DEF: Any parental expenditure (e.g. time, energy, resources) that offspring benefits /Trivers, 1972/.
28 October 2021
Parental investment (PI)
PI in varying cost/benetits
Ghalambor CK, Martin TE (2001) Fecundity-survival trade-offs and parental risk-taking in birds. Science 292:494-497
PI in varying cost/benetits
Ghalambor CK, Martin TE (2001) Fecundity-survival trade-offs and parental risk-taking in birds. Science 292:494-497
Costs of parental care
Costs of parental care
Intra-familial conflicts
Parent-offspring conflict
Parent-offspring conflict
Parent-offspring conflict - resolution
Ex: begging for food also imposes cost
Hinde CA, Johnstone RA, Kilner RM (2010) Parent-offspring conflict and coadaptation. Science 327:1373-1376
Siblings conflict
Siblings conflict
Siblings conflict - evidence
Facultative siblicite
Galapagos fur seal /inter-brood conflict/
one pup per year and normally weaned up to 18 mths, in poor conditions 2-3 yrs, if so competes with the next year young. Trillmich F, Wolf JBW (2008) Parent-offspring and sibling conflict in Galapagos fur seals and sea lions. Behav Ecol Sociobiol 62:363-375
Blue-footed booby /intra-brood conflict/If food is abundant both chicks take turn. If not, and elder chicks is 20-25% below expected weight it attacks the younger sibling. Drummond H, Garcia Chavelas C (1989) Food shortage influences sibling aggression in the blue-footed booby. Anim Behav 37:806-819
Siblings conflict
Obligate siblicide
Anderson D (1990) Evolution of Obligate Siblicide in Boobies. 1. A Test of the Insurance-Egg Hypothesis. Am Nat 135:334-350
Sexual conflict
Sexual conflict - sex roles
- Female care
- Male care
- Both sexes care (equal/different contribution)
Sex roles in parental care - taxonomy
Sex roles in parental care - taxonomy
Furness AI, Capellini I (2019) The evolution of parental care diversity in amphibians. Nat Commun 10:1-12
Single parental care
Hypothesis 1: paternity certainty
Single parental care
Hypothesis 2: order of gamete release - first releases, first goes
Single parental care
Hypothesis 3: association with embryo - (Williams 1975)
Physical link of the parent predispose for the care
* territory - males
* pregnancy - females
Also, sunk costs (questionable)
Kokko H, Jennions MD (2008) Parental investment , sexual selection and sex ratios. J Evol Biol 21:919-948
Single parental care
Who deserts depends on prospects/roles/possibilities
Biparental care
- different male-female contribution
- different male-females role
Biparental care
- similar contribution
Necessity of both parents, ex: little auk
EES - evolutionary stable strategies
| … | Output | Female care | Female desert |
|---|---|---|---|
| Male care | Female gets | wP2 | WP1 |
| Male care | Male gets | wP2 | WP1 |
| Male desert | Female gets | WP1 | WP0 |
| Male desert | Male gets | wP1(1+p) | WP0(1+p) |
P - offspring survival (0-2: number of caring parents)
p - male’s chance for mating, when deserts
W - n eggs laid by females that deserts
w - n eggs laid by females that stays
w < W
P0 < P1 < P2
EES - evolutionary stable strategies
| … | Output | Female care | Female desert |
|---|---|---|---|
| Male care | Female gets | wP2 | WP1 |
| Male care | Male gets | wP2 | WP1 |
| Male desert | Female gets | WP1 | WP0 |
| Male desert | Male gets | wP1(1+p) | WP0(1+p) |
ESS 1: female deserts, male deserts
WP0 > wP1, otherwise female stays
wP0(1+p) > wP1 (1+p), otherwise male stays
EES - evolutionary stable strategies
| … | Output | Female care | Female desert |
|---|---|---|---|
| Male care | Female gets | wP2 | WP1 |
| Male care | Male gets | wP2 | WP1 |
| Male desert | Female gets | WP1 | WP0 |
| Male desert | Male gets | wP1(1+p) | WP0(1+p) |
ESS 2: female deserts, male stays
WP1 > wP2, otherwise female stays
wP1 > P0(1+p), otherwise male deserts
EES - evolutionary stable strategies
| … | Output | Female care | Female desert |
|---|---|---|---|
| Male care | Female gets | wP2 | WP1 |
| Male care | Male gets | wP2 | WP1 |
| Male desert | Female gets | WP1 | WP0 |
| Male desert | Male gets | wP1(1+p) | WP0(1+p) |
ESS 3: female stays, male deserts
wP1 > WP0, otherwise female deserts
wP1(1+p) > wP2, otherwise male stays
EES - evolutionary stable strategies
| … | Output | Female care | Female desert |
|---|---|---|---|
| Male care | Female gets | wP2 | WP1 |
| Male care | Male gets | wP2 | WP1 |
| Male desert | Female gets | WP1 | WP0 |
| Male desert | Male gets | wP1(1+p) | WP0(1+p) |
ESS 4: female stays, male stays
wP2 > WP1, otherwise female deserts
wP2 > wP1 (1+p), otherwise male deserts
EES - evolutionary stable strategies
EES - evolutionary stable strategies
for the conflict, evolves the strategy
the strategy not necesarily optimal but evolutionary stable
if everybody applies the strategy, changing it is disadvantagous
Parents cooperation - conditional
Johnstone RA, Manica A, Fayet AL, et al (2014) Reciprocity and conditional cooperation between great tit parents. 25:216-222
Parents cooperation - conditional
Johnstone RA, Manica A, Fayet AL, et al (2014) Reciprocity and conditional cooperation between great tit parents. 25:216-222
Parents cooperation - conditional
Johnstone RA, Manica A, Fayet AL, et al (2014) Reciprocity and conditional cooperation between great tit parents. 25:216-222
Parents cooperation - coordination
Parents cooperation - coordination
Parents cooperation - coordination
Parents cooperation - coordination
Parents cooperation - coordination
Parental cooperation - ESS
Wojczulanis-Jakubas (2021) Being the winner is being the loser when playing a parental tug-of-war - a new framework on stability of bi-parental care. In press