The allocation between egg size and clutch size depends on local nest survival rate in a mean of bet-hedging in a shoreb
- PDF / 1,449,104 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 95 Downloads / 139 Views
Avian Research Open Access
RESEARCH
The allocation between egg size and clutch size depends on local nest survival rate in a mean of bet‑hedging in a shorebird Zitan Song1, Xin Lin1, Pinjia Que2, Naerhulan Halimubieke3, Qin Huang1, Zhengwang Zhang2, Tamás Székely1,2,3,4 and Yang Liu1*
Abstract Background: The allocation of resources between offspring size and number is a central question of life-history theory. Although several studies have tested the existence of this trade-off, few studies have investigated how environmental variation influences the allocation of resources to offspring size and offspring number. Additionally, the relationship between population dynamics and the offspring size and number allocation is far less understood. Methods: We investigate whether resource allocation between egg size and clutch size is influenced by the ambient temperature and whether it may be related to apparent nest survival rate. We measured 1548 eggs from 541 nests of two closely related shorebird species, the Kentish Plover (Charadrius alexandrinus) and the White-faced Plover (C. dealbatus) in China, in four populations that exhibit contrasting ambient environments. We weighed females, monitored nest survival, and calculated the variance of ambient temperature. Results: Although we found that egg size and clutch size were all different between the four breeding populations, the reproductive investment (i.e. total clutch volume) was similar between populations. We also found that populations with a high survival rate had relatively larger eggs and a smaller clutch than populations with a low nest survival rate. The latter result is in line with a conservative/diversified bet-hedging strategy. Conclusions: Our findings suggest that plovers may increasing fitness by investing fewer, larger or many, small according local nest survival rate to make a similar investment in reproduction, and thereby may have an impact on population demography. Keywords: Ambient temperature, Bet-hedging strategy, Nest survival rate, Resource allocation, Shorebirds Background Understanding the relationship between the size and number of progeny is a central question of life-history theory (Clutton-Brock 1991; Stearns 1992). Indeed, egg and yolk mass can strongly affect the quality of offspring across a variety of taxa (Krist 2011). Larger eggs have a higher hatching rate (Saino et al. 2004) and higher *Correspondence: [email protected] 1 State Key Laboratory of Biocontrol, College of Ecology/School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, Guangdong, China Full list of author information is available at the end of the article
nestling survival rate than smaller eggs (Williams 1994; Arnold et al. 2006), and nestlings from heavier eggs are also more likely to have higher fitness after fledging (Smith and Bruun 1998; Krist 2011). However, given finite resources for breeding females, life-history theory predicts that larger eggs or larger offspring are expected to be produced at the expense of fewer progeny (Clutt
Data Loading...
