Phenotypic correlates of post‐fledging dispersal in a population of greater flamingos: the importance of body condition

Abstract

Summary 1.Factors influencing post-fledging movements before the first breeding attempt were studied in individually marked greater flamingos ( Phoenicopterus ruber roseus ) born in the Camargue, southern France, between their natal area and their principal wintering grounds (Spain, Sardinia, Tunisia and France) from 1995 to 1999. 2. We tested whether post-fledging dispersal was affected by sex, age, year, body condition, body mass and tarsus length using a multistate capture-recapture modelling approach. We focused particularly on the hypothesis that increased movement probabilities were associated with good and poor body condition. Because long-distance dispersal is energetically expensive and may involve a high risk of mortality, the acquisition of a robust physical condition prior to dispersal probably plays a critical role in determining the extent to which animals disperse. At the other extreme, birds in poor condition either leave their natal area or starve, which should result in relatively high dispersal rates. 3. Movement probabilities were not sex-dependent, but were age-dependent with high movement probabilities during the first year of life (above 0·6) and low probabilities after the first year (0·055). Movement probabilities also differed between years and localities. 4. Movement probability from the natal area was related to the body condition (and body mass) of the fledglings, with a high movement probability (0·873) when juveniles were in good body condition, and a relatively lower probability (from 0·629 to 0·724) when juveniles were in poorer condition. The proportion of variability in dispersal explained by body condition and body mass were 90·9% and 63·5%, respectively. 5. Results support the hypothesis that condition affects dispersal patterns from the natal area. They also suggest that body condition and local environmental conditions during the early growth play a role in dispersal.

Effects of rearing conditions on natal dispersal processes in a long‐lived predator bird

“…The fact that we found a measurable signal of the effects of rearing conditions on the probability of surviving until recruitment indicates that conditions in the early lives of individuals may have severe long‐term consequences on future fitness (Hsu et al., 2017). Body condition may also reflect the quality of individuals, which would imply that survival rates are shaped by the individual quality of birds (Barbraud et al., 2003; Green & Cockburn, 2001; Saunders, Arnold, Roche, & Cuthbert, 2014). …”

“…In fact, if dispersal is fueled by stored energy, a disperser with large energy stores (good body condition) might be able to encounter, visit, and sample a larger number of potential habitats before running out of energy than a disperser with low energy resources (Hardouin et al., 2012; Stamps, 2006; Tilgar et al., 2010). This has been reported in ground squirrels Spermophilus beldingi (Holekamp & Sherman, 1989), eagle owls Bubo bubo (del Mar Delgado et al., 2010), greater flamingos Phoenicopterus ruber roseus (Barbraud et al., 2003), and Spanish Imperial eagles Aquila adalberti (Soutullo et al., 2013). As well, as explained above, our data supports the early‐breeding hypothesis that states that birds in good body condition will recruit at younger ages than those in poor body condition.…”

“…Although statistical analyses showed that the interaction between sex and age of recruitment did not have a statistically significant effect on NDD (Supplementary Information Table S5), previous knowledge (Browne, M., Real, J., Ponchon, C., Ravayrol, A., & Hernández‐Matías, A., unpublished data) as well as the complex patterns detected in the exploratory graphical analysis of the data (Figure 2) advised us to analyze males and females separately (see Supplementary Information Table S6 for an analysis of both sexes together). In fact, there is general evidence that sex is an important source of variation in dispersal among birds (Barbraud et al., 2003). In particular, female‐biased dispersal has been a common finding among many species (Bowler & Benton, 2005; Tilgar et al., 2010), especially in territorial dimorphic birds (Acker et al., 2018; Balbontín & Ferrer, 2009; Hernández‐Matías et al., 2010; Soutullo, Urios, Ferrer, & Peñarrubia, 2006).…”

“…On the other hand, high‐quality individuals may also be better competitors and/or be better able to bear the costs of dispersal, in which case the quality of the rearing environment might in fact have a positive rather than negative effect on dispersal (Bonte et al., 2012; Bowler & Benton, 2005; Clobert et al., 2012; Debeffe et al., 2012). So, as long‐distance dispersal is energetically expensive and may involve a high mortality risk, the acquisition of a good body condition prior to dispersal plays a critical role in determining the extent to which animals disperse (Barbraud, Johnson, & Bertault, 2003). As a consequence, a disperser with large energy stores might be able to assess more potential breeding habitats before running out of energy than a disperser with fewer energy resources (Barbraud et al., 2003; Stamps, 2006; Tilgar et al., 2010).…”

“…So, as long‐distance dispersal is energetically expensive and may involve a high mortality risk, the acquisition of a good body condition prior to dispersal plays a critical role in determining the extent to which animals disperse (Barbraud, Johnson, & Bertault, 2003). As a consequence, a disperser with large energy stores might be able to assess more potential breeding habitats before running out of energy than a disperser with fewer energy resources (Barbraud et al., 2003; Stamps, 2006; Tilgar et al., 2010). Also, dispersal can produce net benefits including the avoidance of inbreeding and the reduction of competition for resources and mates; although the distances required to avoid inbreeding are likely to differ from those required to escape resource competition (Bowler & Benton, 2005).…”