Last update: November 24, 2010 12:35:59 PM E-mail Print

 

The Kudu  Tragelaphus strepsiceros  (Pallas, 1766)

 

Deon Furstenburg

ARC-Range & Forage Institute Grootfontein

 


The kudu is one of Africa’s most gracious and handsome antelopes, especially because of the magnificent spiraled horns.  Encounters are often recalled with adoration around camp fires after a day in the bush.  It is the only indigenous antelope at present enlarging its distribution on own acount.  In result of its common presence across more than half of South Africa, it has received little attention from biologists until the study of Allan-Rowlandson in the Andries Vosloo Kudu Reserve in the 1970's.  Very much as for the impala Aepyceros melampus, kudu has long been recognized only as a bonus source for biltong.  More recent the kudu-hunt has become the outdoor adventure for accumulated stress relieve to city dwelling business men.  The well saughted kudu-hunt has become a high priced luxury being the major source of income to many a landowner. 

 

Taxonomy & Distribution

Kudu was first described from a specimen from the Cape of Good Hope and classified in the family Tragelaphinae – spiral horned antelope.  Its name originates from the Hottentot or Khoikhoi word ku:du.  Two species and three sub-species are recognized: Tragelaphus strepsiceros strepsiceros, the southern greater kudu; T.s. bea, the east African greater kudu; T.s. cottoni, the northern greater kudu; and T.s. imberbis, the lesser kudu.  Other closely related species are: the sitatunga T. spekei, the bongo T. eurycerus, the nyala T. angasii, the mountain nyala T. buxtoni and the bushbuck T. scriptus.  Only the southern greater kudu, the nyala and bushbuck are to be found  naturally in the southern sub-region of Africa.  In former times kudu extended across Europe and Asia, their fossiled remains being known from Pliocene and Pleistocene deposits.  It indicates that kudu might have originated in the northern hemisphere, only to have spread into Africa more recently, with the African Savanna or Miombo Biosphere to have become its present destination.

Within South Africa kudu used to roam the entire country north of the Orange river (excluding the Free State and the Lesotho Highlands), Namaqualand, most of the Karoo regions (including Laingsburg, Beaufort West and Murraysburg), the southern coastal regions (including the outer skirts of the Tsitsikamma), as well as the major parts of the eastern Cape (excluding the former Transkei) and most of Kwazulu Natal.

Kudu first became known through Kolbe’s book on “De Kaap de Goede Hoop” in 1727.  In 1764 it  was known as “Le Condoma Coësdoës” after Buffon’s sightings in the Albany district, eastern Cape.  Evidence exists that when the Cape were colonized kudu “koodoos” were found in the locality where Cape Town is today situated.  The eastern Cape kudu became isolated from the rest of South Africa’s populations by human settlement.  The eastern Cape kudu retarded to the Valley Bushveld areas of the Sundays and Great Fish river valleys.  At present it is being managed as a own sub-population differing in size and trophy quality.  Due to the ever expanding game industry over the past two decades kudu distribution is rapidly enclosing to its former ranges.  The present gap between the eastern cape and northern Cape kudu is less than 200km and shrinking.

 

Animal Characteristics

Shoulder height of adult females ranges from 119 to 141cm (avg. 134) and for males 128 to 152cm (no average – dependant upon the post-adult age).  Adult males of the greater kudu is generally 35% taller than the lesser kudu (98cm shoulder height) and double in body mass (170-300kg) than the lesser kudu (104kg).  Kudu from the eastern Cape is markedly smaller than for the rest of southern Africa.  Adult female (>3 years age) varies between 110 and 210kg.  The weighed mean for 220 eastern Cape adult females is 136,8kg whereas for the Lowveld it is 155kg.  Maximum mass for females is reached between the age of four and 5 years, following a slight depletion with ageing thereafter.  Males do not reach an average maximum body size before the age of 12 years.  After adult maturity has been reached at 4 years, bulls keep growing with ageing.  Maximum body size (260-315kg for 280 weighed animals) is reached only at the end of the natural life span (12-16 years).

Young experimental males that were marked by Allan-Rowlandson in the Great Fish river valley had been killed by locals 12 and 14 years later (still in the same area).  A 1-year male that was caught in a livestock fence near Kirkwood had a hole drilled through its horn.  The animal was shot 9 years later in the very same camp (yet it had free movement as the farm was not game fenced).  With the pressure put upon the farming industry by the present socio-economic environment, the life span of kudu bulls has been reduced to 9-11 years.  Adult cows living on natural food resources rarely passes the age of 9 years.  The majority of females die after 6-8 years during the depletion phase coinciding with the frequent droughts and cold-wet spills of the winter seasons.  Main source of death being hypothermia and related pneumonia in collaboration with poor body condition.

Both sexes have a mane on the neck, continued as a whitish dorsal crest from which descent nine to 10 vertical white stripes on each side of the body, the number being less (6-8) in the east African kudu.  East African kudu is more rich in colour than the paler greyish of the southern kudu.  The northern kudu has 4-7 stripes, is smaller and much paler than the southern forms.  Ageing bulls (>8 years) become greyish-blue and the hair dull and less furry.  For adult cows the hair gets dull and starts wearing away after 5 years – hairless patches starts appearing after 6-7 years.  The underside of the short bushy tail is remakedly white as seen from the tail-up flashes when the animal is in flight.  The flashes acts for other members of the group to follow the leading swiftly when in flight.  The ears are large and mobile with a distinct white stripe on the inner edge.  Often it is only the slight flick of an ear giving away the presence of an animal.  Kudu are highly cryptic camouflaged and it takes a well experienced eye to sight them.

Kudu spoor shows a slightly elongated double hoofed print with sharp pointed front end and rounded rare end.  Front spoor is slightly larger (5-6 x 3-4cm than the hind (4,5-5,5 x 3-4cm).  The spoor of most mature bulls (>8 years) are more round at the base and less sharpened at the end – it increase with ageing to 8,5 x 5cm.

 

Kudu Information Table

Characteristic                                      Bull                                          Cow

Adult body mass                    174-315kg, Avg 235kg       110-210kg, Avg 155kg

Adult shoulder height              128-152cm                  119-141cm

Sexual maturity                    21-24 months               15-19 months

Social maturity (first mating)     5 years                    3 years

Gestation period                                              250-260 days

Calving interval                                              10-15 months

Fecundity                                                     93%

Last mating                        9 years                    9 years

Mating (Rutting) season                        April - July

Calving season                                                December - May

Weaning age                                    135-165 days

Sex ratio of population (natural)  1             :            1,1

Sex ratio adults (natural mating)  1             :            1,4-1,8

Sex ratio adults (production)      1             :            2,5-4,2

Sex ratio population (production)  1             :            1,6

Sex ratio calves born              52%           :            48%

Annual population growth           19% (13-28%)

Expected life span                 12-16 years                7-9 years

Home range                         90-600ha                   90-600ha

Territory                          None                       None

                                               

Trophy

The magnificent horns, usually borne by males only, are spread in beautiful open spirals.  No scientific proof exists for the claims that narrow horns relate to bush dwelling or mountainous kudu and wide horns to plains kudu.  Both forms are frequently found in all habitats inhabited by kudu.  Narrow-horned kudu appear to be more mobile in thickets than wide-horned, thus they are more frequently seen on the move in thicker vegetated areas, where as wide-horned kudu tend to rather conceal themselves than to move, when man approaches.  Cows bearing horns is not outrageous but generally the horns are inferior (undersized and\or deformed).  A 37 inch female trophy with a 3¾” circumference and 217/8" tip to tip width had been recorded by F.C. Selous in 1888.  Rowland Ward minimum trophy quality is generally reached only after 7 years.  Trophy quality increases with the depth of the spiral.  Looking from tip to base along the inside core of the horn the quality can easily be defined.  The greater the diameter of the spiral the better the trophy quality.

 

Rowland Ward Trophy Records

Southern Greater kudu T. s. strepsiceros

Minimum qualifying length = 537/8" (136,84cm)

I.     737/8" (187,64cm), Mozambiek, 1963, Carlo Caldresi (picked up)

II.    691/4" (175,90cm), Lydenburg, RSA, 1916, P.G. Rous

III.   675/8" (171,77cm), Marble Hall, RSA, 1996, J.H. Harmse

IV.    67" (170,18cm), Zambia, 1953, R.B. Eitken

V.     655/8" (166,69cm), Louis Trichardt, RSA, H.I.H. Prince Abdorreza of Iran

                Eastern Cape, RSA (maximum)

                1)             58" (147,32cm), Alice, 1994, John William Rance     

 

Habitat Requirements and Distribution

Kudu are widespread in the Savannas of east and southern Africa, ranging from Sudan and Ethiopia in the north to the western and eastern Cape in the south.  Their wide distribution indicates high adaptability, but their use of a specific habitat is reliant on the density of woody plants.  Tree density is the most critical parameter governing their choice of habitat.  Kudu are seldom found in entirely open country, although they may be attracted temporarily by food such as dicot forbs and dwarf succulents.

Trees provide the main fodder resource, refuge against predation and a means of protection against colds.  Kudu are highly sensitive to colds and sudden temperature changes – they are known to move away from lower lying areas up the catena to warmer hill slopes on cold winter nights.  They tend to move between the aspects of slopes to the opposite sides of on-blowing winds.  During hot sunny days kudu will keep close to the shade of trees and on cold winter days they will stick to thickets.  High mortalities are common when sudden wet, cold spills appears, especially during drought periods.  Such mortalities were widespread in the Karoo and eastern Cape in 1979. 1983, 1991-92 and 1996.  Most deaths are from adult females >6 year.  In 1983 almost half of the eastern Cape kudu population died and in 1991-92 almost 30%.  The kudu population in the eastern Cape varied from  49 000 in 1965 to 47 000 in 1974 to an estimate of between 120 000 and 180 000 at present.

It is essential that the habitat encompasses a high diversity of fodder plants, especially trees and shrubs.  Kudu do not thrive on homogenous vegetation of low diversity.  Severe mortalities  occurred in the north-western bushveld areas of the former Transvaal during the late 1970's and early 1980's due to high densities of kudu kept on recently enclosed farms with low diversity of woody vegetation.  A gradual buildup of secondary metabolites (tannin) in the fodder plants as well as limited access to alternative fodder species led to the die-offs.

Kudu prefer broken bushveld and woodland of deciduous plants, with scattered thicket bush clumps.  Highly dense dune thickets and ever green forests are totally avoided.  In areas dominated by karroid  vegetation or grassland, the presence of well-wooded drainage lines in coincidence with nearby  mountain slopes and kloofs permits the invasion or dispersal of kudu.

 

Behaviour  

Kudu are diurnal (day living), but human disturbances and interference have forced it to become predominantly nocturnal.  During day-hours they keep to closed woodland and bush thickets for refuge, but in late afternoon they move to open broken woodland or karroid dwarf succulent plains for feeding, only to return again by dawn.  If not disturbed they will be found roaming for most of the day-hours.

Like humans kudu has individually temperaments and emotional behaviour characteristics.  Some radio collared kudu bulls have repeatedly shown to flee rapidly, covering a distance of 7-9km within 20min on approach by beaters during a hunting operation.  They will only return after 3 to 80 days depending upon the season and extend of the disturbance.  Some bulls repeatedly kept a save distance of 300-500m in front of the beaters, moving slowly in a circle on the periphery of their home range, eventually to end up behind the beaters.  Other bulls repeatedly showed to rely on their camouflage to conceal themselves until the beaters has passed and then flee with lightning speed backwards to the periphery of the home range.  The same individuals repeatedly followed the same behavioural pattern for a period of 6 years (duration of study). 

Breeding herds generally flee ahead of approaching danger, where as non-breeding females and sub-adult bulls tend to circle by short distances trying to avoid being spotted.  Mature and post-mature bulls tend to conceal themselves without moving. 

 

 

Nutrition

Kudu are predominantly non-selective browsers, feeding on leaves, shoots, pods or fruits of a wide range of shrubs, trees, dicot forbes and succulents.  Within their wide distribution range kudu are exposed to a variety of habitats.  It follows that the diet of kudu from different regions differs greatly in terms of plant species composition.  Within most habitats there are virtually no plant species that are completely avoided.  Kudu need a suit of vegetation components which encompasses:

a)         Palatable deciduous woody plants as dietary staple during the wet season;

b)         Soft-stemmed dicot forbs and new woody foliage year round and the lactating phase of cows;

c)         Relatively palatable evergreen or late deciduous woody plants during the dry season;

d)         Fruits and pods in the dry season;

e)         Woody plants which produce new leaves in advance of the first rains to bridge the critical transitional phase at the end of the dry season; and

f)          Relatively unpalatable evergreen woodies which are used as a last resort when all other food reserves had depleted.

In the eastern Cape Valley Bushveld the diet consists of 5-12% grass, 15-18% herbaceous dicot forbes, and 70-80% browse (trees and shrubs).  The forb and browse ratio differs greatly with rainfall and seasonal variations.  Studies from the northern savanna mixed bushveld indicated a diet composition of 18% grass, 21% forbs and 61% browse.  Studies by E.A. Boomker in the Lowveld has shown that adult (non-lactating) kudu of 210kg consume s 3,7kg dried material per day in winter and 5,4kg in summer.  The study clearly indicates that kudu are not concentrate feeders, but a non-selective browser consuming large quantities of roughage material.  There are no particular selection for young fast fermenting plant parts.  Average bite sizes is 3,7-4,5cm pieces from both old and young twig ends.  According to Boomker the kudu switches from foregut (in summer) to hindgut fermentation in winter to overcome the natural decline in nutrition quality.  The hindgut has a greater ability to digest fibre. Non-lactating kudu require 27-33MJ energy per day and lactating cows 47MJ.  A protein intake of 9-11% and 19-23% fibre is maintained year round.  Supplementation of the diet during drought must be based on good quality lucern in order to supply the necessary fibre, and not on a concentrate mixture.  Thus, kudu are adapted to gently slow changing of climate and veldcondition, but intolerant to rapid food quality changes. 

In the eastern Cape Valley Bushveld, 40-60% of the browsing of adult males takes place between 145 and 170cm, and between 135 and 155cm for adult females.  At 1600-3000 edible, acceptable shrubs and trees per hactare, within feeding height of the kudu and maintaining >30% of their foliage year round, kudu can be carried at 9-15ha per kudu (7-11 kudu per 100ha). 

Kudu in the hotter northern and western distribution range need a daily water intake of 7-9 liter.  In the succulent Valley Bushveld of the eastern Cape kudu rarely ever drinks.  This is due to the high moisture content of the diet.

 

 

Territorium & Home Range

Studies in the eastern Cape as well as elsewhere in Africa has revealed kudu not to be migratory nor territorial.   They inhabit a static home range which is shared by various individuals of both genders.  Every individual has its own home range which may overlap by 80% with others.  The core of the home range is fixed and permanent, but the total area and size thereof varies with veldcondition and season.  Mean home range size is 90-350ha during wet summer periods and may expand to 600ha during droughts.  Kudu tend to stick to the area where they were borne.  If translocated within 14 months after birth a youngster will not try to return, but thereafter they have become imprented upon the environment and will try its best to return. 

When disturbed they will flee the area either to return immediately after (depending on the individuals temperament) or it will establish a temporarily additional home range some distance (up to 11km) away.   Within 3 days to 3 months they will return to the original home range.  They repeatedly will flee to the same temporarily home range every time they are disturbed.  From 148 collared kudu studied by Allan-Rowlandson and by Furstenburg, no evidence was found of any movement between home ranges merely for feeding purposes.  Sub-adult bulls reaching social maturity occasionally get forced out by older mature bulls and will leave the original home range in search for a new.  These bulls are mostly responsible for the expansion of the distribution range.

For the rutting season the socially mature bulls may leave their home ranges to become nomadic across a larger area associating with female herds of adjacent home ranges.  After the rut they return.  Daily movement is between 1,5 and 3km (round trip) during wet summer months and up to 8km in dry winter periods.

 

 

Social behaviour & Reproduction

Family bonding is weak and therefore is group structures unstable.  Individuals exchange constantly between adjacent family groups.  The mean number of groups to overlap and share in the same home range area is eight.  Mean family group size is 4,5 (influenced by the degree of human interference).  With least disturbance groups of up to 20 form (mean =  8), and with high interference the mean reduces to 2,8.    Group size increase during the rut and the peak calving season.  In drought temporarily gatherings of up to 60 animals may be found on open “brak”-veld spots where they supplement their diet.  The social structure comprises: a) family groups with 1-2 socially mature males, 2-4 mature females and 1-3 youngsters, b) bachelor groups of 2-6 males (2-5 years age), c) mature male groups of 2-4 (5-8 years) and d) post-mature (non-breeding) male groups of 2-6 bulls (>8 years).

During the rut (May to early July – 70-80% of all matings) one to two socially mature bulls accompanies each family group.  Bulls reach sexual maturity at 22 months, social maturity at 4,5-5 years and post-maturity at 9-10 years.  Their expected live span is 12-16 years.  In good rainfall years the rut expands to almost year round.  Outside the rut the mating bulls join in mature bull groups, but frequently joins up with a family group for a short period only.  Females reach sexual maturity at 18 months and social maturity at 3 years.  Thus, 2nd year heifers is sexually mature but socially immature. Only during abnormal good rainfall years will 2nd year heifers mate.  Generally females start mating at 3 years and bulls at 4,5 years.  Periodic flushes of same aged animals occur in the population (growth increase from 19 to 28% during good rainfall years).  Gestation period is 8,5 months and in good years 94% of calves are born between late December to early March -- in dry years it is 60%.   Males leave the family groups at 2-3,5 years to join bachelor groups.  Females stick with family groups for live, but exchange between groups.  Expected life span for females is 7-9 years, they do not become post-mature.

 

 

Productivity  

In the eastern Cape kudu cows have a fecundity of 93-96%, though the mean birthrate is only 84%, of which only 62% calves generally survives to be weaned.   Adult mortalities is generally 10-15%.

This gives an annual long-term population growth rate of 19-21%.  It changes from 13% in drought years to 28% in good rainfall years.  Long-term production rate in Kruger National Park is 14,8%. Natural population structure is 47% socially mature cows (3-9 years), 7% 2nd year heifers (2<3 years), 7% 1st year heifers (1<2 years), 18% bulls (1<8 years), 4% trophy\post-mature bulls (8 years and older), 9% male calves (<1 year) and 8% female calves (<1 year).  Optimal production is attained with a mating (socially mature) sex ratio of 1% : 4&, thus females need to be cropped as well to achieve and maintain productivity.  In general cropping should be done at 65% % : 35% &.

Maternal instinct of cows are weak.  She does not help the calf to seek refuge, thus the calf has to cope by himself.  The cow returns for suckling 2-4 times per day, but if disturbed may not return for a day or two, resulting in high calf mortalities especially during cold spills.  Internal smallstock (netted) fencing is impenetrable for calves – they can jump it only after 7 months age – therefore the calves get abandoned (left behind) easily by the mothers. 

Sustainable kudu densities are 40ha/kudu at Nylsvley, Naboomspruit and the Kruger National Park; 33ha/kudu in northern Mopane Bushveld (increasing to 10ha in good rainfall years >380mm); in the eastern Cape Valley Bushveld 15ha/kudu at 300-340mm rain, 10ha/kudu at 340-360mm, 8ha/kudu at 360-400mm and 4ha/kudu at >470mm.     

Kudu are highly suceptive to rinderpest, anthrax, corynebacterium, foot-and-mouth disease, tuberculoses, pneumonia (hypothermia), cytauxzoönosis and rabies.  Hartwater is rarely experienced. A healthy kudu can tolerate a tick load of 5 000 ticks per animal.  Tick loads may increase 10 fold when animals come under nutritional stress, having major negative affect upon body condition.

Kudu carcasses dress at 54-57% (86-172kg for adult kudu depending on age and gender).  The best time for cropping or hunting having the least negative affect upon production is August-September for cows and September-December as well as March-April for bulls.  May-July is the rutting as well as the lactating season, and no hunting should be allowed.  After September most adult cows is more than 3,5 months pregnant and hunting is not recommended.

 

South African kudu live sale price dynamics

Average of all game sales:

1976 - R206                            1991 - R868                            1992 - R822                            1993 - R878           

1994 - R1 205                         1995 - R1 347                         1996 - R1 854                         1997 - R1 889

1998 - R1 651                         1999 - R1 813                         2000 - R2 105                         2001 - R2 408

 

 

Mean growth rate for kudu in the eastern Cape

Age                         Body Mass (kg)                     Horn Length

                 Cow     Bull         (cm)    (inch)   Turns

0 months          13      13            0          0       0

6 months          50      60        0,5-8          3       ¼

1 year            90      95         4-45       2-17       ½

1,5 year         105     120        20-65       7-25       1¼

2 year           120     140        50-80      19-31       1½

2,5 year         125     160        65-90      25-35       2

3 year           130     165       85-100      33-39       2¼

4 year           140     180      105-115      41-45       2½

5 year           145     205      115-125      45-49       3

6 year           138     220      125-132      49-51       3¼

7 year           130     240      129-135      50-53       3½

8 year           130     250      132-137      51-54       3½

9 year           128     260      135-139      53-54       3½

10 year          125     265      136-140      53-55       3½

11 year          120     270      137-140      54-55       3½

12 year           —      275      138-141      54-55½      3½

13 year           —      280      139-142      55-56       3½

 

 

 

Deon Furstenburg

Wildlife Scientist, Agricultural Research Council,

Middelburg, Eastern Cape,

email : Deon Furstenburg

(Available for professional consultancies)