Geographic Range
The range of
Mustela subpalmata
is restricted to the lower Nile Valley, from Alexandria in the west to Port Said
in the east and from the Delta south to Beni Suef.
- Biogeographic Regions
- palearctic
Habitat
Egyptian weasels are terrestrial animals mostly found in urban areas living synanthrophic
with humans. Only a few specimens have been collected outside cities; mostly on cultivated
fields. They are often found in public buildings and houses, where they regularly
get trapped in underground food stores. They are considered as common to abundant
with densities estimated from trapping ranging from 0.5-1 individuals/ha.
- Habitat Regions
- temperate
- terrestrial
- Other Habitat Features
- urban
- suburban
- agricultural
Physical Description
Egyptian weasels have a distinctive mustelid body shape; long, elongated and slender body with short legs and tail. They are very small carnivores with an average body size, which is measured as head to body length (HBL), of 289 mm in males and 242 mm in females. The average tail lengths for males and females, respectively, are 116mm and 99mm, which are approximately 30-40 % of the body size, whereas the tail in least weasels ( Mustela nivalis ) is less than 25%. The size of Egyptian weasels is larger than the closely related least weasel. Head sizes also exceed those of the least weasel but are in general small and flattened with a short and broad rostrum. An unusual feature can be found in M. subpalmata and weasels in general; the sagittal, nuchal and lamboidal ridges (crests) are present and pronounced. The zygomatic arch is widely separated (wider than M. nivalis ) and is not strongly curved upwards. They also lack the postorbital swelling, which is found in other mustelids in Africa, and the bulla is not fused with parapterygoid. The pinnae of M. subpalmata are small. They walk with a plantigrade posture with 4 whitish digits on each foot. The dental formula of this specific species has not been studied but for the subfamily Mustelinae it is I 3/3,C 1/1,P 3/3,M 1/2=34, where the upper M2 is reduced to a simple form in M. subpalmata . The canine is pronounced and the outer upper incisor is faintly larger than the two other incisors.
The appearance of M. subpalmata is brown dorsally, and the ventral side varies from white to creamy yellowish with an unequal margin between the two sides. The tail is unicolor with a slightly darker tip in comparison to the body and tail. A general weasel characteristic is that they molt twice a year; in spring and in autumn. The Egyptian weasels remain their same brownish color, whereas winter whitening of the fur occurs at higher latitudes in related species such as the least weasel. The Egyptian weasel does not have the same thermoregulatory issues as smaller weasels living in higher latitudes. The mustelid body is small, long and slender, which means a high surface area to volume ratio, resulting in high metabolic requirement but specific metabolic rates have not been measured in M. subpalmata .
Sexual dimorphism is present in Egyptian weasels but not pronounced compared to least
weasels. The mean condylobasal length of female Egyptian weasels comprises 90 % of
the males. This is an overestimation of what could be expected from a weasel of that
size according to existing literature. The average body mass of females is 200 g according
to Flower (1932) and in average 209 g according to Handwerk (1993). The average body
mass of males is 390 g.
M. subpalmata
usually has four pairs of nipples. The average baculum (os penis) size of males is
25.90 mm and is described as slender, grooved below with a hooked distal end.
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- male larger
Reproduction
The mating system has not been described in this species but the closely related species
M. nivalis
has a polyangyndrous mating system, which means that both males and females have
multiple copulations with multiple partners. Individuals of
M. subpalmata
are solitary and territorial. Males, which are larger than females, also have larger
territories, usually overlapping several females. The two sexes avoid each other except
during the breeding season as the female are subordinate to males most of year. In
the breeding season the opposite takes place; females defend themselves vigorously
against unwanted males. Egyptian weasels use urine and scats to mark of their territory,
which is typical of male carnivores. Females mainly defend their territories against
other females. Both sexes defend themselves vigorously and strongly when facing stressful
situations. The courtship sound repertoire includes trilling and chattering. After
copulation both sexes rest either together or separately and will either continue
copulation or find new mates.
- Mating System
- polygynandrous (promiscuous)
Breeding occurs around April and August and litters have been recorded in August and
December. Mating occurs only when the female weasel has reached full estrus and mating
is vigorous, loud and prolonged. Ovulation is induced and an outer physical stimulation
is needed. The male baculum (os penis) has a key role in ovulation as ovulation only
occurs when the male baculum (os penis) stimulates the female upon copulation. Female
M. subpalmata
have a gestation period of 4-5 weeks. They build nests in any opening like a crevice
in a wall etc. The young of
M. subpalmata
are called kits and dens with kits found in Egypt have contained between 4-9 kits
per litter. Studies of litter size in this species are lacking but in the close relative
M. nivalis
the average litter size is 5.1 ± 2.3 SD. Depending on food availability they can
have 2-3 litters per year. Kits are born helpless and naked. They develop hunting
behaviors approximately 10 weeks after birth and soon afterwards become independent
juveniles. They reach sexual maturity around 4-8 months after birth.
- Key Reproductive Features
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- induced ovulation
Specific studies regarding parental care have not been done on
M. subpalmata
but the general mustelid pattern has been well described. The male weasel does not
contribute to parental care after copulation. All parental care is given by the female
weasel. Maternal care includes huddling (kits are born naked) and lactation over 4-7
weeks.
- Parental Investment
- altricial
- female parental care
Lifespan/Longevity
M. subpalmata
does not usually live longer than 1 year.
Behavior
Egyptian weasels are commensal with humans. They are solitary and highly territorial.
The larger male territories can overlap with several female territories. The boundaries
of territories are marked by scent from faeces, urine and a scent producing gland.
A general mustelid character is that subordinate males and females avoid encounters
with larger, dominant males. The only exception is during the breeding season when
males seek for mates. They are mainly nocturnal but can be seen during the day. A
typical interaction with humans is running across the street at night and hiding underneath
nearby parked cars.
- Key Behaviors
- nocturnal
- motile
- solitary
- territorial
Home Range
The home range and territory size of M. subpalmata are not known.
Communication and Perception
Mustela subpalmata
relies on several senses in hunting and perceiving the environment. They have good
sight and hearing; the main sense used in hunting rodents is olfaction. They have
a sharp, barking alarm call. A general mustelid characteristic is that they communicate
via scent. Scent is used to communicate between neighboring weasels and to advertise
territories. The scent producing gland used to mark territories is located along the
dorsoventral and ventral sides of the body. When marking territories they rub their
body on the ground releasing a substance. Other substances such as scats and urine
are also used in mark routes. The use of scents to communicate with other weasels
and how they perceive these scents has not been studied in
M. subpalmata
. In another closely related species, the stoat or the short-tailed weasel (
Mustela erminea
), dominant individuals show no obvious reaction when encountering the scent of a
subordinate weasel but if a subordinate detects the scent of a dominate individual
they show signs of anxiety. Subordinates will then look for escape routes while simultaneously
calling out trilling calls that imitate the sound of young weasels, to mitigate the
response of the dominant weasel.
- Other Communication Modes
- scent marks
Food Habits
Mustela subpalmata
is an opportunistic feeder; for example they scavenge at restaurants and eat insects,
fish etc. in major cities. Contrary to their European relatives, rodents do not apparently
play a big part in their diet. The diet is unusual for a weasel as it contains a high
percentage of fruit and vegetables (≈50%), including grapes, dates, wheat (bread)
and beans. This diet emphasizes the opportunistic lifestyle of this species; living
in an urban space with a lot of markets and food stores. Their diet does include some
small mammals (
rats
, house mice (
Mus musculus
) and the common rabbit (
Oryctolagus cuniculus
) (2%)), chicks and ducklings (23%), fish leftovers (1%) and insects such as cockroaches
(11%). In addition they will scavenge in trash bins and waste heaps.
- Primary Diet
- omnivore
- Animal Foods
- birds
- mammals
- fish
- carrion
- insects
- Plant Foods
- seeds, grains, and nuts
- fruit
Predation
Data available for this particular species are lacking but some of the predators of
closely related species likely prey on Egyptian weasels. Possible predators include
raptors
,
crows
feral and domestic cats (
Felis catus
) and dogs (
Canis lupus familiaris
),
foxes
and large owls (
Strigidae
).
Ecosystem Roles
A disease of concern in Egypt, schistosomiasis, is caused by trematodes such as
Schistosoma mansoni
and
S. heamatobium
.
Mustela subpalmata
is not a good host of these trematodes; the susceptibility is poor.
Mustela subpalmata
is commensal with humans mainly in the larger cities in Egypt. They may regulate
rodent populations but their role in rodent population dynamics has not been studied.
The closely related
M. nivalis
plays a vital role in regulating lemmings in the tundra.
Economic Importance for Humans: Positive
The Egyptian weasel consumes a substantial amount of fruits and berries (≈50%) but
it also hunts pest rodents living in inhabited areas.
- Positive Impacts
- controls pest population
Economic Importance for Humans: Negative
Mustela subpalmata
lives in closely association with humans and prey upon domestic livestock such as
chicken and hens, as well as eating fruit from markets.
- Negative Impacts
- household pest
Conservation Status
Although
M. subpalmata
is found in a restricted geographic range, it is still considered as the category
of Least Concern on the IUCN. The species lives commensalistic with humans where it
is common and considered adaptable. The species has currently no known threats.
Other Comments
The population of weasels in Egypt is considered as a post-glacial relict of more
widely distributed populations that occurred north and east into Israel, as fossils
found in Shaar Ha'amaqim reveal. Until recently the Egyptian weasel was considered
to be a subspecies of the least weasel, and was named
Mustela nivalis subpalmata
. It has been treated as its own species
Mustela subpalmata
in the literature since 2000 and was given species status by Wozencraft (2005). This
new taxonomy is based on its unique cranial morphology, larger body size, and lower
degree of sexual dimorphism. The population in Egypt has been isolated from
Mustela nivalis
in Europe since the last glacial period.
Additional Links
Contributors
Morten Swayne Storgaard (author), University of Manitoba, Jane Waterman (editor), University of Manitoba.
- Palearctic
-
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- urban
-
living in cities and large towns, landscapes dominated by human structures and activity.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- induced ovulation
-
ovulation is stimulated by the act of copulation (does not occur spontaneously)
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- female parental care
-
parental care is carried out by females
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- solitary
-
lives alone
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- carrion
-
flesh of dead animals.
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
References
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