A meta-analysis of global avian survival across species and latitude

Abstract

24Tropical birds are purported to be longer lived than temperate species of similar size, but it has 25 not been shown whether avian survival rates covary with a latitudinal gradient worldwide. Here, 26we perform a global-scale meta-analysis to investigate the extent of the latitudinal survival 27 gradient. We modeled survival as a function of latitude for the separate northern and southern 28 hemispheres, and considered phylogenetic relationships and extrinsic (climate) and intrinsic (life 29 history) predictors hypothesized to moderate these effects. Using a database of 1,004 estimates 30 from 246 studies of avian survival, we demonstrate that in general a latitudinal survival gradient 31 exists in the northern hemisphere, is dampened or absent for southern hemisphere species, and 32 that survival rates of passerine birds largely account for these trends. We found no indication that 33 the extrinsic climate factors were better predictors of survival than latitude alone, but including 34 species' intrinsic traits improved model predictions. Notably, species with smaller clutch size 35 and larger body mass showed higher survival. Our results illustrate that while some tropical birds 36 may be longer lived than their temperate counterparts, the shape of the latitude-survival gradient 37 differs by geographic region and is strongly influenced by species' intrinsic traits. 38 39 40 41 42 43 44 48 and behaviors, and also show considerable variation in their lifespan and annual survival. For 49 example, in large-bodied landbirds, such as some raptors and parrots, annual survival is often 50 high (Newton et al. 2016; Maestri et al. 2017) and individuals are long lived, but for small-51 bodied species like warblers and kinglets, rates of annual survival can be low (DeSante et al. 52 2015; Johnston et al. 2016). While differences in body mass account for some of this variation 53 larger species tend to live longer than smaller ones (Lindstedt

Coevolution of relative brain size and life expectancy in parrots

“…Our study also departs from most previous studies of longevity by using data from captivity on life expectancy (41,(56)(57)(58). This provided several important advantages.…”

“…Brain mass was collected by AI, from Iwaniuk et al (36), from Schuck-Paim et al (25) and from Ksepka et al (37), and similarly to body size, we fitted a Bayesian multi-level model to extract species-level averages and standard errors. We also collected data for six additional potential explanatory variables, based on previously proposed causal relationships with life expectancy: diet (estimated protein content of main food items) (18), insularity (whether a species includes a continental range or not) (18), maximum latitudinal range (as a proxy for environmental variability) (38), clutch size (39), developmental time (from the start of incubation until fledging) and age of first possible reproduction (AFR) (14). Diet, insularity, maximum latitude range, clutch size and developmental time were collected from the literature.…”

Bridging gaps in demographic analysis with phylogenetic imputation

“…However, vital-rate data may be missing not at random (MNAR) for species of conservation concern, and such biases in missing values can influence comparative analyses by skewing trait distributions (Nakagawa & Freckleton 2008;González-Suárez et al 2012). Although geographical variation in demographic traits (e.g., differences in clutch size and survival across latitudes) could create different patterns of covariance among vital rates, including phylogeny, life-history traits, and latitude may be sufficient to control for such variation (Jetz et al 2008;Scholer et al 2020). Future studies could use a broader coverage of avian life history to investigate how biases in the availability of demographic data affect imputation accuracy and could assess imputation of vital rates in other taxonomic groups.…”

Latitudinal gradient in the intensity of biotic interactions in terrestrial ecosystems: Sources of variation and differences from the diversity gradient revealed by meta‐analysis

“…Nevertheless, several factors have been suggested to explain this variation (Andrew et al, 2012; Anstett et al, 2016; Carmona et al, 2020; Dyer & Forister, 2019). They include differences in sampling design, such as the use of gradients or contrasts between latitudes (Anstett et al, 2016), the use of gradients located between and within climate zones or biomes (Dyer & Forister, 2019; Marquis et al, 2012), the origin of data from different hemispheres (Scholer et al, 2020; Zhang et al, 2016) and the assessment of interactions in individual systems or at the level of entire communities (Anstett et al, 2016; Zvereva et al, 2020a), as well as the assessment of interactions using standardised or natural prey (Chen & Moles, 2018; McKinnon et al, 2010). Variation in the latitudinal patterns of biotic interactions was also explained by differences between predation and parasitism (Hawkins et al, 1997; Zvereva et al, 2020b) and between invertebrate and vertebrate (or ectothermic and endothermic) predators (Peco et al, 2014; Roslin et al, 2017; Zvereva et al, 2019) and herbivore feeding guilds (Andrew et al, 2012; Carmona et al, 2020).…”