Felicia B. Nutter

Extreme Conservation Leads to Recovery of the Virunga Mountain Gorillas

As wildlife populations are declining, conservationists are under increasing pressure to measure the effectiveness of different management strategies. Conventional conservation measures such as law enforcement and community development projects are typically designed to minimize negative human influences upon a species and its ecosystem. In contrast, we define “extreme” conservation as efforts targeted to deliberately increase positive human influences, including veterinary care and close monitoring of individual animals. Here we compare the impact of both conservation approaches upon the population growth rate of the critically endangered Virunga mountain gorillas (Gorilla beringei beringei), which increased by 50% since their nadir in 1981, from approximately 250 to nearly 400 gorillas. Using demographic data from 1967–2008, we show an annual decline of 0.7%±0.059% for unhabituated gorillas that received intensive levels of conventional conservation approaches, versus an increase 4.1%±0.088% for habituated gorillas that also received extreme conservation measures. Each group of habituated gorillas is now continuously guarded by a separate team of field staff during daylight hours and receives veterinary treatment for snares, respiratory disease, and other life-threatening conditions. These results suggest that conventional conservation efforts prevented a severe decline of the overall population, but additional extreme measures were needed to achieve positive growth. Demographic stochasticity and socioecological factors had minimal impact on variability in the growth rates. Veterinary interventions could account for up to 40% of the difference in growth rates between habituated versus unhabituated gorillas, with the remaining difference likely arising from greater protection against poachers. Thus, by increasing protection and facilitating veterinary treatment, the daily monitoring of each habituated group contributed to most of the difference in growth rates. Our results argue for wider consideration of extreme measures and offer a startling view of the enormous resources that may be needed to conserve some endangered species.

Simulating Free-Roaming Cat Population Management Options in Open Demographic Environments

Large populations of free-roaming cats (FRCs) generate ongoing concerns for welfare of both individual animals and populations, for human public health, for viability of native wildlife populations, and for local ecological damage. Managing FRC populations is a complex task, without universal agreement on best practices. Previous analyses that use simulation modeling tools to evaluate alternative management methods have focused on relative efficacy of removal (or trap-return, TR), typically involving euthanasia, and sterilization (or trap-neuter-return, TNR) in demographically isolated populations. We used a stochastic demographic simulation approach to evaluate removal, permanent sterilization, and two postulated methods of temporary contraception for FRC population management. Our models include demographic connectivity to neighboring untreated cat populations through natural dispersal in a metapopulation context across urban and rural landscapes, and also feature abandonment of owned animals. Within population type, a given implementation rate of the TR strategy results in the most rapid rate of population decline and (when populations are isolated) the highest probability of population elimination, followed in order of decreasing efficacy by equivalent rates of implementation of TNR and temporary contraception. Even low levels of demographic connectivity significantly reduce the effectiveness of any management intervention, and continued abandonment is similarly problematic. This is the first demographic simulation analysis to consider the use of temporary contraception and account for the realities of FRC dispersal and owned cat abandonment.

Seroprevalence of Toxoplasma gondii and Trichinella spiralis in North Carolina Black Bears (Ursus americanus)

Serum samples from 143 hunter-killed black bears were collected during the 1996 and 1997 black bear hunting seasons in eastern North Carolina. All samples were tested for antibodies to Toxoplasma gondii by the modified agglutination test. Antibodies to T. gondii were present in 120 of 143 (84%) bears. Females had significantly higher titers than males (Wilcoxon rank sums test, P = 0.045), and titers increased with age (Jonckheere test, P = 0.01). Samples collected during 1996 (n = 79) were tested for antibodies to Trichinella spiralis by enzyme-linked immunosorbent assay. No samples were positive for antibodies to T. spiralis.

Proximate composition of milk from free-ranging mountain gorillas (Gorilla beringei beringei)

Published data on milk composition for nonhuman primates, especially great apes, are lacking. Milk composition data are important for understanding the physiology and evolution of mammalian milk production, as well as the nutritional requirements of infants. For many primate species these data have added relevance because of the need to hand raise infants orphaned by poaching or separated from their mothers in captivity. The proximate composition (dry matter (DM), protein, fat, sugar) of free-ranging mountain gorilla (MG) (Gorilla beringei beringei) milk was characterized from samples (N = 10) collected opportunistically during field procedures. The mean values for mid-lactation (1-50 months) milk samples from healthy MGs (N = 7) were: 10.7% DM, 1.9% fat, 1.4% crude protein, 6.8% sugar, and 0.53 kcal/g. These results are lower in fat and total energy than most other Hominidae, including humans. One early-lactation sample was high in protein content while the composition of two samples from gorillas with poor health and suspected poor milk quality both deviated from the normal, mid-lactation pattern. This survey adds to the data available for primate milk composition and suggests that wild MG infants normally consume milk that is lower in fat and total energy than human milk.

Muscular Sarcocystis infection in a bear (Ursus americanus).

Sarcocysts of an unidentified Sarcocystis species were found in sections of skeletal muscles of a black bear (Ursus americanus) from North Carolina. Two sarcocysts in a section measured 45 x 37.5 microm and 67.5 x 50 microm and had a thin (<2 microm) sarcocyst wall. The villar protrusions on the cyst wall were up to 2 microm long and up to 0.7 microm wide. The bradyzoites were approximately 6 X 2.5 microm in size. This is the first report of muscular Sarcocystis in a bear.

Failure to Transmit Avian Vacuolar Myelinopathy to Mallard Ducks

Avian vacuolar myelinopathy (AVM) is a neurologic disease that has been diagnosed in free-ranging birds in the southeastern United States. Bald eagles (Haliaeetus leuocephalus), American coots (Fulica americana), and mallards (Anas platyrhynchos) have been affected. Previous investigations have not determined the etiology of this disease. In November and December 2002, we attempted to induce AVM in game-farmed mallards through four, 7-day exposure trials. Mallards were housed in six groups of eight, with two of these groups serving as controls. One group was housed with AVM-affected coots; one group was tube fed daily with water from the lake where affected coots were captured; one group was tube fed daily with aquatic vegetation (Hydrilla verticillata) from the same lake; and another group was tube fed daily with sediment from the lake. No ducks exhibited clinical neurologic abnormalities consistent with AVM and no evidence of AVM was present at histopathologic examination of brain tissue. Although limitations in sample size, quantity of individual doses, frequency of dose administration, duration of exposure, and timing of these trials restrict the interpretation of the findings, AVM was not readily transmitted by direct contact, water, hydrilla, or sediment in this investigation.

Health Assessment, Antibiotic Treatment, and Behavioral Responses to Herding Efforts of a Cow-Calf Pair of Humpback Whales (Megaptera novaeangliae) in the Sacramento River Delta, California

A mother and female calf humpback whale (Megaptera novaeangliae) pair were observed at an atypical location, 72 nmi inland in the Port of Sacramento, California, on 16 May 2007. Sequencing of mtDNA from a skin biopsy showed the cow to be an E1 haplotype, which is common in the California feeding population. Both animals had lacerations, suggesting sharp trauma from a boat strike. Photographs taken over 11 d showed generalized deterioration of skin condition and necrotic wound edges. Behavioral responses were recorded during attempts to move the animals downriver to the Pacific Ocean. The attempts included playback of alarm tones, humpback and killer whale sounds, banging hollow steel pipes (“Oikami pipes”), spraying water from fire hoses on the water surface, and utilizing tug and power boat engine noise and movement. None of these deterrents resulted in significant, consistent downstream movement by the whales. Antibiotic therapy (ceftiofur) was administered by a dart, representing the first reported antibiotic treatment of free-ranging live whales. After 11 d, the animals swam downstream from fresh water at Rio Vista to brackish water, and their skin condition noticeably improved 24 h later. The animals followed the deep-water channel through the Sacramento

Congenital Neuroglial Heterotopia in a Neonatal Harbor Seal (Phoca vitulina richardsi ) with Evidence of Recent Exposure to Polycyclic Aromatic Hydrocarbons

A male neonatal Pacific harbor seal (Phoca vitulina richardsi) stranded off the coast of California, USA, was presented for rehabilitation with numerous partially haired, soft tissue masses around the mouth and in the oropharynx. Because of the extent of the lesions, the seal was humanely euthanized. Histologically, the masses consisted of subepithelial connective tissue and subcutis expanded by a proliferation of streams and bundles of spindle to stellate cells. Morphology of these cells suggested a neural origin, which was confirmed by positive immunohistochemistry for two neural markers, S-100 protein and glial fibrillary acidic protein, so the masses were diagnosed as neuroglial heterotopia. Heterotopic neuroglial tissue is a rare lesion comprised of benign mature neural tissue in an ectopic location with no connection to the central nervous system. Results of polycyclic aromatic hydrocarbon (PAH) metabolite analysis of bile indicated recent exposure to a petroleum source. Although fetal exposure to PAHs in utero can cause neurotoxicity and affect normal embryonic development, it is unknown whether gestational exposure occurred in this case.

Use of thermography and fluorescein angiography in the management of a Chilean flamingo with avascular necrosis of the wing.

Abstract A Chilean flamingo (Phoenicopterus chilensis) was presented to the veterinary clinic at the North Carolina Zoological Park for evaluation of acute weakness of the right wing. Results of a physical examination revealed a lack of a palpable pulse in the radial artery, which suggested occlusion or obstruction of the vessel. Radiography, thermography, and fluorescein angiography confirmed right wing injury and vascular compromise. Based on the poor prognosis for return to function associated with irreversible vascular damage, the wing was amputated. After a period of observation and treatment, the bird was returned to public exhibit.