Decreasing parental task specialization promotes conditional cooperation

Abstract

How much to invest in parental care and by who remain puzzling questions fomented by a sexual conflict between parents. Negotiation that facilitates coordinated parental behaviour may be key to ease this costly conflict. However, understanding cooperation requires that the temporal and sex-specific variation in parental care, as well as its multivariate nature is considered. Using a biparental bird species and repeated sampling of behavioural activities throughout a major part of reproduction, we show a clear division of tasks between males and females in provisioning, brooding and foraging. Such behavioural specializations fade with increasing nestling age, which stimulates the degree of alternated feeding visits, as a recently promoted form of conditional cooperation. However, such cooperation is thought to benefit offspring development, which is not supported by our data. Thus, from a proximate point of view, conditional cooperation via alternation critically depends on the division of parental tasks, while the ultimate benefits have yet to be shown.

How to quantify animal activity from radio‐frequency identification (RFID) recordings

“…The level of coordination among cooperating individuals is expected to correlate with the fitness payoffs for all individual team members (Arueti et al, 2013;Mariette & Griffith, 2015;Nowicki et al, 2018;Taborsky et al, 2016). However, estimates for coordinated behavior like alternation and synchronization (Bebbington & Hatchwell, 2016;Iserbyt et al, 2017) may be more sensitive to errors. Such parameters rely on the exact timing of visits and missed-and overrated registrations for each involved individual have accumulating effects.…”

“…Parameters that rely on the exact timing of multiple individuals and may therefore be more susceptible for errors. Two concurrent estimates for within‐pair coordination are the level of alternated and synchronized number of nest visits (detailed in Bebbington & Hatchwell, ; Iserbyt, Fresneau, Kortenhoff, Eens, & Müller, ). Nest visit alternation was calculated as the number of male visits that followed female visits, and vice versa , relative to the total number of nest visits, minus one.…”

Testing the Conditional Cooperation Model: What Can We Learn From Parents Taking Turns When Feeding Offspring?

“…The conditional cooperation model predicts that parents take turns in provisioning their offspring, because they reduce their effort after each feeding visit and increase it again after their partner visited. Consequently, empirical studies examined whether parents that are provisioning their brood indeed take turns more often than expected by chance (Bebbington and Hatchwell, 2016;Koenig and Walters, 2016;Iserbyt et al, 2017;Savage et al, 2017;Leniowski and Wegrzyn, 2018). Almost all these studies report that the degree of alternation was higher than expected by chance and conclude that parents adjust their provisioning effort to one another.…”

“…Several studies calculated "chance" levels of alternation by simply randomizing the order in which visits took place (Koenig and Walters, 2016;Iserbyt et al, 2017;Leniowski and Wegrzyn, 2018). A similar approach is the runs test which examines whether the order in which nest visits take place differs from randomness (Khwaja et al, 2017; see also Johnstone et al, 2014;Savage et al, 2017).…”

Acoustic Cooperation: Acoustic Communication Regulates Conflict and Cooperation Within the Family

“…Likewise, parental care coordination, either by alternating or synchronising nest visits, has been evidenced in several other avian species (e.g., Raihani et al, 2010;Bebbington and Hatchwell, 2016;Koenig and Walters, 2016;Savage et al, 2017; but see Khwaja et al, 2017), including in bi-parental care species with short-term pair bonds (Johnstone et al, 2014;Lejeune et al, 2019) and complex acoustic communication between partners (Gorissen and Eens, 2005). Although the effect on nestling growth is largely unknown (but see Iserbyt et al, 2017;Wojczulanis-Jakubas et al, 2018) and varies with ecological conditions (Lejeune et al, 2019) and foraging behaviour (Mariette and Griffith, 2015), the accumulation of recent studies clearly show that parental care coordination and equitable negotiation are more common than previously assumed.…”