TY - JOUR
T1 - Brood size affects future reproduction in a long-lived bird with precocial young
AU - Leach, Alan G.
AU - Sedinger, James S.
AU - Riecke, Thomas V.
AU - Van Dellen, Amanda W.
AU - Ward, David H.
AU - Boyd, W. Sean
N1 - Publisher Copyright:
© 2019 by The University of Chicago.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - Estimation of trade-offs between current reproduction and future survival and fecundity of long-lived vertebrates is essential to understanding factors that shape optimal reproductive investment. Black brant geese (Branta bernicla nigricans) fledge more goslings, on average, when their broods are experimentally enlarged to be greater than the most common clutch size of four eggs. Thus, we hypothesized that the lesser frequency of brant clutches exceeding four eggs results, at least partially, from a future reduction in survival, breeding probability, or clutch size for females tending larger broods. We used an 8-year markrecapture data set (Barker robust design) with 5 years of clutch and brood manipulations to estimate long-term consequences of reproductive decisions in brant. We did not find evidence of a trade-off between reproductive effort and true survival or future initiation date and clutch size. Rather, future breeding probability was maximized (0:92±0:03 [SE]) for manipulated females tending broods of four goslings and was lower for females tending smaller (one gosling; 0:63±0:09 [SE]) or larger (seven goslings; 0:52±0:15 [SE]) broods. Our results suggest that demographic trade-offs for female brant tending large broods may reduce the fitness value of clutches larger than four and, therefore, contribute to the paucity of larger clutches. The lack of a trade-off between reproductive effort and survival provides evidence that survival, to which fitness is most sensitive in long-lived animals, is buffered against temporal variation in brant.
AB - Estimation of trade-offs between current reproduction and future survival and fecundity of long-lived vertebrates is essential to understanding factors that shape optimal reproductive investment. Black brant geese (Branta bernicla nigricans) fledge more goslings, on average, when their broods are experimentally enlarged to be greater than the most common clutch size of four eggs. Thus, we hypothesized that the lesser frequency of brant clutches exceeding four eggs results, at least partially, from a future reduction in survival, breeding probability, or clutch size for females tending larger broods. We used an 8-year markrecapture data set (Barker robust design) with 5 years of clutch and brood manipulations to estimate long-term consequences of reproductive decisions in brant. We did not find evidence of a trade-off between reproductive effort and true survival or future initiation date and clutch size. Rather, future breeding probability was maximized (0:92±0:03 [SE]) for manipulated females tending broods of four goslings and was lower for females tending smaller (one gosling; 0:63±0:09 [SE]) or larger (seven goslings; 0:52±0:15 [SE]) broods. Our results suggest that demographic trade-offs for female brant tending large broods may reduce the fitness value of clutches larger than four and, therefore, contribute to the paucity of larger clutches. The lack of a trade-off between reproductive effort and survival provides evidence that survival, to which fitness is most sensitive in long-lived animals, is buffered against temporal variation in brant.
KW - Barker robust design
KW - Branta bernicla nigricans
KW - Breeding probability
KW - Costs of reproduction
KW - Demographic buffering
KW - Lack’s clutch size hypothesis
UR - http://www.scopus.com/inward/record.url?scp=85061024360&partnerID=8YFLogxK
U2 - 10.1086/701783
DO - 10.1086/701783
M3 - Article
C2 - 30794452
AN - SCOPUS:85061024360
SN - 0003-0147
VL - 193
SP - 458
EP - 471
JO - American Naturalist
JF - American Naturalist
IS - 3
ER -