Abstract

Flamingos are widely recognized birds kept in numerous zoological collections around the world. Some species are threatened and all are economically valuable. While numerous factors are important in their reproductive success, flock size may be of greatest importance.^4,6,7 Maintaining the numbers needed to promote reproductive success may be difficult in zoos due to economic constraints, space limitations, and the real or perceived fragility of these birds. These same concerns may have also contributed to the lack of biomedical information in these birds as well. In general, the smallest flocks to reproduce include 20 individuals⁴ while the largest group sampled for biomedical data is less than 30 individuals.^3,5 This report describes the relocation of over 130 birds twice, the capture of approximately 40 semi-free ranging flamingos, and the opportunistic biomedical data collection of these birds.

The largest collection of American flamingos (Phoenicopterus ruber ruber) at Busch Gardens Tampa Bay (BGT) consisted of a group of an estimated 150 animals on 10 acres. They shared this habitat with a group of Grant's gazelle (Gazella granti) and white bearded wildebeest (Connochaetes taurinus). This group was reproductively active, with several chicks fledging out yearly, but were not intensively managed or individually identified. New exhibit construction demanded that these birds be moved to a holding area, sorted, and then approximately 80 birds go into the new display. Over 3 wk in late March and early April of 1997 the flock was herded into a burlap holding pen. From here an estimated 40 birds were cut out of the flock and funneled into a catch pen where they were manually restrained. Each bird was then banded, given an i.m. dose of ivermectin (Ivomec, Merck Agvet, Whitehouse Station, NJ 08889 USA) and vitamin E/selenium combination (BoSe, Schering-Plough Animal Health Corp.,Union, NJ 07083 USA) and a blood sample collected from the right jugular with a 22-ga needle and 3-ml syringe. Up to 3 ml of blood was collected and placed in lithium heparin blood tubes. All samples were processed within 1 hr of collection. The birds were placed in a horse trailer and held until they would stand on their own. Four such sessions were conducted until all the birds were removed. A total of 142 birds were translocated. Two birds were culled from the flock with severe bilateral tibiotarsal rotations and one bird was trampled enroute to the new holding pen and was euthanatized. Complete blood cell counts (CBC), plasma chemistries were run as economics allowed and results are summarized in Table 1. Plasma was banked at -80°C for future analysis.

Lymphocytes, mean cell hemoglobin concentration (MCHC), glucose, white blood cell count (WBC), and hematocrit (HCT) were all significantly increased (P < 0.05) from established values¹ while monocytes, basophils, globulin, phosphorus (P), alkaline phosphatase (AP), and creatinine kinase (CPK) were all significantly decreased (P < 0.05). The increase in WBC, HCT, and glucose may be related to the stress of herding the birds just prior to sampling. The increase in MCHC is in discordance with the increase in HCT and may reflect some mild hemolysis occurring during sample handling. The difference in the lymphocytes, monocytes, and basophils are difficult to explain. While statistically different perhaps they are not functionally different and may even reflect the fact that reference laboratories interpret cell lines differently. Hypophosphatemia may occur with hypovitaminosis D, but we did not appreciate a corresponding decrease in calcium.² The birds in this group were apparently healthy so changes in globulin levels are not readily explained. Breeding was disrupted by the construction and the moving so perhaps a potential anabolic effect from hormones was nullified.² Again differences in technique may be responsible for the differences seen. CPK levels may be lowered because the entire procedure was relatively atraumatic or perhaps due to the sampling interval. While the herding, capture, and restraint was relatively atraumatic, increases in CPK may have not had time to be reflected in the plasma. Low levels of AP have been linked to zinc deficiencies² and need to be investigated further at BGT.

In August of 1998, several zoological facilities from central Florida obtained the proper permitting and collaborated on an effort to collect American flamingos from the racetrack at Hialeah Park. The capture was initiated at dusk. After several failed efforts to herd this group, 44 individuals were caught by hand as opportunity allowed. All birds were treated and bled as above. One sample was too lipemic and three were insufficient for complete analysis. Plasma was separated within 4 hr of collection and submitted for biochemical analysis. Logistics prevented CBCs but blood smears were made on 40 individuals and examined for hemoparasites. The birds were then released into a rented refrigerator truck maintained at approximately 17°C. All birds were restrained until they could stand on their own and then left free-standing during the transport back to the respective institutions. One bird sustained injuries during the transport and was euthanatized 3 wk later. The remaining birds were all reported well at the time of this report. No blood parasites were found and plasma biochemical findings are summarized in Table 2. Given the manner in which these birds were handled, no attempts were made to compare the plasma biochemistry values with other captive populations of flamingos although some expected differences can be seen.

Table 1. Comparison of hematology and plasma chemistry values between International

Species Inventory System (ISIS)1 and Busch Gardens Tampa Bay (BGT) American flamingos. (Italicized parameters are significantly different at P < 0.05).

Table 2. Mean plasma biochemical parameter values from semi-free ranging American flamingos (n = 40).

References

1.  International Species Inventory System (ISIS). 1989. Normal physiological data. Apple Valley, MN.

2.  Hochleithner M. 1994. Biochemistries. In: Ritchie, B. W. Harrison, G. J., Harrison, L. R (eds.) Avian Medicine: Principles and Application. Wingers Publishing, Inc., Lake Worth, Florida. Pp. 223-245.

3.  Merritt E. 1996. Hematologic and serum biochemical values in captive American flamingos (Phoenicopterus ruber ruber). J. Avian Med. Surg. 10: 163-167.

4.  Pickering S, E Creighton, B Stevens-Wood. 1992. Flock size and breeding success in flamingos. Zoo Biol. 11: 229-234.

5.  Puerta M, V Huecas, A Garcia del Campo. 1989. Hematology and blood chemistry of the Chilean flamingo. Comp. Biochem. Physiol. 94A: 623-625.

6.  Simmons R 1996. Population declines, viable breeding areas, and management options for flamingos in southern Africa. Conserv. Biol. 10: 504-514.

7.  Stevens E, C Pickett. 1994. Managing the social environments of flamingos for reproductive success. Zoo Biol. 13: 501-507.