Picture Australasian gannet (Morus serrator) of bird www.nzbirdsonline.org.nz/species/australasian-gannet
Introduc on Ecology and life history The Australasian gannet is one of only three gannet species in Normal adult weight range: 2.16-2.40 kg the world. Dense breeding colonies can be found on the cliffs Moult: Gannets moult their feathers gradually and beaches of headlands on the NZ mainland and on coastal over 10-14 months. islands, as well as along the south-east coast of Australia. Breeding: August to May Majority (>85%) of the breeding popula on is found in New Egg laying between August to January Zealand. Fledglings from NZ will o en migrate to Australia and Monogamous then return to their NZ home colony a er 4-7 years to breed. Incuba on 43-53 days. Gannets are mostly coastal birds and forage on the con nental Age at Fledging 91-119 days shelf. They are plunge divers and can hit the water at speeds up Age at first breeding 4-7 years. to 145km/h, therefore they do not have external nostrils. Lifespan: greater than 25 years. Instead they breath through gaps in the corner of their bills. Diet: Piscivorous
CAPTURE AND HANDLING WARNING – Gannets have very sharp and serrated bill edges and a strong neck that can cause severe injuries to humans. It is ESSENTIAL to wear eye-protec on and addi onal hand protec on in the form of rubber welding gloves. Two people are required for procedures on gannets: one to restrain and one to perform the procedure (e.g. feeding)
Personal protec ve equipment (PPE): Appropriate PPE must be worn when capturing and handling oiled wildlife to prevent exposure to oil (disposable nitrile gloves, safety glasses/goggles, protec on for clothing e.g. Tyvec suit). Capture Handling Consider the safety of both humans and birds. Use a towel to restrain wings (prevents Oiled birds may s ll have the ability to fly damage to feathers and wing bones) and depending on the amount and loca on of oil restrain strong feet. Wear normal examina on on the body. Long-handled fishing nets are gloves if not oiled. useful for capture. If the bird is on land and Gannets do not have nostrils and breath unable to fly then towels are useful for through their mouth so it is extremely capture by throwing it over the bird then important not to hold their mouth closed. gathering it up ensuring the wings are Instead, their head can be restrained with restrained in the towel and the head is fingers under the lower jaw and thumb covered. If the bird is on land then ensure gripping on top of the head (not the upper bill) that someone is standing between the bird or by holding the back of the head in the palm and the water to prevent them from entering and gripping the corners of the jaw with the it. Most birds will defecate a er being caught. fingers on one side and thumb on the other.
Transport to WARNING – NEVER place your eyes close to holes in transport boxes. facility Herons, gannets & shags will lunge at eyes causing serious injury or blindness.
Transport box: Box made of plas c (NOT wood) as oil contamina on can be cleaned and the box reused. Top-loading corflute transport boxes allow for easier access to the bird, however front-loading PetPaks can also be used. Only ONE bird per box. Flooring: Correct flooring in the transport box is important. It should (i) be so and non-abrasive in order to prevent development of bumblefoot during transport, (ii) be non-slip so that the bird can steady itself and (iii) prevent build up of faecal ma er that can cause urate burns. Blue-tube rubber ma ng covered with blue incon nence pads or a suspended ne ng floor are the best op ons. Folded newspaper is inappropriate as it becomes too slippery when contaminated by faeces. Shredded paper, straw, hay and seagrass should be avoided as it increases the risk of Aspergillosis
Vehicle transport: van or ute, with canopy and a separate air space from people to prevent inhala on of oil fumes. Ideally temperature controlled (hea ng on cold days, cooling on hot days). Australasian gannet HUSBANDRY REQUIREMENTS Housing Keep indoors and temperature controlled at 25-27°C because oiled animals cannot thermoregulate. pre-cleaning The area must be well ven lated to disperse the oil fumes. (oiled) Enclosure: • Temperature controlled rooms. • If room is very large then build temporary aviaries with a roof. Ensure walls of temporary enclosure are made of materials that can easily be cleaned of oil such as plas c or metal, not wood. Examples of suitable walls include temporary metal fencing with the walls and roof lined with shade cloth to prevent damage to feathers. Ensure metal fencing is not galvanised with zinc or lead as this could lead to heavy metal poisoning if the birds chew on the fence. • Gannets are gregarious species and therefore mul ple birds can be housed together. Do not overcrowd. Enclosures should be large enough to allow birds to stretch their wings. Minimum recommended dimensions are 3m2 of floor space per bird. Height of enclosure 2.5m. • Reduce visibility of humans and noise to minimise stress. Flooring • Correct flooring is very important to prevent uric acid and faecal buildup which can cause feather damage and bumblefoot. The best op on is fine (0.5cm) non-kno ed co on ne ng using PVC pipe as a frame and suspended at least 15cm above floor. • Alterna vely blue tube ma ng can be used (available at hardware stores). • Avoid oil coming into contact with a concrete floor as it is very difficult to clean. Line floor with heavy duty plas c sheets (e.g. pond liner or large garbage bags) then place ne ng or tube ma ng on top. Housing Enclosure post-cleaning Outdoor aviary with shade cloth covering the roof and walls. Large enough to allow them to stretch (no oil) their wings. Minimum recommended dimensions are 3m2 of floor space per bird. Height of enclosure 2.5m. Flooring Blue tube ma ng on floor to prevent uric acid and faecal buildup and bumblefoot. NOTE: grey tube flooring is harder than the blue version which increases risk of bumblefoot. Gregarious species Gannets roost on land in groups and should be housed together in an aviary, but ensure that it is 2 not overcrowded and watch for bullying. Allow for floor space of 3m per bird. Perches Gannets require perches. Perches made of PVC tubing covered in blue tube ma ng are easy to make and clean. Diameter of piping should be appropriate for the size of their feet. Clean perches daily. Pool • Seabirds in the rehabilita on phase need access to water in their enclosure to aid waterproofing. • Suitable in-aviary pool types: built-in, large plas c containers or children’s swimming pool or shell. • Non-slip ramps to allow easy access and exit of water. • Water must be deep enough to allow birds to swim on surface without feet touching the bo om. • Preferably use seawater, but freshwater can be used. If using freshwater then provide birds with a salt supplement in order to maintain salt glands (see “Supplements” sec on). • Heat water during winter months if ambient air temperature is below ~10-15°C. • Con nuous flow of water is required to prevent buildup of fish oil and faeces on the surface of the water which inhibits the waterproofing process. This is most easily achieved by placing a hose above the pool allowing the running water to break the surface of the pool water and le ng it overflow. Good drainage around the pool is required. • Surface skimmer is useful for removing oil, food and faeces floa ng on the surface. Transport As per handling instruc ons. Wear safety glasses. within If bird is oiled then appropriate PPE must be worn to prevent oil exposure. Use large towels for facility restraint and dispose if contaminated with oil. Iden fica on Leg band (temporary iden fica on to be removed before release). Visually check leg band each day as leg bands o en get stuck at the top of the leg under the plumage. Australasian gannet NUTRITION, SUPPLEMENTS and FLUIDS At admission Triage assessment: physical examina on by trained personnel (preferably a veterinarian) Record cloacal temperature. Give fluids at ini al stabilisa on rates below. Dosing If large numbers of birds require dosing then calculate dose based on the weight of the heaviest bird. Group animals into age and/or size class for dosing calcula ons. Fluid rate Ini al stabilisa on: 75-80ml/kg body weight/day divided into two doses PO Once hydrated: 50-60ml/kg body weight/day divided into two doses PO Fluid type For long term maintenance use either isotonic saline (0.9%) or Vytrate®/Lectade® Amount Feed 10% of body weight (BW) TWICE a day. (i.e. 20% of body weight total each day) Food type If weak, emaciated, severely dehydrated or unable to hold head up: Give oral electrolyte fluids at ini al stabilisa on rate listed above for 24 hours to rehydrate gut. Use either: Equal parts (50:50) Hartmann’s solu on and 2.5% dextrose in 0.45% saline 5% dextrose in 0.9% saline or Vytrate®/Lectade®
Once gut is hydrated, then start with small amounts of fish slurry. If able to take solids: human grade small whole salmon. Food Fish slurry: Place human grade salmon in heavy duty blender and blend. Add just enough isotonic prepara on (0.9% NaCl) fluid into blender to achieve a smooth consistency. Sieve slurry using a metal sieve to remove any chunks that may clog the feeding tube. Discard a er 24 hours in the refrigerator. Do not let it sit at room temperature on bench. Whole fish: Ideally defrost covered in refrigerator to retain nutri onal quality. However, if large amounts of food are required then fish can be defrosted under cold running water immediately before feeding so long as vitamin supplements are given. Supplements ① Mazuri seabird vitamins: 1 tablet per 225g fish. (Available at Carlyle Vet Clinic, Napier 06 835 1096). ② Itraconazole (Sporonox): 5mg/kg BW PO once daily via so crop tube to prevent Aspergillosis. ③ Salt (sodium chloride) to recondi on salt gland: Only required if birds have been housed long- term in freshwater. Start at least 2 week before release. Give orally either as 3% saline solu on at maintenance fluid rates or 100mg/kg BW PO once daily. Gradually increase dose over four days: Day 1 give ¼ dose, Day 2 give ½ dose, Day give ¾ dose, Day 4 give full dose, then con nue at full dose.
Delivery & Heat fluids and slurry to 38-40°C. device Large volumes of fluid and fish slurry are easier to deliver with a large, plas c, lamb stomach tube 16” in length and a 60ml catheter- p syringe. Force feed (FF) whole salmon head first. Unlike other birds, it is unsafe for the handler to let go of the head to allow the gannet to swallow. Keep a firm hold of the head at all mes. To assist with swallowing, the person feeding can gently massage the fish down the oesophagus. Avoid ge ng fish juices on the skin and feathers at the corner of the mouth as this disrupts waterproofing and can cause derma s. If fish juice/oil gets onto skin or feathers DO NOT ATTEMPT TO WIPE OFF. Rinse area with a large syringe of water and allow bird to preen. HEALTH SCREENING Venepuncture sites: The medial metatarsal vein is the easiest to access. Brachial vein can also be used.
Anaemia Kidney func on Birds exposed to oil can quickly become anaemic Uric acid (UA) levels in birds are a measure of kidney (decreased red blood cells) due to the toxic affects of oil func on. Elevated UA levels >600 IU/dl indicate that the and starva on. As a minimum, packed cell volume (PCV) kidneys are failing or the animal is severely dehydrated, and serum total protein (TP) should be measured at both of which commonly occur in oiled birds. (1) intake (2) pre-wash (3) post-wash (4) pre-release. Treatment: IV or PO isotonic fluids at twice maintenance Severely anaemic (PCV<15-20%) birds require blood rates (100ml/kg/24 hours) transfusion. Birds should not be released un l their UA levels return Birds should NOT be: to within the normal range (<600 IU/dl). If UA levels • washed un l PCV ≥30% and TP ≥25g/L remain elevated despite treatment then the bird likely • released un l their PCV & TP levels return to within the has irreversible kidney failure and should be euthanised normal range for gannets = PCV 29-44%, TP 20-50g/L on humane grounds. Australasian gannet
Common Medica ons Washing An -fungals: Preventa ve treatment of Aspergillosis Birds must be stable and strong enough to withstand (a severe respiratory fungal infec on) is highly the stress of washing. This may mean that a bird will recommended as these birds are extremely suscep ble remain oiled for several days un l it has been stabilised. to this life-threatening disease when in cap vity. Itraconazole available only by veterinary prescrip on. Requirements for washing are very specific, such as See dose rate on page 1. water temperature, water so ness and brand of detergent. Refer to the “Washing” factsheet for detailed An bio cs: are only required if the animal has an open informa on. or infected wound or known bacterial infec on and should only be given if prescribed by a veterinarian a er examina on of the animal. Waterproofing To regain waterproofing, birds must be given access to a Dose rates: Amoxicillin/clavulanic acid 125mg/kg PO BID pool with haulouts so that they can preen and dry off Enrofloxacin 5-10mg/kg PO BID between swims. Degree of waterproofing should be Pain relief: is only required if the animal has a painful assessed using the Waterproofing Assessment sheets condi on (e.g. open wound) and should only be given if (hyperlink). prescribed by a veterinarian a er examina on of the animal. Dose rates: Meloxicam (for mild to moderate so ssue pain) Release criteria 0.5-1 mg/kg BID Birds should only be released if they fulfill ALL the Butorphanol (for moderate to severe bone pain) following criteria: 5mg/kg IM ideally every 2-3hours but can be given 1. Fully waterproof a er 6 hours swim test (refer to twice a day “Waterproofing” guidelines).
Ac vated charcoal: not recommended 2. Weight within normal range (on page 1) AND Body Condi on Score at least 3/5 using pectoral Problems associated with cap vity muscle scoring system: ALL secondary complica ons require veterinary a en on. Isolate any sick birds from the group.
1. Aspergillosis A serious, life-threatening respiratory fungal infec on. Clinical signs include noisy or difficulty breathing. Treatment involves daily nebulisa on with a specific an fungal agent only available through a veterinarian.
2. Pressure sores: keel lesions, hock lesions or pododerma s (bumblefoot) 3. PCV is 35-55% and TP is 30-55 g/L Best prevented with good husbandry and appropriate 4. UA <600 IU/dl floor coverings. Depending on severity the bird may 5. Secondary complica ons resolved and checked by require surgery. Treatment involves specific wound care veterinarian and bandaging. Other things to consider: • 3. Trauma c injuries Is their release habitat free from oil? • Gannets can be released on land near the shoreline Trauma c injuries such as bone fractures can occur in cap vity due to excessive force used during handling or or at their colony site. issues in the enclosure (eg. gaps where legs or flippers Authors: S. Finlayson, B. White, L. Chilvers, G. Frankfurt, G. Finlayson. can get stuck). Thanks to the veterinary technicians and veterinary residents in the Wildbase Hospital and to others for their input, feedback and photos. Disclaimer: This fact sheet is managed by Wildbase Oil Response (WOR) for 4. Feather damage informa on purposes only. Informa on contained in it is drawn from a variety of sources external to WOR. Although reasonable care was taken in its Usually occurs from inappropriate handling or enclosure. prepara on, WOR does not guarantee or warrant the accuracy, reliability, Birds cannot be released if feather damage effects completeness, or currency of the informa on or its usefulness in achieving waterproofing. If it is the wrong me of year for a any purpose. To the fullest extent permi ed by law, WOR will not be liable for any loss, damage, cost or expense incurred in or arising by reason of any natural moult, please seek advice from Wildbase on how person relying on informa on in this fact sheet. Persons should accordingly to induce moult. make and rely on their own assessments and enquiries to verify the accuracy of the informa on provided. Pictures: Unless otherwise credited, all pictures are copyright of Wildbase.