AVICULTURAL

MAGAZINE

No. 1 1995

THE AVICULTURAL SOCIETY

The Avicultural Society was founded in 1894 for the study of British and foreign birds in freedom and captivity. The Society is international in character, having members throughout the world.

Membership subscription rates per annum for 1995 as for 1994 : British Isles £18.00: Overseas £21.00 (plus £6.00 for airmail). (U.K. funds please). The subscription is due on 1st January of each year and those joining the Society later in the year will receive back numbers of the current volume of the AVICULTURAL MAGAZINE.

Subscription, changes of address, orders for back numbers etc. should be sent to:

THE HON. SECRETARY AND TREASURER, THE AVICULTURAL SOCIETY, c/o BRISTOL ZOOLOGICAL GARDENS, CLIFTON, BRISTOL, BS8 3HA, ENGLAND.

THE AVICULTURAL MAGAZINE welcomes original articles that have not been published elsewhere and that essentially concern the aviculture of a particular bird or group of birds, or that describe their natural history. Articles should be preferably typewritten, with double spacing, and the scientific names as well as the vernacular names of birds should be given. References cited in the text should be listed at the end of the article. Line drawings should be in Indian ink on thick paper or card; black and white or colour photographs which illustrate a particular point in the article will be used where possible and should be clearly captioned. If authors wish their eventual return, they must say so when submitting the article and write their name on the back of each photograph.

ADDRESS OF THE EDITOR

Frank Woolham, Hon. Editor, The Avicultural Magazine, 32, Caughall Road, Upton-by-Chester, Chester, CH2 1LP. England.

Avicultural Magazine

THE JOURNAL OF THE AVICULTURAL SOCIETY

VoLlOl - No 1 All rights reserved ISSN 0 005 2256 1995

EDITORIAL

One of my most enjoyable annual writing assignments is com¬ piling a review of zoos and bird gardens in Britain for two IPC publications, CAGE & AVIARY BIRDS and BIRD KEEPER. The theory each year is that the people in charge will mail or fax me the latest news of what is happening in their particular collection.

However, in about 70% of cases, theory is not translated into fact and I invariably have to spend the better part of two or three days telephoning around Britain for information needed urgently to meet editorial deadlines.

It is always a rewarding exercise - hearing of new arrivals and interesting breedings, and perhaps most of all of people’ s hopes and ambitions for another new season.

There are some quite excellent public collections in the UK and they share many interesting exhibits. Sadly there is an understand¬ able reluctance on the part of many to provide details of species known to be especially vulnerable to that modern predator, the bird thief.

But thieves are unlikely to trouble two new arrivals at The National Birds of Prey Centre at Newent in Gloucestershire. A juvenile pair of Steller’s Sea Eagles Haliaeetus pelagicus arrived there a few weeks ago from Moscow. With a spectacular pair of Martial Eagles Polemaetus bellicosus already in the collection, Director Jemima Parry-Jones now has a formidable ‘big two’.

At Pensthorpe Waterfowl Park in Norfolk, wildfowl enthusiasts can admire a number of rarities - Pink-eared Duck Malacorhynchus membranaceus , Harlequin Duck Histrionicus histrionicus and Freck¬ led Duck Stictonetta naevosa to name but three.

Australian Brush Turkeys Alectura lathami are an interesting feature in the collection at Lotherton Hall Bird Gardens in York¬ shire, while across the Pennines in Lancashire a breeding group of Western Slender-billed Corellas Cacatua pastinator are a highlight.

2

EDITORIAL

Spectacular exhibits at Flamingo Gardens and Zoological Park are large groups of several species of pelicans (three species were incubating recently). In conversation with Christopher Marler a few weeks ago, he confirmed that he hoped soon to have all eight of the world’s pelican species in the park in the near future.

There are other interesting and unusual birds held in British collections - Roadrunner Geococcyx californina at Banham in Norfolk, where a first UK breeding of the species has been achieved. In Berkshire there are 20 species of laughing thrushes in Beale Park’s collection where more than 70 young birds have been reared successfully during the past three years.

The Avicultural Society has a number of members who are much involved with the running of some of these establishments, either as Curators, in other staff posts or, in some instances, as owners.

There is almost certainly a zoo or bird garden within reasonable travelling distance of most UK members. Many are regular visitors - others turn up less frequently. If you are part of the latter group, let me persuade you that you don’t know what you are missing. People such as Council Members Roger Wilkinson (Chester Zoo) and Mike Curzon (Tropical Bird Gardens, Rode), and Peter Player of Flimwell Bird Park in Sussex, would certainly confirm that!

F.W.

3

MAINTAINING PARAKEET AUKLETS, AT THE CINCINNATI ZOO & BOTANICAL GARDENS; HAND-REARING PROTOCOL WITH DEVELOPMENT AND BEHAVIOURAL OBSERVATIONS

By David A. Oehler, Susan C. Schmid and Matthew P. Miller

Abstract

Parakeet Auklets Cycl orrhyn chus psittacula, were collected as chicks on St. Lawrence Island in 1993, for the Cincinnati Zoo. The burrows in which the Parakeets nested were well dispersed along the talus slopes and cliffs and offered protection from predators such as Arctic Fox Alopex lagopus. The Parakeet chicks were reared in artificial burrows and adapted to being fed Krill Euphausia superba and Sand Eels Ammodytes hexapterus. A mean weight of 216 gr. was obtained at fledging while food intake decreased to 28% of body mass, at that time, from amounts of over 40% in ages estimated up to 15 days. Measurements and weights were recorded on the sub-adults (N=22) at one year of age; mean weight: 236 gr., measurements, mean wing span: 48.6 cm and mean length: 26.0 cm First year plumage varies from 30% of the colony transforming into typical adult plumage, 50% intermediate transformation and 20% remaining in the typical juvenile form.

Introduction

Alcidae are distinguished among charadriiforms by their com¬ pact form, short wings and feeding habits (Cones, 1868), Cyclorrhynchus are further defined by the reduction of the lateral sternal notch to a fenestra, six costal processes on the sternum and nesting in natural crevices (Strauch, 1985).

In this monotypic genus the Parakeet Auklet, once known as "paroquet", is found. The sexes of this species are alike marked by seasonal variations. During the breeding season this auklet's head is sooty black with mottled whitish throat and foreneck. A yellow¬ ish auricular streak runs from the eye to the ear. The sooty black colour continues onto the upper back with the underparts being mostly white, while the transitional areas of the breast and flank are mottled gray. The tail is black and the bill is upturned and red. Non-breeding plumage changes to a mottled white area on the chin and throat while the bill becomes a dull brownish-red (Harrison,

4 OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

1983). The chicks have down that is very fleecy and dense. This down ranges in length from 7 mm in the capital tract to 16 mm on the dorsal region. The iris is black and the bill is grey with a white egg tooth on the upper mandible. At 30 days of age the chicks have obtained the white superciliary line from the eye to the ear, although the feathers are not elongated. The iris has become bluish grey and the bill is pale black with a yellow mouth cavity (Bedard & Sealy, 1984).

The range of the Parakeet Auklet overlaps that of the Least Auklet Aethia pusiila and the Crested Auklet A. cristatella. In Russia these birds are reported to breed on seashore cliffs and in the winter wander the seas, keeping clear of frozen seas. Parakeet Auklets breed along the shores of the Chukotskiy and Kamachatka Peninsulas, the Sea of Okhotsk, Commander and Kuril Island. In winter it can reach Japan. The breeding range continues along Cape Lisburne on the Bering Strait south through the Bering Sea includ¬ ing St. Lawrence, Pribilof and Aleutian Islands, then east through the Kodiak archipelago as far as Prince William Sound (Freethy, 1987). Parakeet Auklets nest deep within the rubble of talus slopes and in cracks and crevices on rocky shorelines or cliffs. The colonial tendency is seemingly less strong than in other Auklets. The pairs nest in scattered groups or in solitary pairs (Sowls et al, 1978). In each nest a solitary white egg is laid (Peterson, 1961).

These auklets avoid strong pycnocline gradients, thus are pre¬ sumed to have greater diving abilities than the Least Auklet (Haney, 1991). This conclusion may need further study since gelatinous zooplankton (e.g., jellyfish and ctenophores) is an important part of the Parakeet Auklet's diet and probably are their preferred foods. The primary reason for feeding on jellyfish may be the high nutritive value of associated crustaceans and fish larvae; hyperiid amphipods and fish larvae are easily observed on and around jellyfish in the surface waters (Harrison, 1990). These items are important to the auklet along with other seabirds due to the fact that they have a unique capacity for assimilating wax esters with higher efficiences (>90%) than that attainable by mammals (<50%) (Place, 1992). The Parakeet Auklet's bill is highly special¬ ized and unusual in that the lower mandible is a narrow hook that curves up and around the blunt mandible, suggesting these birds hook gelatinous animals or pick zooplankton from medusae/jelly¬ fish (Harrison, 1990).

Parakeet Auklets also occur in areas of the eastern Bering Sea where Least and Crested Auklets are absent (Bedard, 1969). Par-

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

5

akcet Auk Jets consistently had larger reserves of subcutaneous fat than the other Aethia species. Parakeets display less annual variation in breeding success and would appear to have a depend¬ able supply of food (Harrison, 1990). The Parakeets also have been observed to have less mortality due to predation by fox than other auklet species. While the Least and Parakeets were nesting in the same area of St. Lawrence, Leasts were observed being taken by one pair of Arctic Fox at a rate of up to 10 per hour during daylight hours, while the parakeet Auklets remained undisturbed (Drischman, 1993).

Methods

In August 1993, staff members of the Cincinnati Zoo and Wildlife Concepts International set up collecting operations, of the Parakeet Auklet, in the village of Savoonga (63°42’N, 170°30’W) on St. Lawrence Island. Seabirds were observed along Punelok Bay and on Cape Myaughee where the colonies had been estimated at up to 100,000 birds and 1,000,000 birds respectively (Sowls, et al 1978). Collection of 28 juvenile birds began on 20th August 1993 and were held in Savoonga until the departure date of 25th August. All chicks were hand fed krill Euphausia superba four times a day.

Transport of the birds to Cincinnati was accomplished through air charters and commercial flights which hastened the journey and limited the time that each bird had to remain in the crates. Once the birds arrived at the zoo they were placed in brooders within a specially prepared holding facility where further observations were made on growth patterns by taking daily weights, morphology changes through photo-documentation, daily food intake by re¬ cording items ingested until each bird fledged and behaviour patterns through daily observations and video documentation. Results Collection

The Parakeet Auklet nests were found by climbing down over the cliffs of the colonies and searching crevices by hand or with flashlights. Nest-sites were discovered above the tide line at the base of the cliffs up to the top of the ridge. Unlike the other auklet species encountered, the Parakeet Auklets did not nest in large numbers in any one area, preferring to disperse their numbers along larger tracts. The typical nest found on the cliff face was a cavity large enough to accommodate the auklet 's body size and provide security by having a chamber up to one meter in length. Occupancy of a cavity was foretold by a small amount of "white wash" at the entrance and the accumulation of feather sheaths, from the chick’s

6

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

feathers as they opened, which formed a grey dust along the burrow floor. Nest-sites within the boulder rubble were more difficult to locate, due to the many crevices formed by the mass of rocks. In these areas the nest size was comparable to t he cavities found along the cliff face although the preferred sites usually had one entrance that branched off into several diverging tunnels. Observed mortal¬ ity within the colony could only be attributed to rock slides trapping adults within the nest cavity, no evidence of predation was noted.

Once the chicks were removed from the nests, they were taken to the holding facility in Savoonga to be maintained until their extraction to Cincinnati. Each chick was housed in separate compartments that remained darkened. An ambient temperature of 45° to 55° F + - 5 degrees surrounded the crates for the duration of this period. Each chick was tubed with a pureed mixture of krill four times a day. After several days the chicks began to take whole krill by hand and the tubing was discontinued.

Rearing

Upon collection, each chick was placed in an individual com¬ partment of a holding crate for hand-rearing. Ambient temperature was maintained at 55°F + - 5 and moss collected and dried from the surrounding area used as a substrate. Initial food intake was offered via a feeding tube with a formula of krill (placed through a blender until liquefied) four times a day over a twelve hour period. The average age of the chicks at the time of collection was estimated at 12 days. The chicks quickly tamed down and began to take krill by hand within two days of being collected, the morning feeding of blended krill continued (See Table 1).

The holding facility in Cincinnati was readied prior to receiving the alcids from St. Lawrence. Brooders were constructed measur¬ ing 4ft x 8ft divided into eight equal 1ft x 4ft sections with an open top and lin welded wire bottom. Within each section two cardboard boxes, one foot square and waxed on the inside, were placed in the centre dividing the section into two areas. The cardboard boxes had a three-inch hole cut in the front and a flap cut in the top to be used as a lid. Medical (disposable) underpads were used to absorb any faecal matter not ejected through the entrance of the artificial burrow. The holding facility was maintained at 55°F and the air was constantly filtered, removing all particles larger than three mi¬ crons. The water system utilized UV sterilizer units, a cooling system that regulated the water at 45° F and a filtration system of Jacuzzi, DE and Zeolite filters. A rate of three gallons of water per

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

7

minute was injected into the thousand-gallon pool to create on overflow to reduce surface oils. Lighting was achieved through eight banks of 400 watt sodium vapour and metal halite fixtures and controlled via a timer that maintained the bird’s natural photoperiod throughout the year.

A morning weight was taken on each chick and the four feedings per day continued along with the addition of Sand Eels Ammondytes hexapterus and vitamin supplements to the diet. The chicks were weaned onto a regimen of eating whole krill and fish placed on a plate within the entrance of the box. The process of eating off a plate began as the chicks approached 18 days of age and food intake was monitored closely. Based on body mass, the highest rate of food consumption was obtained within the first 15 days of age. Chicks would ingest between 31% to 45% of their body weight in food, up to 15 days of age and the quantity decreased to its lowest point prior to fledging at 23% (See Table 2). As the juvenile birds advanced toward 30 days of age and fledging they would begin to spend time at the entrance of the box or venture outside of the box entrance. Upon fledging the juvenile birds’ appetites increased and they were consuming 28% of their body weight in food per day. Rocks were introduced into the brooders to allow the birds access to a substrate other than wire.

After the plumage was completely developed and the chicks’ down feathers were replaced, the birds were introduced to open water. The first three days of the introduction occurred for periods of six to seven hours and then the birds would be placed back into the brooders at night. Once it was observed that an individual was waterproofed and acclimating well to the new surroundings the bird would remain out in the main section of the enclosure. Food plates were place in the shallow portion of the pool allowing the birds, which spent a large amount of time in the water, to become proficient at finding their food before the plates were relocated on the deck area. Blocks of frozen krill were floated on the water to allow the juvenile birds to forage in a more natural manner. The Parakeets showed less propensity for diving than the other alcid species housed in the enclosure at that time (Least Auklets, Pigeon Guillemots, Horned Puffin and Tufted Puffin) and further investi¬ gation of feeding techniques of these birds will be forthcoming.

As the birds matured, smaller and more numerous food plates were distributed around the enclosure to reduce the increasing amount of competition that developed. This competition coincided with the increased photoperiod and the onset of what would normal-

8

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

ly be the breeding season. While no breeding did occur in these sub-adults, there was increased usage of burrows (six inch PVC tubes) and pair bonds were established between several pairs. Defence of burrows and individuals bringing food back and feeding the other within the pair was observed.

Table 1:

PARAKEET AUKLET DIET

Beginning formula

Krill and Mazuri vitamins; blend until liquefied and fed through a syringe and tube.

Day 7 - 10

Four feedings per day over a 12 hour period. A.M. feeding consists of the krill formula. The next three feedings are krill and sand eel by hand.

Day 11 - 14

A.M. feeding limited to lOcc of krill formula. All other food offered by hand four times per day.

Day 15 - 17

Discontinue formula. All krill and sand eels offered by hand four times per day.

Day 18-21

Krill and sand eels given on plates four times per day. Known quantities given and intake monitored.

Day 22-30

Krill and sand eels given fresh three times per day ad-lib.

Day 31

Krill and sand eel given BID/ad-lib.

Morphology

The development of the Parakeet Auklets was recorded through a photographic register at intervals of 90 days. Colour bands on each individual's leg aided in tracking the general progress within the colony.

At an estimated age of 30 to 35 days, the chicks had lost all of their natal down, the last remaining portions being on the head and nape. At this point the plumage was developed sufficient for survival on the open water. The white superciliary line from the eye to the ear had been acquired but the elongated feathers were not observed until 90 days of age, as the birds underwent a partial moult. During this period of development the bluish grey iris of each chick changed to a pale yellow colour. The juvenile plumage pattern consisted of a moderate grey tone over most of the head and a light white to pallid grey under the chin and over the region of the nape toward the back. The breast and throat were solid white and the mandibles varied in standard although all were black with cream colour markings.

At eight months of age a portion of the colony began to obtain plumage similar to that of mature adults. The white mottled throat and chin with the mottled grey continuing around to the nape began

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS 9

Table 2:

PARAKEET AUKLET DEVELOPMENT/FEEDING REGIME

Day *

Mean A.M. Diet

Weight (gr)

Number of Feedings per 12 hrs.

Amount Fed (mean/gr)

Vitamins

8

81

F/K/S

4

25.5 gr/day

Mazuri

9

89

F/K/S

4

34.0 gr/day

Mazuri

10

99

F/K/S

4

42.6 gr/day

Mazuri

11

100

lOcc/F/K/S

4

44.7 gr/day

Mazuri

12

108

lOcc/F/K/S

4

41.7 gr/day

Mazuri

13

116

lOcc/F/K/S

4

48.8 gr/day

Mazuri

14

120

lOcc/F/K/S

4

49.1 gr/day

Mazuri

15

126

K/S

4

49.8 gr/day

Mazuri

16

134

K/S

4

56.7 gr/day

Mazuri

17

146

K/S

4

44.3 gr/day

Mazuri

18

146

K/S

4

50.8 gr/day

Mazuri

19

168

K/S

4

50.9 gr/day

Mazuri

20

174

K/S

4

51.0 gr/day

Mazuri

21

185

K/S

4

48.6 gr/day

Mazuri

22

193

K/S

3

55.5 gr/day

Mazuri

23

199

K/S

3

57.9 gr/day

Mazuri

24

205

K/S

3

60.4 gr/day

Mazuri

25

308

K/S

3

60.0 gr/day

Mazuri

26

214

K/S

3

59.9 gr/day

Mazuri

27

215

K/S

3

48.5 gr/day

Mazuri

28

220

K/S

3

57.1 gr/day

Mazuri

29

215

K/S

3

60.6 gr/day

Mazuri

30

216

K/S

3

ad-lib

Mazuri

31

215

K/S

2

ad-lib

Mazuri

32

214

K/S

2

ad-lib

Mazuri

33

224

K/S

2

ad-lib

Mazuri

34

224

K/S

2

ad-lib

Mazuri

35

220

K/S

2

ad-lib

Mazuri

36

223

K/S

2

ad-lib

Mazuri

37

209

K/S

2

ad-lib

Mazuri

38

214

K/S

2

ad-lib

Mazuri

39

210

K/S

2

ad-lib

Mazuri

40

207

K/S

2

ad-lib

Mazuri

41

207

K/S

2

ad-lib

Mazuri

42

205

K/S

2

ad-lib

Mazuri

43

187

K/S

2

ad-lib

Mazuri

1 year

256

K/S

2

ad-lib

Mazuri

KEY: F - Krill Formula K - Whole Krill S - Sand Eels *Ages estimate; based on initial weight and date of fledging

10

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

to transform into the dark black chin, nape and head. Along with these changes came the transformation of the mandibles from complete black with diminutive cream colour markings to the reddish-orange found in the adults. By 1 1 months there was, in the 22 birds, a marked deviation in the sub-adult plumage. At this age 30% of the Parakeet Auklets had developed plumage that included the above mentioned reddish-orange bill and black head, chin and nape. The remaining birds could be placed into two categories; 50% of the total colony developed partial adult patterns i.e. upper anterior portion of the mandible acquiring an orange colour and partial development of a dark head, chin and nape, while the remaining 20% retained the juvenile paradigm.

Wing span and length (point of mandible to termination of the tail) measurements were recorded on each bird at one year of age. The wing span of the auklets ranged from 45.7 cm to 50.8 cm with a mean of 48.6 cm. The length measurements ranged from 22.2. cm to 25.5 cm with a mean length of 26.0 cm.

Discussion

Parakeet Auklets were found to establish their nest-sites in less concentration than other auklets species on St. Lawrence Island. This dispersion, coupled with the inaccessibility of the cliffs or boulder rubble, emerge as one possibility for the lower mortality observed due to predation.

By emulating the nutrient-rich portions of their diet, zooplankton and fish, rearing of the Parakeet Auklet in a captive situation became possible. Artificial burrows provide a stable and secure environment for the chicks to develop and allowed for natural feeding behaviour until the time of fledging. Food consumption ranged from up to 45% of body mass per day at 8 to 15 days of age to 23% of body mass 2 to 3 days prior to fledging. This decrease in appetite probably coincides with a decrease in food offered by the adults at that time. A temperature range at or near 55° F was well suited for these birds once they left the protective accommodation within the brooders. By providing food items in the water the fledglings quickly recognised the objects from which to feed and were then self sufficient. Fledglings were ingesting greater amount of food at 30 days of age (28%) in comparison to body mass when compared to the days leading up to this event.

The morphological transformation of the Parakeet Auklet was tracked through the first year of maintaining the species at the Cincinnati Zoo. The development of the elongated feathers of the superciliary line from the eye to the ear along with the change in

GEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

11

eye colouration from bluish grey to pale yellow occurred at approx¬ imately ninety days of age. Sub-adult plumage was developed by eight months of age. 30% of the colony were represented by adult plumage consisting of black sooty head colouration, black chin and nape along with transformation of the mandibles from the black and cream colour pattern to the reddish-orange colour typified by the adults. 50% of the colony developed partial adult patterns exhib¬ iting orange colouration on the top anterior portion of the mandible and development of an intermediate transformation to a slightly darker head, nape and chin. The remaining 20% showed no deviation in plumage pattern or mandible modification. Further study into the diverging variety of plumage demonstrated by first year birds is needed in order to understand the Parakeet's life history. By one year of age, the birds had developed full body mass and size, exhibiting a mean weight of 256 grams and dimensions of an average 48.6 cm wing span and 26.0 cm length from the point of the mandibles to the terminating point of the tail.

Behavioural patterns consistent with that of adult breeding birds were demonstrated in an immature manner during the first breeding season. Mutual feeding, defence of territory/cavities and increased aggression was all observed within the colony. Clearly Parakeet Auklets are not mature enough in the development to breed at one year of age.

By collecting juvenile birds, it has become possible to maintain the Parakeet Auklet in a captive situation. Information on hand¬ rearing, first year morphology and juvenile behaviour patterns have been documented, while further studies regarding feeding techniques and breeding are now possible.

LIST OF PRODUCTS MENTIONED

Underpads: Sure Care, Regular underpads (17" x 23.5"), medical Disposable

Division, 1165, Hayes Industrial Drive, Marietta, Georgia, 30062

USA.

Vitamins: Mazuri, Mazuri Vita-Zu Bird Tablet 5m25, Purina Mills, Inc., P.O.

Box 548, Richmond, Indiana 47375, USA.

ACKNOWLEDGEMENT

The Cincinnati Zoo would like to thank the PNC Bank for their financial support in this endeavour. A special acknowledgement to Scott Drischman, Cory Laughlin, Frank Twohy and Ron Bleem for their assistance.

At this time we would also like to mention the vast amount of support and confi¬ dence that our Executive Director, Edward Maruska demonstrated towards the

12

OEHLER, SCHMID AND MILLER - PARAKEET AUKLETS

Aviculture Department and this project. We sincerely thank him and the remainder

of the Cincinnati Zoo's staff.

REFERENCES

BEDARD, J. 1969. Feeding of the Least, Crested, and Parakeet Auklets around St. Lawrence Island, Alaska. Canad. J. Zoo. 47: 1025 - 1050.

BEDARD, J., SEALEY, S.G., 1984. Moults and feather generations of the Least, Crested and Parakeet Auklets, J. Zool 202: 461 - 488.

COUES, E., 1868. A monograph of the Alcidae. Proc. Acad. Nat. Sci. Philadelphia 20: 1 - 81.

DRISCHMAN, S., 1993. Wildlife Concepts International. Personal communicat¬ ion.

FREETHY, R., 1987. Auks; An Ornithologist's Guide. Blandford Press. 149 - 152.

HANEY, J. C., 1991. Influence of pycnocline topography and water-column structure on marine distributions of alcids (Aves; Alcidae) in Anadyr Strait, Northern Bering Sea, Alaska. Marine Biology 110, 419 - 435.

HARRISON, N. M., 1990. Gelatinous Zooplankton in the Diet of the Parakeet Auklet: Comparisons with other Auklets. Studies in Avian Biology No. 14: 114 - 124.

HARRISON, P., 1983. Seabirds: An Identification Guide. Houghton Mifflin Company. 402 - 403.

PLACE, A.R., 1992. Comparative aspects of lipid digestion and absorption: p hysiological correlates of wax ester digestion. Am. J. Physio. 263 (Regulatory integrative Comp. Physiol. 32): R464 - R471.

SOWLS, A.L. HATCH, S.A., and LENSINK, C.J., 1978. Catalog of Alaskan Seabirds Colonies. Fish and Wildlife Service: U.S. Department of the Interior. 25.

STAUCH, J.G. Jr., 1985. The Phylogeny of the Alcidae. The Auk 102: 520 - 539.

* * *

13

THE FALKLAND ISLANDS FLIGHTLESS STEAMER DUCK AT MARTIN MERE:

A BRIEF HISTORY.

By P. J. Wisniewski and A. Wooldridge

The Falkland Islands Flightless Steamer Duck Tachyeres brachypterus is a large, sexually dimorphic coastal duck endemic to the Falkland Islands. The term "flightless" is a slight misnomer as they can fly low over the water but never attain any height. Wild birds breed from September to December usually in tussock grass or abandoned burrows. Outside the breeding season they may be found in pairs, family parties or larger flocks. They feed by upending or diving, usually at sea but occasionally in freshwater pools. They are extremely aggressive, especially the more mas¬ sively built drakes. Captive breeding of this species has been achieved irregularly with few published records (Gewalt, 1968; Schmidt, 1969).

The Wildfowl and Wetlands Trust centre at Martin Mere near Burscough, Lancashire has had a long association with the Falkland Island Flightless Steamer Duck and the following account provides a brief history of the species in captivity at this centre.

The First Pair

During 1974 the first pair arrived at Martin Mere. These were captive-bred individuals originating from adults hatched from the wild collected eggs during the 1960's and maintained at the Wild¬ fowl and Wetlands Trust at Slimbridge. These were housed in a pen measuring 15 x 5m and comprising 60% land and 40% water. The land area consisted mostly of grass with a small group of bushes close to the water. They were fed on a diet identical to that used at Slimbridge i.e. Beta dried dog food and trout pellets. The birds appeared to settle well but the female expired after seven months from visceral gout. The drake died after twelve months; an x-ray had revealed a metal staple in his gut and the bird did not recover from an operation to remove it. Post mortem revealed amyloidosis of the kidneys. The latter condition and the visceral gut observed in the female may have indicated too high a protein content in the diet. The swallowing of foreign bodies as observed in the drake is a common phenomenon and has been reported as a cause of death in other collections, presumably because these birds are used to swallowing hard objects i.e. shellfish, Crustacea in the wild.

14 WISNIEWSKI & WOOLDRIDGE-FALKLAND ISLANDS

FLIGHTLESS STEAMER DUCK

The Second Pair

During 1977 a second pair of Steamer Ducks arrived at Martin Mere, one being a Slimbridge-bred bird and the other from Wuppertal. Both were approximately two years old on arrival. These were housed in a lens shaped pen 26m long and 7.5m at its widest point with water at the front and a rocky area at the back sloping down to a pebbled area. Barrels were installed under rock caves to provide breeding sites similar to those used by eiders. This time the diet was altered to a mix of Beta dried dog food plus SDS Maintenance Pellet.

The drake was always very dominant and the first to come to food. He was also extremely aggressive with the female prior to the breeding season (in February and March in Britain) and the female had to be removed on several occasions to prevent damage. At the end of the breeding season (late March to April) the female could safely be put back with the drake as he no longer showed any interest in her. This lack of satisfactory pair bonding may have been a result of the birds being put together at too advanced an age (2 years old) and possibly to differences in rearing techniques for the two individuals. Later observations suggest that pairs need to be formed before birds reach one-year old for successful bonding.

In 1979 the drake was found drowned (at an approximate age of four years). Subsequent post-mortem revealed a catalogue of problems including aspergillosis (see also Schmidt, 1969), cyathostomiasis, Acuaria and atherosclerosis. The female died in 1980 (five years old) from enteritis.

The First Breeding

In autumn of 1982 two pairs of Steamer Ducks arrived from Slimbridge where they had been bred in the spring of that year.

The first pair (‘A’ & ‘B’) were put into the pen used by the previous pair from 1977 - 80. The second pair (‘C’ &‘D’) were released onto the large South American Lake which measured 60m by 100m and also housed a flock of Chilean Flamingos Phoenicopterus chilensisx Muscovy Duck Cairina moschata, Red¬ billed Whistling Duck Dendrocygna autumnalis, Bahama Pintail Anas bahamensis a Chiloe Wigeon A. sibilatrix \ Argentine Red Shoveler A, platalea x Rosybill Netta peposaca a Brazilian Teal Amazonetta brasiliensis A and Ringed Teal Callonetta leucophrys. A new pen was ready for the Steamers by April 1983 but during the intervening period they had killed about half a dozen birds, mostly Ringed Teal and Bahama Pintail. The new pen measured 16m by 24m and again consisted of a large pool with rocky backdrop and

WISNIEWSKI & WOOLDRIDGE-FALKLAND ISLANDS 15

FLIGHTLESS STEAMER DUCK

pebble shore. (Diet comprised SDS, Diet A.) The birds did not settle well in the new pen as it was adjacent to the large area that they once occupied and on several occasions one or both birds would leave the pen despite their “flightlessness”

The answer was to swap the two pairs around so that ‘C’ and ‘D’were no longer adjacent to the South American Lake and this solved the problem.

In 1986 the female CD’ laid the first eggs. The birds had been provided with several potential nest sites and eventually nested in a plastic barrel covered with turf on an island. The first egg was laid on 4 April and a total of eight were produced. An egg was collected every other day while the female was away from the nest and each replaced with a wooden egg. The clutch was placed under a domestic goose but when candled after twelve days all proved to be clear. The dummy eggs were subsequently replaced by three European Eider Somateria mollissima eggs. Some aviculturalists would disagree with this practice but we felt it to be important for first-time breeders to have something to rear in order to gain experience. We feel that this is particularly important for single pairs in side pens where they are not stimulated by the sight and sound of the other birds.

Experience has also shown that where eggs are taken from pairs of waterfowl year after year and allowed nothing to rear then they tend to cease laying. This female Steamer subsequently reared two young eider ducks.

The next egg was laid on 23 March 1987 again by female ‘D and the final egg of the clutch on 8 April. In total nine eggs were laid with periods of two to three days between eggs. All eggs were removed to the duckery where they were turned twice daily. No suitable foster parents were available so the first five eggs were placed in a moving air incubator shortly followed by the remaining four. After four days the eggs were candled revealing that the fifth egg to be laid was addled. The first four eggs were then placed under a broody hen. Of the remaining four eggs, the last to be laid was clear and the others were placed under a different broody hen. The first egg began to chip on day 29 and hatched on day 3 1 . There was a gap of eight to nine hours between hatching in the first four eggs but the last three emerged together. Although initially placed in a brooder together, the last three to hatch had to be separated as the others showed aggression towards them even at one day old. The ducklings were very lively, pecking at each others feet and showed no hesitation in taking live crickets and mealworms in

16 WISNIEWSKI & WOOLDRIDGE-FALKLAND ISLANDS

FLIGHTLESS STEAMER DUCK

addition to chickcrumb, chopped lettuce and chopped sand-eel.

No measurements were taken to avoid stress. As the species was known to be susceptible to aspergillosis and Candida the young¬ sters were treated with Ketoconazole. At an age of 22 days, one 12. 5 mg tablet was given to each bird every day for ten days and the dose was then increased to 25mg for a further ten days. Seven young steamers were successfully reared and weaned onto a diet of SDS Diet A, sprats and sand-eels and in the evening were seen to catch midges, moths and even the occasional House Sparrow Passer domesticus which came down to bathe. The youngsters were eventually moved to WWT Centres at Slimbridge (5) and Washing¬ ton (1 pair).

After removal of their eggs the adult Steamer Ducks were given Aylesbury duck eggs to rear and subsequently hatched and reared four ducklings, making excellent parents. However the drake4 C’ was suspected as having aspergillosis and was treated with Ketoconazole for twelve days after which the symptoms subsided.

Further Breeding

During 1988 the drake 4C’ of the breeding pair appeared to be losing condition and as a result the two clutches of eggs produced by his mate, one of nine eggs and the second of seven,