Ardeola 52(1), 2005, 79-90

THE GREAT BUSTARD OTIS TARDA IN MOROCCO: A RE-EVALUATION OF ITS STATUS BASED

ON RECENT SURVEY RESULTS

Juan C. ALONSO* 1, Carlos PALACÍN*, Carlos A. MARTÍN*, Nourdine MOUATI**, Zine L. ARHZAF*** & Driss AZIZI***

SUMMARY.—The Great Bustard Otis tarda in Morocco: a re-evaluation of its status based on recent sur-vey results.Aims: Between 1999 and 2005 five spring censuses of the Great Bustard Otis tarda population in Moroccowere carried out, one of which (2003) was finally discarded due to bad weather conditions. Some comple-mentary, partial counts in autumn 2000, winter 2001-2002 and spring 2004 were also carried out. The aimswere to survey new areas where occurrence of the species was suspected but not confirmed, re-evaluate all re-cently published counts, establish reliable productivity, sex-ratio, and age structure values, and assess the con-servation status of this endangered population.Results and Conclusions: Seven leks were identified, two of which had not been described in earlier studies(Chekbouchan, Mrhitane). The total numbers of birds counted in spring varied between 70 and 84. Based onthese, 80-113 birds were estimated in Morocco. The annual estimates of 99, 98, 90 and 80 birds, respectivelyfor 1999, 2001, 2002 and 2005, suggested a decline in numbers throughout the study period, particularly at thetwo northern leks. Compared to the scarce data from previous decades, these counts suggest that the popula-tion has suffered a moderate decrease. The sex-ratio was extremely female-biased, with 3.9 observed and 4.1estimated females per male. The age structure of the male population was remarkably young, with 23.5% im-mature males (range 11.1-33.3%), a higher proportion than that recorded in Iberian populations of the species.Average annual recruitment was 0.10 juvenile birds survived up to March from the previous breeding season,per adult female (range 0.045-0.178), a reasonable value compared to Iberian populations. These data suggestthat Moroccan Great Bustards are subjected to high adult male mortality. This was corroborated with nume-rous well-documented cases of illegal hunting. Poaching was identified as the main current threat for the po-pulation, followed by collision with powerlines. It is suggested that poaching, and particularly male trophyhunting, has caused the decreases in numbers observed at some leks during the present study. Other threats in-clude the foreseeable extension of the powerline network, and the agriculture intensification at current bree-ding areas. Immediate conservation actions are urgently required to save this extremely endangered popula-tion from extinction.

Key words: Distribution, Great Bustard, Morocco, Otis tarda, status.

RESUMEN.—La población de Avutarda Común Otis tarda de Marruecos: análisis de su estado de con-servación basado en censos recientes.Objetivos: Entre 1999 y 2005 se realizaron cinco censos de la población reproductora de Avutarda ComúnOtis tarda de Marruecos, uno de los cuales (2003) fue descartado por sus pobres resultados como conse-cuencia de malas condiciones meteorológicas. Además se llevaron a cabo censos parciales complementariosen otoño de 2000, invierno 2001-2002 y primavera de 2004. Los objetivos fueron la prospección de nuevaszonas, en las que la presencia de la especie aún no había sido confirmada, la evaluación de la estima pobla-cional a la luz de los nuevos censos, la determinación de valores fiables de proporción de sexos, estructura deedades y productividad juvenil, y la diagnosis del estado de conservación de esta población de avutardas, unade las más amenazadas del mundo.Resultados y Conclusiones: Se identificaron siete leks, dos de los cuales no habían sido descritos en estudiosanteriores (Chekbouchan, Mrhitane). Los totales de aves censados en primavera variaron entre 70 y 84, sobrelos que estimamos un total de 80-113 avutardas en Marruecos. Las estimas anuales fueron de 99, 98, 90 y 80individuos, respectivamente en 1999, 2001, 2002 y 2005, lo que sugiere una tendencia decreciente a lo largodel periodo de estudio, debida sobre todo al declive en los dos leks más septentrionales. La comparación con

* Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, 28006 Madrid, España.** Av. Mohamed Daoud c/ Souisse n.o 3 (Touable Essoufla) 93000 Tetouan, Marruecos.*** Association d’Education Environnementale et de Protection des Oiseaux au Maroc (SEEPOM), n.o 3,

Lot 1, Haj Kaddour, Région de Méknès, Marruecos.1 Corresponding author: E-mail: jcalonso@mncn.csic.es

INTRODUCTION

The only African population of Great Bus-tards Otis tarda breeds in northwestern Moroc-co (Glutz et al., 1973; Cramp & Simmons,1980; Collar, 1985; Del Hoyo et al., 1996).Until recently, only a few incomplete reportswere available on numbers and distribution ofthis population, which represents the southernlimit of the world breeding area of this species.In the 1970s, three flocks totalling some 60birds were counted between Tangier and Souk-el-Arba-du-Rharb (Pineau & Giraud Audine,1977). Later, Thévenot et al. cited the presenceof the species between Tangier and the middlecourse of the Sebou river. Finally, on 28 Fe-bruary 1982, 58 birds were sighted in threeflocks between Tangier and Asilah (Goriup,1983). Based on these reports, a total of 100birds was estimated for Morocco in the mid-1980s (Collar, 1985; Urban et al., 1986; Johns-gard, 1991; Collar et al., 1994; Del Hoyo etal., 1996).

More recently, various counts have been ca-rried out in Morocco (Alonso et al., 2000; Hell-mich & Idaghdour, 2002). These studies repre-sent the first serious attempts to census thecurrent population in this country. The first sur-veys by Hellmich and colleagues greatly im-proved the knowledge of the species’ distribu-tion (see Hellmich, 1999), and Alonso et al.suggested that a decline in numbers had pro-bably occurred during the last decades. Howe-ver, due to the difficulties inherent in surve-ying this elusive species in a vast region withfew passable tracks, some breeding groups

were discovered only after publication of thestudies mentioned above. Here, an up-to-dateaccount of the species’ status in Morocco ispresented, including a re-evaluation of all re-cently published counts, and new data on num-bers and distribution. For example, males werefound at a site where they had not been sightedin previous studies, and two sites are descri-bed as leks for the first time. New and detailedestimates of breeding success, sex-ratio and agestructure of the population are also presentedand their meaning discussed as indicators ofvarious aspects of its conservation status. Fi-nally, the six years elapsed between the firstand last counts enable suggestion of a demo-graphic trend for this endangered population.

STUDY AREA AND METHODS

The study area comprises ca. 5000 km2 ofhabitat identified as potentially suitable for Gre-at Bustards in previous studies between Tangierand Meknes (see Hellmich, 1999; Alonso etal., 2000; Hellmich & Idaghdour, 2002). Allof these sectors had been visited by Hellmichand his colleagues at least once, and in March2001 most of ca. 30 zones recognized as thebest ones for the species were surveyed. In sub-sequent years, work was concentrated on theseven zones where bustards had been seen du-ring previous surveys (Fig. 1). Within each ofthese sectors, a so-called lek area was delimi-ted, comprising all flocks seen and a fringe ofsuitable habitat surrounding them. For the pur-poses of this study, a lek is defined an aggrega-

80 ALONSO, J. C., PALACÍN, C., MARTÍN, C. A., MOUATI, N., ARHZAF, Z. L. & AZIZI, D.

Ardeola 52(1), 2005, 79-90

los escasos datos de décadas pasadas sugiere que la población debe haber sufrido un descenso moderado a lolargo de las mismas. La proporción de sexos resultó ser extremadamente sesgada, con 3,9 hembras observa-das —4,1 estimadas—por macho. Se encontró una estructura de edades llamativamente joven en la poblaciónmasculina, con un 23,5% de machos inmaduros (rango 11,1-33,3%), valor claramente superior al de las po-blaciones ibéricas de la especie. La tasa anual media de incorporación de jóvenes a la población, medida enmarzo del año siguiente al de su nacimiento, fue de 0,10 jóvenes por hembra adulta (rango 0,045-0,178), va-lor superior al de algunas poblaciones ibéricas amenazadas. Estos datos sugieren que la población estudiadaestá sometida a una elevada mortalidad de machos adultos, lo que fue corroborado mediante numerosos tes-timonios de caza ilegal. El furtivismo se identificó como la principal amenaza para la especie en Marruecos,seguida de las colisiones con tendidos eléctricos. Los datos sugieren que la caza ha debido ser la causa del de-clive numérico observado en varios núcleos reproductivos a lo largo del periodo de estudio. Las otras ame-nazas más patentes son la previsible expansión de la red de tendidos eléctricos y la intensificación agrícola queprobablemente se producirá en las zonas rurales en las que actualmente se reproduce la especie. Es urgente laaplicación de medidas de conservación si se pretende evitar la extinción de esta amenazadísima población deAvutardas.

Palabras clave: Avutarda Común, censo, distribución, Marruecos, Otis tarda.

STATUS OF GREAT BUSTARD IN MOROCCO 81

Ardeola 52(1), 2005, 79-90

FIG. 1.—Map of the study area showing the intensively surveyed areas (white sectors delimited by a solidline), the seven Great Bustard lek areas (black patches) and two areas where bustards were seen only in win-ter (Charkane) or occasionally reported (Ksar-el-Kebir).[Mapa del área de estudio mostrando las zonas prospectadas con mayor intensidad (sectores blancos deli-mitados por línea continua), las siete áreas de lek identificadas (zonas negras) y dos areas más, una de in-vernada (Charkane) y otra con citas esporádicas sin confirmar (Ksar-el-Kebir).]

tion of one or more males with females at tra-ditional places where they gather for matingevery spring.

All spring surveys were carried out betweenlate February and mid March: 11-13 March1999, 4-10 March 2001, 28 February-7 March2002, 2-8 March 2003, and 14-19 March 2005.Only 46 birds were counted in 2003, a signifi-cantly lower total than in other years, probablybecause some flocks were missed at severalleks due to very bad weather conditions thatyear. Thus, it was decided not to use the 2003census to calculate a population estimate thatyear. Each survey was carried out by one(1999), two (2003) or three (2001, 2002, 2005)teams working simultaneously as a rule in thesame lek area, and being in contact through ra-dio. Each team consisted of two observers, atleast one of them with extensive previous ex-perience in censusing the species, operatingfrom a four-wheel drive vehicle, using binocu-lars and telescopes 20-60x, GPS and maps1:50000. An additional survey was carried outby NM in March 2004 to confirm numbers ofbirds at Chekbouchan, and complementarycounts were carried out continuously betweenJune 2001 and February 2002 to confirm num-bers at these leks and help arrive at the springestimate for 2002. Surveys started at dawn andended at dusk, with a pause during midday(11:00-15:30 h GMT), when bustards lie downand become difficult to see. The census itine-rary was carried out at very low speed (< 20km/h), with frequent and prolonged stops atvantage points to carefully look for birds. Be-cause of the terrain difficulties, lack of tracksand inaccessibility due to water courses or wetground, it was frequently necessary to leavethe car and continue walking relatively longstretches to reach hilltops and survey some are-as. Three age-classes were distinguished in ma-les, according to criteria recently developedwith marked birds (unpubl. data; see also ageclasses in Gewalt, 1959): first-year males, tho-se hatched in the previous year; immature ma-les, those aged 2-3 years; and adult males, > 4years. Female ages cannot be distinguished inthe field. The exact coordinates of leks are notgiven in the interests of security for this popu-lation. The names given to leks were those ofthe closest towns.

In spite of long experience surveying GreatBustards, it is extremely difficult to census

them in Morocco. First, because here there arevery few flocks, missing one might alter theresult notably. Second, accessibility to mostlek sites was reduced due to lack of tracks. Andthird, birds were extremely shy and secretive,being active only during very short morningand evening periods, and remained hiddenmost of the daytime, probably due to the fre-quent disturbances caused by numerous shep-herds and local people moving around in thelek areas.

Farmers and shepherds were interviewed du-ring all surveys about the presence or absenceof Great Bustards there in the present and in thepast. They were also asked them about huntingand other mortality causes. Pictures of GreatBustards were shown and they were asked keyquestions about the courtship, nesting and otherbehavioural characteristics to see whether theyknew the species and to judge the reliability oftheir reports. Only when reports from two ormore persons coincided these were consideredreliable and used to guess an estimated numberof birds missed in the counts.

As an index of productivity, the annual re-cruitment of juveniles into the population wasused and expressed as the number of juvenilebirds counted in March per non-juvenile fema-le. To calculate these figures, the juvenile maleswere counted and an estimated number of ju-venile females added. The latter was obtainedmultiplying the number of juvenile males by1.61, the mean sex-ratio of a sample of 843 ju-veniles counted in September between 1995and 2004 in Madrid region. The sex-ratio didnot change significantly between Septemberand the following March in a sample of 328radio-tagged juveniles tracked between 1991and 2003 (pers. obs.). The total number of ju-veniles was then divided by the number of non-juvenile females (= total females minus the es-timated number of juvenile females).

RESULTS

Numbers and distribution in spring

Seven Great Bustard leks were identified, allof them in the northern part of Morocco, northof the Sebou river, and west of the Rif moun-tain chain (Fig. 1). Previous studies had repor-ted males only at four of them (Kanouat, Ara-

82 ALONSO, J. C., PALACÍN, C., MARTÍN, C. A., MOUATI, N., ARHZAF, Z. L. & AZIZI, D.

Ardeola 52(1), 2005, 79-90

STATUS OF GREAT BUSTARD IN MOROCCO 83

Ardeola 52(1), 2005, 79-90

oua, Tendafel and Had-Kourt, Alonso et al.,2000; Kanouat, Araoua, Tendafel and Tleta-Rissana, Hellmich & Idaghdour, 2002). AtChekbouchan and Mrhitane birds were foundfor the first time during the present study, in2002 and 2001 respectively.

The total numbers of birds counted duringthe spring surveys varied between 70 and 84(Table 1). However, these were minimumcounts, which were used to calculate more rea-listic population estimates as follows. First, in1999 and 2001 some leks had not yet been dis-covered and thus were not visited (Chekbou-chan in 1999 and 2001, and Tleta-Rissana andMrhitane in 1999). Therefore, to calculate anestimated total for these two years the num-bers counted in later years at those three lekswere added (see Table 1). In Chekbouchan thiswas justified by the apparent interannual stabi-lity of numbers suggested by the 2002 and2005 counts, as well as by two counts made atthis site on 7 and 26 March 2004 (2 males and13 females on both dates). As for Tleta-Rissanaand Mrhitane, the addition of a minimum esti-mate in 1999 was also justified by the relativestability in counts between, respectively, 2001-2005, and 2001-2002. Second, in 2002 the ma-ximum numbers of females seen at Kanouatand Araoua during complementary surveys ca-rried out in January-February, were consideredas they were considered to be more reliable to-tal estimates than the March count for thesetwo areas. Finally, some reliable enquiry re-sults for Mrhitane and Had Kourt were inclu-ded. The estimates obtained this way for 1999-2005 were, respectively, 99, 98, 90 and 80birds (Table 1).

The sex-ratio was highly female-biased,with more than 3 females per male in 1999-2002, and more than 5 females per male in2005 (Table 1). Values derived from popula-tion estimates varied between 3.29 in 2002 and5.67 in 2005, and the four-year means were3.85 and 4.13 females per male, respectivelyfor the birds counted and estimated. Sex-ratiovaried considerably among leks, with more ba-lanced values at Kanouat and Araoua, wherenumbers of males were highest and extremelybiased values at Tendafel, where a big malewas accompanied by 20-24 females and 1-2immature males in 1999-2002. In 2005 the twomales seen at this lek were apparently of simi-lar size.

Winter census

During the survey carried out in winter2001-2002, Great Bustards were found at fourof the seven lek sites occupied in spring (Table2). Enquiries with local people suggested thatbirds were also present at the two southern si-tes, Mrhitane and Had-Kourt, as well as atKsar-el-Kebir, where a small flock of 5 birdswas reported in December 2001. Only at Ten-dafel Great Bustards were missing, but a flockof 11 birds (10 females with an immature male)was found in Charkane, some 15 km southeastof Tendafel. No birds were found at Tendafelduring additional surveys in November 2000and October 2001 to January 2002.

The number of males counted in winter wassimilar to that counted in spring, suggestingthat all males from Kanouat to Tleta-Rissanawere found, but the number of females was lo-wer. This was mainly due to the absence ofbirds at Tendafel, which was not compensatedby the flock found at Charkane. This suggeststhat some female wintering area was probablymissed.

During a partial count in November 2000, 5males were seen at Kanouat, 12 females with ajuvenile male at Oued-el-Hachef in the north-western part of Araoua, and no birds at Tenda-fel.

Annual recruitment and age structure

Annual recruitment figures were 0.107,0.178, 0.094, 0.076 and 0.045 birds survived upto March 1999 through 2005 from the previousbreeding season (average = 0.100, Table 1; fi-gures calculated from numbers of juvenile ma-les counted in March, as explained in Methods;2003 was included, when 1 juvenile male and36 females were counted). A relatively highnumber of immature males (mean = 23.5%,range = 11.1-33.3% of all non-juvenile males)were also observed in all years at several leks.

DISCUSSION

Current population estimate and distribution

The five complete spring surveys carried outin Morocco between 1998 and 2005 have pro-

84 ALONSO, J. C., PALACÍN, C., MARTÍN, C. A., MOUATI, N., ARHZAF, Z. L. & AZIZI, D.

Ardeola 52(1), 2005, 79-90

TA

BL

E1

Gre

at B

usta

rd s

prin

g ce

nsus

es a

nd e

stim

ates

(in

brac

kets

) in

Mor

occo

199

9-20

05. D

ata

for 1

999

are

base

d on

Alo

nso

et a

l. (2

000)

, tho

se fo

r 200

1 ar

e ba

sed

on o

urow

n co

unt (

12 a

dult

mal

es, 2

imm

atur

e m

ales

, 2 ju

veni

le m

ales

, 41

fem

ales

) com

bine

d w

ith th

at o

f Hel

lmic

h &

Idag

hdou

r (20

02) (

7 ad

ult m

ales

, 4 im

mat

ure

mal

es,

4 ju

veni

le m

ales

, 60

fem

ales

). Se

e te

xt fo

r an

addi

tiona

l cen

sus

in 2

003,

and

foot

note

1 fo

r a c

ompl

emen

tary

cou

nt in

Che

kbou

chan

in 2

004.

The

«T

otal

est

imat

ed»

repr

esen

ts a

min

imum

pop

ulat

ion

estim

ate,

whi

ch in

clud

es, a

t are

as n

ot s

urve

yed

in 1

999

and

2001

, the

num

bers

of a

dult

bird

s co

unte

d in

sub

sequ

ent y

ears

, and

for

som

e ot

her a

reas

, ver

y re

liabl

e en

quir

y re

sults

(see

text

and

foot

note

s fo

r det

ails

). ad

= ad

ults

(>4

year

s), i

mm

= im

mat

ures

(2-3

yea

rs),

juv

= fi

rst-

year

mal

es.

[Cen

sos

y es

timas

(en

tre

paré

ntes

is)

prim

aver

ales

del

núm

ero

de A

vuta

rdas

en

Mar

ruec

os e

ntre

199

9 y

2005

: L

os d

atos

de

1999

est

án b

asad

os e

n A

lons

o et

al.(

2000

), a

quel

los

de 2

001

en n

uest

ros

prop

ios

dato

s (1

2 m

acho

s ad

ulto

s, 2

mac

hos

inm

adur

os, 2

mac

hos

juve

nile

s y

41 h

embr

as)

junt

o a

los

de H

ellm

ich

& I

dagh

dour

(20

02)

(7 m

acho

s ad

ulto

s, 2

mac

hos

inm

adur

os, 4

mac

hos

juve

nile

s y

60 h

embr

as).

Par

a m

ás in

form

ació

n so

bre

los

cens

os d

e 20

03 v

er e

l tex

-to

, y e

l pri

mer

pie

de

la ta

bla

para

cen

sos

com

plem

enta

rios

en

Che

kbou

chan

en

2004

. El t

otal

est

imad

o re

pres

enta

una

est

ima

mín

ima

pobl

acio

nal,

que

in-

cluy

e la

s zo

nas

estu

diad

as e

n 19

99 y

200

1, e

l núm

ero

tota

l de

adul

tos

cont

ados

en

años

pos

teri

ors,

y p

ara

algu

nas

otra

s zo

nas,

dat

os r

eali

stas

obt

enid

os e

nen

cues

tas

(ver

text

o y

pies

de

la ta

bla

para

más

det

alle

). a

d =

adu

ltos

(>

4 añ

os),

imm

= in

mad

uros

(2-

3 añ

os),

juv

= m

acho

s de

pri

mer

año

.]

1999

2001

2002

2005

Lek

s�

��

��

��

���

Tot

al��

Tot

al��

Tot

al��

Tot

alad

.im

m.

juv.

ad.

imm

.ju

v.ad

.im

m.

juv.

ad.

imm

.ju

v.

Kan

ouat

51

08

144

01

38

20

0 (1

) 4

3 (5

) 4

5 (8

) 4

10

04

5

Ara

uoa

41

219

265

11

1926

51

0 (1

) 4

11 (

19)

417

(26

) 4

20

014

16

Cke

kbou

chan

1(1

)(0

)(0

)(1

2)(1

3)(1

)(0

)(0

)(1

2)(1

3)1

21

1216

12

012

15

Ten

dafe

l1

10

2224

11

124

271

20

2023

20

015

17

Tle

ta-R

issa

na 2

(1)

(0)

(0)

(9)

(10)

11

19

121

00

56

11

114

17

Mrh

itane

3(1

)(0

)(0

)(5

)(6

)0

(1)

00

55

(6)

0 (1

)0

05

5 (6

)0

00

0 (6

)(6

)

Had

-Kou

rt2

03

6 5

10

05

60

(1)

01

34

(5)

0 (1

)0

01

(3)

1 (4

)

Tot

al c

ount

ed

123

252

70 5

123

465

8410

52

5976

73

160

71

(Tot

al e

stim

ated

) (1

5)(3

)(2

)(7

8)(9

9) 5

(14)

(3)

(4)

(77)

(98)

(12)

(5)

(4)

(69)

(90)

(8)

(3)

(1)

(68)

(80)

1A

rea

not s

urve

yed

in 1

999

and

2001

, whe

n w

e in

clud

e th

e ad

ults

cou

nted

in 2

002

as a

rea

sona

ble

min

imum

est

imat

e, g

iven

the

stab

ility

in s

ubse

quen

t yea

rs’

num

bers

; in

Mar

ch20

04 o

ne o

f us

(N

M)

also

vis

ited

this

are

a an

d co

unte

d 1

adul

t mal

e, 1

imm

atur

e m

ale

and

13 f

emal

es[Z

ona

no c

ensa

da e

n 19

99 y

200

1, a

ños

en lo

s qu

e se

incl

uye

el c

enso

de

adul

-to

s de

200

2 co

mo

esti

ma

min

ima;

en

mar

zo d

e 20

04 u

no d

e no

sotr

os (

NM

) ce

nsó

de n

uevo

2 m

acho

s y

13 h

embr

as e

n es

ta z

ona,

can

tida

d si

mil

ar a

la d

e 20

02 y

200

5.]

2A

rea

not v

isite

d in

199

9; w

e ta

ke th

e 20

01 c

ount

as

an e

stim

ate

for

1999

[Z

ona

no c

ensa

da e

n 19

99;

tom

amos

el c

enso

de

2001

com

o es

tim

a pa

ra 1

999.

]3

Are

a no

t vis

ited

in 1

999;

we

take

the

2001

cou

nt a

s an

est

imat

e fo

r 19

99; a

ccor

ding

to v

ery

relia

ble

refe

renc

es f

rom

loca

l peo

ple

in 2

002,

one

mal

e ha

s be

en s

een

disp

layi

ng r

e-gu

larl

y in

this

are

a du

ring

the

last

yea

rs a

t lea

st u

ntil

2002

[Zon

a no

cen

sada

en

1999

; to

mam

os e

l cen

so d

e 20

01 c

omo

estim

a pa

ra 1

999;

seg

ún e

ncue

stas

muy

fiab

les

real

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duced total counts ranging between 66 and 84Great Bustards (Hellmich, 1999; Alonso et al.,2000; Hellmich & Idaghdour, 2002, presentstudy). The differences between counts are dueto variable survey effort and success amongyears. For example, sites Chekbouchan and Mr-hitane had not been mentioned at all in earlierstudies, and in the recently published accountby Hellmich & Idaghdour (2002), no maleswere reported in Had-Kourt. These defects ofthe first surveys are reasonable, considering thedifficulties inherent in censusing Great Bus-tards in Morocco. However, this series ofcounts allows a good estimate of the wholeGreat Bustard population in this country, intwo ways. First, adding to the counts the num-bers estimated at areas not surveyed in someyears, and the results of the most trustworthyenquiries. This was done for 1999, 2001, 2002and 2005, obtaining relatively similar figures(80-99 birds), which should be considered themost reliable minimum estimates of the GreatBustard population in Morocco. An alternativeway is to add maximum counts obtained ateach area through the study period. This gave113 birds (26 males, including juveniles, and

87 females). This is a reasonable way to esti-mate lek sizes, provided that breeding dispersalis rare in this species (Morales et al., 2000;Alonso et al., 2001; Alonso et al., 2004).

Nevertheless, it cannot completely discardthat some other breeding groups might haveremained undetected, particularly in the cen-tral and southern parts of the surveyed distri-bution range. In some of these areas, reportsfrom local people suggest birds might still bre-ed (surroundings of Ksar-el-Kebir, Mrhitane,Had-Kourt, and even further south, at Sidi Ka-cem, where the species was considered to beextinct, see Alonso et al., 2000). Hellmich &Idahgdour estimated 90-109 birds in spring, ba-sed on lower spring counts than the ones gi-ven here, with no birds at Chekbouchan andMrhitane, and no males at Had-Kourt (66 birdsin 1998, 30 in 2000, and 75 in 2001). To theirmaximum count they added 15-34 birds esti-mated from interviews with local people. If si-milar guesses are added to these figures, theestimated population size given here couldamount to 100-150 birds.

The only complete winter count availablesupports these estimates at least for males, and

STATUS OF GREAT BUSTARD IN MOROCCO 85

Ardeola 52(1), 2005, 79-90

TABLE 2

Great Bustard 2001-2002 winter census in Morocco. Estimates based on reliable data from enquiries inbrackets. ad = adults (> 4 years), imm = immatures (2-3 years), juv = first-year males.[Resultados del censo de Avutardas en Marruecos en el invierno 2001-2002. Entre paréntesis, datos esti-mados a partir de encuestas muy fiables. ad = adultos (> 4 años), imm = inmaduros (2-3 años), juv = jóve-nes nacidos el año anterior.]

���� Total

ad. + imm. juv.

Kanouat 3 1 5 9

Araoua 8 3 19 30

Ckekbouchan 0 1 9 10

Tendafel 0 0 0 0

Charkane 1 0 10 11

Tleta-Rissana 0 0 5 5

Ksar-el-Kebir (0) (0) (5) (5)

Mrhitane (0) (0) (2) (2)

Had-Kourt (0) (0) (10) (10)

Total counted (estimated) 12 5 48 (65) 65 (82)

shows that some lek sites are abandoned in au-tumn and early winter (Tendafel), whereassome females use some sites preferably or onlyduring the nonbreeding season (e.g., Charkane,the mouth of Oued-el-Hachef, and probably anarea close to Ksar-el-Kebir, see Fig. 1 and Hell-mich & Idaghdour 2002). Up to 50 birds wereobserved in Oued-el-Hachef, at the northwes-tern edge of Araoua lek area, in December1993, 33 in December 1995 (Chahlaoui et al.,1994; Cantronight & Cantronight, 1995), 30 inDecember 1998 (Hellmich, 1999), and 12 and8, respectively in November 2000 and 2001(this study).

Recent and past trends

Although this series of annual counts is stilltoo short, both the total numbers of birds coun-ted and those estimated suggest a decreasingtrend for the population. This trend is particu-larly remarkable among males, which have ap-parently decreased from 12-15 adults in 1999 to7-8 in 2005. The two leks contributing to thedecreasing trend are Kanouat and Araoua. InKanouat only one male remained in 2002 atthe traditional display place. The second maleobserved there in 2002, but not in 2005, was atmore than 2 km east from that place. The de-creasing trend at this lek started in 1998, when7 males and 11 females were counted (Hell-mich & Idaghdour, 2002), and might be in gre-at part attributable to illegal hunting (see be-low). However, the most remarkable changeshave been noticed after the setting up in Ja-nuary 2000 of a shepherd’s hut only 100-200 msouth of the traditional display centre. The se-cond lek showing a decrease in the last threeyears is Araoua, where the number of maleswas relatively stable until 2002, but went downto only 2 males in 2005. Numbers of femaleshave also apparently decreased at these twoleks.

The exceptional sex-ratio at Tendafel, themost extreme we have found in a Great Bustardlek (the second most extreme case was a groupof 17 females with a male in Andalusia, Alonsoet al., 2005), could best be explained by theeffects of repeated male trophy hunting. At ot-her leks males have been either missed (Mrhi-tane), or apparently disappeared in the last ye-ars (Had-Kourt), and trends in females are

uncertain due to the small numbers, so furthercounts are needed to confirm tendencies at the-se sites. The last trustworthy reference of amale at Mrhitane was in 2002, when at leasttwo separate farmers stated they had seen everyyear a displaying male at a very precise site,where we didn’t find it that year, nor in 2005.As for Had-Kourt, the presence of young birdsin our 2002 survey and reliable reports ofchicks seen or captured in some other yearsstrongly suggest that at least one male survivesnowadays. Detailed reports to us in 2002 des-cribing how two large birds (respectively, 16kg and 9 kg) were shot more than a decade agoconfirm that the number of males has decreasedrecently at this site. Finally, various reports gat-hered during our surveys described local ex-tinctions at some areas: a group near Ksar-el-Kebir that disappeared during the mid 1990s,and presence of Great Bustards 20-30 yearsago north of Fez and near Tetouan, where to-day no birds are seen any more.

In conclusion, with the data available it isbelieved that the Great Bustard population inMorocco is still suffering a decrease that startedsome decades ago. Considering the small sizeand fragmentation of this population, any de-crease would seriously threaten its survival.Surveys should be carried out every year in thefuture to confirm this. With respect to thetrends in earlier decades, in a previous study itwas suggested that Moroccan Great Bustardsdecreased at least during the second half of thepast century (Alonso et al., 2000). The estima-te of 100 Great Bustards made by Collar in themid-1980s surely underestimated the popula-tion at that time. However, the scarce observa-tions of Great Bustards cited in the literaturefrom the beginning of last century (Whitaker,1905; Cabrera, 1914) suggest that the specieswas probably never abundant in Morocco, sothe maximum number of birds might have pro-bably never exceeded a few hundred birds.

Threats and conservation prospects

Two results of this study suggest a relativelyhigh turnover rate for the Great Bustard popu-lation in Morocco. First, the annual recruitmentvalues were relatively high, when comparedwith Iberian Great Bustard populations forwhich such data are available. The mean num-

86 ALONSO, J. C., PALACÍN, C., MARTÍN, C. A., MOUATI, N., ARHZAF, Z. L. & AZIZI, D.

Ardeola 52(1), 2005, 79-90

ber of first-year birds counted in spring was0.10, higher than that recorded in Andalusia(0.07 for 2001-2004), and similar to the valuein Madrid region (0.11 for 1997-2004) (ownunpubl. data). Second, a high proportion of im-mature males was found (11-33% of all non-ju-venile males, in comparison with only 7-10%in Andalusia, and 6-22% in Madrid; own un-publ. data). The highest number of immaturemales was recorded in spring 2002, in agree-ment with the high number of juvenile malescounted in March 2001. It is thought that theextreme proportions of immature males cited inHellmich & Idaghdour for 1998 (5 adults, 12immatures) and 2001 (7 adults, 4 immatures)are unrealistic and should be attributable towrong aging. Data here indicate a remarkablyyoung age structure of the male population, andsuggest that Moroccan Great Bustards are sub-jected to a high adult male mortality.

Hunting and other man-induced factors aresurely contributing to such increased adult malemortality, as suggested by the reports obtainedfrom local people during the surveys (Table 3).

In spite of legal protection of the species inMorocco, poaching was by far the main morta-lity cause reported. Although a precise quanti-fication of mortality rates due to different cau-ses cannot be made from data obtained throughinterviews, Table 3 shows that illegal hunting isstill a major threat for the species in Morocco,with at least 20 birds shot in the last 8 years.Hunting might have been not only responsibleof the marked decrease of the population sus-pected to have occurred since about the middleof last century in the whole country (Alonso etal., 2000), it might also be the factor causingthe decreases observed nowadays at Kanouatand Araoua during the present study. Well-do-cumented cases of poaching were recorded atsix of the seven leks, being particularly impor-tant in Kanouat, Tleta-Rissana and Had-Kourt,in terms of number of casualties compared tonumber of birds at the lek. The reported casesincluded birds shot by local hunters at mostareas, trophy hunting by foreign hunters in Ka-nouat and Mrhitane, killing of males by a shep-herd in Kanouat, and shooting of males and fe-

STATUS OF GREAT BUSTARD IN MOROCCO 87

Ardeola 52(1), 2005, 79-90

TABLE 3

Main causes of man-induced mortality of Great Bustards in Morocco. Data from 1997 to 2003, based on li-terature review (see details in Hellmich, 1999; Alonso et al., 2000; Hellmich & Idaghdour, 2002), and from in-terviews with local people during the present study.[Principales causas de mortalidad de Avutardas provocada por actividades humanas en Marruecos. Datos de1997-2003, procedentes de revisión bibliográfica (ver detalles en Hellmich, 1999; Alonso et al., 2000; Hell-mich & Idaghdour, 2002), y de encuestas realizadas durante el presente estudio.]

Collision with Capture ofIllegal powerline young birds Other All causes

hunting [Colisión [Captura causes [Todas[Caza ilegal] con tendidos de aves [Otras causas] las causas]

eléctricos] jóvenes]

Kanouat 2 1 3

Araoua 3 1 4

Chekbouchan 2 2

Tleta-Rissana 7 7

Mrhitane 1 1

Had-Kourt 4 2 6

Other areas 1 1 5 1 7

Total casualties 20 7 2 1 30

1 Hunting southwest of Had-Kourt; collisions with powerlines east of Ksar-el-Kebir in 1997; collison with aircraft atTangier airport in 1997.

males at waterholes in Araoua. The shepherdwho settled at the lek centre of site Kanouat inJanuary 2000 used to hunt Great Bustards. Hedescribed in detail how he shot at a male thatfinally escaped on the morning of 25th March(Hellmich & Idaghdour, 2002). In that area se-veral people reported us that they had seen the-re three hunters from Saudi Arabia in 1998. Atleast two adult males were known to be killedin March that year (Hellmich, 1999). In March2003 we found two cartridge-cases at the dis-play site in Tleta-Rissana, and the local shep-herd confirmed us that poachers used to cometo hunt bustards. Finally, the incidence of hun-ting in Had-Kourt could be the cause of maledisappearance at this site. Two farmers told usthat some local people used to hunt them fortheir meat.

The second most important mortality causeidentified was collision with powerlines, withseven casualties reported in the last years, inspite of the poor development of the electricitynetwork in most Great Bustard areas. Finally, atleast in Had-Kourt there are reports of localpeople capturing young birds in summer.

In Spain hunting has been identified as themain factor determining population decreasebefore the hunting ban was established in 1980.It caused the extinction of many breedinggroups at marginal areas of the species’ distri-bution range (Alonso et al., 2003). Today themain adult mortality cause, not only in Iberiabut also in other European countries, is colli-sion with powerlines (Reiter, 2000; Martín,2001, T. Langgemach, pers. comm., R. Raab,pers. comm.). Hunting and collision with po-werlines affect males more than females (pers.obs.). These mortality causes have surely con-tributed to the extremely female-biased sex-ra-tio found in Morocco. In the Andalusian po-pulation in southern Spain, which has beensubjected to severe hunting pressure during thelast decades, sex-ratio is also markedly biasedtowards females (3.28 females per male in An-dalusia, southern Spain, Alonso et al., 2005).These values contrast with those of other Spa-nish populations with a better conservation sta-tus (1.35-1.56 females per male in León, and1.21-1.40 in Cáceres, Alonso & Alonso, 1990;1.7 in Villafáfila, Alonso et al., 1996; 2.42 inthe Madrid region, Alonso et al., 2003).

The development of Moroccan rural areasthat might be expected at an early date will su-

rely bring about an expansion of human infras-tructures, as well as an intensification of agri-culture. The growth of the current powerlinenetwork will mean an increase in Great Bustardadult mortality. As for the progress in roadbuilding and farming techniques, they will pro-duce a decrease in habitat quality and a conse-quent decline in productivity, as has happenedin many Iberian populations (Palacín et al.,2004). One of these roads, the new highwayRabat-Tangier, will cause a significant reduc-tion of the habitat available, particularly at Ka-nouat and Tendafel. At Kanouat the highwaycrosses the western and eastern sectors of thedisplay area, and at Tendafel it has been built atless than 500 m of the male display site. Thewestern part of Kanouat will also be affectedby the recently opened 350-400 megawatt po-wer station at the Tadahart river mouth. In HadKourt a network of wide roads for farm traffichas been built in 2004. It is conceivable thathunting pressure, currently the major threat forMoroccan Great Bustards, will decrease in fu-ture years, but probably not before all other ne-gative factors have begun to show their effects.

Finally, the Moroccan population is probablytoo isolated to receive dispersing males fromthe Iberian Peninsula. Two genetic studies ofthe Afro-Iberian Great Bustard population haveshown that Moroccan birds descend from Ibe-rian ones (Alonso et al., in press), and that bothpopulations have been isolated from each otherfor a long time (Broderick et al., 2003). This iscorroborated by the absence of direct observa-tions of birds crossing the Straits of Gibraltar,in spite of frequent birdwatching in this region(Finlayson, 1992; SEO/BirdLife, 1999; 2001).Moreover, the extremely endangered status ofGreat Bustards in southern Spain, and particu-larly in Cádiz, the southernmost Andalusianprovince, where only one adult male but no fe-males have been sighted in the last years (ownunpubl. data), make immigration from Iberiaeven more improbable. Thus, the survival ofMoroccan Great Bustards depends on protec-tion measures taken at their breeding areas.

In conclusion, it seems that the Great Bus-tard population in Morocco has suffered a mo-derate decrease through the last decades, whichcontinues nowadays, at least at some leks. Ho-wever, the scarce data available suggest thatnumbers were never very abundant in thiscountry. Perhaps natural and man-induced mor-

88 ALONSO, J. C., PALACÍN, C., MARTÍN, C. A., MOUATI, N., ARHZAF, Z. L. & AZIZI, D.

Ardeola 52(1), 2005, 79-90

tality has been compensated for many decadesby the species’ productivity, which is not aslow as one would expect from the high den-sity of rural people and domestic animals mo-ving around in the field. More concerning arethe very recent and current decreases at someleks, caused mainly by illegal hunting, and thenegative prospects derived from developmentprojects, mainly the foreseeable extension ofthe powerline network, and the agriculture in-tensification. Immediate conservation actionsare urgently required if this population, one ofthe most endangered of this species worldwide,is to be saved from a very probable extinctionin the next few decades.

ACKNOWLEDGEMENTS.—We thank Damien Bro-derick, Mohamed Dakki, Bob Dawson, JoachimHellmich, Youssef Idaghdour, Ahmed Jaafari, Si-mon J. Lane, Beatriz Martín and Abdeljebbar Qninbafor their collaboration in some of the counts. Thanksalso to Diego Jerez Abad for providing useful data tointerpret counts at some areas, to the families of Z.Arhzaf and D. Azizi, as well as the guards KassimiHamid and Tamar El Manti for their hospitality, andin general to all local people for their kindness andreports. Matilde Sánchez Ayuso and Adela Martí-nez, of CSIC, and the personnel of the AECI helpedduring various stages of the project. The study wasfunded by the Agencia Española de Cooperación In-ternacional (AECI) of the Ministry of Foreign Af-fairs, through project Viabilidad de la población deAvutardas de Marruecos. Bases científicas para suconservación (2000-2003) to J. C. Alonso. The 1999survey was co-financed by the British EcologicalSociety and the International Foundation for Con-servation and Development of Wildlife, Inezgane,Morocco. The 2005 census was part of a Spanish-Moroccan cooperative project between the ConsejoSuperior de Investigaciones Cientificas (CSIC) andthe Centre National pour la Recherche Scientifique etTechnique (CNRST) (principal researchers, J.C.Alonso, CSIC, and M. Dakki, Institut Scientifiquede Rabat).

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