To decide when to increase or decrease the amount of food, the body condition score should be used. Body condition scoring (BCS) involves the visual assessment of specific parts of the body for muscle and fat content, and can be a useful indicator of general health and condition of an individual.
A standardised body condition scoring system has previously been developed for Black rhinoceros (Reuter and Adcock 1998), which assesses seven key areas of the body, ranging from BCS 1.0 (emaciated) to 5.0 (heavy). Ideally, a 0.5 point scale can be used to assess these areas, to give a representation of the relative condition of individuals. It should be noted that the Reuter and Adcock (1998) BCS was designed for wild living rhinos where they consider a score of 5 to be excellent. In zoos however we see overweight animals and therefore consider a BCS of 4 to be ideal.
Reuter and Adcock (1998) have made a list of criteria for each body condition score. These criteria can be found in Appendix I of the pdf that can be downloaded from the home page (Reuter and Adcock). Another way to assess the nutritional status of the rhinos is by regularly weighing the animals and recording this data (Clauss and Hatt, 2006). Weighing of the diet is recommended.
Body condition may be of relevance to reproductive performance, particularly in females, as recent research has indicated that non-breeding females tend to have higher BCS than breeding females (60% of non-proven females were scored 4.5 compared to only 6% of proven females) (Edwards et al. 2013).
It is recommended that a side view and rear view colour photograph (not taken in bright sunlight) are sent to Becca Biddle at Chester Zoo (firstname.lastname@example.org) annually, to validate the body condition score.
A rhino with a good body condition score can be recognised by:
- The neck appears thick across the top, and is well muscled, with a smooth gradation between the neck and the shoulder blade.
- The shoulder (scapular region) is well covered, and slightly rounded but not bulging.
- The ribs (costal region) are covered with thick skin folds, especially just behind the shoulder and elbow region.
- The spine (vertebral region) appears rounded and the long back muscle and fat deposits fill the gap between the ribs and the spine.
- The bony points of the rump (gluteal region) are covered and the rump appears flat as opposed to rounded.
- The abdomen (abdominal region) appears filled and taught.
- The tail base should be rounded but not bulging.