Rhino Husbandry Manual
Black Rhinoceros
Management
Black rhinos may not be as solitary as is commonly portrayed. Black rhinos often associate briefly at water holes or salt licks. Although females are rarely observed alone, adult males are usually solitary and possibly territorial (Estes, 1991). Cows with calves tend to stay alone; however, the twosome sometimes allow an unrelated immature male or female to join them until that individual reaches maturity (Goddard, 1967). Data on rhinoceros social organization, combined with preliminary analyses of parameters affecting reproductive success in captivity, may be used to generate recommendations regarding possible social groupings in zoos and conservation centers (Tables 3.1 and 3.2). Many variables affect the probability of success for any managed social group, including the animals’ dispositions and available holding space. Further, depending on space and animal and staffing availability, institutions may hold animals for breeding or for exhibit-only. Facilities that wish to hold rhinos for exhibit purposes only are advised to maintain two animals (male. female: 1.1 or 0.2 or, more recently 2.0 because of the skew in male births.)
Table 3.1 Possibilities for rhino social groupings within the same exhibit in captivity
Multiple animals of same sex
Multiple animals of opposite sex
Species
Adult Males
Adult Females
Black
Not recommended
Successful in related females in test groups.
(See Cleveland Metroparks/Blank Park Zoo)
Possible and recommended for breeding (optimal: 1.1)
In addition, breeding institutions must also have space to hold offspring for up to three years after birth. Within a single exhibit or holding area, the recommended minimum numbers for breeding are one male and one female. In general, mature males should not be held together because of the increased likelihood of serious aggression.
Table 3.2 Recommended numbers of animals for institutional holding.
Rhino Species
Recommended Min. Group
For Breeding
Preferred Optimal Holding for a Breeding Institution
Exhibit Only (For exhibition only)
Black
1.1
2.2 (2 pairs)
1.1 or 0.2
Introductions
Changing social groupings of rhinos through the introduction of additional individuals to an established individual, pair or group is a process requiring care and planning. Rhino species vary widely in social structure, and rhinos periodically vary their grouping patterns in the wild according to factors such as reproduction and the rearing of young. Social groupings in captivity, therefore, should also vary according to species, as well as to the circumstances within each institution. Rhinos may be very protective of their individual boundaries, but proper introduction procedures can minimize injury from conflict and aggression. The following section outlines general considerations for any rhino introduction and provides systematic descriptions of aggression, procedural recommendations, and descriptions of potential species-specific introduction types.
The Living Desert Mixed Species
It is possible to house black rhinoceros in multi-species habitats of sufficient size and/or proper design. The Living Desert Zoo and Gardens and San Diego Safari Park have maintained multi-species habitats of various sizes, 4-acre and 20-acre areas, respectively. Smaller areas designed with adequate hides/safe zones have potential to work as well. For example, one side of The Living Desert’s multi-species habitat is just over 0.5 acres and still allows a variety of ungulates and birds to coexist comfortably with the black rhinos.
Species successfully housed with black rhinoceros to date are springbok, waterbuck, klipspringer, great white pelican, pink-backed pelican, cattle egret, helmeted guinea fowl, crowned crane, marabou stock, cape vulture, Eurasian griffon vulture. Note: birds that have been housed successfully with black rhinoceros at The Living Desert are flight restricted and included a vulture with an amputated wing and a geriatric pelican with significant mobility issues.
Individual rhino personality/temperament can play a factor in the success of multi-species exhibits, and younger, more “novice” animals may be preferred in these situations, allowing them to “grow up” with other species and consider them less novel. Smaller ungulate calves have been born in multi-species with black rhino and have lived with the rhinos essentially from day one, however, ungulate calf mortalities due to black rhinos have been reported. Exclusion zones and branch/thicket hides have been used successfully to allow smaller ungulate mothers opportunities to ca their calves to be safe from rhinos.
Environmental design is the key to success when planning a black rhino multi-species habitat. Designing a variety of “safe zones” for the smaller species is important. Rock and/or deadfall barriers can be effective, but it should be noted that black rhinos can be capable climbers and easily navigate rock wall barriers that do not have higher than 4-5 feet of a sheer rock face. They are also quite able to climb and/or move large deadfall pieces if not positioned properly. The higher risk in these situations is not the climbing over these exclusionary areas, so long as they are not primary containment, but the rhino’s confidence in descending from rock/deadfall exclusion areas. Their body structure makes this action more difficult, and rhinos are hesitant to climb down. Though bramble piles have been successful as a deterrent for black rhinos from climbing and have also offered shelter to smaller ungulate calves within a multi-species habitat. Bramble piles should not be used as primary exclusion for black rhinos.
The most effective way to create “safe zones” is to use steel bollards. These “safe zones” can vary in size depending on the number of animals that may use them. At The Living Desert a mixed herd of springbok and waterbuck utilize even ~500 sq ft exclusion zones together. Bollards in these exclusion zones should have throughways that allow animals to pass through at speed; even flighty ungulates have shown the ability to learn to uses these passages very quickly.
Example dimensions of “safe zone” barriers: rails with two horizontal beams one at 5 ft and one at 3 ft. The distance between bollards of throughways and any upright bollards is 21 inches. It is important to note that a 21.5-inch gap between bollards is enough for a 2-year-old black rhino to push through them. This becomes a risk of the rhino becoming stuck in the bollards and should be weighed against the space needed to accommodate the passage of the next largest animal. (Moeller; 2023)
Identification
Although physical characteristics such as horn size and shape make individual rhinos fairly easy to distinguish from one another, sound rhino management requires that animals be identified through permanent and reliable methods. Trovan transponders (Electronic Identification Devices, Ltd., Santa Barbara, CA), implanted at the base of the left ear during post-natal examination or as soon after birth as possible, are one means of permanent primary identification for all individuals. Adults should be transpondered opportunistically. Transponder numbers need to be reported to the studbook keeper. Photographs or sketches in the animal’s records may also serve this purpose.
Keeper Training and Interaction
As with any position involving the management of large animals, rhinoceros keepers should have as much formal training and experience as possible and should be familiar with rhino behavior and husbandry. In order to ensure safety and to properly meet the requirements of management, it is recommended that more than one keeper be responsible for the care of these animals on a daily basis. Keeper interaction should be restricted to designated areas and should be conducted in accordance with institutional protocols. Finally, consistency of routine is vital.
There are no conclusive data to indicate the effects of different styles of keeper interaction on rhinoceros behavior or reproductive success in captivity. Interaction styles range from no contact at all to daily hands-on contact. In an effort to create an environment patterned after the wild,
however, at no time should relationships with keepers substitute for natural interaction among individuals. It is important that rhinoceros personnel keep a daily log, noting any unusual behavioral or physical changes. It is the responsibility of management to supply all pertinent data to the studbook keeper.
Daily Regimen
Fresh water should be available at all times and should be changed daily or supplied by an automatic-fill or continuous-flow device. Regular cleaning and disinfecting should occur at a rate that inhibits the growth of algae and bacteria. Water devices should be constructed to prevent upset, spillage or leakage. Rhinos need access to mud baths to keep their skin healthy; mud wallows should be renovated periodically to prevent contamination (see Enclosure Design chapter for more information on wallows).
Natural substrates in confined areas (e.g., holding corrals) can be spot-cleaned daily, but daily removal of feces from larger enclosures is not necessary as defecating at dung piles is an important natural behavior. Hard-surfaced areas not exposed to the elements should be dry-cleaned or hosed daily and disinfected at least weekly. Indoor housing surfaces, as well as walls and rub areas, should be cleaned daily.
In order to facilitate participation in many research programs involving rhinos, it is recommended that institutions implement training programs following the protocols recommended in the Training chapter. Additionally, it is recommended that some form of environmental/behavioral enrichment be integrated into daily rhino management.