Correlates of postfledging survival, the timing of dispersal, and local recruitment in American Dippers

2008 ◽  
Vol 86 (8) ◽  
pp. 875-881 ◽  
Author(s):  
Holly A. Middleton ◽  
David J. Green

Natal dispersal is a complex process that involves decisions about when to leave the natal territory, how to move through the landscape, and where to settle. We investigated what factors influence the timing of dispersal and local recruitment of American Dippers ( Cinclus mexicanus Swainson, 1827) in Chilliwack, British Columbia. We monitored 102 fledglings from 30 broods between 2003 and 2005. Survival to 5 days after fledging was high (>80%), but individuals fledging early in the season and at an older age had higher survival than those fledging later and younger. Fifty-four percentage of surviving fledglings dispersed within 14 days of nest departure. Females and individuals that spent more time foraging were more likely to disperse within 14 days than males and individuals that foraged less. For those that dispersed, individuals that fledged early in the season and at older ages spent less time in their natal territory. Approximately 10% (10/82) of dispersing individuals were known to recruit locally. Local recruitment of individuals that delayed dispersal was higher than local recruitment of individuals dispersing early. Our study demonstrates that fitness benefits associated with extended natal philopatry are not restricted to cooperatively breeding birds.

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 482-491 ◽  
Author(s):  
Susan J. Daniels ◽  
Jeffrey R. Walters

Abstract Natal dispersal is a key life-history component that may be influenced by the fitness consequences of inbreeding. We studied natal dispersal and inbreeding within a large population of cooperatively breeding, endangered Red-cockaded Woodpeckers (Picoides borealis). We assessed the costs of close inbreeding, the spatial distribution of related males and its relationship to dispersal distance of females, and the change in dispersal behavior of females in the presence of closely related males. Close inbreeding resulted in a significant loss of fitness, through two separate effects: closely related pairs (kinship coefficient ≥ 0.125) exhibited lowered hatching rates and lowered survival and recruitment of fledglings relative to unrelated pairs. Despite a highly predictable spatial clustering of closely related males near the female's natal territory, natal dispersal distance of females was not sufficient to avoid these males as mates. Females changed dispersal behavior in the presence of closely related males on the natal territory: female fledglings were significantly more likely to disperse from natal territories if there were closely related males breeding there in the following year. Females did not change dispersal behavior in the presence of related males that were not on the natal territory. We suggest that dispersal behavior is a trade-off between benefits of short-distance dispersal, e.g., an advantage in competing for scarce breeding vacancies, and the substantial cost of close inbreeding.


Oikos ◽  
2008 ◽  
Vol 117 (9) ◽  
pp. 1371-1379 ◽  
Author(s):  
Stuart P. Sharp ◽  
Mitchell B. Baker ◽  
Jarrod D. Hadfield ◽  
Michelle Simeoni ◽  
Ben J. Hatchwell

2019 ◽  
Vol 374 (1770) ◽  
pp. 20180114 ◽  
Author(s):  
Emma I. K. Vitikainen ◽  
Faye J. Thompson ◽  
Harry H. Marshall ◽  
Michael A. Cant

Kin selection theory defines the conditions for which altruism or ‘helping’ can be favoured by natural selection. Tests of this theory in cooperatively breeding animals have focused on the short-term benefits to the recipients of help, such as improved growth or survival to adulthood. However, research on early-life effects suggests that there may be more durable, lifelong fitness impacts to the recipients of help, which in theory should strengthen selection for helping. Here, we show in cooperatively breeding banded mongooses ( Mungos mungo ) that care received in the first 3 months of life has lifelong fitness benefits for both male and female recipients. In this species, adult helpers called ‘escorts’ form exclusive one-to-one caring relationships with specific pups (not their own offspring), allowing us to isolate the effects of being escorted on later reproduction and survival. Pups that were more closely escorted were heavier at sexual maturity, which was associated with higher lifetime reproductive success for both sexes. Moreover, for female offspring, lifetime reproductive success increased with the level of escorting received per se , over and above any effect on body mass. Our results suggest that early-life social care has durable benefits to offspring of both sexes in this species. Given the well-established developmental effects of early-life care in laboratory animals and humans, we suggest that similar effects are likely to be widespread in social animals more generally. We discuss some of the implications of durable fitness benefits for the evolution of intergenerational helping in cooperative animal societies, including humans. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.


2020 ◽  
Vol 12 (5) ◽  
pp. 701-714 ◽  
Author(s):  
Sarah E Bluher ◽  
Sara E Miller ◽  
Michael J Sheehan

Abstract Relatively little is known about the processes shaping population structure in cooperatively breeding insect species, despite the long-hypothesized importance of population structure in shaping patterns of cooperative breeding. Polistes paper wasps are primitively eusocial insects, with a cooperative breeding system in which females often found nests in cooperative associations. Prior mark-recapture studies of Polistes have documented extreme female philopatry, although genetic studies frequently fail to detect the strong population structure expected for highly philopatric species. Together these findings have led to lack of consensus on the degree of dispersal and population structure in these species. This study assessed population structure of female Polistes fuscatus wasps at three scales: within a single site, throughout Central New York, and across the Northeastern United States. Patterns of spatial genetic clustering and isolation by distance were observed in nuclear and mitochondrial genomes at the continental scale. Remarkably, population structure was evident even at fine spatial scales within a single collection site. However, P. fuscatus had low levels of genetic differentiation across long distances. These results suggest that P. fuscatus wasps may employ multiple dispersal strategies, including extreme natal philopatry as well as longer-distance dispersal. We observed greater genetic differentiation in mitochondrial genes than in the nuclear genome, indicative of increased dispersal distances in males. Our findings support the hypothesis that limited female dispersal contributes toward population structure in paper wasps.


2017 ◽  
Vol 190 (4) ◽  
pp. 547-556 ◽  
Author(s):  
Nyil Khwaja ◽  
Ben J. Hatchwell ◽  
Robert P. Freckleton ◽  
Jonathan P. Green

The Auk ◽  
2001 ◽  
Vol 118 (4) ◽  
pp. 996-1007 ◽  
Author(s):  
Peter Pyle ◽  
D. Nettleship

Abstract Age of first breeding (AFB) and natal dispersal distance (NDD) were investigated relative to proximate and ultimate factors in 276 known-age Cassin's Auklets (Ptychoramphus aleuticus) breeding during 1981–1999 on Southeast Farallon Island, California. Breeding density in 446 study boxes declined significantly during the period 1987–1999, confirming other information indicating a long-term decline (since at least the 1970s) in the population. Mean AFB was 3.34 years when sexes were combined, ranging from 2–10 (mean 3.36) years in females and 2–9 (mean 3.36) years in males. AFB showed a significant linear increase with decreasing colony density, suggesting that increased stress on the entire population, such as that caused by decreasing food availability, may have prevented younger birds from attaining breeding condition at an early age. Median NDD was 8.84 m, ranging from 0–448.7 m; two individuals of each sex recruited into their natal boxes. NDD showed a significant linear increase with decreasing breeding density but no significant linear or curvilinear correlations with mate fidelity, annual reproductive success, or lifetime reproductive output. A significant proportion (66.9%) of movements after recruitment (breeding dispersal) resulted in closer proximity to the natal site. Thus, although natal philopatry was strongly developed in the Cassin's Auklet, it did not seem to be adaptive. Those paradoxical results suggest that selective equilibrium may be acting on natal philopatry in response to the population decline: a low-philopatry, low-cost (later breeding and increased survival) strategy has become increasingly adaptive in Cassin's Auklets, explaining increases in AFB and NDD with the declining breeding densities. The lack of sex-specific effects on AFB and NDD suggests that an even sex-ratio and roughly equal roles in reproduction among Cassin's Auklets exists on Southeast Farallon Island, and that inbreeding avoidance may be counter-balanced by relatively low mate fidelity in this species.


2010 ◽  
Vol 277 (1698) ◽  
pp. 3299-3306 ◽  
Author(s):  
Ki-Baek Nam ◽  
Michelle Simeoni ◽  
Stuart P. Sharp ◽  
Ben J. Hatchwell

Helping behaviour in cooperative breeding systems has been attributed to kin selection, but the relative roles of direct and indirect fitness benefits in the evolution of such systems remain a matter of debate. In theory, helpers could maximize the indirect fitness benefits of cooperation by investing more in broods with whom they are more closely related, but there is little evidence for such fine-scale adjustment in helper effort among cooperative vertebrates. In this study, we used the unusual cooperative breeding system of the long-tailed tit Aegithalos caudatus to test the hypothesis that the provisioning effort of helpers was positively correlated with their kinship to broods. We first use pedigrees and microsatellite genotypes to characterize the relatedness between helpers and breeders from a 14 year field study. We used both pedigree and genetic approaches because long-tailed tits have access to pedigree information acquired through social relationships, but any fitness consequences will be determined by genetic relatedness. We then show using both pedigrees and genetic relatedness estimates that alloparental investment by helpers increases as their relatedness to the recipients of their care increases. We conclude that kin selection has played a critical role in moulding the investment decisions of helpers in this cooperatively breeding species.


2012 ◽  
Vol 21 (21) ◽  
pp. 5348-5362 ◽  
Author(s):  
Hazel J. Nichols ◽  
Neil R. Jordan ◽  
Gabriel A. Jamie ◽  
Michael A. Cant ◽  
Joseph I. Hoffman

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