Giraffe skin disease: Clinicopathologic characterization of cutaneous filariasis in the critically endangered Nubian giraffe (Giraffa camelopardalis camelopardalis).

Giraffe skin disease (GSD) is an emerging disease of free-ranging giraffe recognized in the last 25 years in several species, including the critically endangered Nubian giraffe (Giraffa camelopardalis camelopardalis) of Uganda. Identifying the cause of GSD and understanding its impact on health were deemed paramount to supporting these vulnerable populations. Sixty-four giraffes were immobilized in Murchison Falls National Park, Uganda, from 2017 to 2019, and GSD lesions were opportunistically biopsied. Fifty-five giraffes (86%) had GSD lesions on the neck, axilla, chest, and cranial trunk. Lesions were categorized into early, intermediary, and dormant stages based on gross and histological characteristics. Early lesions were smaller, crusted nodules with eosinophilic and pyogranulomatous dermatitis and furunculosis. Intermediary lesions were thick plaques of proliferative and fissured hyperkeratosis and acanthosis with dense dermal granulation tissue and severe eosinophilic and granulomatous dermatitis. Lesions appeared to resolve to dormancy, with dormant lesions consisting of hairless plaques of hyperkeratosis with dermal scarring and residual inflammation. The periphery of early and intermediary lesions included follicular granulomas containing adult filarid nematodes, with myriad encysted microfilariae in the superficial dermis. Stage L3 larvae were common in early and intermediary lesions, and dormant lesions had remnant encysted microfilariae with no adult or stage L3 larvae. Nematodes were morphologically and genetically novel with close identity to Stephanofilaria spp. and Brugia malayi, which cause infectious filariasis. Identification of potential insect vectors, long-term monitoring of GSD lesions, and evaluating response to therapy is ongoing in the efforts to help conserve the Nubian giraffe.

The many faces of fear: a synthesis of the methodological variation in characterizing predation risk.

Predators affect prey by killing them directly (lethal effects) and by inducing costly antipredator behaviours in living prey (risk effects). Risk effects can strongly influence prey populations and cascade through trophic systems. A prerequisite for assessing risk effects is characterizing the spatiotemporal variation in predation risk. Risk effects research has experienced rapid growth in the last several decades. However, preliminary assessments of the resultant literature suggest that researchers characterize predation risk using a variety of techniques. The implications of this methodological variation for inference and comparability among studies have not been well recognized or formally synthesized. We couple a literature survey with a hierarchical framework, developed from established theory, to quantify the methodological variation in characterizing risk using carnivore-ungulate systems as a case study. Via this process, we documented 244 metrics of risk from 141 studies falling into at least 13 distinct subcategories within three broader categories. Both empirical and theoretical work suggest risk and its effects on prey constitute a complex, multi-dimensional process with expressions varying by spatiotemporal scale. Our survey suggests this multi-scale complexity is reflected in the literature as a whole but often underappreciated in any given study, which complicates comparability among studies and leads to an overemphasis on documenting the presence of risk effects rather than their mechanisms or scale of influence. We suggest risk metrics be placed in a more concrete conceptual framework to clarify inference surrounding risk effects and their cascading effects throughout ecosystems. We recommend studies (i) take a multi-scale approach to characterizing risk; (ii) explicitly consider 'true' predation risk (probability of predation per unit time); and (iii) use risk metrics that facilitate comparison among studies and the evaluation of multiple competing hypotheses. Addressing the pressing questions in risk effects research, including how, to what extent and on what scale they occur, requires leveraging the advantages of the many methods available to characterize risk while minimizing the confusion caused by variability in their application.

Activitybudget and foraging patterns ofNubian giraffe (Giraffa camelopardalis camelopardalis) in Lake Nakuru National Park, Kenya.

The activity budget of giraffe in various African populations has been studied extensively, revealing that it is affected by body size, foraging patterns, and sex. Foraging patterns show an animal's feeding choices in its environment and are influenced by resource availability, competition, and predation risk. The ability of giraffe to survive and reproduce is significantly impacted by the variation in activity budget and foraging across different ecosystems. Our study focused on evaluating the seasonal activity budgets and foraging patterns of Nubian giraffe in Lake Nakuru National Park, Kenya. We used the scan sampling method to record the activity budget of giraffe which included foraging, movement, resting, and drinking water. We then evaluated if activities varied with the seasons. A total of 11,280 activities were documented, with 4560 (40.4%) occurring during the dry season and 6720 (59.6%) during the wet season. Foraging accounted for 53% of the time budget during the dry season, but increased to 57% during the wet season. There was a slight drop in records of movement (22%; n = 995 of 4560) and resting (25%; n = 1145 of 4560) from the dry season to the wet season (20%; n = 1375 out of 6720 and 22%; n = 1515 of 6720). During the dry season, females (53%) foraged longer than males (47%), whereas males (44%) had longer resting periods than females (56%). Giraffe frequently fed on Vachellia xanthophloea (67%; n = 4136 of 6215 foraging records), Maytenus senegalensis (19%), and Solanum incanum (9%) over both seasons. Overall, seasons had little impact on giraffe activity time budgets and foraging patterns in Lake Nakuru National Park. A better insight into the behavioural patterns of this subspecies will allow managers to enhance the protection and conservation of the species and its habitat. Heavy foraging on Vachellia by giraffe at LNNP has been associated with a population decline in number, so perhaps planting more of this species in LNNP could promote a rebound in numbers.

QUANTIFYING THE SEVERITY OF GIRAFFE SKIN DISEASE VIA PHOTOGRAMMETRY ANALYSIS OF CAMERA TRAP DATA.

Developing techniques to quantify the spread and severity of diseases afflicting wildlife populations is important for disease ecology, animal ecology, and conservation. Giraffes (Giraffa camelopardalis) are in the midst of a dramatic decline, but it is not known whether disease is playing an important role in the broad-scale population reductions. A skin disorder referred to as giraffe skin disease (GSD) was recorded in 1995 in one giraffe population in Uganda. Since then, GSD has been detected in 13 populations in seven African countries, but good descriptions of the severity of this disease are not available. We photogrammetrically analyzed camera trap images from both Ruaha and Serengeti National parks in Tanzania to quantify GSD severity. Giraffe skin disease afflicts the limbs of giraffes in Tanzania, and we quantified severity by measuring the vertical length of the GSD lesion in relation to the total leg length. Applying the Jenks natural breaks algorithm to the lesion proportions that we derived, we classified individual giraffes into disease categories (none, mild, moderate, and severe). Scaling up to the population level, we predicted the proportion of the Ruaha and Serengeti giraffe populations with mild, moderate, and severe GSD. This study serves to demonstrate that camera traps presented an informative platform for examinations of skin disease ecology.