Extreme precipitation reduces reproductive output of an endangered raptor

Abstract

Summary1. The frequency and intensity of extreme weather has increased in North America against a backdrop of anthropogenic land change. Few studies have examined how wildlife is affected by extreme weather, and none have examined whether any resulting effects are contingent upon the degree of anthropogenic landscape change. 2. Using an 8-year study in Canada (2003Canada ( -2010, we examined how nest survival of burrowing owls Athene cunicularia varied in relation to weather, vegetation and soil type around the nest. Using a 3-year (1992, 1993 and 1996) feeding experiment, we examined whether food limitation also causes owlet mortality during inclement weather. Lastly, we examined how productivity (i.e. annual fledgling output) between 2003 and 2010 varied as a function of breeding season precipitation anomalies. Using this relationship, we estimated how productivity has changed in response to breeding season precipitation anomalies from 1960 to 2012. 3. During extreme precipitation events, nest survival decreased because of flooding. When burrow flooding did not occur, the youngest owlets in broods that were not food-supplemented had the lowest survival rates when there was precipitation, yet almost all food-supplemented owlets survived bouts of inclement weather. Accordingly, annual productivity from 2003 to 2010 varied inversely with breeding season precipitation anomalies, and we estimated that mean annual productivity decreased by 12% from 1960 to 2012. 4. Synthesis and applications. Extreme rainfall during the breeding season reduced reproductive success of burrowing owls. Given that many raptors experience food limitation during extreme rainfall, large-scale habitat management to increase the abundance and availability of prey may allow these species to better withstand acute food shortages. In light of predicted increases in the frequency and intensity of extreme weather, supplemental feeding could be used in triage situations for burrowing owl management and has the potential to be an effective short-term conservation measure for other raptors. Protecting or reclaiming pastures in uplands that are less prone to flooding would further buffer burrowing owls and other ground-nesting species from extreme precipitation. These actions should mitigate the negative effects of extreme rainfall in the short term; however, long-term persistence of many species will become increasingly uncertain, as climate change scenarios predict an increase in the frequency and intensity of extreme weather.

Extremes of heat, drought and precipitation depress reproductive performance in shortgrass prairie passerines

“…Although predation has been considered the primary direct cause of nest failure in songbirds in general (Martin ), storm events can also directly lead to nest mortality through exposure to hail damage and flooding (Skagen & Yackel Adams , Fisher et al . ). In this study, nest survival of the two species that place nests in scrapes or depressions in the ground, Horned Lark and McCown's Longspur, was more strongly and negatively affected by daily storms than was the case for the species that place their nests in and adjacent to taller grasses and shrubs (Chestnut‐collared Longspur, Lark Bunting and Western Meadowlark).…”

“…Storm events may also disrupt provisioning of young in the nest if parents halt foraging during the storm event (Fisher et al . , Öberg et al . ).…”

“…The inconsistency among studies is likely to be due to the variety of factors, including the temperature variables considered (daily or seasonal), the range of temperatures during the study, nest substrates (cavity or open cup) and microclimates (open arid lands or forest; vegetation surrounding the nest) involved across the various studies (Rotenberry & Wiens 1991, Dinsmore et al 2002, Drever & Clark 2007, Dickey et al 2008, Dreitz et al 2012, Skagen & Yackel Adams 2012. Although predation has been considered the primary direct cause of nest failure in songbirds in general (Martin 1995), storm events can also directly lead to nest mortality through exposure to hail damage and flooding (Skagen & Yackel Adams 2012, Fisher et al 2015. In this study, nest survival of the two species that place nests in scrapes or depressions in the ground, Horned Lark and McCown's Longspur, was more strongly and negatively affected by daily storms than was the case for the species that place their nests in and adjacent to taller grasses and shrubs (Chestnut-collared Longspur, Lark Bunting and Western Meadowlark).…”

Maxent modeling for predicting the spatial distribution of three raptors in the Sanjiangyuan National Park, China

“…Temperature can impact animal reproduction and growth directly, and it can also indirectly affect there is relatively high temperature and relatively strong light during the day in geography. The Saker falcon was also affected by the highest temperature in December and the lowest temperature in January, meaning that the species is sensitive to extreme tem- (Fisher et al, 2015;Robinson, Franke, & Derocher, 2017), but the three species of Raptors are located in areas where precipitation is small and there is almost no extreme precipitation, so the impact on the three species is not significant. Stronger sunlight is conducive to plant photosynthesis, which affects plant production to affect phytophagous prey, thereby affecting the food supply of raptors (Hawkins et al, 2003).…”

Influence of human footprint and sensory disturbances on night-time space use of an owl

“…1). Nests were located in early May using call play-back surveys, and were visited once per week throughout the breeding season (see Fisher et al 2015 for additional details). After the female finished laying, and before juveniles fledged, each adult male owl was captured with either a 1-way walk-in (Winchell 1999) or bow-net trap (Bloom 1987).…”