High Rates of Exposure to Simulated Winter Storm Cues Negatively Affect White-Throated Sparrow (Zonotrichia albicollis) Energy Reserves

Abstract

Birds are often able to cope with, and respond to, inclement weather with physiological and behavioral responses. As storms become more severe or frequent as a result of climate change, the adaptive coping responses of many species may be pushed beyond current tolerance limits. We investigated the effects of experimental recurrent inclement winter weather cues on body composition, glucocorticoid hormones, and behavior of white-throated sparrows (Zonotrichia albicollis). We used a hypobaric climatic wind tunnel to simulate storms by transiently decreasing barometric pressure and temperature, and measured behavioral responses, body composition, and baseline corticosterone levels in birds exposed, or not exposed (control), to different frequencies of simulated storms. In study 1, experimental birds were exposed to one storm per week over 9 weeks. In study 2, experimental birds were exposed to two storms per week over 12 weeks. Birds exposed to one simulated storm per week had higher fat and lean masses than control birds, with no differences in the amount of time groups spent feeding. This change in body composition suggests that birds were coping by increasing energy stores. In contrast, birds exposed to two simulated storms per week had lower fat masses compared to control birds, even though they spent more time feeding. Experimental birds in study 2 also had lower baseline corticosterone levels than controls. These changes suggest that the coping response observed in study 1 was not possible in study 2. These findings provide novel experimental evidence that birds detect and respond to changes in temperature and barometric pressure independent of other storm-related cues. One simulated storm per week resulted in potentially adaptive responses of increased mass. However, increasing the frequency of storm exposure to twice per week exceeded the birds' capacity to maintain these energy reserves. These results also experimentally demonstrate that repeated exposure to inclement weather cues can directly affect birds' energy reserves, even in the absence of a storm itself, with strong implications for survival as severe weather events continue to become more prevalent.

Seasonal Changes in Locomotor Activity Patterns of Wild Social Natal Mole-Rats (Cryptomys hottentotus natalensis)

“…Additionally, trapping efforts indicated that mole-rats appeared to exhibit reduced activity during periods of rain when compared to clear days. It is possible that mole-rats may be able to respond to the change in air pressure or temperature caused by the rain or cold fronts as seen in other animals (Garthe et al, 2009;Boyer and MacDougall-Shackleton, 2020). Lastly, because Natal mole-rats exhibit only behavioral reproductive suppression compared to that of the Damaraland mole-rats, which exhibit behavioral and physiological suppression (Bennett et al, 1996;Molteno and Bennett, 2000;Oosthuizen et al, 2008), we predicted that locomotor activity differences between the breeders and nonreproductive individuals would be less distinct than in species with higher reproductive skew.…”

Varying intensities of chronic stress induce inconsistent responses in weight and plasma metabolites in house sparrows (Passer domesticus)

“…Other studies ( Awerman & Romero, 2010 ; Cyr et al, 2007 ; Fokidis et al, 2011 ; Kern et al, 2007 ; Xie et al, 2015 ) showed no change in plasma glucose with chronic stress. We were unable to find any other papers on changes in ketones with chronic stress in birds, but changes in fat scores suggest that fat mobilization can be affected by chronic stress ( Boyer & MacDougall-Shackleton, 2020 ). Uric acid has been reported to not change ( Xie et al, 2015 ), increase ( Gormally et al, 2019a ), or decrease ( Gormally et al, 2019b , 2018 ).…”

Do sulphur-crested cockatoos (Cacatua galerita) call the weather?

“…Severe storms can be life-threatening, thus it is beneficial for birds to predict the weather and adjust their behaviour to suit (Cohen et al 2021). Lower temperatures, rainfall and wind increase metabolic expenditure, which negatively affects their body condition and ability to incubate eggs (Breuner et al 2013;Boyer and MacDougall-Shackleton 2020). Inclement weather coping responses include increasing foraging activity (Metcalfe et al 2013;Boyer and MacDougall-Shackleton 2020), nest-maintenance behaviour (Laux et al 2016), migration (Boyle et al 2010), and abandonment of territories (Streby et al 2015).…”

“…Lower temperatures, rainfall and wind increase metabolic expenditure, which negatively affects their body condition and ability to incubate eggs (Breuner et al 2013;Boyer and MacDougall-Shackleton 2020). Inclement weather coping responses include increasing foraging activity (Metcalfe et al 2013;Boyer and MacDougall-Shackleton 2020), nest-maintenance behaviour (Laux et al 2016), migration (Boyle et al 2010), and abandonment of territories (Streby et al 2015). Many of these behaviours occur just prior to an extreme weather event, which suggests that birds can predict the coming weather and prepare for it.…”