Zoo Biology 7:293-312 (1988)

RESEARCH ARTICLES

Biology, Husbandry, and Veterinary Care of Captive Chinese ( pentadactyla)

We report observations on the biology, diet, husbandry, and veterinary care of four adult Chinese pangolins (Manis pentadactyla) maintained at the University of California, San Diego, for 1.5 years; and the births of two baby pangolins. Experience indicates that the minimum requirements for Chinese pangolins is an enclosure 10-12 m2, 26°C ambient temperature, a nest box with sand floor, and litter boxes placed in one or two corners of the enclosure for defecation and urination. A diet of two cans of cat food (Science Diet or ZuPreem), 6 tablespoons Esbilac, 2 tablespoons psyllium seed powder, and two raw egg yolks provide adequate nutrition for four pangolins for 1-2 days. Veterinary care should include a complete physical examination of integument and organ systems, determination of blood values, fecal analysis, and treatment with the anthelmintic thiabendazole for elimination of internal parasites. Parasites observed in the four pangolins included Strongyloides, hookworms, filarial nematodes (species unidentified), and nematodes of the genus Cylicospimra. The baby pangolins were born in Novem- ber (male) and February (female), weighed 93 g and 92 g at birth, and lived 1 and 5 days, respectively. All adult pangolins observed strictly nocturnal behavior patterns.

Pangolins (Figs. 1-4) are eutherian (placental) having specialized characteristics for procuring and eating ants and termites and a unique external armor of overlapping scales-hence the common English name “scaly ant-eater. ” Pangolins are classified in an order (Pholidota, meaning “scaled ”) and a family (Mani- dae) of their own [Simpson, 19451. It is believed that pangolins represent an early radiation of the mammalian (eutherian) lineage occurring in the period

Received for publication August 18, 1987; accepted February 28, 1988 Address reprint requests to Dr. Martha E. Heath, Research Laboratory, Box 38, Department of Rehabilitation Medicine, Columbia University, College of Physicians and Surgeons, 630 W. 168th Street, New York, NY 10032.

0 1988 Alan R. Liss, Inc. 294 Heath and Vanderlip

Fig. 1. Mature male Chinese (identified as pangolin 2 in the text). Photo by S.L. Vanderlip.

Fig. 2. Adult male (right) and female (left) Chinese pangolins coiled into their usual defense posture. Both individuals are adults, thus the size difference illustrates sexual dimorphism. Photo by S.L. Vanderlip.

[Eisenberg, 19811. records indicate that pangolins once inhabited Europe [Storch, 1978: Von Koengswald, 19811 and North America [Emry, 1970; Peterson et al., 19831. Seven extant species are limited to the Old World, three species occur in Asia (Manis pentadactyla, M. crassicauduta, and M. javanica), and four species occur in Africa (M. gigantea, M. longicaudata, M. tricuspis, M. temminckii). Differ- ent species of pangolins are distinguished by anatomy, size, range, and arboreal or terrestrial-fossorial lifestyles. External characteristics used for identification have been reported by Pocock [ 19241. Biology and Husbandry of Pangolins 295

Fig. 3. Lateral view X-ray radiograph of head region of male (left) and female (right) Chinese pangolin.

The objective of this paper is to report 1.5 years of observations on diet, husbandry, biology, and veterinary care of four Chinese pangolins. The difficulties of maintaining pangolins in captivity arise primarily from their very specialized diet of ants and termites and their unusual anatomy and physiology. There has been ex- tremely limited success of maintaining arboreal species of pangolin in captivity. Two individuals have lived longer than 1 year in captivity (Table 1). Although there are records of 24 individuals of various terrestrial-fossorial pangolin species living for longer than 1 year in captivity (Table l), the majority die [Kuehn, 19861, many within a few days or a few weeks of capture [Crandall, 19641. Information about appropriate diet, husbandry methods, and veterinary techniques needed for successful mainte- nance in captivity is extremely limited.

MATERIALS AND METHODS Subjects The subjects of this study were two male and two female Chinese pangolins. They arrived at the University of California at San Diego from China on the evening of November 4, 1984. Initial weight and length measurements are listed in Table 2. The pangolins were identified by numbers written on their scales with a black waterproof marker. The female pangolins, numbers 1 and 3, were smaller than the males, although all individuals were sexually mature. Pangolins 1 and 3 each had one offspring during their initial 3 months at the University of California at San Diego. 296 Heath and Vanderlip

Fig. 4. Left, upper and lower: Ventral dorsal view radiograph of a mature female Chinese pangolin (5.2 kg). Right, upper and lower: Ventral dorsal view radiograph of a mature male Chinese pangolin (7.1 kg).

Monitoring of Body Weight The pangolins were weighed at intervals to help ascertain their relative health in captivity. During the first 3 months in captivity, body weight was recorded more than once a week. Subsequently the pangolins were routinely weighed at least once monthly. These recorded weights were supplemented by measurements recorded during physical examinations or for experiments. Biology and Husbandry of Pangolins 297 Housing Initially the pangolins were housed in a cage 1.2 m wide X 2.8 m deep X 3 m high within a metal building normally used as a dog kennel. The cage had a cement floor, metal walls, a door of aluminum bars, and a wire roof. A plastic flight crate measuring 0.45 m wide X 0.65 m deep X 0.5 m high served as a nest box. Straw was supplied as nesting material and for insulation. The pangolins were moved in April 1985 to an indoor enclosure 3.7 m wide X 3.7 m deep which was composed of cement walls and floor. Ambient temperature was regulated at 26°C and photoperiod was set to 12-h light and 12-h dark. The nest box described above was again used but without the straw bedding.

Diet Food was provided on an ad libitum basis in a ceramic dish 170 mm in diameter and 80 mm deep. Because pangolins are nocturnal, food was provided in the evening. Water was provided in an aluminum pan 30 x 50 x 100 cm. In China the pangolins had been fed a mixture of silkworm larvae, orchid leaves, fish protein, boiled egg yolk, yeast, powdered milk, and earth. A l-week supply of the Chinese diet accompanied the pangolins. During the first week after arrival, the pangolins were offered both the Chinese diet and an alternative diet. The alternative diet had been used successfully for feeding captive armadillos and was considered by the authors to be more nutritional than the Chinese diet. The armadillo diet consisted of 16 oz Gerber Meat Base Formula (Gerber, Freemont, MI), 14 oz Zu-Preem Feline (Hill’s Pet Products, Inc., Topeka, KS), 12 oz Borden spf-lac (Borden Inc., Pet-Ag Division, Hampshire, 1L)-which was unavailable for the first 3 months-and two boiled egg yolks, for the four animals to share. From the first day the pangolins were offered a choice, they consumed the new “armadillo” diet and refused the Chinese diet. When Borden spf-lac became available and was added to the diet, all pangolins developed severe diarrhea. Borden spf-lac was eliminated from the diet, and the pangolins’ stools resumed previous consistency. In May 1985 (approximately 160 days after arrival), Konsyl (Lafayette Phar- macal, Inc., Easton, MD), a psyllium seed powder, was added to the diet to increase fecal bulk. Also in May 1985, Gerber MBF became unavailable and no dietary equivalent existed. This was compensated for by increasing protein content via the addition of Science Diet Feline Maintenance Formula (Hill’s Pet Products, Inc.) and Esbilac (Borden Inc., Pet-Ag Division). Boiled egg yolks were replaced by two raw egg yolks. The new diet consisted of 15 oz Science Diet Feline Maintenance Formula, 14 oz Zu-Preem Feline, 6 tablespoons Esbilac, 2 tablespoons Konsyl, and two raw egg yolks per day for four animals.

Anesthesia Because it is almost impossible to uncoil an unanesthetized pangolin, the use of anesthesia was required for physical examinations, blood collection, radiography (Figs. 3, 4), and biopsy. Ketamine HCI was selected as a possible safe anesthesia for pangolins based on a report of its use in the black-bellied pangolin (M. tetraductyla) at a dose of 22 mg/ kg IM [Robinson, 19831. 298 Heath and Vanderlip

Blood Drawing Blood samples were obtained on several occasions during the 460 days of observation. No superficial veins were apparent. Because of the peculiar anatomy of the pangolin, it is virtually impossible to bleed from the jugular vein (obstructed by large salivary glands in a very short cervical region), the femoral vein (obstructed by testes in the male and fat pads in the female), or the saphenous vein (obstructed by scales). Cardiac puncture was deemed inappropriate because of the potential for tissue damage and pain. Therefore, initial blood samples were obtained using a nail clip method. This method was unsatisfactory for four reasons: I) blood collection took several minutes; 2) blood clotted rapidly, making it difficult to obtain a nonclotted sample; 3) the pangolins could no longer use their claws for digging; and 4) the claws are large and their base is highly vascularized, thus clipping could cause discomfort and health risks. Subsequently, a blood-collection technique, not previously recorded for the pangolin, was developed. A scale was clipped from the proximal ventral surface of the tail, allowing visualization of the skin. A 21-gauge needle was then inserted into the tail vein (not visible) to a depth of more than 2 cm and blood was drawn into a 3- cc or 6-cc syringe (Fig. 5). This technique proved to be an excellent method for obtaining unclotted blood for analysis without inducing unnecessary discomfort in the . Because the pangolin rolls into a tight sphere in self-defense (Fig. 2), the animals required a light anesthesia (discussed above) in order to unroll the tail from the body to collect the blood sample. Blood Chemistry and Hematology Blood chemistry and hematological analysis were performed by Veterinary Reference Laboratories, Inc.

Parasitology Fecal samples were obtained from all four pangolins upon arrival and at intervals during their I .5 years in our care and analyzed for intestinal parasites. Ten weeks after arrival in the U.S., pangolin 4 had developed hard, red nodules, approximately 0.25 cm in diameter, about the face, on the pinnae of the ears, in the groin area, and on the penis. A biopsy was performed using sterile technique and ketamine HCI anesthesia (25 mg/kg). Two nodules were removed from the face, one from the ear pinna, one from the groin, and one from the penis. These nodules were submitted for histopathology . On the morning of June 6, 1985, eight months after arrival in the U.S., pangolin 4 was found dead and submitted for necropsy and histopathology. Vermifuge There is little knowledge or documented experience of drug use or reactions to drugs in this rare and endangered species. Several captive pangolins of different species have died following treatment for external parasites [van Ee, 19661. These deaths suggested a sensitivity of pangolins to chemical and pharmacological agents. Thus, although Kuehn [ 19861 had reported that thiabendazole administered in doses of 55-1 10 mgikg body weight had been used successfully in other species of pango- lins, it was decided initially to proceed cautiously, postpone any vermifuge treatment Biology and Husbandry of Pangolins 299 until the pangolins had adjusted to their new environment and diet, and avoid the use of anthelmintics unless deemed absolutely necessary. Because of the continued diarrhea in all individuals, the death and necropsy findings of gastric and mesenteric parasites in pangolin 4. and the heavy intestinal parasite load in the other pangolins indicated by fecal analysis, thiabendazole treat- ment was clearly essential to the continued health of the remaining three individuals. On July 18 and 31, 1985, 700 mg thiabendazole was added to the food shared by pangolins I, 2, and 3, which then weighed 3.1, 5.5, and 3,2 kg, respectively. This provided a dose of approximately 59 mg/kg body weight.

Activity Pattern lnformation about the animals' daily pattern of activity was thought to be of particular relevance in determining the suitability of this species for display in zoological gardens and as a possible aid in assessing the housing and husbandry practices being employed. During the third month of captivity, and while still in the initial enclosure, the pangolins were observed for four or five 24-h periods to study the pattern of daily activity. Since the pangolins slept only in their nest and were active whenever they were outside the nest box, it was only necessary to observe their leaving and returning to the nest. The pangolins' activity pattern was similarly observed after 15 months in captivity and transfer to their new enclosure. Although this latter data has been reported previously [Heath, 19871, it provides a useful comparison to the initial data. Heart Rate and Electrocardiogram (ECG) Electrocardiograms were recorded in unanesthetized, resting individuals via adhesive cutaneous electrodes and a Hewlett Packard dual channel DC amplifier recorder. Resting heart rate and a limited amount of ECG characterization were determined from these recordings. Respiratory frequency was also monitored and recorded in the resting pangolins.

RESULTS Body Weights Initial body weights (Table 2) for pangolins 1, 2, 3, and 4 were 2.35, 4.95, 2.95, and 4.43 kg, respectively. Pangolin 4 lost weight consistently and died 212 days postarrival after having lost a total of 1.09 kg (contributing factors are discussed at the end of the Results section). Pangolins 1, 2, and 3 gained 1.85 kg. 2.11 kg, and 2.35 kg, respectively, over 460 days of records (Fig. 6). A11 three pangolins gained weight from the week of arrival; however, as illustrated in Figure 6, the greatest weight gains occurred after the pangolins received vermifuge treatment with thiaben- dazole (258-260 days after arrival). Housing: Problems With Initial Housing and Subsequent Changes The building in which the pangolins were housed initially was not completely closed from the outside environment and the gas ceiling heaters did not prevent large daily fluctuations in ambient temperature within the building. These fluctuations were exacerbated by air drafts entering the building. Early morning temperatures in the enclosure were 12-15"C, rising to 22-25°C during the day. Evening temperatures TABLE 1. Pangolin longevity in captivity for individuals survivingmore than one year Longevity in Species captivity (days) Zoological garden Dates Asian Manis pentadactyla 62 1 Prague 20 Nov 20, 56 - Sept 12, 58 605 St. Louis Zoo Sept 3, 71 - Apr 30,73 483 Prague Nov 20, 56 - Apr 27, 58 Manis crassicaudata 6,999 Oklahoma City Zoo Nov 27, 65 - Mar 1, 85 4,546 Oklahoma City Zoo July 16, 68 - Dec 29, 80 1,136 Antwerp Sept 18, 70 - Nov 29, 73 834 Evansville Zoo 22 Apr 71 - 4 Aug 73 733 Evansville Zoo Sept 18, 71 - Sept 21,73 717 Antwerp May 3, 67 - Apr 20,69 558 Milwaukee Zoo June 24, 70 - Dec 3,7 1 493 Evansville Zoo Dec 10, 69 - Apr 17, 71 Manisjavanica 915 San Diego Zoo May 1, 66 - Jan 2,69 368 Washington NationalZoo Oct 3, 66 - Oct 6, 67 363 Houston Zoo Sept 2, 66 - Aug 31, 69 27 1 Houston Zoo Sept 2, 66 - June 68 African Manis gigantea 1,770 Antwerp Aug 28,59 - sent out live 1,670 Antwerp Feb 2, 66 - Sept 10, 70 1,461 Antwerp June 15,62 - June 16, 66 816 Antwerp Jan 3, 57 - Mar 30, 59 727 Antwerp Apr 12, 57 - Apr 9, 59 Manis temminckii 1,506 Milwaukee Sept 9, 65 - Nov 25,68 479 Washington Nat. Zoo Oct 13, 59 - Feb 4, 61 Manis tricuspis 543 Rotterdam Zoo Aug 5, 70 - Jan 30, 72 407 San Diego Zoo Oct 18, 68 - Dec 29, 69 Biology and Husbandry of Pangolins 301

TABLE 2. Size of pangolins at time of arrival Mass Total length Tail length Gender (kg) (m) (m) Pangolin 1 Female 2.35 0.545 0.260 2 Male 4.9s 0.795 0.347 3 Female 2.95 0.660 0.325 4 Male 4.43 0.770 0.340 New born S Female 0.093 0.200 0.067 New born 6 Female 0.092 0.210 0.075

Fig. 5. Technique used for obtaining blood samples from pangolins. The tail is held straight in line with the body, and the needle is inserted at an angle into the center of the ventral surface of the tail. Photo by S.L. Vanderlip. were 21-22°C. When temperatures were 12-15°C inside the pangolin cage, the temperature was 18.4-23°C inside the nest box. In these conditions the pangolins were often observed to shiver, even with straw insulation provided. Additionally, the straw tended to lodge in the conjunctiva of the pangolins’ small eyes, causing irritation and inflammation of the conjunctiva and some temporary corneal abrasion. Finally, the cage size was inadequate to house four animals. The new, larger enclosure (3.7 m2) with regulated temperature (26°C) and photoperiod (12-h light) was a significant improvement in spatial and thermal environ- ment. Nevertheless, sanitation became a serious problem. The pangolins defecated and urinated randomly in this enclosure. During the night, when the pangolins were most active, they walked in, and dragged their tails through, their excrement. When 302 Heath and Vanderlip

PRNGOLIN 1 PRNGOLIN 2 q d

I Jan86 4

DRYS DRYS

PANGOLIN 3 PRNGDLIN 4 5

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Fig. 6. Weight records of the four Chinese pangolins during 460 days in captivity

the animals returned to the nest box and rolled into a sphere or curled around each other-their normal sleeping postures-their fouled tails further spread the excreta to other parts of their bodies and to other individuals. This situation required laborious and extensive cleaning of the enclosure on a daily basis and that the pangolins be bathed. When dirt was subsequently provided in a shallow tray to determine whether the pangolins would use a “litter box,” the animals were observed to defecate and urinate almost exclusively in the dirt and usually bury their feces, but, unfortunately, they also showed a preference to sleep in the dirt box rather than in the nest box. Ultimately, sterilized children’s sandbox sand was put in the nest box and in two litter boxes. The litter boxes were situated in two corners of the enclosure because the pangolins preferred to stand in the corners on their hind legs with their forelegs against the wall when defecating and urinating. These changes resulted in the nest box being used solely for sleeping and for a relatively clean, easily maintainable enclosure (since the pangolins usually used the litter boxes rather than the floor for excretion).

Diet Initially the four pangolins were chronically affected with diarrhea. Improper diet was considered as a contributing cause of diarrhea, although the animals were Biology and Husbandry of Pangolins 303 also carrying a heavy intestinal parasite load (see Parasitology section below). The addition, in May 1985, of psyllium seed powder to the “armadillo diet” significantly reduced the occurrence of diarrhea. After this and the other final changes to the diet, the pangolins continued to find it palatable. Although pangolin 3 lost 0.14 kg, pangolins 1 and 2 showed subsequent weight gains of 0.4 and 0.48 kg, which were attributable to these dietary changes since they occurred before vermifuge treatment.

Parasitology Intestinal parasites. Fecal samples were found to contain large numbers of Strongyloides and hookworms. The species were not positively identified. Filarial parasites. The biopsy of nodules from pangolin 4’s face, ear pinna, groin, and penis revealed a parasitic (filarial) dermatitis. Microscopic examinations of the tissue samples submitted showed extensive eosinophilic infiltration into the dermis with a heavy perivascular accumulation of eosinophils and lymphocytes. Occasional filarial nematodes, measuring approximately 5 pm in diameter, were seen within the inflammatory nodules. The perivascular inflammatory response suggested that the microtilaria were blood-borne. Parasite samples were submitted to the Armed Forces Institute of Pathology, but species identification was not possible. Stains for acid-fast bacteria were negative. Gastric and mesenteric parasites. The necropsy findings from pangolin 4 revealed numerous unattached nematodes in the stomach and esophagus, measuring approximately 5 mm in length. Smaller, U-shaped, thin nematodes were encysted within the mesenteric fat and were also found free in large numbers within the peritoneum. All nematodes were identified as belonging to the genus Cylicospiruru, but the species was not determined.

Vermifuge There were no side effects observed in response to treatment with thiabendazole in a dose of approximately 59 rng/kg body weight. Weight gains of 0.9, 1.5, and 2.1 kg in pangolins 1, 2, and 3 followed, and were directly attributable to, the thiaben- dazole treatment. Following vermifuge with thiabendazole, stools became more formed and lost their periodic tarry appearance. Subsequent fecal examinations were negative for ova and parasites, although occasional soft stools were observed. Because of the absence of ova and parasites in the subsequent fecal samples, use of DNP for hookworm eradication was considered an unnecessary risk. It is noteworthy that although the pangolins were initially housed in close proximity to a large dog-breeding colony and exposed to distemper, corona, and parvoviruses , the pangolins exhibited no signs of these canine diseases. Anesthesia On November 12, 1984, pangolin 3, weighing 3 kg, was the first to be anesthetized. Fifty milligrams of ketamine HCI (dose of 16.6 mg/kg) was adminis- tered IM between the scales in the post-femoral muscle mass. She uncoiled after 5 min, the palpebral reflex was present, she salivated profusely, respiration was 33 breaths per min, and heart rate was 100 beats per min. The pangolin maintained some rigidity and regained her righting reflex with slow ambulating efforts within 15 min and appeared entirely recovered 20 min after administration of anesthesia. Because pangolin 3 did not completely relax in response to the 16.6 mg/kg dose, a larger dose 304 Heath and Vanderlip

of 25 mg/kg was used subsequently on pangolin 4, also on November 12, 1984. Weighing 4 kg, he was administered 100 mg of ketamine HCI IM between the scales in the post-femoral muscle mass. Pangolin 4 uncoiled after 5 rnin although some rigidity persisted. The palpebral reflex was present and he also salivated profusely. At 5 min post-injection his respiration was 38 breaths per rnin and heart rate was 86 beats per min. Pangolin 4 began to regain motor coordination after 10 min and appeared recovered from anesthesia 15 rnin post-ketamine administration. Pangolins 1, 2, 3, and 4 were subsequently anesthetized on various occasions for blood collec- tion, radiographs, and biopsy (pangolin 4) at a dose of 25 mgikg with similar findings and safe recoveries.

Blood Chemistries and Hematology Hematology and blood chemistry values for each blood collection are shown in Table 3. The values are similar to those observed in dogs. There were no consistent changes in blood values that were clearly attributable to pregnancy, dietary changes or vermifuge.

Activity Pattern Figure 7 presents the activity pattern for three of the pangolins on four or five different days. A strict nocturnal activity pattern was exhibited with the pangolins never leaving the nest box before 1690 h. Over a 10-11-h period the animals emerged and returned to the nest box intermittently and their active period ended by 02:00 h. The length of time when a pangolin remained outside the nest box varied from 30 sec to 1.5 h. The total amount of time spent out of the nest on any given night differed from one individual to the next. The percentage of the 24-h day spent outside the nest averaged 5.6% with a range of 2.9%-7.6%. While in the nest box the pangolins were either coiled as individuals or curled up one around another to sleep. This could provide an important thermoregulatory function to reduce the area of exposed surface per unit body mass and thereby conserve heat. No aggressive behavior was ever observed. ECG and Resting Heart Rate ECG recordings revealed heart rates of 80-86 beats per min for the resting animals. The width of the P-wave averaged 0.06 sec, the P-R interval averaged 0.11 sec, the QRS complex width averaged 0.06 sec, the S-T segment averaged 0.05 sec, and the Q-T interval averaged 0.25 sec. Respiratory frequency normally varied from 14-20 breaths per min to 42-53 breaths per min in the same individual over a short period of time. Births Pangolin 3 gave birth to a 93 g baby male pangolin between 17:00 h and 2190 h on November 14, 1984, ten days after arrival at the University of California at San Diego. The newborn was found outside the nest box on the concrete floor of the cage and noted to be hypothermic. The mother was in the nest box sleeping. No placenta could be found and only approximately 0.2 ml of semi-dry blood appeared on the vulva of pangolin 3. Pangolin 3 weighed 3 kg at the time of the birthing. Obviously she was pregnant before arrival in the U.S. An initial physical examination on November 5, 1984, provided no evidence of pregnancy. During a more extensive Biology and Husbandry of Pangolins 305 examination on November 12, 1984, while she was anesthetized with ketamine HCL (16.6 mg/kg, IM) a dry waxy substance, assumed to be colostrum, was noted on each (there are two) of her pectoral mammae. Palpation was difficult and did not reveal the presence of a fetus. Pangolin 1 gave birth to a 92 g female pangolin at approximately 16:OO h on February 5, 1985, 93 days after arrival. No placenta or blood could be found in the cage where pangolin 1 had been housed. Similar to pangolin 3, pangolin 1 weighed 3 kg at the time of delivery and showed no overt signs of pregnancy even during a thorough physical examination conducted while she was anesthetized with ketamine (25 mg/kg, IM) on January 15, 1985 (three weeks before the birth). On each occasion mother and baby were separated from the other adults. In the case of pangolin 3, the pair were put in a separate flight crate equipped with a heating pad below the floor to provide additional warmth. Pangolin 1 and offspring were housed in a plastic warming unit (TensiveKare) to keep the two together and to prevent chilling of the newborn. The unit was set to 38°C floor heat and both mother and baby appeared to be comfortable in this environment. Both mothers were attentive to their babies and curled into a sphere around them. The baby of Pangolin 1, however, often wandered off while the mother slept, and the mother showed no signs of retrieving the baby upon waking. The newborn pangolins were extremely well developed. Eyes were open and fore legs were very strong with long, well-developed claws (Fig. 8). Motor coordi- nation was good, and the newborn pangolins demonstrated normal suckling behavior and were generally very active (Fig. 9). Unfortunately, pangolin 3's baby was found dead 24 h after its birth. A necropsy was performed. The cause of death was could not be identified. A blood sample was obtained from the dead newborn for Hb analysis as well as tissues for chromosome analysis. Pangolin f 's baby also died, but after 5 days of seemingly vigorous healthy activity and frequent bouts of suckling. Gross necropsy and histopathology could not determine the cause of death. All tissues appeared normal except for microscopic examination of the lungs, which revealed congestion with diffuse areas of alveolar collapse. In addition, the lungs did not appear to be symmetrically aerated.

Difficulties in Caring for Mothers and Babies A major difficulty arose for feeding pangolin 1 in the presence of her newborn. Because the pangolins are nocturnal and preferred to eat in the early morning, food had normally been provided in a dish in the evening. This feeding method posed a serious problem because the baby pangolin repeatedly climbed and fell into the food dish. It was feared the baby pangolin might accidentally drown in the food or water bowls. Pangolin 1 did not respond to altering the schedule of feedings and there was concern that, unless provided her usual wet diet in her usual dishes, she would stop eating. Various methods of blocking the dishes from the baby pangolin were tried but no matter how high the dishes were placed or how slick the walls surrounding the dishes, the baby pangolin managed to climb and fall into the dishes. The baby pangolin posed more of a problem to house and feed as it developed over the next few days, appearing almost hyperactive and climbing into everything. Its mother seemed oblivious to its behavior, making no attempt to keep it in one place or to retrieve it. TABLE 3. Chronologic blood values for captive M. pentuductylu

Individual Pangolin 1 Pangolin 2 Pangolin 3 Pangolin 4 Date 15 Jan 85 17 July 85 30 Jan 86 15 Jan 85 17 July 85 30 Jan 86 12 Nov 84 30 Jan 86 12 Nov 84 15 Jan 85 Days aftcr arrival 72 257 454 72 257 454 16 - 454 16 72 Hematology WBC (thou imm') 7.9 11.0 4.8 6.7 14.4 10.4 6.5 5.0 6.3 8.6 RBC (milimm') 5.46 5.52 5.64 4.5 5.87 5.33 5.76 5.2 4.72 4.94 Hemoglobin (gmil) 14.5 15.9 15.3 12.3 18.3 14.9 14.9 13.3 10.6 12.6 Hematocrit (%) 40.9 45.9 44.5 34.0 52.5 43.4 43.3 39.7 32.5 35. I MCV (fl) 75.0 83.0 79.0 76.0 89.0 81.0 75.0 76.0 69.0 71.0 MCH (pg) 26.5 28.8 27.2 27.4 31.2 28.0 25.9 25.5 22.4 25.6 MCHC (%) 35.4 34.6 34.4 36.3 34.9 34.4 34.4 33.4 32.6 36.0 Differential Neutrophils (%) 30.0 20.0 18.0 33.0 31.0 46.0 61 .O 85.0 49.0 60.0 Lymphocytes (%) 64.0 77.0 72.0 45.0 55.0 41 .0 26.0 14.0 42.0 33.0 Monocytes (%) 5.0 3.0 7.0 5 .o 2.0 3.0 2.0 I .o 3.0 4.0 Eosinophils (%) 1.0 - 3.0 __ 1.2 8.0 11.0 - 6.0 3.0 Chemistry SCOT (IU/I) 75.0 162.0 18.0 21.0 48.0 68.0 15.0 48.0 59.0 SGPT (IUII) 370.0 690.0 147.0 276.0 165.0 264.0 150.0 260.0 274.0 Alk. phosphatse (IU/l) 122.0 138.0 96.0 72.0 60.0 60.0 102.0 60.0 86.0 BUN (mg/dl) 29.0 27.0 21.0 18.0 18.0 28.0 18.0 20.0 29.0 Cholcstcrol(mgid1) 142.0 249.0 180.0 111.0 87.0 188.0 297.0 96.0 115.0 Total protein (gidl) 7.2 9.0 8.4 7.2 7.8 7.2 6.3 8.4 7.6 Total bilirubin (mgidl) 0.6 0.1 0.3 0.6 0.1 0.2 0.3 0. I 0.5 Creatinine (mgidl) 1.1 0.9 0.6 0.9 0.9 0.8 0.9 0.4 0.8 Phosphorus (mgidl) 6.4 8.4 3.3 5.4 3.3 7.2 3.9 3.6 8.0 Calcium (mgidl) 10.4 9.9 8.7 9.0 7.8 10.1 7.5 8.0 13.5 Albumin (gm/dl) 3.2 4.8 4.2 4.0 4.5 4.8 3.9 3.6 3.2 Potassium (meqil) 5.3 - - - - 4.4 - 4.0 4.4 Sodium (mcqil) 152.0 - 150.0 - 144.0 156.0 Chloride (meq/l) ------T-3 (ng/dl) - - - - 32.0 - T-4 (mgidl) 1.4 2.1 - -1.3 -- - - 0.6 0.2 Arnvlase (TIJil) 158.0 - - - - 305.0 - 251.0 212.0 ------Biology and Husbandry of Pangolins 307 Time 12 00 IS00 24 00 6 00 12 00 1111111~~~~~~~~~~~''~~'' Pangolin 1 Days i imi 111 111 I !in 2 I II I II

3 II I 1111 111 1 4 m II II 111

Pangolin 2 1 I

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5 I I I

Pangolin 3 I 1 IU !I!I I I UII 7 m II IN am 3 I IIUI in II 4 I II I

5

Fig. 7. Activity pattern of captive Chinese pangolins. Black marks indicate time out of the nest.

Deaths Pangolin 4 died on June 6, 1985, 212 days after arrival and after having lost 1.09 kg. Fecal samples taken 8 days after arrival demonstrated hookworm and Strongyloides infestation. Fecal culture revealed abundant growth of Escherichia coli, (both beta hemolytic and nonhemolytic), Proteus vulgaris, Klebsiella pneumoniae, and Pseudomonas fluroescens. Because of the continued loss of weight, a very irregular feeding pattern, a heavy internal parasite load, and a low red blood cell count (attributed to blood loss in the stools due to internal parasites)? pangolin 4 was separated from the other pangolins 2 months after arrival. Elevated eosinophil count (6%) was also attributed to parasitism. As noted above, the nodules that appeared about the face, ears, groin and genital region 3 months post-arrival proved to be parasitic filarial dermatitis of possible blood-borne origin. Despite dietary and housing improvements (described previously), pangolin 4 continued to lose condition. A complete necropsy performed on pangolin 4 revealed a thin animal with an extensively mineralized aorta. The stomach was empty, but large numbers of unat- tached nematodes (genus Cylicospimru) were found within the stomach and esopha- gus. Smaller, U-shaped nematodes (also genus Cylicospiruru) were encysted within the mesenteric fat. Black, decomposed nodules were noted in the liver. The aorta and smaller vessels of the heart revealed medial calcification of the vessel walls. There were thickened, fibrotic areas noted within the liver, that were presumed to represent arterial walls. Several unidentified nematodes containing numerous developing larvae could be seen within the fibrotic nodules of the liver. There were no obvious lesions noted in the other organs. Diagnosis was arteriosclerosis, medial calcification, and nematode infestation. The authors believe pangolin 4 may have been a very old individual and that advanced old age, coupled with the above findings, was the cause of death. 308 Heath and Vanderlip

Fig. 8. Newborn pangolin suckling. Photo by S.L. Vanderlip.

DlSCUSSlON Our experience indicates that pangolins can be easily maintained in captivity in good health if attention is paid to proper housing, diet, and veterinary care. The following recommendations are made. Housing The enclosure should have adequate amount of floor space; 12-14 m2 was sufficient for 3-4 pangolins but the enclosure of 3-4 m2 was too small. The temperature of the enclosure should be 25-30°C. This was established from measurements of metabolic rate at different ambient temperatures in these individuals [Heath and Hammel, 19861. These measurements showed that ambient temperatures between 26 and 30°C are thermally neutral and at temperatures below 26°C pangolins raised metabolic heat production to maintain body temperature. Providing one or more litter boxes was perhaps the most important step in establishing an enclosure that is easily maintained in an acceptably clean condition. Without litter boxes, pangolins urinate or defecate in random locations, and all individuals tend to walk through, and drag their tails through, the excrement. This leads to the pangolins becoming literally covered with excrement and fouling them- selves and each other. Since some pangolins tend to stand with their forelegs against the wall when defecating and urinating, and they prefer to do so in corners rather Biology and Husbandry of Pangolins 309

Fig. 9. Newborn female (92 g) Chinese pangolin. Photo by S.L. Vanderlip. than along straight walls, and because all pangolins bury their excrement if dirt or sand is available, simply providing one or more litter boxes with 5-6 cm deep sand or dirt positioned in corners of the enclosure is adequate for keeping the enclosure remarkably clean. A nest box or burrow is also important. We supplied only one nest box for all individuals. Sand provides satisfactory bedding material. The use of straw as bedding material is discouraged because it can become lodged in the pangolins’ eyes and cause corneal abrasion. Wood shavings or sawdust should not be used since they have been reported to cause stomach impaction and death [Griner, 19831. Housing Mothers With Babies In view of the housing and feeding difficulties encountered with pangolin 1 and her offspring, we suggest that Chinese pangolins giving birth in captivity be provided 310 Heath and Vanderlip with a warm, deep den in which to house their young. This den should be of such depth that the adult can climb out to the surface for feeding but so steep that the young pangolin can neither escape nor reach the food dishes at the surface. This type of den with a “brood” chamber is used in the wild [Anderson and Jones, 19671 and, combined with the habit of closing the entrance of the burrow with dirt, prevents the loss of active, climbing offspring. This could explain the lack of retrieval behavior in the mother pangolin. Display of Pangolins The amount of time spent active and outside the nest was not known until the 24-h observations of activity made during this study and a 72-h period of observation made for another study [Heath, 19871. These observations demonstrate the strict nocturnal nature of this species. The observation that pangolin behavior is intermittent but persists over 10-11 h indicates that this species would make a very good display in a nocturnal house with reverse photo-period, particularly if observers could see inside the nest chamber as well as the entire enclosure. The fact that the 24-h and the 72-h continuous observations were made nearly a year apart and still showed approx- imately the same pattern of activity suggests that prolonged captivity does not alter their activity pattern. Diet The weight gains shown by the three healthy pangolins, especially the gain before vermifuge with thiabendazole (see Fig. 6) clearly demonstrate that the modi- fied “armadillo diet” provided adequate nutrition for the pangolins. The addition of psyllium seed powder for bulk and vermifuge treatment were both important in minimizing diarrhea. Although the consistency of pangolin stools in the wild are not documented, the continued occurrence of soft stools suggests that further improve- ments in diet are necessary. Other diets have been used successfully [Tenaza and Schulz, 19771, but, to our knowledge, no record exists of their effect on the weight of individuals. It is clear from the low metabolic rate of these animals (Le, one-fourth to one-third that of physiologically more typical eutherian mammals) [Heath and Hammel, 19861 that the nutritional need of adult individuals should be less than that of more typical mammals of similar size. Veterinary Care Blood should be collected as soon as possible after capture and hematology and serum chemistries performed to determine baseline blood values. This is important both for monitoring the health of the individuals and for establishing normal values for this and other pangolin species. Only one other report of hematology values exists for pangolins [Soifer, 19701. An average hematocrit of 33 %, 63 % neutrophils, 36% lymphocytes, and 1% eosinophils were observed for four individuals of unnamed species. Once the newly captive pangolins adjust to their new habitat, the presence of parasites probably provides the greatest health threat and stress to the pangolins. An early examination for external and internal parasites is essential. Fecal examinations for ova and parasites should be continued on a regular basis. Parasites found in the Chinese pangolins studied included Strongyloides (species undetermined), hookworm, Biology and Husbandry of Pangolins 311 filarial parasites (unidentified), and nematodes of the genus Cylicospiruru (species undetermined). Singh [ 19761 reported on Strongyloides and the identification of a new nematode, Leipernem leiperi, in M. pentuductylu. Since vermifuge with thia- bendazole worked effectively against the various nematodes without harmful side effects, it is recommended soon after the arrival of newly captive individuals. Treatment for external parasites should be approached cautiously as several captive individuals have succumbed to the chemicals used for dusting or as dip [van Ee, 19661. Two Cape pangolins also died after being transferred to a new cage that had been cleaned with soluble Lindane (containing BHC; 10 percent gamma) (van Ee, 19661. It would be preferable to remove ectoparasites manually if possible. Births Noteworthy are the consistency of the weights of both mothers at the time of giving birth (3 kg) and of their babies (92 and 93 g) and the fact that the births occurred in late autumn and mid-winter. The latter is apparently normal in pangolins [Kuehn, 19861. Except for the observation of a waxy substance (possibly dried colostrum) on the mammae of pangolin 3 just two days before it gave birth, there were no external signs of pregnancy. Curiously, no placenta was found for either birth. A baby born to a newly captive Chinese pangolin at the Ueno Zoo in Tokyo provided a placenta weighing 13 g and measuring 24 X 3 x 6.5 mm [Masui, 19673. The length of gestation in most pangolin species, including M. pentadactylu, is undocumented, but a gestation period of 139 days has been reported for M. te~rni~~k~i (van Ee, 19661.

CONCLUSIONS Captive Chinese pangolins (M. pentuductylu) are particularly well suited for display in a nocturnal house environment because of their prolonged period of intermittent activity during the dark phase of the 24-h day and because they can be maintained healthy with relative ease if proper attention is paid to their diet, spatial needs, and enclosure design.

ACKNOWLEDGMENTS The authors wish to thank animal health technicians Peggy Felt, Larry Gustaf- son, and Gwyn Barbaro and animal caretaker Madison Lowe for caring for the pangolins and Dr. Clayton Swanson of the San Diego Zoological Society for help in acquiring the pangolins from China. We also wish to acknowledge the contribution of Dr. Jeff Roberts in development of the blood collection technique and the assistance of Doris Alcorn in collecting behavioral data.

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