The effects of temperature on nest predation by mammals, birds, and snakes

Indirect effect of climate change: Shifts in ratsnake behavior alter intensity and timing of avian nest predation

“…unpublished data) and our model indicate that nest survival is highest in the spring and then declines later in the nesting season, a pattern reported for many bird species (Borgmann et al, 2013). Ectothermic nest predators are relatively inactive when temperatures are suboptimal, but as temperatures increase these predators become more active, thus increasing the possibility of interaction with nests (Sperry et al, 2008;Cox et al, 2013). Avian population viability may rely on the production of offspring in the early part of the season when predation rates are lowest and clutch sizes are largest (Perrins, 1970;Daan et al, 1990;Nager and Noordwijk, 1995).…”

“…This work predicts both an expansion of seasonal snake activity in response to warmer climates, with snakes becoming active earlier in the spring and continuing later in the fall, and a shift in diel patterns, with snakes in warmer climates switching from diurnal to nocturnal activity at the warmest time of the year. Because snake activity and behavior can be directly linked to songbird nest predation risk (Sperry et al, 2008;Klug et al, 2010;Weatherhead et al, 2010;Cox et al, 2013;DeGregorio et al, 2014b), this shift in seasonal and nocturnal activity is likely to alter the predator-prey interactions between snakes and birds, most likely to the detriment of bird populations.…”

The Influence of Temperature on Black-Capped Vireo Nest-site Selection

“…In addition, the majority of data loggers placed across sites experienced readings over 40 °C in both years. In previous studies temperature increases as low as 2 − 3 degrees during bird breeding seasons resulted in changes in reproductive success (Cox et al 2013b). Most temperature loggers have a warning threshold set at 40°C (Case andRobel 1974, Spiers et al 1983), and while I did not test for operative temperatures for vireo, evidence of temperature studies show that operative temperatures above 40°C can be harmful for various bird species (Forrester et al 1998, Cox et al 2013b).…”

“…Evidence suggests that birds select nest sites for thermoregulatory purposes in addition to factors involving predator avoidance and food availability (Forrester et al 1998, Nelson and Martin 1999, Tieleman et al 2008, Morgan 2012, Cox et al 2013b, Cox et al 2013a). Increases in temperatures may be influencing vireos nest site selection, as they may need more thermal refuge later in the season.…”

“…Increases in temperatures may be influencing vireos nest site selection, as they may need more thermal refuge later in the season. Increasing temperatures may also effect the predator assemblage and the rate of predation (Cox et al 2013b), causing vireos change nest site characters for increases chance of success (Conkling et al 2012). Because the black-capped vireo is a habitat specialist, with a very limited distribution, any change in its environment and or habitat structure may have detrimental effects on individuals and overall population status (Graber 1961).…”