birds. Pages 19–48 in J.M. Marzluff, R. Bowman, R.
Donnelly, editors. Avian ecology in an urbanizing world.
Norwell, MA, Kluwer.
McKinney, M.L. & Lockwood, J.L. (1999). Biotic
homogenization: a few winners replacing many losers in
the next mass extinction. Trends Ecol. Evol.,14, 450–453.
Millennium Ecosystem Assessment. (2005). Ecosystems and
human well-being: synthesis. Island Press, Washington.
Mundy, P., Butchart, D., Ledger, J. & Piper, S. (1992). The
vultures of Africa. Academic Press, London.
Negro, J.J., Grande, J.M., Tella, J.L. et al. (2002) Coprophagy:
an unusual source of essential carotenoids. Nature,416,
807–808.
Pain, D., Cunningham, A.A., Donald, P.F. et al. (2003). Causes
and effects of temporospatial declines of Gyps vultures in
Asia. Cons. Biol.,17, 661–671.
Plachter, H. & Hampicke, U. (2010). Large-scale livestock
grazing. A management tool for nature conservation. Springer-
Verlag, Berlin, Germany.
Porter, R. & Stone, F. (1996) An introduction to Socotra and
its birds. Sandgrouse,17, 73–80.
Porter, R. & Suleyman, A.S. (2012). The Egyptian vulture
Neophron percnopterus on Socotra, Yemen: population,
ecology, conservation and ethno-ornithology.
Sandgrouse,34.
Sar´
a, M., Grenci, S. & Di Vittorio, M. (2009). Status of
Egyptian vulture (Neophron percnopterus) in Sicily. J. Raptor
Res., 43, 66–69.
UNEP/WCMC. (2008). Socotra Archipelago, Yemen. UNESCO
Fact Sheet. World Heritage Sites – Protected Areas and
World Heritage. United Nations Environment Programme
& World Conservation Monitoring Centre, 11pp. Available
from: http://whc.unesco.org/en/list/1263 (visited Nov. 20,
2011).
Van Damme, K. (2011). Insular biodiversity in a changing
world. Nature Middle East, doi: 10.1038/nmiddleesast.
21011.61.
Van Damme, K. & Banfield, L. (2011). Past and present
human impacts on the biodiversity of Socotra Island
(Yemen): implications for future conservation. Biodiversity
Conservation in the Arabian Peninsula. Zool. Middle East,3,
31–88.
Verissimo, D., MacMillan, D.C. & Smith, R.J. (2011). Toward
a systematic approach for identifying conservation
flagships. Conserv. Lett.,4,18.
Wenny, D.G., Devault, T.L., Johnson, M.D. et al. (2011). The
need to quantify ecosystem services provided by birds. The
Auk,128, 1–14.
Whelan, C.J., Wenny D.G. & Marquis, R.J. (2008). Ecosystem
services provided by birds. Ann. NY Acad. Sci.,1134,
25–60.
8Conservation Letters 0(2012) 1–8 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc.
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Scavenging is an important ecological process. By quickly locating and consuming carrion, vertebrate scavengers cycle nutrients, stabilize food webs, and may help mitigate disease transmission to humans. Across Africa, many scavengers feed at abattoirs (i.e. slaughterhouses), thereby aiding in waste removal. Little information exists on the scavenger community composition and dynamics at abattoirs, and, to our knowledge, the carrion removal that scavengers provide at these sites has never been quantified. We studied vertebrate scavenger ecology at 6 abattoirs in Ethiopia with time‐lapse photography and in‐person surveys from 2014–2019. Specifically, we investigated daily, seasonal, and inter‐annual patterns in use of abattoirs by vertebrate scavengers and estimated carrion consumption rates. We demonstrated the importance of abattoirs for supporting a large number and diversity of scavenger species, including 3 critically endangered, 2 endangered, 1 vulnerable, and 2 regionally endemic bird species. At the start of the study, vultures contributed 57% of carrion removal provided by vertebrate scavengers. Detections of critically endangered Rüppell's (Gyps rueppelli) and white‐backed (G. africanus) vultures declined by 73% and critically endangered hooded vultures (Necrosyrtes monachus) declined by 15% over the study period. Simultaneously, the detections of dogs more than doubled. Using estimates of species‐specific carrion consumption rates from the literature, coupled with changes in scavenger detections in our study, we estimated a 12% (54 kg/day) reduction in carrion consumption, or nearly 20,000 kg carrion less consumed per year by the end of the study at these 6 abattoirs. Our results indicate that ongoing vulture declines across Africa could significantly reduce carrion removal. We recommend that improving fencing around abattoir facilities could help restrict access by feral dogs, increase foraging by vultures, and, therefore, increase overall carrion removal rates. We studied scavenger ecology over 5 years in Ethiopia and vultures consumed 57% of the carrion at the start of the study, but detections declined substantially while feral dog detections doubled. Overall ecological function (carrion consumption) was reduced and we recommend adaptive fencing around abattoir waste disposal sites.
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Vulture species worldwide play a key role in ecosystems as obligate scavengers, and several populations have had precipitous declines. Research on vulture health is critical to conservation efforts including free-living vultures and captive breeding programs, but is limited to date. In this systematic review, we determined the reported causes of free-living vulture species morbidity and mortality worldwide. The most commonly reported cause of mortality was from toxins (60%), especially lead and pesticides, followed by traumatic injury (49%), including collisions with urban infrastructure and gunshot. Neglected areas of research in free-living vulture health include infectious diseases (16%), endocrine and nutritional disorders (6%), and neoplasia (< 1%). Almost half of the studies included in the review were conducted in either Spain or the USA, with a paucity of studies conducted in South America and sub-Saharan Africa. The highest number of studies was on Griffon (Gyps fulvus) (24%) and Egyptian vultures (Neophron percnopterus) (19%), while half of all vulture species had five or fewer studies. Future investigations on free-living vulture health should focus on neglected areas of research, such as infectious diseases, and areas with gaps in the current literature, such as South America, sub-Saharan Africa, and under-studied vulture species.
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The Socotra Archipelago south of Yemen is one of only four United Nations Educational, Scientific and Cultural Organization (UNESCO) Natural World Heritage Sites in the Arab world. This group of small islands in the Western Indian Ocean formed from land that detached from the continental Arabian Peninsula about 20 million years ago, and the group of four isolated islands is now home to some of the world's most bizarre life forms. The characteristic swollen-trunked bottle trees of Socotra are striking examples, such as the cucumber tree (Dendrosycios socotrana) or the Socotra fig (Dorstenia gigas). Since being declared a World Heritage Site in 2008, Socotra has changed. The changes are quick and multifaceted, from the political to the cultural and environmental. When UNESCO evaluates the Socotra site status in 2012, Yemen should have undergone political reform as a result of the current uprisings and the rapidly changing political landscape. On 22 March 2011, the Yemeni minister of water and environment, Abdulrahman Fadhl Al-Eryani, announced his resignation by email. Al-Eryani has been an enthusiastic and strong advocate for the involvement of the international scientific community in Socotra's conservation. He was a major driving force behind the island's UNESCO designations as a Man and Biosphere reserve in 2003 and later as a World Heritage Site in 2008. The speed with which events unfold in the Middle East has taken everyone by surprise. While international visitors to Yemen have been evacuated and the country is temporarily shut to the outside world, there is no contingency plan to tackle environmental issues on the islands during these trying times. Yet Yemen harbours globally important natural treasures, on which local communities depend, and which are now under threat.
Book
One of the main objectives of nature conservation in Europe is to protect valuable cultural landscapes characterized by a mixture of open habitats and hedges, trees and patchy woodland (semi-open landscapes).The development of these landscapes during the past decades has been characterized by an ongoing intensification of land use on the one hand, and an increasing number of former meadows and pastures becoming fallow as a result of changing economic conditions on the other hand. Since species adapted to open and semi-open landscapes contribute to biodiversity in Europe in a major way, this development is of great concern to nature conservation. In several countries largescale, nature-adapted pastoral systems have been recognized as one solution to this problem. These systems could offer an alternative to industrial livestock raising and keep a high biodiversity on the landscape level. Against the background of livestock diseases such as BSE and Foot and Mouth Disease and the efforts to reform the Common Agricultural Policy in the EU by changing the criteria for agricultural subsidies, these concepts gain particular significance.They could also represent an alternative to the established, costly habitat management tools.
Chapter
Human populations are increasing and becoming predominantly urban. Resulting land cover changes reduce, perforate, isolate, and degrade bird habitat on local and global scales. I review: 1) urbanization of the Earth, and 2) published studies of bird responses to human settlement, and then: 3) suggest how and why birds respond to settlement. In a slight majority of studies, bird density increased, but richness and evenness decreased in response to urbanization. The most consistent effects of increasing settlement were increases in non-native species of birds, increases in birds able to nest on buildings (esp. swifts and swallows), increases in nest predation, and decreases in interior- and ground-nesting species. Effects of urbanization on hawks, owls, and cavity nesters were less consistent, in part being dependent on the surrounding habitat. The factors favoring species in urbanizing areas appear simpler than those reducing species. Increased availability of food was primary among factors benefiting species; predator reduction, reduced human persecution, and habitat enhancement were less important. Decreased habitat availability, reduced patch size, increased edge, increased non-native vegetation, decreased vegetative complexity, and increased nest predation were commonly associated with bird declines in response to human settlement. Urban planners and policy makers can profoundly affect how and where cities grow. Avian ecologists can help inform these important decisions by: 1) quantifying how the pattern of settlement affects birds and 2) understanding how bird populations and resulting communities change along entire gradients of urbanization.