65 PENGUINS

other continucd to grow for another week until it too experienced a slight decline. Both birds eventually stabilised at about gzo g, a little below the average weight of a mature Fairy penguin.

The young penguins were marked with flipper tags whcn they were six months old and were transferred to the main display enclosure at ten months. After a brief spell of about three days during which they showed some reluctance to join the other birds, they adjusted well to their new environment. All adult penguins are hand fed by their keeper twice daily and the two juveniles soon settled to this regime. At rime of writing they are established members of the group and justify all the patience and time involved in their rearing.

P R O D U C T S M E N T I O N E D I N THE TEXT Calost-500: calcium tablets manufactured by V. R. Laboratories (Aust.) Pty Ltd, 8 Pioneer Avenue, Thornleigh, NSW, Australia.

Cod liver oil tablets: concentrated cod liver oil vitamins manufactured by H. W. Woods Pty Ltd, 10 Clifford Street, Huntingdale, Victoria, Australia. Halamid: water soluble disinfectant powder manu- factured by Philips-Duphar Pty Ltd, 67 Mars Road, Lane Cove, NSW, Australia. Heinz Junior tuna in white sauce: manufactured by H. J. Heinz Co. Australia Ltd. Polyvisol: multivitamin supplement manufactured by Mead Johnson, 345 Pacific Highway, Crows Nest, NSW, Australia. Tribrissen Piglet Suspension: trimethoprim/sulpha- diazine, antibacterial manufactured by Burroughs Wellcome & Co. (Australia) Ltd, Cressy Street, Roseberry, NSW, Australia.

Manuscript submitted 7 December 1976 (revised J.ly 1977)

Penguins at Basle Zoo HANS WACKERNAGEL Vice-Director, Curator OfBirds and Animal Nutrition, Zoologischer Garten Busel, CH-$054 Busel, Switzerland

Bade Zoo has an outdoor enclosure which, at time of writing, contains 16 Black-footed penguins Spheniscus demersus and an indoor exlnbit housing eight King Aptenodytes patagmica and ten Gentoo penguins Pygoscelis papua. As the results of keeping these birds have proved encouraging, as indicated by the general condi- tion and, in some instances, the longevity, a few points might be mentioned which seem to us of importance.

L O N G E V I T Y A N D D I E T

A Black-footed penguin has been living in Basle for 23 years. A King penguin, imported in June 1957, is still alive, and also one which was hatched in the zoo in July 1959. A Gentoo penguin imported in July 1959 has now been with us for 18 years. A Macaroni penguin Eudyptes chrysolophus lived here from November 1954 to March 1973 for over 18 years and a Rockhopper penguin E. crestatus received in June 1957 died in June 1974 after 17 years.

These data are relevant in considering the suitability of diet and we have developed to a high degree of efficiency and success a vitamin mixture for fish-eaters which has been amended and improved since it was first published (Wackernagel, 1966). From Table I it can be seen that this contains a high dosage of the fat- soluble vitamins which may reflect the supply in the sea. Not only penguins but also sealions Zdophus calijhnianus and sea turtles Eretmochelys imbricata receive t h i s mixture which is offered in gelatine capsules inserted into a fish. In addition the King and Gentoo penguins receive a daily supply of c. I g common salt, also given in gelatine capsules.

A tendency in the Gentoo penguins to swallow feathers and foreign bodies such as small sticks can be relieved by scattering shrimp on to the water. These creatures are pecked up with relish, since crustaceans form a substantial part of the Gentoo’s diet in the wild. The Black-footed penguins, on the other hand, whose food under

66 PENGUINS

VITAMINS PER KG FEED

A Bl Ba Be h a

D, C

E K Biotin Folic acid Pantothenic acid Nicotinic acid Choline Santoquin (antioxydant) Formocihazol (Ciba-Geigy)

DOSAGE: penguins sealions sea turtles

10,000,000-12,000,000 iu IO,OOO-II,O~~ mg

goo400 mg 3so-4so mg

s,ooob,ooo mcg 15,000-20,000 mg

9oo,ooo-1,100,0oo iu 40,0oo-60,0oo mg

300-400 mg 30-50 mg

250-300 mg 4.000-4,soo mg I,ZOO-I,SOO mg

~ ~ , O O O - ~ O , O O O mg 2,000 mg

120,000 mg

I-2s-z-5 g/day

1.25/week 10 g b Y

Table I. Vitamin mixture for fish-eaterr.

natural conditions comprises mainly fish and squid do not react to shrimp.

I N D O O R EXHIBIT

The total surface area of the indoor exhibit is t. 54 m2. The 14 m2 pool, which is some 4 m deep and has a volume of 75 m3, is used inten- sively with obvious enjoyment. An underwater view is obtained from the side and a winding incline brings the viewer to shore level in front of the exhibit. The land area is composed of con- crete, coated with plastic, and in certain areas is further treated with a foam material (which sets hard after application) in order to enhance the insulation. Two water jets installed in the land area produce ‘rain’ and ‘streams’. The pool,

which also functions as a drain, contains fresh water which has a turnover rate of two to three days. The tcmperature of the water and air is controlled at 10-12”C and the enclosure is lit by natural daylight entering through the roof.

To promote exercise, which we consider essential for well being, the birds living indoors are regularly taken out for an airing.

BREEDING

Platforms have been placed in the indoor exhibit for nesting but the birds have preferred to choose their own nesting sites. Although the Gentoo penguins imported from Edinburgh Zoo in 1974 are still rather young, they produced two eggs in 1976 and succeeded in raising one chick.

Disease resistance has increased in recent years and diseases caused by environmental factors are rare. Aspergillosis has not occurred at all for a number of years.

AUTHOR’S N O T E In 1977 one of the young Gentoo penguins paired with the old $. imported in 1959 and a healthy chick hatched on 12 June.

PRODUCTS MENTIONED IN THB TEXT Polyuretan: plastic foam, setting hard after application, used for insulation, manufactured by Dally Ltd, CH- SchGnenwerd, Switzerland. Solaplast: plastic coating material manufactured by Lehmann & Co. AG, Lettenweg SO, CH-4123 Allschwil, Switzerland.

REFERENCES WACKERNAGEL, H. (1966): Feeding wild animals in zoological gardens. Int. Zoo Yb. 6: 23-37.

Manuscript submitted 15 April 1977

Penguin management at the Detroit Zoo [Plate IS]

WILLIAM A. AUSTIN Curator ofEducation, Detroit Z o o , Royal Oak, Michigan 48068, USA

By the early 1960s the Detroit Zoo, like a majority of large mixed collections, had at various times during its history displayed one or other penguin species. These displays in general

had been satisfactory neither from a husbandry nor from an exhibition standpoint. Mortality rates were depressingly high, and it was rare indeed for a bird to survive longer than 90 days.