CAUSES OF MORTALITY AND COMORBIDITIES IN CAIMAN LIZARDS (DRACAENA GUIANENSIS) AT SIX ZOOLOGICAL INSTITUTIONS.

An understanding of the main causes of mortality in caiman lizards (Dracaena guianensis) under managed care is imperative to promote optimal husbandry, health, and welfare. A retrospective review of morbidity and mortality in caiman lizards from North American zoological institutions between 2005 and 2020 was conducted. Postmortem data, including gross necropsy and histopathology findings, were available for 32 caiman lizards (n = 12 subadults, n = 20 adults) from six zoological institutions. Necropsy reports were evaluated to collect general demographic data, categorize cause of death (accident/trauma, congenital/genetic, degenerative/geriatric, infectious, deposition disease, neoplastic, unknown, and multifactorial), and assess common comorbidities. Infectious disease was the most common cause of mortality in adult lizards (8/20; 40%) with amoebiasis and bacterial etiologies being overrepresented. Demise due to traumatic/accidental injury was the second most common cause of death in adult lizards (3/20;15%) and included blunt force trauma or suspected drowning. Infectious disease (4/12; 33.3%) and trauma/accidental injury (4/12; 33.3%) were also the most common causes of death in subadults. The most common comorbidities or other incidental findings identified during necropsy included trematode parasitism (15/32; 46.9%), arteriosclerosis (11/32; 34.4%), and adrenocortical hyperplasia (6/32; 18.8%). This retrospective review suggests that management practices to prevent and control infectious diseases and mitigate traumatic injury play a pivotal role in the long-term care and survival of caiman lizards in managed care.

Factors influencing bird-building collisions in the downtown area of a major North American city.

Bird-building collisions are the largest source of avian collision mortality in North America. Despite a growing literature on bird-building collisions, little research has been conducted in downtown areas of major cities, and no studies have included stadiums, which can be extremely large, often have extensive glass surfaces and lighting, and therefore may cause many bird collisions. Further, few studies have assessed the role of nighttime lighting in increasing collisions, despite the often-cited importance of this factor, or considered collision correlates for different seasons and bird species. We conducted bird collision monitoring over four migration seasons at 21 buildings, including a large multi-use stadium, in downtown Minneapolis, Minnesota, USA. We used a rigorous survey methodology to quantify among-building variation in collisions and assess how building features (e.g., glass area, lighting, vegetation) influence total collision fatalities, fatalities for separate seasons and species, and numbers of species colliding. Four buildings, including the stadium, caused a high proportion of all collisions and drove positive effects of glass area and amount of surrounding vegetation on most collision variables. Excluding these buildings from analyses resulted in slightly different collision predictors, suggesting that factors leading some buildings to cause high numbers of collisions are not the exact same factors causing variation among more typical buildings. We also found variation in collision correlates between spring and fall migration and among bird species, that factors influencing collision fatalities also influence numbers of species colliding, and that the proportion, and potentially area, of glass lighted at night are associated with collisions. Thus, reducing bird collisions at large buildings, including stadiums, should be achievable by reducing glass area (or treating existing glass), reducing light emission at night, and prioritizing mitigation efforts for glass surfaces near vegetated areas and/or avoiding use of vegetation near glass.

Demographic and urban environmental variables associated with dog bites in Detroit.

OBJECTIVE: To identify demographic and urban environmental variables associated with prevalence rates of dog bites per zip code in Detroit. DESIGN: Retrospective ecological study. SAMPLE: 6,540 people who visited any 1 of 15 hospital emergency rooms in the 29 zip codes in Detroit between January 1, 2006, and December 31, 2013, with a primary complaint of dog bite. PROCEDURES: The number of dog bites over the study period was determined per zip code. Data for the human population in each zip code in 2011 and demographic and urban environmental variables were obtained from federal, state, and municipal databases. The prevalence rate of dog bites in each zip code was calculated, and regression analysis was used to identify variables associated with this outcome. RESULTS: Results of multivariate analysis indicated that demographic variables (eg, gender, age, and education) accounted for 23.2% (adjusted R2 = 0.232) of the variation in prevalence rates of dog bites per zip code, whereas urban environmental variables (eg, blight, crime with weapons, and vacancy rate) accounted for 51.6% (adjusted R2 = 0.516) of the variation. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggested that demographic variables had poor association with variation in prevalence rates of dog bites per zip code, whereas urban environmental variables, particularly crime, vacancy rate, and blight, were better associated. Thus, public health and education policies need to address these urban environmental issues to lower the prevalence of dog bites in distressed urban areas.