IDENTIFICATION
A medium-sized owl (29–38cm), generally disc. Upperparts sometimes with
very
fine speckles. Facial disc distinctly rimmed. A Blackish-brown area
surrounds
dark brown eyes. Erectile ear-tufts very tiny and mostly invisible, set near the center of the forehead. Wings and tail barred tawny and dark
brown. In-flight
shows prominent dark wrist-patch, visible from above and below; upper
primaries
with rather plain tawny bases. Below, diffusely vermiculated dusky on
paler
brown, appearing rather plain (birds from Madagascar more finely barred
below).
Tarsi feathered; toes partly covered with short plumes; outermost tips
rather
bare.
Similar species
Short-eared Owl is generally pale yellowish-brown with distinct dusky
streaking, especially on underparts; eyes pale yellow. Long-eared, Abyssinian
Long-eared and Madagascar Long-eared Owls have prominent ear-tufts, yellow to
orange eyes, and boldly patterned underparts. Tawny Owl is more boldly
patterned, has a broad, rounded head and large blackish-brown eyes (lacks
blackish mask), and has whitish outer webs to scapulars. African Wood Owl has
barred underparts and a whitish scapular stripe. Eagle owls (Bubo) are larger,
with prominent ear-tufts. African fishing owls have bare tarsi and toes.
African Grass Owl is larger, dark brown above and pale below, has heart-shaped
facial disc with relatively small, blackish eyes and relatively long legs with
bristled toes.
VOCALISATIONS
Little studied. Very different from all other members of this genus. Most
common is a hoarse, grating call, uttered when perched or when circling
overhead and clapping wings in the display, sounding like the noise produced by
breaking a dry branch by bending it slowly, kerrrrrrrr; being repeated at
variable intervals. This vocalization might be the territorial song, often
accompanying wing-clapping. Also gives sequences of croaking, raven-like calls
on the wing: quarrk-quarrk-quarrk.
Female utters similar
but higher-pitched and softer calls. These vocalizations might perhaps express
aggression against intruders. Female and fledged young utter far-carrying,
wailing hisses with ventriloquially character: shooeeh. If disturbed at the
nest, both sexes may fly around with croaking calls and high mewing screams.
DISTRIBUTION Africa and Madagascar. An isolated population exists in extreme NW
Africa in Morocco. Patchily earth-brown, with a rounded head and distinct pale
facial distributed south of the Sahara from Senegambia and Ethiopia to the
Cape.
MOVEMENTS
In general resident, but partly nomadic within sub-Saharan Africa and an
intra-African migrant. Stragglers have been observed in S Iberian Peninsula and The Canary Islands. Displacements are generally caused by responses to food
abundance (e.g. rodent plagues) or shortage or are the result of bush fires,
floods, etc.
HABITAT
Open country from coastal marshes to savanna, with or without scattered trees
and bushes; also, inland marshes, moors, and montane grassland, from sea-level
up to c.3000m. Avoids extensive long grass, but favors terrain with short
vegetation and some patches of long grass or weeds. Locally in rice fields and
drainage strips in wooded savanna (‘dambos’), sometimes open areas near or even
in human settlements. Absent from forested areas, rocky landscapes, and deserts.
DESCRIPTION
A. c. capensis Adult Sexes alike, but males generally paler than
females;
individually variable in tone. Facial disc pale buff, with the dark
brown area
around eyes; distinct facial rim dark brown with buff speckles.
Ear-tufts
earth-brown, very tiny and barely visible, set near the center of the
forehead.
Upperparts plain earth-brown, crown, and nape finely vermiculated buff,
upper tail-coverts barred buff. Primaries with rather plain, pale
tawny-buff
bases, contrasting with a dusky patch at the wrist; rest of flight feathers barred
dark brown and tawny-buff. Tail dark brown, barred pale buff, with whitish tip.
Underparts brown, finely vermiculated buff, becoming more uniform pale
buff on
thighs, belly, and under tail-coverts.
Underwing-coverts
buff with dark brown wrist patch, very conspicuous in flight. Tarsi
feathered
pale tawny-buff; toes covered with pale buffish plumes, leaving tips
bare.
Juvenile Downy chick covered with buffish down, has pink skin, blackish bill, and pink toes. Mesoptile buff barred brown above; facial disc
darker than
an adult, with the marked blackish rim. After molt (at c.10 weeks),
distinguishable
from an adult by buff tips to scapulars and lower back feathers. Bare
parts Eyes
dark brown. Cere grey-brown. Bill blackish-horn. Bare parts of toes dark brown.
Claws blackish.
MEASUREMENTS AND
WEIGHT - Total length 31–38cm. Wing 284–380mm, tail
132–186mm. Weight 225–485g.
GEOGRAPHICAL
VARIATION - We distinguish three subspecies. A. c. capensis
(A. Smith, 1834). Africa south of Sahara. See Description. Wing 285–330mm, tail
132–163mm. Weight: males 243–340g, females 305–376g. A. c. tingitanus (Loche,
1867). Morocco, rarely straggling to S Iberia and Canary Islands. Darker than nominate,
with rufous wash and some small whitish markings, especially below. Wing
284–312mm, tail 132–153mm. Weight 310–350g. A. c. hova Stresemann, 1922.
Madagascar. Largest subspecies. Underparts more barred and spotted; pale parts
of primaries paler. Bill and talons are more powerful than in other races. Wing
322–380mm, tail 176–186mm.
Weight of one male
485g. HABITS Occurs singly or in pairs, sometimes in larger numbers (especially
outside breeding season). Mostly crepuscular and nocturnal, but sometimes also
active during cloudy days. By day, normally roosts on the ground in a hollow
among grass or other vegetation. At dusk or by night, often perches on fence
posts, stumps, or tops of bushes watching for prey. May be aggressive near the
nest or feign injury in order to distract potential enemies. Flight very
similar to that of a harrier Circus.
FOOD
- Depends largely on availability. Normally small rodents form the major part
of its diet, but sometimes small birds may be predominant; also takes other
small vertebrates and insects. Prey includes mice, voles, rats, shrews, young
hares, bats, birds up to the size of small ducks and doves, frogs, lizards,
scorpions, beetles, grasshoppers, termite alates, etc. Most prey is captured by
flying close to the ground with slow but powerful wingbeats, interspersed with
fast swerves and hovering, before dropping on to victim; sometimes hawks flying
insects, even those attracted by streetlamps in urban areas.
BREEDING
- Monogamous and territorial. Sometimes nests in loose colonies. Territories
are normally 0.8–2km2 in size, sometimes smaller when the population is denser; in
South Africa, nests have been found c.75m apart. Hunting areas of neighboring
pairs may overlap. Male claims territory by circling over it, clapping wings
and croaking; during courtship, pair-members often fly in wide circles at dusk
and on moonlit nights, with wing-clapping and croaking calls (song?).
Copulation normally occurs on the ground. A hollow within a patch of tall grass or
weeds, often beside a bush and with an ‘entrance tunnel’ from one side, is used
for nesting, vegetation often being pulled over by the female to form a canopy.
The depression itself is lined with some dry leaves to form a pad (this is
probably done by the female but needs confirmation).
In Morocco, a nest
was found c.4m above ground in an old corvid nest in a bush, the only known
case of a nest not at ground level. Locally, nests in close vicinity to African
Grass Owl; in one case the nests were only 20m apart. Nesting normally occurs
towards the end of the wet season. The female lays 2–6 (normally three) white
eggs (40 x 34.1mm), at intervals of about two days, and incubates alone,
starting with the first egg. During incubation she is fed by her mate, who
brings food to the nest in its talons, calling as he approaches. He lands at
the nest, walks in through the tunnel, and delivers food mostly from bill to
bill, but the female sometimes snatches it from his talons. If food is
abundant, items may be cached at the nest by the female, or in deposits outside
by the male. Incubation lasts 27–28 days for each egg.
Chicks’ eyes open at
seven days, and by ten days the facial disc is well developed, already showing
characteristic blackish mask and black rim. Up to this age, they are regularly
brooded by the female. At 18 days (sometimes as early as 10–14 days), when
young still appear downy, they begin to leave the nest and scatter in the
surrounding vegetation. An adult defended its chicks by chasing off an African
Marsh Harrier Circus ranivorus. Adults carry food directly to their offspring,
the young indicating their position by calls and trampling movements. When 30
days old, young have acquired most contour feathers. By 70 days they are fully
feathered but are able to fly earlier, by 29–35 days. Both parents care for
them for some time before they become independent.
STATUS AND
CONSERVATION Uncertain. The NW Moroccan population
is declining and endangered by habitat loss and disturbance. South of the
Sahara, locally common in years with abundant food. Is affected by bush fires,
floods, overgrazing by cattle, and the use of pesticides. Some are killed by
road traffic or by entanglement in barbed wire fences.
REMARKS
This species, the ecological counterpart in Africa of the Short-eared
Owl has been
assumed to be a close relative of the latter, but we believe the
similarities
in ecology and external appearance are due to convergence and not to
the relationship. Their totally different vocalizations support this
view. In any
case, it would be unwise to consider the two as comprising superspecies,
and
certainly not as members of the same species. The Marsh Owl’s
vocalizations, behavior, reproductive biology, taxonomy, and DNA
relationships need further
study.