Failure to advance migratory phenology in response to climate change may pose a significant threat to a declining Nearctic-Neotropical songbird.

Populations of long-distance migrants that breed in seasonal habitats can be significantly impacted by climate change. We examined the migratory and breeding phenologies of the cerulean warbler (Setophaga cerulea), a declining long-distance Nearctic-Neotropical migrant that breeds in deciduous forests of Indiana. Our primary objectives were to determine temporal trends in cerulean warbler migratory timing, and to identify climate variables that explain variation in this species' migratory and breeding phenologies. We reviewed trends in cerulean warbler first arrival to Indiana from 1982 to 2019, and compared them to several explanatory climate variables: spring temperature, growing degree days (GDD), North Atlantic Oscillation (NAO) index, and Oceanic Niño Index (ONI). We also compared the timing of cerulean warbler first lay dates from 2012 to 2019 with the aforementioned climate variables and annual spring precipitation. Cerulean warblers exhibited a minimal advance in first arrival timing (≤4 days in 38 years). Arrival timing was best predicted by GDD and a null model, but trends in GDD indicate that spring warming in Indiana has advanced by a greater margin, approximately 14 days. Climate variables did not predict first lay timing better than a null model. Springtime in Indiana is occurring earlier, but cerulean warblers are advancing their migratory timing to a much smaller degree. This failure to adapt may have a detrimental effect on warbler populations if it results in an asynchronization of important biological timings between them and their prey. Further studies of cerulean warbler breeding and prey phenologies are necessary to determine how climate change is impacting this species' reproductive success.

Hospitalization of unintentional fall injuries in Kuwait: a national database study.

BACKGROUND: Accidental falls are a major cause of morbidity placing pressure on hospital capacity and utilizing costly services. Evaluating the burden of falls is key for planning, implementation, and evaluation of prevention strategies. To date, no studies have been published on accidental falls at the population level in Kuwait. We studied the burden of accidental falls on public hospital inpatient capacity in Kuwait and identified the subgroups with the highest utilization of inpatient service days. METHODS: From the national database of inpatient hospitalizations, we selected hospitalizations of patients admitted to Kuwait's public hospitals for unintentional injury caused by an accidental fall from 1 January through 31 December 2016. We studied the number of inpatient service days (bed days), length of stay (LOS), and number of hospitalizations by age group, gender, and nationality. Mann-Whitney, Kruskal-Wallis, and Chi square tests were used for comparison. Logistic regression was used to quantify the risk of prolonged LOS and fractures among fall-related hospitalizations. RESULTS: Accidental falls were responsible for 2.9% of inpatient hospitalizations, 3.7% of inpatient service days (61,140 days) with an ALOS of 9.1 days in Kuwait's public hospitals in 2016. Accidental falls were responsible for 4.6% of older adult service days, and an even higher 5.6% of older women service days. In the age group 13-64, fall-related service days for non-Kuwaitis (5.7%) were more than triple those for Kuwaitis (1.8%) with a substantial percentage among male non-Kuwaitis (8.1%). The risk factors for exceeding the national ALOS for fall-related hospitalizations were female gender (OR 1.36), age 65 and older (OR 9.72), age 13-64 (OR 5.20), being non-Kuwaiti (OR 1.39), sustaining a femur fracture (OR 11.67), and undergoing surgery (OR 2.63). Fall-related hospitalizations associated with a higher risk of fractures were females (OR 1.22), patients 65 years and older (OR 5.09), patients aged 13-64 (OR 3.65), and non-Kuwaitis (OR 1.28). CONCLUSIONS: Accidental falls impose a considerable burden on inpatient service utilization in Kuwait. This varies by age, gender, and nationality. To reduce this burden, prevention programs should target working-age non-Kuwaiti males and older females.

Analysis of microhabitat characteristics at roost sites of Cerulean Warblers.

Little information exists on songbird roosting habits and the types of habitats that songbirds select. To better understand a species' habitat requirements, all aspects of its biology should be studied. The Cerulean Warbler (Setophaga cerulea, Wilson) is a Nearctic-Neotropical migrant that is a species of conservation concern across its range. It is one of the fastest declining species of wood-warbler (Parulidae) in North America. Since 2007, a breeding population of Cerulean Warblers has been monitored in southern Indiana, as part of the Hardwood Ecosystem Experiment. The Hardwood Ecosystem Experiment is a 100 yr project that studies the effects of different forest management practices on plant and animal communities. During the 2017 breeding season, 10 male Cerulean Warblers were tracked to roost locations. Roost sites selected by male Cerulean Warbler were characterized with less basal area, higher canopy cover, greater grapevine (Vitis spp., L.) presence, less shrubs, steeper slopes, and less white oak (Quercus alba, L.) abundance. With this new knowledge we can incorporate additional features of habitat in the formulation of a management plan for this declining species.

Post-fledging habitat use in a declining songbird.

BACKGROUND: Fledglings of many mature forest-dependent Neotropical songbirds move from mature forest habitats into areas of thick vegetation such as regenerating clearcuts. The Cerulean Warbler (Setophaga cerulea), a Neotropical migratory songbird, is a species of conservation concern across its range and it is listed as endangered in Indiana. This species has declined faster than any other species of wood-warbler in North America. Most prior research on Cerulean Warblers has examined the breeding biology, but there are no data on habitat use by fledgling Cerulean Warblers. Our research aimed to determine where fledgling Cerulean Warblers dispersed after they left their nest, but before they migrated to their wintering grounds. METHODS: Since 2007, Cerulean Warbler breeding populations have been monitored in Yellowwood and Morgan-Monroe state forests in southern Indiana as part of a 100-year study called the Hardwood Ecosystem Experiment. To identify habitats used by fledgling Cerulean Warblers, we captured by hand or mist-nets, adult and juvenile Cerulean Warblers once young had fledged from a nest. We attached radio-transmitters to individuals and tracked each bird daily using radio-telemetry. Radio-telemetry data were collected from May to July 2015-2017, and microhabitat data on fledgling locations and random locations were collected during the same years in the month of July. RESULTS: Fledgling presence, when compared to random non-use sites, was positively correlated to presence of grapevines, greater vertical vegetation density, and greater ground and canopy cover. Fledgling presence was negatively correlated with white oak abundance, aspect, basal area, and the abundance of mature trees that Cerulean Warbler adults use for nesting. CONCLUSIONS: Our study is the first to demonstrate that Cerulean Warbler fledglings occupy habitats that are characterized by specific habitat components. Fledgling sites were located in areas with high vegetation density, such as clusters of grapevine, which provided cover from predators. Identifying Cerulean Warbler habitats throughout the breeding season can better inform natural resource personnel on how to manage forests to meet the habitat needs of this rapidly declining migratory songbird.

Roads are associated with a blunted stress response in a North American pit viper.

Whereas numerous studies have examined roads as anthropogenic stressors in birds and mammals, comparatively few studies have been undertaken on reptiles. We investigated plasma corticosterone (CORT) levels at baseline and following 30min of restraint stress in free-ranging copperhead snakes (Agkistrodon contortrix) captured within the forest interior or while in contact with public roads. There was no difference in baseline CORT levels between snakes in the forest and on roads. Copperheads responded to restraint stress by increasing plasma levels of CORT; however snakes on roads exhibited a lower CORT stress response compared to forest snakes. Additionally, among snakes captured on roads there was a negative association between road traffic and baseline CORT, stressed CORT, and the magnitude of the CORT response. Our results suggest that roads are associated with a blunted stress response in copperheads. Reduced stress responses may be indicative of acclimation, the inhibited ability to mount a stress response in the face of prolonged chronic stress, or that road environments select for individuals with lower CORT responsiveness. Either scenario could result in increased road mortality if snakes do not perceive roads as a potential threat.