Inbreeding Depression Accumulation across Life‐History Stages of the Endangered Takahe

  title={Inbreeding Depression Accumulation across Life‐History Stages of the Endangered Takahe},
  author={Catherine E. Grueber and Rebecca J. Laws and Shinichi Nakagawa and Ian G. Jamieson},
  journal={Conservation Biology},
Abstract:  Studies evaluating the impact of inbreeding depression on population viability of threatened species tend to focus on the effects of inbreeding at a single life‐history stage (e.g., juvenile survival). We examined the effects of inbreeding across the full life‐history continuum, from survival up to adulthood, to subsequent reproductive success, and to the recruitment of second‐generation offspring, in wild Takahe ( Porphyrio hochstetteri ) by analyzing pedigree and fitness data… 

Variable inbreeding effects across life‐history stages in a captive carnivorous mammal population

The results indicate that even in populations maintained in benign conditions of captivity, deleterious effects of inbreeding are differentially expressed across life‐history stages, and underscore that investigating a single life‐ history stage could lead to erroneous conclusions about inbreeding and purging effects.

Life stage-specific inbreeding depression in long-lived Pinaceae species depends on population connectivity

It is suggested that life stage data should be included in inbreeding depression studies and that inbreeding needs to be managed over life stages in commercial populations of long-lived plants.

Multiple life-stage inbreeding depression impacts demography and extinction risk in an extinct-in-the-wild species

Impacts of inbreeding depression across life-history stages for an extinct-in-the-wild species and incorporation of multiple life-stage B into population models can be important for informed conservation management decision-making show magnitude of B can translate into demographic consequences.

Cryptic inbreeding depression in a growing population of a long‐lived species

The results illustrate that substantial, cryptic inbreeding depression may still be present when a population is growing, especially in long‐lived species with overlapping generations.

Environmental conditions during early life determine the consequences of inbreeding in Agrostemma githago (Caryophyllaceae)

It is found that deleterious recessive alleles have not been effectively purged from the focal population, the expression of inbreeding depression decreases over the course of the life cycle, and a stressful early environment reduces the variance in inbreeding depressed expressed later in life, but does not consistently influence the relative fitness of inbred versus outcrossed individuals.

Inbreeding and inbreeding depression in endangered red wolves (Canis rufus)

The evaluation of inbreeding and inbreeding depression in a small, re‐introduced population of red wolves in North Carolina highlighted the variable expression of in breeding depression across traits and the need to measure a number of different traits when evaluating inbreeding depressed in a wild population.

Inbreeding depression across the lifespan in a wild mammal population

Investigating inbreeding depression in a range of life history traits and fitness in a wild population of red deer in Scotland using individual inbreeding coefficients derived from dense Single-Nucleotide Polymorphism (SNP) data finds associations between Fgrm and annual breeding success in both sexes, and between maternal inbreeding coefficient and offspring survival.

Heterozygosity-fitness correlations in a continental island population of Thorn-tailed Rayadito.

The results along with the long-term demographic stability of the study population contradict the hypothesis that inbreeding depression occurs in this population of thorn-tailed rayadito and predict a positive relationship between individual heterozygosity and fitness-related traits.

The inbreeding strategy of a solitary primate, Microcebus murinus

Results indicate that sex‐biased dispersal is a primary inbreeding avoidance mechanism at the population level, and mating biases represent an additional strategy that may mitigate residual inbreeding costs at the individual level, which explain the rarity of inbreeding and the lack of detectable inbreeding depression in this large, genetically diverse population.


It is shown, for the first time in a wild population, that the strength of an HFC is partially dependent on the presence of inbreeding events in the recent pedigree history.



Inbreeding depression along a life‐history continuum in the great tit

Analysis of the effects of close inbreeding, based on observations of mating between relatives, in a large, free‐living noninsular great tit (Parus major) population monitored over 41’years, shows that inbreeding depression acts independently at each life‐history stage in this population, and suggests that estimates of the fitness costs of inbreeding must focus on the entire life cycle.


  • L. Keller
  • Biology
    Evolution; international journal of organic evolution
  • 1998
Examination of data from a long‐term demographic study of an insular population of song sparrows and evidence for inbreeding depression shows that costs of inbreeding in this population were substantial and slightly above those expected from laboratory studies.

Severe inbreeding depression in collared flycatchers (Ficedula albicollis)

The results illustrate how severe inbreeding depression and considerable genetic load may exist in natural populations, but detecting them may require extensive long–term datasets.

Inbreeding effects in wild populations.

Inbreeding and Loss of Genetic Variation in a Reintroduced Population of Mauritius Kestrel

The rates of inbreeding and loss of genetic variation in the subpopulation of Mauritius Kestrel the authors examined were extreme and among the highest yet documented in a wild vertebrate population.

Sex‐Specific Consequences of Recent Inbreeding in an Ancestrally Inbred Population of New Zealand Takahe

It is concluded from the pedigree analysis that island Takahe are undergoing further inbreeding depression, but the reduction in fitness appears to be expressed in inbred females only.

Seasonal and lifetime reproductive consequences of inbreeding in the great tit Parus major

It is concluded that the costs of mating with a relative in the short term do not necessarily imply lifetime fitness consequences, and individuals may have scope for avoidance of inbreeding after inbreeding depression.

Quantifying and managing the loss of genetic variation in a free-ranging population of takahe through the use of pedigrees

The results demonstrate the value of maintaining pedigrees for wild populations, especially in the years immediately after a translocation event, and suggest that 90% genetic diversity could be maintained over the next 100 years.

An investigation of inbreeding depression and purging in captive pedigreed populations

The study re-emphasises the necessity to avoid inbreeding in captive breeding programmes and shows that purging cannot be relied upon to remove deleterious alleles from zoo populations.