Despite major declines in the population of vultures around the world, noticeable increases were reported in the populationsof Hooded Vultures Necrosyrtes monachus over the past decade in Accra—an important vulture habitat in Ghana. In recenttimes, however, there is a growing concern that the vulture numbers are decreasing even though scientific data to support thisis nonexisting. As a vital zoogeographical and conservation tool, it is important to keep an up-to-date knowledge about urbanbird populations amidst rapid urbanization and associated changes. Using a combination of field data, literature review, andstakeholder consultations, it was indicative that severe decline might have indeed occurred in the populations of Hooded Vulturesin Accra. Evidence suggests the killing of vultures for consumption, traditional medicine, and black magic in an undercover tradewith possible transboundary connections as important underlying factor. Additional factors suspected to underlie the declinesinclude changes in management of urban facilities and destruction of roosting and nesting trees. The implications of interspecificcompetition with Pied Crows Corvus albus on Hooded Vultures however remain unclear. There is an urgent need for conservationcampaign and education to save the Hooded Vulture in Ghana.
1. Introduction
Since the 1980s, the populations of vultures in many areasaround the world have decreased drastically and, in severalplaces, vultures are now absent or confined only to protectedareas [1, 2]. Published literature recognised the decline inHooded Vulture Necrosyrtes monachus populations acrossAfrica resulting in the species being reclassified from thestatus of Least Concern to Endangered [3] and, quite recently,Critically Endangered.
Despite the drastic decreases in vulture numbers in manyparts of the world, the population of Hooded Vultures inGhana is generally considered to be stable [3]. Indeed, theHooded Vulture had been so common in Ghana that itoccurred in 59 out of 93 atlas squares [3] and commonlymakes use of open food markets, landfill sites, open dump-sters, and slaughterhouses [4–6].
Accra is one of the most important habitats for vulturesin Ghana and according to [7] flocks of about 500 Hooded
Vultures were regularly seen around slaughterhouses andmeatmarkets in Accra (the capital city of Ghana) andKumasi(the second largest city in Ghana). Over the past decade,noticeable increases in Hooded Vulture populations havebeen reported in Accra [5, 6, 8, 9]. In recent times, however,there is a growing concern that vulture numbers are rapidlydecreasing in Ghana even though scientific data to supportthis is practically nonexisting. As a vital zoogeographicaland conservation tool, it is important to keep an up-to-dateknowledge about urban bird populations amidst rapid urban-ization and associated changes. In this paper, we support fielddata on Hooded Vultures in Accra with reviewed literatureand consultation to demonstrate that declines might haveindeed occurred in the populations of Hooded Vulturesin the city. Literature search and stakeholder consultationsfurther revealed changes in management of urban facilitiesand destruction of roosting and nesting trees as well as killingof vultures for consumption, traditional medicine, and blackmagic as possible underlying causes of the declines. The role
Hindawi Publishing CorporationInternational Journal of ZoologyVolume 2016, Article ID 7946172, 6 pageshttp://dx.doi.org/10.1155/2016/7946172
2 International Journal of Zoology
of interspecific competition with Pied Crows Corvus albus inthe decline of vultures remains unclear.
2. Materials and Methods
2.1. Study Area. The study was carried out in Accra, thecapital city of Ghana. Accra had a human population of377,558 in 1960 which increased to 1,657,856 in 2000 [10, 11].In 2010, Accra had an urban population of about 2.9 millionand a metropolitan population of about 4 million [12]. Withan area of 241 km2, the capacity of Accra to contain thepopulation growth was exceeded, leading tomajor challengesincluding difficulties with waste management, developmentof shanty towns, and increased rates of housing development[10, 11, 13, 14]. As Hooded Vultures are primarily associatedwith human settlements, a large number of the vulturesinhabit Accra making use of landfill sites, slaughterhouses,open markets, open lawn areas, and the tall trees lining thestreets in the city [4, 6, 8].
2.2. FieldWork. Thework in [15] reported the LegonCampusof the University of Ghana as the second most importantarea for Hooded Vultures in Accra. Between June 2005 andFebruary 2006, weekly counts of Hooded Vultures and PiedCrows were conducted on foot in some major foraging areason the Legon Campus of University of Ghana as outlinedin [5]. Counts which were conducted simultaneously inthe academic and residential areas of the Campus involvedwalking the foraging areas and counting the total number ofHooded Vultures and Pied Crows without width limits.
Analysis of the data collected between June 2005 andFebruary 2006 as indicated by [5] revealed that peak countof Hooded Vultures occurred on the Legon Campus betweenNovember 2005 and January 2007. Therefore, the countswere repeated weekly between the months November 2010and January 2011, November 2014 and January 2015, andNovember 2015 and January 2016 to monitor trends.
2.3. Review of Field-Based Scientific Reports and PublishedLiterature. We reviewed published peer-reviewed papersincluding [3, 5, 6, 8, 9, 16]. In addition, reports from field-based studies of Hooded Vultures and Pied Crows in Ghanawere reviewed including [15, 17–22].
2.4. Consultation of Key Stakeholders. We also had informalinteractions with vulture researchers in Ghana and wastemanagers including scrap dealers and individuals frequentlyfound in waste dumps sorting out potentially useful objectsfor reuse or reprocessing (referred to in this work as “refusescavengers”).
3. Results and Discussion
3.1. Field-Based Studies
3.1.1. Trends in Vulture Populations. The daily abundance ofHooded Vulture on the Campus (mean ± SE) for the periodfrom June 2005 to February 2006 as reported by [5] was 84±9with a peak of 115 ± 4 between November 2005 and January
2005/2006 2010/2011 2014/2015 2015/2016Period of count (year)
Hooded VulturesPied Crows
0
100
200
300
400
500
600
Mea
n nu
mbe
r rec
orde
d (±
SE)
Figure 1: Number of Hooded Vultures and Pied Crows counted inimportant foraging areas of vultures on the Legon Campus.
2006. This daily abundance however increased to 220 ± 49between November 2010 and January 2011. On the contrary,the daily abundance decreased to 5 ± 2 between November2014 and January 2015 (Figure 1). Thus, the number recordedin 2014/15 constituted 2.3% of the number of vultures presenton the Campus in 2010/11 whilst no vultures were seen onthe foraging areas of the Campus between November 2015and January 2016. Indeed, over four simultaneous visits toall known roosting sites on the Legon Campus in June 2015,no Hooded Vulture was seen. Clearly, a severe decline mighthave occurred in the vulture population on the Campus afterthe population increased to about 220± 49 in the year 2010/11.
Hooded Vultures in West Africa are primarily knownto be associated with human settlements foraging on meat,vegetables, and rubbish [3, 5, 6, 9] and therefore there wasthe possibility that the vulturesmight have redistributed fromthe Campus to other urban areas as a result of developmentalchanges.However, in a count ofHoodedVultures in the entirecity of Accra in the year 2012 [15], only 257 Hooded Vultureswere recorded including 55 individuals on the LegonCampus(Table 1).Thus, the number ofHoodedVultures counted dailyat forage sites on the Legon Campus in 2010/11 (220 ± 49)constituted 86% of the total number of vultures recorded inthe entire city of Accra in 2012 [15]. Also, the number ofvultures recorded on the Campus in 2012 [15] (55) constitutesonly 25% of the number recorded in 2010/11 (220± 49) whilstthe number recorded in 2014/15 (5 ± 2) constituted 9% of the2012 records, not forgetting that no vultures were seen on theCampus between November 2015 and January 2016.
Although [15] counted vultures at roost sites in Accracompared to forage sites by earlier works, the methodologyof [15] was chosen as a result of the unavailability of vulturesat known forage sites. These are therefore indications thatHooded Vulture populations in Accra might have indeeddecreased. Indeed, major decreases in the populations ofHooded Vultures have already been reported in Ghana’sneighbouring countries such as Burkina Faso and IvoryCoast[3, 23].Withmajor decreases in an important area like Accra,
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Table 1: Roost counts of verified active roost sites ofHoodedVulture[15]. Counts were undertaken simultaneously from the hours of16:00 hrs to 19:30GMT.
Site name Mean number of roosting vulturesUniversity of Ghana Campus 55Ridge area 115Achimota area 25Presec high school area 10Gimpa Campus 15Burma camp 5Cantonments 7Atomic energy area 10Labone area 5Total 257
it appeared that trends in the population of Hooded Vulturesin Ghana as a whole may equally be in jeopardy and wouldthus need research and management attention.
3.1.2. Competition between Pied Crows and Hooded Vultures.Closely associated with Hooded Vultures in the urban WestAfrican environment are Pied Crows although the later didnot attract as many published works as vultures [6, 9].Contrary to the number of Hooded Vultures that increasedto a peak in 2010/11 on the Legon Campus and decreasedthereafter (Figure 1), Pied Crow population on the Campushas gradually been increasing from about 93 ± 31 to anestimated present population of 453± 52 in 2014/15 (Figure 1).By dividing the number of vultures by Pied Crows countedsimultaneously on the Legon Campus, a vulture-to-crowratio was obtained. This ratio generally decreased from 0.9in 2005/6 to 0.01 in 2014/15 (as indicated in Figure 2)in a manner that is consistent with general competitiveextinction models. The results of additional simultaneouscounts obtained from literature search including [6, 9, 17, 18]are shown in Table 2 with values that are clearly consistentwith our findings that Hooded Vulture populations faroutnumbered crows in the past.
In the study of antagonistic behaviour and resourcepartitioning among scavenging birds in Ghana, [9] reportedHooded Vultures and Pied Crows to feed on the sametypes of food resources with frequent robberies occurringbetween the two. A strong competition could thereforehave ensued between the growing numbers of vultures andcrows for a number of resources. Nevertheless, comparedto Hooded Vultures, Pied Crows are known to forage on awider range of food items including seed and fruits and areknown to outcompete many species of birds [24]. Annorbahand Holbech (2012) indicated that crows transported stolenfoods to faraway distances contrary to the vultures’ frequentattempts to consume food items in the immediate vicinity.With both species fighting back to recapture stolen food [9],vultures might be disadvantaged as “kleptoparasitic crows”fly far away to avoid repeated fight backs. At the same time,the tall trees used by vultures for nesting are equally usedby crows but whilst the vulture would not nest in trees that
2005-2006 2010-2011 2014-2015Time
00.10.20.30.40.50.60.70.80.9
1
Vultu
re-to
-cro
w ra
tio
Figure 2: Trends in vulture populations expressed as a ratio tocrow populations in simultaneous count of the two species on LegonCampus.
had Pied Crows nests, the latter additionally specialised onnesting on pylons and therefore have a wider nesting nichethan vultures.Thus, the possibility of vultures succumbing tocompetition from crows in the presence of limited resourcesexists and this has indeed been reported by [25]. Furtherresearch is however needed to clarify the outcome of vulture-Pied Crow interactions.
3.2. Stakeholder Consultations and Literature Review
3.2.1. Management of Urban Facilities. The work in [5]reported littering of streets and defecation by roosting vul-tures on human and cars as major challenges associatedwith increasing Hooded Vulture populations on the LegonCampus. Hooded Vultures were also implicated as majorrisk to the aviation industry in Ghana [16]. In this regard,some directmeasures were instituted to curbHoodedVulturepopulations.
On the Legon Campus, contrary to the inefficient wastemanagement practices identified by [5], major advances havebeen made including the provisioning of covered bins atvantage points all over the Campus. These bins are emptiedinto waste trucks for direct transport into designated off-Campus waste disposal sites therefore limiting the availabilityof rubbish to scavenging birds on the Campus. Also, inthe bid to avoid bird strikes in the aviation industry, theKotoka International Airport in Ghana considered a rangeof options to cut down on bird numbers [16]. Such measuresinclude limiting the availability of major bird attractants suchas food sources, open water, roosting sites, nesting sites,and perching sites, as well as bird scaring patrol and lethalcontrol methods [16]. The airport authority working withother government agencies has implemented all but lethalcontrol options within the 13 km radius of the airport. Thus,either all open refuse dumps have been closed or coveredskips have been installed and are evacuated in the evenings.The outcome has generally been described by the airportauthorities as successful.
Also, in addition to specific measures targeting thereduction in vulture populations as a result of their perceived
4 International Journal of Zoology
Table 2: Results of literature search on simultaneous count of crows and vultures in Ghana.
Year in which datawas collected Location Mean number of
nuisance, rapid urbanization in Sub-Saharan Africa is asso-ciated with changes in the management of urban facilities[10]. The open refuse dump sites utilized by vultures areconstantly threatened in the bid to improve sanitation acrosscities. For instance, a check from Districts Assemblies inthe Accra Metropolis indicated that there were five landfillsites in Accra in the year 2010 but four of these were closeddown by 2012. Also, there is a campaign for the closure ofunhygienic slaughterhouses across the country although theexact numbers that have been closed down or rehabilitatedare not known. Clearly more efficient and hygienic means ofwaste management are being introduced across the countryand these would not be without consequence to HoodedVulture populations.
3.2.2. Use of Hooded Vultures in Traditional Medicine andBlack Magic. Our consultations with “refuse scavengers”indicated that they were abreast with noticeable reductionin the number of Hooded Vultures in Accra and manyother parts of Ghana. Several of them indicated that HoodedVultures in their numbers can now be found only in Tamale,the regional capital of the Northern Region of Ghana.They attributed the low vulture populations to the closureof landfill sites and trade in vulture and vulture parts inGhana. According to the “refuse scavengers” the trade invulture and vulture parts is a close market that is patronisedby individuals interested in traditional medicine and blackmagic. This trade was reported to be connected to marketsin Nigeria such that some killed vultures and vulture partsare smuggled from Ghana to markets in Nigeria. Indeed,[15] reported an encounter with a man at a landfill site inAccra capturing Hooded Vultures meant for export and usein Nigeria. In a confidential agreement to test the veracity ofthe existence of these markets, a confidant led a member ofthis team to an undercover sales point in a market at Tamalewhere many animal parts including Hooded Vultures werefound (Figure 3). The head of a vulture in this market costs200 Ghana cedis (∼60 USD) whilst a whole vulture was 500cedis (∼140 USD).
There may be several reasons why vultures would stillthrive in Tamale. In Ghana, cattle production is concentratedin the Northern Savannah Zone in which Tamale is located[26]. Unlike Accra that has witnessed the renovation ofseveral slaughterhouses, the main Tamale slaughterhouse hasnot been renovated until very recently [27]. Also, althoughAccra has seen the closure of many landfill sites, these landfillsites still exist in Tamale and are reported to be poorlymanaged [28, 29]. Thus availability of food to the HoodedVulture in Tamale might not be as difficult as it would bein Accra. Besides, the driving distance from Accra to Tamale
Figure 3: Exhibits of five Hooded Vulture specimens (concealed inbrown paper) among other items being sold in a market at Tamale.
is about 618 km and it is possible that, until recently, manystakeholders in the vulture trade might be reluctant to go allthe way to Tamale.
3.2.3. Killing of Vultures for Human Consumption. A searchthrough archive electronic news of Ghana revealed that thekilling and sale of vulture meat were alien to the Ghanaianculture until the first reported case in 2001. Although manyof these incidents might have gone unnoticed or treatedas a rumour, at least six archive pieces of news have beenuncovered inwhich the culprits were seenwith killedHoodedVultures [30–35]. In 83% of the cases, the killed vultures wereintended for sale to local restaurant operators or kebab sellersfor onwards sale of the cooked meat to the unsuspectingpublic compared to 17% intended for blackmagic.Thehighestnumber of killed Hooded Vultures reported per each of suchincidents was 32 and the last reported case was in 2012 [24].Indeed, many of the vulture killing incidents may have goneunnoticed.Thus, with the killing of 32 Hooded Vultures per asingle encounter, it is clear that such individuals could easilyhunt down Hooded Vulture populations given the low clutchsize of vultures.
3.2.4. Destruction of Roosting and Nesting Trees. Table 3indicates some physical characteristics of tree species used byroosting Hooded Vultures in Accra together with their meanheight and mean thickness at breast height [15, 21]. Only verytall trees including Bombax sp., Khaya senegalensis, Antiaristoxicaria, Roystonea regia, and Anogeissus olitorius were usedby the roosting vultures. Nests were also recorded on Bombaxsp. and Khaya senegalensis, Ceiba pentandra, and Roystonearegia [8, 21]. In many urban areas of Ghana including Accra,these trees are matured avenue trees several of which haverecently fallen down after heavy downpours in response to
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Table 3: Tree species used by roosting Hooded Vultures in Accra[15, 21].
Name of treeMean thicknessat breast height(cm) ± SD
which many are also cut down to prevent loss of life anddestruction of property [15]. The cutting down of trees byproperty owners to reduce littering of cars and people byroosting vultures and crows has earlier been reported by[15]. According to [15], loss of roosting trees did not havea devastating impact on vultures because of the availabilityof alternatives. The impact of such destructions on nestingvultures would however not be overemphasised.
4. Conservation Implications
Hooded Vulture populations thrived well in Accra as aresult of problems with the management of waste generatedfrom the ever-increasing number of urban dwellers and thepresence of tall trees used for nesting and roosting [15, 17].It is clear that improvements in urban sanitation wouldaffect the species population. However, factors such as thekilling of vultures for consumption, traditionalmedicine, andblackmagic also appeared to be important underlying causes.There is therefore the need for an intensive education of theGhanaian populace on the significant status and the need forthe protection of the species.
Competing Interests
The authors declare that they have no competing interests.
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