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Received: 26 October 2017
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Accepted: 11 December 2017
DOI: 10.1002/zoo.21395
HUSBANDRY REPORTS
First report of a hatched, hand-reared, and released African
oystercatcher
Romy Klusener
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Renata Hurtado
1,2
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Nicola Stander
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Nola J. Parsons
1
1
Southern African Foundation for the
Conservation of Coastal Birds (SANCCOB),
Cape Town, South Africa
2
Institute of Research and Rehabilitation of
Marine Animals (IPRAM), Espírito Santo, Brazil
Correspondence
Romy Klusener, 55 Pentz Drive, 7441, Cape
Town, South Africa.
Email: romy@sanccob.co.za
The African oystercatcher Haematopus moquini is a near-threatened wader that is
endemic to southern Africa. In the past, the species suffered a drastic decrease in
nesting success due to human disturbance. We present the case report of an African
oystercatcher that was hatched, hand-reared, and released in the Western Cape, South
Africa. African oystercatchers are semi-altricial birds that tend to be highly sensitive to
stress; as a result, strategies to minimize stress and the employment of surrogate
parents and pre-release acclimatization are important to ensure post-release survival
of hand-reared chicks. Considering the lack of literature on the incubation and hand-
rearing of oystercatchers, this case report provides a basis for the development of
hand-rearing techniques that might be useful for the protection of this and other
threatened wader species.
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STATEMENT OF THE PROBLEM
The African oystercatcher Haematopus moquini (Charadriiformes:
Haematopodidae) is a near-threatened species with a global popula-
tion of c. 6,500 individuals breeding on the coasts of Namibia and
South Africa (BirdLife International, 2016a, 2017; Hockey, 1983;
Underhill, 2014). They breed on the rocky and sandy shoreline of
offshore islands and the mainland during the summer season, from
November to March. Because their breeding coincides with the peak
of the tourism season, they are vulnerable to the direct and indirect
effects of human disturbance. In the past, the African oystercatcher
population suffered a drastic decrease in nesting success that was
largely related to human disturbance (Jeffery, 1987). This is acutely
concerning since human disturbance and exploitation of the shore are
also believed to have been the primary factors leading to the extinction
of the Canarian oystercatcher Haematopus meadewaldoi (Hockey,
1987). Another significant threat to the African oystercatchers is the
frequent occurrence of oil spills along the South African coast, with
several oiling incidents affecting aquatic birds since 1948 (Whitting-
ton, 1999, Wolfaardt, Underhill, Altwegg, Visagie, & Williams, 2008).
There is no scientific literature on the techniques that may be used
for the incubation and hand-rearing of oystercatchers. Because these
are semi-altricial birds that rely on a prolonged bond with their parents
in order to fledge successfully (Elphick, Dunning, & Sibley, 2001), the
hand-rearing of oystercatcher can be particularly challenging. In this
study, we report the successful incubation, hand-rearing and release of
an African oystercatcher. The development of such husbandry
techniques may be valuable tools for the mitigation of environmental
impacts to the African oystercatcher, and may also provide a basis for
the development of hand-rearing techniques for other species of
waders that are even more acutely threatened, such as the Chatham
oystercatcher Haematopus chathamensis which has a global population
of c. 120 pairs (BirdLife International, 2016b).
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DESCRIPTION OF THE PROCESS
On 20 January 2016, two African oystercatcher eggs (E01 and E02)
were removed from a nest at a construction site at the Ore Terminal in
Saldanha, Western Cape, South Africa (33°01′S 17°59′E). Both eggs
were placed horizontally in foam-cases designed for egg transporta-
tion and set in a portable incubator at 30 °C; clean towels were placed
on the base of the incubator and around the foam-cases to protect the
eggs (Figure 1a).
Eggs were admitted to the Chick Rearing Unit (CRU) of the
Southern African Foundation for the Conservation of Coastal Birds
(SANCCOB) (33°50′02″S 18°29′29″E). Egg measurements (E01:
63.5 × 41.8 mm, 56.9 g; E02: 59.8 × 36.5 mm, 56.4 g) were consistent
Zoo Biology. 2018;1–5. wileyonlinelibrary.com/journal/zoo © 2018 Wiley Periodicals, Inc.
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with previous studies for the species (Spiby, 2012; Underhill and Calf,
2005). Candling showed that both eggs contained yolk with no visible
embryo. Eggs were placed horizontally in an incubator at 36.5 °C and 45%
humidity (Grumbach
®
Compact S84 model 8015, Mücke, Germany) and
set to continually rotate eggs widthways (complete rotation every 2 hr);
additionally, eggs were manually rotated 180° lengthways every 24 hr.
Eggs were weighed daily and candled every 7 days.
E02 was discarded after 22 days of incubation because no embryo
development was observed. E01 developed adequately and pipped
externally after 23 days of incubation. The pipping egg weighed 50 g,
following a stable weight loss rate of 0.3 g per day. The pipping egg was
placed in a plastic container with soft paper towels and moved to a
hatcher incubator (same model) set at 36.5 °C with 60% humidity. The
chick hatched about 38 hr after external pipping was first noticed (total
of 25 days of incubation) (Figure 1b).
The chick was checked for external abnormalities, weighed (42 g),
placed in a container with clean soft paper towels, and relocated to the
incubatorfor 3–4 hrto dry out. When dry, it was tubedand received 1 ml
of probiotics [10 g/L Kyron Protexin
®
Soluble (Johannesburg, South
Africa),containing total viable count equal to or greaterthan 2 × 10
8
cfu/
g of the following organisms: Lactobacillus plantarum, Lactobacillus
debrueckii bulgaricus, Lactobacillus acidophilus, Lactobacillus rhamnosus,
Bifidobacterium bifidum, Streptococcus salvarius thermophilus, and
Enterococcus faecium] and then transferred to a brooder crate placed
FIGURE 1 Hand-rearing of an African oystercatcher at SANCCOB. legend: (a) portable incubator used to transport eggs (African penguin
eggs are shown in the photograph); (b) newly-hatched African oystercatcher; (c) brooder crate under a heat lamp; (d) chick (arrow) bonding
with surrogate parent (plush toy resembling an adult African oystercatcher); (e) usage of surrogate parent to teach the chick how to eat by
pointing its beak at food items; (f) outdoor netted shaded sand pen; (g) portable acclimatization enclosure at the beach; (h) oystercatcher
approaching the surrogate parent after release; and (j) oystercatcher successfully feeding on a limpet (arrow) after having been released.
Photographs: (a, b, g–i): Romy Klusener; c-f: Renata Hurtado
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KLUSENER ET AL.
under a heat lamp (Figure 1c). The brooder crate (40 × 33 × 30 cm,
plastic) waslined with towels on the bottom andall sides; rubber matting
was placed under the bird to prevent splayed legs.
After 3 days the chick was moved to a larger plastic crate
(70 × 50 × 54 cm) with towels on the bottom, under a heat lamp.
Wading and bathing dishes of appropriate depth were provided
according to the size and age of the oystercatcher (Osnes-Erie, 2007).
The chick was exposed to direct sunlight for 15 min, three times a day.
Crates were washed and disinfected (quaternary ammonium) on a daily
basis. Table 1 summarizes changes in the external appearance of the
oystercatcher chick as it developed.
A plush toy resembling an adult African oystercatcher was used to
serve as a “surrogate parent”and was kept with the chick during the
entire hand-rearing process (from hatching to release). The chick
promptly bounded with it (Figure 1d), becoming stressed when the
plush had to be removed to be washed. The plush was also used to
teach the chick how to eat and drink/bath by pointing its red beak at
food pieces and water, to which the chick promptly responded
(Figure 1e). Audio recordings of wild African oystercatchers vocalizing
were also played to the chick; however, the chick did not exhibit
interest and did not appear calmer, therefore the playbacks were
discontinued. It is possible, however, that the audio recording that was
played did not represent the type of call that would be most suited to
elicit the desired behavioral response (see Baker & Hockey, 1984).
When the chick reached 42 days of age, it was moved to an
outdoor netted shaded sand pen (280 × 280 × 95 cm) (Figure 1f) during
days of good weather and returned to its indoors crate in the evening.
The pen had an artificial nest box (providing shelter and a hideout), the
plush toy, and a shallow water tray with stones. Both the outdoor and
indoor areas where the chick was kept were quiet and had a reduced
people flow.
Table 2 summarizes the feeding regime. The chick was weighed
daily before the first feed to monitor its development and calculate
the daily feeds. The diet included primarily fresh-caught limpet and
mussel, redbait, clam, shrimp, and squid based on the published diet
in the wild (del Hoyo, Elliott, & Sargatal, 1996; Hockey, Dean, &
Ryan, 2005; Scott, Dean, & Watson, 2012; Urban et al., 1986). Food
was offered in empty mussel shells with ∼0.5 ml of fresh water each
(Figure 1e). Food items were cut into small bite-sized pieces and
were gradually cut larger as chick grew, until it could open mussels
on its own and tear limpet meat from the shells. Supplementation
with Kyron Cani-cal
®
(1 g contains: vitamin A 400 IU, vitamin D3 30
IU, vitamin E 1 IU, iron 4 mg, zinc 1 mg, calcium 70 mg, phosphorus
58 mg), and Kyron Cani-vit
®
(vitamin A 100 IU, vitamin D3 10 IU,
vitamin E 3 IU, vitamin B1 0.02 mg, vitamin B2 0.05 mg, vitamin B6
0.04 mg, vitamin K 0.8 μg, vitamin B12 0.6 μg, calcium pantothenate
0.3 mg, biotin 0.03 mg, nicatinamide 0.6 mg, folic acid 5 μg, choline
bitartrate 10 mg, magnesium 0.4 mg, iron 1 mg, copper 0.08 mg,
manganese 0.1 mg, zinc 2 mg, iodine 0.03 mg, selenium 2 μg, sodium
chloride 5 mg, calcium 60 mg, phosphorus 60 mg, protein 0.3 g) was
added to every feed (c. 0.3 g each). The quantity of untouched food
at each meal was recorded, aiming to monitor the chick's appetite
and food preferences, and to verify if the weight gain was consistent
with the amount of food consumed.
At approximately 50 days of age the pre-release training was
initiated. The first stage was to take the bird to a large aviary
(10 × 4.5 × 3 m) once a day to exercise for 20 min (under supervision).
As the bird grew more comfortable in the aviary, this period was
gradually increased up to 8 hr per day. When the bird was
approximately 120 days-old, the second stage of pre-release training
was initiated. The bird was transported to a local beach in a large
portable enclosure (200 × 120 × 95 cm) for acclimatization (Figure 1g).
Duringthe entire hand-rearing process, the birdwas checked weekly
by a veterinarian and blood and fecal samples were regularly examined;
results showed no signs of on-going disease. Deworming treatment
(ivermectin 0.2 mg/kg PO and praziquantel 7.5 mg/kg PO) was given
15 days before release and repeated on the day before release.
Having passed all the release criteria (healthy, in good body
condition, waterproof feathers, normal behavior and flight, wariness of
predators and humans) (Osnes-Erie, 2007), a metal band (South
African Bird Ringing Unit −SAFRING K48319) was placed on the right
leg of the bird. Baboon Point at Elands Bay (32°18'55“S 18°18'56“E)
TABLE 1 External changes observed during the development of a
hand-reared African oystercatcher chick
Age Changes
20 days-old Beak starts changing color, downy feathers only
30 days-old Juvenile feathers start to push through on wings,
head, and body
38 days-old Juvenile feathers growing through on tail, beak
halfway orange
47 days-old Orange beak with black tip
60 days-old All juvenile feathers grown through with no downy
feathers present, black tip on beak almost gone
67 days-old Beak completely orange
TABLE 2 Feeding regime used to hand-rear an African oystercatcher chick
Age Amount Food description 6hr 9hr 10hr 12hr 14hr 15hr 18hr 21hr
1to46
days
Ten percent of
body mass
Chopped seafood X X X X X X
47 to 139
days
Ten percent of
body mass
Whole or chopped (in large chunks) seafood.
Mollusks with shell slightly open
XXXXX
140 days
onwards
Ad libitum Mollusks (whole in shell) X X X
KLUSENER ET AL.
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was chosen as the release site as it is known to be an important site for
juveniles and pre-breeding oystercatchers (Underhill, 2014).
On 25 July 2014, the162 days-old bird was taken to therelease site
at 08:00 hr. The release crate was left on the rocks for a few minutes for
the bird to acclimatize to the environment; the plush toy was placed a
short distance in front of the crate. When the lid was opened, the bird
hopped out and ran to the plush toy (Figure 1h). Shortly afterwards, it
started pokingits beak into mussels and limpets, as wellas taking baths in
a shallow rock pool. The oystercatcher flew off and continued searching
for food; it was seen to successfully catch a limpet (Figure 1i). After 6 hr
of observation, the bird was left to fend for itself.
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DEMONSTRATION OF EFFICACY
The oystercatcher was re-sighted 3 weeks later at Baboon Point,
apparently in a fit and healthy condition (no further re-sightings have
been reported to SAFRING), indicating that the husbandry techniques
were successful to ensure that the bird could feed on its own and
survive after having been released.
Considering how fragile oystercatcher eggs are, the use of portable
incubator with foam-cases and towels was an efficient way to keep eggs
warm and preventing them from crushing/rupturing internal veins
during transportation. Incubation temperature was set according to the
temperature range (32.2–37.0 °C) described for natural African
oystercatcher nests in South Africa (Adams, Kerley, & Watson, 1999).
Assuming a total incubation weight loss of 16–18%, as is consistently
observed in other avian species (Rahn & Ar, 1974), it maybe estimated
that the egg would haveweighed between 59.5 and 61.0 g when laid. An
egg of such mass would be expected to lose 0.309–0.314 g per day
during incubation (calculations based on Rahn & Ar, 1974); the loss of
0.3 g per day therefore indicates that the incubation parameters
(temperature and humidity) were nearly optimal.
Despite oystercatcher chicks being fed by their parents for up to
a month (Elphick et al., 2001), the techniques we employed enabled
the bird to learn how to feed by itself since its first day of life.
Offering whole mollusks to the oystercatcher also developed its food
acquisition skills, as it was seen properly capturing and consuming
these items shortly after being released. All the implemented
measures ensured an appropriate weight gain curve (Figure 2), with
four stages of growth. Stage I began at hatching and extended up to
20 days of age, with a relatively slow weight gain (average daily
weight gain = 3.82% ± 6.04%), and body mass increased to 86 g over
this period (105% increase in 20 days). At stage II, between the ages
of 21–40 days, there was a sharp increase in weight gain
(7.26% ± 4.44%), and the bird reached 344 g at 40 days of age
(300% increase in 20 days). At stage III, between the ages of 41–80
days, weight gain slowed down (1.21% ± 4.59%) and body mass
increased to 512 g over this period (49% increase in 40 days). Finally,
a plateau was reached after 81 days, with virtually no weight gain
(0.18% ± 3.13%). The last weight obtained prior to release was 534 g
after 158 days (4% increase in 78 days).
Keeping the plush toy with the chick during the entire hand-
rearing process was found to be an efficient strategy to minimize
stress, since oystercatchers in the wild may remain with parents for up
6 months of age (Elphick et al., 2001). The plush toy was also
instrumental in inducing the chick to feed by itself very early (despite
the semi-altricial nature of this species) and preventing the human
imprinting, as the bird would become stressed/vocal when handled.
Furthermore, keeping human contact, noise and handling to a
minimum during daily routine was clearly beneficial to minimize stress.
In conclusion, despite the high sensitivity of this species the
incubation and hand-rearing techniques employed in this case were
successful and provide a basis for the future hand-rearing of
oystercatcher's eggs and chicks. These husbandry techniques might
prove valuable to protect the African oystercatcher and other
threatened waders.
ACKNOWLEDGMENTS
We are grateful to all the interns and staff who worked in the CRU at
SANCCOB, and also to Dr. Natasha Ayres and Dr. Katrin Ludynia.
Thank you to Dr. Ralph Vanstreels for his constructive contributions on
this manuscript, to Dr. Les Underhill for the recommendation on the
ideal release site, and to Two Oceans Aquarium for providing limpets
and redbaits. We hugely thank the Chick Bolstering Project for helping
on funding the Chick Rearing Unit at SANCCOB.
CONFLICTS OF INTEREST
The authors have declared no conflicts of interest.
ORCID
Renata Hurtado http://orcid.org/0000-0003-2256-7131
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FIGURE 2 The body mass curve of the african oystercatcher
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How to cite this article: Klusener R, Hurtado R, Stander N,
Parsons NJ. First report of a hatched, hand-reared, and
released African oystercatcher. Zoo Biology. 2018;1–5.
https://doi.org/10.1002/zoo.21395
KLUSENER ET AL.
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