Kerri J. Morgan

Wildlife and oil in the Antarctic: a recipe for cold disaster

The increasing rate of incidents involving vessels in the Southern Ocean (including vessels sinking) has highlighted the potential for substantial fuel spills into the Antarctic environment. An increasing number of tourist and fishing vessels, often without ice strengthened hulls, are penetrating farther into, and staying longer in, Antarctic waters, with a focus for destinations of wildlife concentrations. Based on a survey of national operators in the Antarctic, there is little preparation for an oil spill event that involves Antarctic wildlife. This is a recipe for a catastrophic spill event, with the potential for high numbers of oiled wildlife in a remote part of the world where there are major logistical constraints on the provision of equipment and skilled response personnel. Here we chronicle shipping incidents that have led to oil spills in the Southern Ocean, the current legislation and contingency plans currently in place by national Antarctic operators, and examine their preparedness and expertise for an oiled wildlife event response. It is clear that national, fishing and tourism operators are manifestly unprepared for an oiled wildlife event in the Southern Ocean. We identify five critical constraints to any response and provide recommendations that address these constraints.

Cloacal papillomatosis in the absence of herpesvirus and papillomavirus in a sulphur-crested cockatoo (Cacatua galerita)

Abstract CASE HISTORY A 21-year-old male sulphur-crested cockatoo (Cacatua galerita) was presented following the sudden appearance of blood associated with the passage of faeces and urates. CLINICAL AND PATHOLOGICAL FINDINGS: There was fresh blood-staining of the feathers around the vent. The dorsal mucosal wall of the proctodeum was erythematous and roughened in appearance. An endoscopic biopsy was performed, and histological examination revealed multiple fronds of epithelium; the mucosa varied from simple to pseudostratified columnar epithelium, with diffuse hyperplasia of goblet cells. The underlying connective tissue stroma was well vascularised and was infiltrated with mixed inflammatory cells, comprising granulocytic cells and macrophages. PCR testing for both herpesvirus and papillomavirus, using consensus primers, was negative. DIAGNOSIS: Cloacal papillomatosis. CLINICAL RELEVANCE: This case manifested typical clinical signs and histological lesions of cloacal papillomatosis in the absence of demonstrable herpesvirus or papillomavirus. Veterinarians need to consider this disease in the differential diagnosis of blood in the droppings of parrots and cockatoos even in countries where psittacine herpesviruses are exotic diseases.

Extra-intestinal coccidiosis in the kiwi (Apteryx spp.)

Despite significant conservation intervention, the kiwi (Apteryx spp.) is in serious population decline. To increase survival in the wild, conservation management includes rearing of young birds in captivity, safe from introduced mammalian predators. However, an increase in density of immunologically naïve kiwi increases the risk of exposure to disease, including coccidia. Intestinal coccidiosis has recently been described in the kiwi, and although extra-intestinal coccidiosis was first recognized in kiwi in 1978, very little is known about this disease entity. This study used archived histological tissues and reports from routine necropsies to describe the pathology of naturally occurring extra-intestinal coccidiosis. At least 4.5% of all kiwi necropsied during 1991 to 2011 (n=558) were affected by extra-intestinal coccidiosis, and it is estimated that it caused death in 0.9 to 1.2% of kiwi in the study group. Four forms were recognized: renal, hepatic, and, less commonly, splenic and pulmonary. At necropsy, renal coccidiosis was associated with miliary white streaks and foci through the kidneys, renomegaly, and renal pallor or congestion. Renal meronts and gametocytes were confined to the distal convoluted tubules and collecting ducts, and were associated with renal tubular necrosis and tubular obstruction. Hepatic miliary pinpoint foci were present throughout the hepatic parenchyma associated microscopically with macromeronts measuring 304×227 µm. In two cases, clusters of splenic meronts were identified, and a similar lesion was identified in the pulmonary interstitium of another case. Juvenile, captive kiwi were most often affected with extra-intestinal coccidiosis, illustrating an increased expression of disease with population manipulation for conservation purposes.

Fibrous osteodystrophy in two Northern Royal albatross chicks (Diomedea sanfordi)

Abstract CASE HISTORY: In February 2004, two Northern Royal albatross chicks aged 20 and 25 days old were presented for necropsy. Both chicks had been hand-fed in situ at a breeding colony, from 2–3 days post-hatch. The hand-rearing diet consisted of boneless hoki fillets (Macraronus novaezelandiae), electrolytes, and sooty shearwater (Puffinus griseus) proventricular oil obtained as a by-product of cultural harvest. PATHOLOGICAL FINDINGS: Routine necropsies on the affected chicks revealed many bones were soft and easily bent. Radiography and histopathology revealed decreased bone density, pathological fractures, and extensive remodelling suggestive of fibrous osteodystrophy. DIAGNOSIS: Nutritional secondary hyperparathyroidism, resulting from an imbalance in the dietary Ca:P ratio. CLINICAL RELEVANCE: The imbalance in the dietary Ca:P ratio was a result of feeding deboned and eviscerated fish. This investigation also highlighted potential health risks associated with the practice of feeding stored rancid proventricular oil, including the destruction of fat-soluble vitamins. It is therefore possible that oxidative degradation of vitamin D may have contributed to the development of nutritional secondary hyperparathyroidism. Subsequently, dietary recommendations for supplementary feeding of orphaned Northern Royal albatross chicks include the feeding of whole human-grade fish with an appropriate Ca:P ratio, and the exclusion of proventricular oil. These cases highlight the need for scientific input into wildlife conservation projects, as lack of appropriate nutritional advice resulted in the feeding of a nutritionally inadequate diet. Following the recommended changes in diet, no further cases of osteodystrophy have been diagnosed in hand-raised chicks in the albatross colony.

Aspergillosis in a North Island robin (Petroica longipes)

Abstract CASE HISTORY: A 3-year-old female North Island robin (Petroica longipes) was found dead on Tiritiri Matangi Island during the breeding season. CLINICAL FINDINGS: The bird was in poor condition, and there was a 13 x 8 mm granulomatous mass in the thoracic cavity causing displacement of the heart and left lung. Histologically, the mass was a large granuloma infiltrated with fungal hyphae, and the liver contained multifocal aggregates of inflammatory cells. DIAGNOSIS: Thoracic aspergillosis and multifocal hepatitis. CLINICAL RELEVANCE: Determining the causes of death in populations of wild birds is often hampered by a lack of recovery of carcasses, autolysis and poor clinical history. In this case, the life history of the bird was known and recovery of the body was relatively swift. This is the first published description of aspergillosis in a free-living North Island robin.

DIPHTHERITIC STOMATITIS IN YELLOW-EYED PENGUINS (MEGADYPTES ANTIPODES) IN NEW ZEALAND

Abstract Diphtheritic stomatitis is a seasonal disease that has been recognized as a syndrome in Yellow-eyed Penguin (Megadyptes antipodes) chicks in New Zealand for >10 yr. It was present in about 50% of 234 chicks examined since 2002 and is characterized by a thick serocellular exudate in the oral cavity of 1–4-wk-old chicks. The syndrome includes inanition, weight loss, and death in many affected birds. Microscopically, the lesions varied in severity. Most affected chicks had severe, locally extensive, ulcerative stomatitis with large amounts of exudate containing numerous bacteria; a smaller number had mild focal lesions with smaller amounts of exudate and bacteria. Although Corynebacterium amycolatum has been consistently isolated from the oral lesions, it was also present in the oral cavity of 34% of normal adult penguins and their chicks and is not known to possess diphtheritic toxins. A primary viral pathogen was therefore suspected, and intracytoplasmic inclusion bodies were occasionally seen in oral mucosal epithelial cells. No herpesvirus DNA was detected with PCR. Avipoxvirus DNA and an unidentified virus-like agent were detected in some early oral lesions, but could not be confirmed in subsequent testing. Electron microscopy on early affected epithelium with intracytoplasmic inclusion bodies was unrewarding. Our findings raise the possibility that the disease is caused by an unknown primary virus infection followed by secondary Corynebacterium invasion, but this requires confirmation. The means of transmission has not been established but insect vectors are suspected.

Ventral dermatitis in rowi (Apteryx rowi) due to cutaneous larval migrans.

Graphical Abstract

Prevalence of and risk factors for coccidiosis in kiwi between 1977 and 2011.

AIMS: To identify risk factors associated with coccidiosis in kiwi (Apteryx spp.) using a retrospective analysis of historical data from kiwi examined post-mortem, and to determine the prevalence of coccidial oocysts in the droppings of wild and captive kiwi. METHODS: Necropsy reports were examined from kiwi submitted to the National Wildlife Mortality Database of New Zealand (Huia) between February 1977 and May 2011. All cases that reported histological examination of one or more hepatic, intestinal or renal tissues were included in the study (n=372). Data collated for analysis included the presence or absence of coccidiosis in one or more tissues, age, host species, habitat, and season of submission. Fishers exact test was used to determine the association between each independent variable and the prevalence of coccidiosis. Droppings opportunistically collected from wild and captive kiwi between January 2008 and June 2010 were also examined for the presence of coccidial oocysts. RESULTS: Coccidiosis was evident in 47/372 (12.6%) kiwi examined post-mortem and was considered the primary cause of death in 12/47 (26%) infected cases. Examination of 412 droppings from wild and captive kiwi collected over a 29-month period revealed that 98 (23.8%) samples contained coccidia at the time of sampling. Enteric (n=27) coccidiosis was the most common form diagnosed using histology, followed by renal (n=19) and hepatic (n=11), with splenic (n=2) and pulmonary (n=1) infections infrequently seen. Many kiwi demonstrated infections in multiple tissues. The prevalence of coccidiosis was greater in juvenile kiwi (36/148, 24.3%) than adults (8/133, 6.0%) or chicks (2/83, 2.4%) (p<0.001), although there was no difference in mortality between age groups. Season of year was also associated with overall prevalence (p=0.05), with most cases being diagnosed in the autumn and winter. Coccidiosis was histologically evident in four of five species of kiwi examined, and in all host species upon analysis of droppings. Host species or habitat (captive vs. wild) did not influence the prevalence of disease detected histologically. CONCLUSIONS: Age and season were the only factors that influenced the prevalence of coccidiosis in kiwi in this study. Coccidiosis was present in all species of kiwi, and this is the first report of coccidiosis in rowi (Apteryx rowi).

Captive husbandry and veterinary care of northern New Zealand dotterels (Charadrius obscurus aquilonius) during the CV Rena oil-spill response

Abstract Context. Oil spills cause significant detrimental impacts on many shoreline species. There is limited information in the scientific literature about the management and response of shorebirds to oil spills. Northern New Zealand dotterels (Charadrius obscurus aquilonius) were pre-emptively captured as part of the oiled wildlife response to the container vessel Rena oil spill, to ensure the survival of a regional population should there be a catastrophic release of oil. Previous attempts to hold dotterels in captivity have resulted in high mortality. Aims. To describe the captive husbandry and veterinary management of wild-caught adult dotterels, to outline the common problems encountered, and make recommendations for future captive management. Methods. The dotterels were caught by noose mat on beaches at risk of further contamination by oil. Initially, dotterels were kept individually indoors and force-fed until they converted to self-feeding on a diet of an artificial insect analogue, ox heart and mealworms. Once self-feeding, the birds were shifted to individual outdoor aviaries. Key results. Sixty dotterels were caught. About half of birds had oil contamination of the legs, nine birds had light oil staining of feathers and only three of these birds required washing. The degree of oiling and washing did not affect survival. Dotterels took a median of 5 days (range 1–15 days) to convert to the captive diet. Common problems encountered in captivity included carpal and beak abrasions (61.7%) and pododermatitis (75%); however, these did not affect survival. Seven birds (11.7%) developed respiratory disease and six of these died from aspergillosis. The incidence of aspergillosis increased with length of time in captivity and was largely refractory to treatment. The 54 surviving birds were released at their capture sites after a median time of 49 days in captivity (with a range of 39–61 days). Conclusions. The captive management of the dotterels achieved a 90% survival rate over a period of about 2 months. Deaths were solely due to respiratory aspergillosis, but intensive captive husbandry was required to convert the birds to a captive diet, to minimise traumatic injuries and to manage pododermatitis. Implications. Although the captive management of shorebird species as a pre-emptive strategy to minimise the effects of oil spills carries significant costs and risks to the birds, it should be considered in the emergency management of high-priority species.

Using sea water for cleaning oil from seabird feathers

Summary During an oil spill, marine wildlife, particularly birds, are at risk of external contamination, affecting insulation, waterproofing and consequently survival. Decontamination of oiled wildlife usually involves a succession of washes and rinses with warm, freshwater and detergent. However, accessibility of large quantities of freshwater needed for cleaning oiled wildlife can be limited. To assess the efficacy of sea water as an alternative, we used 80 seabird feathers, 40 saturated with heavy fuel oil and 40 unoiled feathers as controls, then washed and rinsed them using either freshwater or sea water, or a combination of both. Cleanliness and water repellency were assessed visually, and a barbule amalgamation index (BAI) was calculated to evaluate feather microstructure. Particulate residue was assessed using scanning electron microscopy. Results indicate that for oiled feathers, a sea water wash/rinse produced clean, low BAI/unclumped feathers with minimal particulate residue. Sea water cleaning trials should now be undertaken on live birds to understand links with sea water use and waterproofing. The method described has world-wide application for oiled wildlife response activities and could be readily modified for the cleaning of other taxa such as mammals.