In most socially structured populations, the formation of new groups depends on the survival and reproduction of dispersing individuals. Quantifying vital rates in dispersers, however, is difficult due to logistic challenges of following wide-ranging animals. Here, using data from free-ranging meerkats (Suricata suricatta), we estimated survival and reproduction of dispersing and established resident females. Meerkat groups consist of a dominant pair and several subordinate helpers. Female helpers are evicted from their resident groups by the dominant female, allowing her to monopolize reproduction, and evicted females may form small dispersing coalitions. As in established resident groups, one female is behaviourally dominant in parties of dispersing females.

We compared the survival, birth, and recruitment rates of dominant and subordinate females in dispersing coalitions to those of dominant and subordinate females in resident groups. We further compared the frequencies of different mortality causes (e.g., predation, disease) between dispersers and residents. For dispersers, we assessed if survival rates varied with dispersal distance and between transience and settlement stages of dispersal.

During dispersal and the first four months after new group formation, survival is lower for all females compared to established resident groups. At the same time, subordinates in disperser groups have higher birth rates than those in established groups, which rarely breed successfully. This may partly offset the survival costs of dispersal to subordinate females. Further studies of dispersal based on direct observation of dispersing animals are needed to explore the costs and benefits of dispersal in species with contrasting breeding systems.

Using GPS and VHF tracking methods, we located animals and collected life-history data from dispersing and resident female meerkats, inlcuding survival rates at daily intervals and reproductive rates at monthly intervals.

The data and code are structured as follows:

1) Survival and mortality causes (code: Survival_code.R):

1.1. Survival probability - two Cox proportional hazard models with mixed effects (data: 1a_Survival_data.Rdata, 1a_Survival_data_addRun.Rdata, 1b_Survival_data.Rdata)

1.2. Probability of different mortality causes - one multinomial logistic regression (data: 2_Mortality_data.Rdata)

2) Reproduction (code: Reproduction_code.R)

2.1. Conception and birth probability - two binomial mixed effects models (data: 3_Conc_Birth_data.Rdata)

2.2. Number of produced subadults - two Poisson mixed effects models (data: 4_Recruit_data.Rdata)