Weather radar data correlate to hail‐induced mortality in grassland birds

Abstract

Small-bodied terrestrial animals such as songbirds (Order Passeriformes) are especially vulnerable to hail-induced mortality; yet, hail events are challenging to predict, and they often occur in locations where populations are not being studied. Focusing on nesting grassland songbirds, we demonstrate a novel approach to estimate hail-induced mortality. We quantify the relationship between the probability of nests destroyed by hail and measured Level-III Next Generation Radar (NEXRAD) data, including atmospheric base reflectivity, maximum estimated size of hail and maximum estimated azimuthal wind shear. On 22 June 2014, a hailstorm in northern Colorado destroyed 102 out of 203 known nests within our research site. Lark bunting (Calamospiza melanocorys) nests comprised most of the sample (n = 186). Destroyed nests were more likely to be found in areas of higher storm intensity, and distributions of NEX-RAD variables differed between failed and surviving nests. For 133 ground nests where nest-site vegetation was measured, we examined the ameliorative influence of woody vegetation, nest cover and vegetation density by comparing results for 13 different logistic regression models incorporating the independent and additive effects of weather and vegetation variables. The most parsimonious model used only the interactive effect of hail size and wind shear to predict the probability of nest survival, and the data provided no support for any of the models without this predictor. We conclude that vegetation structure may not mitigate mortality from severe hailstorms and that weather radar products can be used remotely to estimate potential for hail mortality of nesting grassland birds. These insights will improve the efficacy of grassland bird population models under predicted climate change scenarios.

Hail‐induced mortality of Asian Openbill (Anastomus oscitans) in Southern Tropical China

“…Moreover, the carcass of birds could be scavenged by domestic dogs/cats or local small carnivores such as Leopard Cat ( Prionailurus bengalensis ), Yellow‐throated Marten ( Martes flavigula ) and rats, and some dead birds could be decomposed quickly, considering the high decomposition rate in tropical zone (Chin et al, 2008 ). More information should be collected for forest species if similar events happen in the future, and new technology such as weather radar can be used to detect such damage (Carver et al, 2017 ).…”

“…More information should be collected for forest species if similar events happen in the future, and new technology such as weather radar can be used to detect such damage (Carver et al, 2017).…”

Weather Influences Multiple Components of Greater Prairie‐Chicken Reproduction

“…Although many researchers have demonstrated the link between weather and nest survival in grassland birds, few have investigated the mechanisms that cause nest loss under adverse conditions (Carver et al 2017). Weather events can directly cause nest failure through destruction of the nest (e.g., flooding, hail) or through abandonment of the nest by the adult under extreme conditions (Skagen and Yackel Adams 2012, Conrey et al 2016, Carver et al 2017). Alternatively, extreme weather can influence the behavior of the attending adult and potential nest predators making the nest more vulnerable to depredation.…”

Review of Conservation Challenges and Possible Solutions for Grassland Birds of the North American Great Plains

“…The effects of precipitation on grassland bird demographics are also complex, and the timing and intensity of precipitation events are important. While greater average precipitation may facilitate more productive grasslands, and subsequently greater food availability (McCauley et al 2017; Zuckerberg et al 2018), increased heavy rainfall or hail events may cause mortality and nest destruction, disrupt foraging activity, and cause physiological stress (Fisher et al 2015; Carver et al 2017; Freeman et al 2023). In shortgrass prairie songbirds, storm events were linked to declines in daily nest survival while lighter rain events had the opposite effect (Conrey et al 2016).…”