Adaptation and Latitudinal Gradients in Species Interactions: Nest Predation in Birds

Abstract

The "biotic interactions" hypothesis proposes that strong species interactions in the tropics drive faster divergence in the tropics. However, support for the idea that interactions are stronger in the tropics is mixed. Here we propose an explanation for why observed interaction strengths might often be similar across latitudes. We suggest populations might adapt to latitudinal differences in species interaction regimes, which can have the effect of flattening observed latitudinal gradients in interaction rates. To investigate this idea, we examine a canonical example of a strong tropical biotic interaction-nest predation rates in land birds. Surprisingly, we find that daily rates of nest predation vary minimally with latitude. We then consider the possibility that evolved life history differences across latitudes contribute to the flat gradient. We focus on the duration of the nesting period, which is longer in the tropics than in the temperate zone and thought to represent a component of adaptation to tropical nest predators. Greater nesting period duration is known to be associated with lower daily predation rates. When we statistically control for nesting period duration, we recover a pattern where daily rates of nest predation are highest in the tropics. The implication of this analysis is that the evolution of longer nesting periods in tropical species (and shorter nesting periods in the temperate zone) has helped to flatten a "baseline" latitudinal gradient in daily rates of nest predation. More generally, we propose that adaptation to latitudinal differences in biotic interactions can flatten latitudinal gradients in interaction strength.

Diel timing of nest predation changes across breeding season in a subtropical shorebird

“…We found nest predation to be relatively low in a subtropical population of the poorly studied red-wattled lapwing, breeding in an arid, artificial habitat. Such low predation rate contrasts with higher predation rates found in many related and unrelated species breeding both in the desert and other habitats (Mezquida & Marone, 2001; Mayfield based predation rates in Bulla et al, 2019;Freeman et al, 2020;Kubelka, Zámečník, et al, 2018). Although we found little variation in daily nest predation rate across the breeding season, the probability of night predation increased over the season, likely due to the extreme heat during the midday.…”

“…The low predation rate also contrasts with nest predation rate of most other plovers and shorebirds (Šálek & Šmilauer, 2002;Watson et al, 2006;Cepáková et al, 2007;Macdonald & Bolton, 2008;Sheldon et al, 2013; Mayfield based predation rates in Vojtěch , as well as with nest predation rate of many other birds breeding in arid and also nonarid environments (Freeman et al, 2020;Mezquida & Marone, 2001;Shkedy & Safriel, 1992;Weidinger, 2002).…”

“…In contrast, the relatively low nest predation rate in our red‐wattled lapwing population (~25%) dramatically contrasts with the 60% nest predation rate of red‐wattled lapwings breeding in rural India (Sethi et al., 2011 ), as well as with the nest predation rate of other related subtropical plover species (35%–75%; Makrigianni et al., 2008 ; Lomas et al., 2014 ; AlRashidi, 2016 ; Mishra et al., 2020 ). The low predation rate also contrasts with nest predation rate of most other plovers and shorebirds (Šálek & Šmilauer, 2002 ; Watson et al., 2006 ; Cepáková et al., 2007 ; Macdonald & Bolton, 2008 ; Sheldon et al., 2013 ; Mayfield based predation rates in Vojtěch Kubelka et al., 2018 ; and Bulla et al., 2019 ), as well as with nest predation rate of many other birds breeding in arid and also nonarid environments (Freeman et al., 2020 ; Mezquida & Marone, 2001 ; Shkedy & Safriel, 1992 ; Weidinger, 2002 ).…”

“…Indeed, predation is the most common cause of nest failure in birds (Ricklefs, 1969 ; Skutch, 1985 ). While nest predation is relatively well studied in general, our knowledge is biased toward the Northern hemisphere temperate and arctic regions (Bulla et al., 2019 ; Freeman et al., 2020 ; Kubelka, Šálek, et al., 2018 ; Unzeta et al., 2020 ), which hampers global comparative analyses. Moreover, regardless of the region, we know fairly little about when within a day nests are predated (Tulp et al., 2001 ; hereafter “diel timing of nest predation”; Praus & Weidinger, 2010 ; Weidinger, 2010 ; DeGregorio et al., 2015 ; Brynychová et al., 2020 ; Laidlaw et al., 2020 ), perhaps because it requires continuous nest monitoring (Pietz et al., 2012 ; Weidinger, 2006 ).…”

Timing of Release Influence Breeding Success of Translocated Captive-Bred Migrant Asian Houbara Bustard

“…However, these hypotheses require further investigation in the case of the houbara. Higher nest survival in Kazakhstan supports a positive latitudinal trend reported in many migratory species, which is usually explained by a decrease in predator density (Freeman et al, 2019). Furthermore, more intensive herding activity in Uzbekistan (Koshkin et al, 2016) resulted in more nest failures (10.91%) compared to Kazakhstan (6.66%), primarily due to livestock disturbance and trampling, predation by domestic dogs, or being poached by shepherds (Appendix D).…”