S were built only for these parameters. Thus, in models with heterogeneity on these parameters there will be a state with low survival for one category of individuals and a state with high survival for the other category of individuals and different proportions for both categories. We thus considered an initial model with four KF-89617 site events as defined above, and nine states (FB1 = failed breeder category 1, FB2 = failed breeder category 2, SB1 = successful breeder category 1, SB2 = successful breeder category 2, PFB1 = post-failed breeder category 1, PFB2 = post-failed breeder category 2, PSB1 = postsuccessful breeder category 1, PSB2 = post-successful breeder category 2, and dead). The most general model we consideredDataFrom 1960, adults and chicks were ringed with stainless steel rings and since 1966 a capture-mark-recapture program has been C.I. 75535MedChemExpress Shikonin undertaken annually between December and April. Most rings of breeding birds were checked in January and February, just after laying, and all chicks were ringed in September and October just before fledging. At fledging, breeding performance was determined for most individuals. Breeding individuals (i.e. those attending a nest) were classified as successful breeders (SB) when they fledged a chick, or failed breeders (FB) otherwise. However, during the early years of the study, the breeding performance of some individuals was not ascertained; they were classified as breeders (B). Each year, new individuals found in the colony were ringed. We used data on breeding adults identified from the 1960 through 2010 breeding seasons, which were either ringed as adults or as chicks. The data were coded with one digit per year: 0 = not observed, 1 = seen as a FB, 2 = seen as a SB, 3 = seen as a B (which were used to build capture histories). This yielded a total of 4339 individual capture histories for a period of 50 years. A restricted data set only including individuals of known sex was also used to test our predictions. Individuals were sexed from plumage characteristics and size. This yielded a total of 1876 female and 1998 male life histories. Foraging areas were identified from information on the at-sea distribution of breeding and non-breeding adults obtained by telemetry from 1989 to 2010 (satellite tracking using Argos PTT satellite transmitters, global positioning system, and geolocator). Numerous longline fleets operate in the Southern Ocean and are known, or suspected, to interact with Crozet wandering albatrosses and other seabirds. Focusing on the Indian Ocean fleets, because the Crozet wandering albatross population breeds in the southern Indian Ocean and breeding birds forage in the Indian Ocean [22], the fleets with the greatest overlap with the foraging distribution and therefore the greatest potential interactions are the high-seas pelagic longline fleets of Japan and Taiwan [26,27]. Annual fishing effort was calculated from monthly reported fishing effort dataPLOS ONE | www.plosone.orgDifferential Susceptibility to Bycatchs refers to state dependency in proportion, breeding (denoted as b), success (denoted as c), encounter (denoted as p) and state determination (denoted as d) probabilities, and superscript t refers to time. To test for linear and quadratic temporal trends over time in initial proportions of individuals in observable states we fitted models where the initial proportion varied according to a quadratic (or linear) trend on a logit scale as: pt log log it(pt ) azb|Tt zc|Tt2 1{pt.S were built only for these parameters. Thus, in models with heterogeneity on these parameters there will be a state with low survival for one category of individuals and a state with high survival for the other category of individuals and different proportions for both categories. We thus considered an initial model with four events as defined above, and nine states (FB1 = failed breeder category 1, FB2 = failed breeder category 2, SB1 = successful breeder category 1, SB2 = successful breeder category 2, PFB1 = post-failed breeder category 1, PFB2 = post-failed breeder category 2, PSB1 = postsuccessful breeder category 1, PSB2 = post-successful breeder category 2, and dead). The most general model we consideredDataFrom 1960, adults and chicks were ringed with stainless steel rings and since 1966 a capture-mark-recapture program has been undertaken annually between December and April. Most rings of breeding birds were checked in January and February, just after laying, and all chicks were ringed in September and October just before fledging. At fledging, breeding performance was determined for most individuals. Breeding individuals (i.e. those attending a nest) were classified as successful breeders (SB) when they fledged a chick, or failed breeders (FB) otherwise. However, during the early years of the study, the breeding performance of some individuals was not ascertained; they were classified as breeders (B). Each year, new individuals found in the colony were ringed. We used data on breeding adults identified from the 1960 through 2010 breeding seasons, which were either ringed as adults or as chicks. The data were coded with one digit per year: 0 = not observed, 1 = seen as a FB, 2 = seen as a SB, 3 = seen as a B (which were used to build capture histories). This yielded a total of 4339 individual capture histories for a period of 50 years. A restricted data set only including individuals of known sex was also used to test our predictions. Individuals were sexed from plumage characteristics and size. This yielded a total of 1876 female and 1998 male life histories. Foraging areas were identified from information on the at-sea distribution of breeding and non-breeding adults obtained by telemetry from 1989 to 2010 (satellite tracking using Argos PTT satellite transmitters, global positioning system, and geolocator). Numerous longline fleets operate in the Southern Ocean and are known, or suspected, to interact with Crozet wandering albatrosses and other seabirds. Focusing on the Indian Ocean fleets, because the Crozet wandering albatross population breeds in the southern Indian Ocean and breeding birds forage in the Indian Ocean [22], the fleets with the greatest overlap with the foraging distribution and therefore the greatest potential interactions are the high-seas pelagic longline fleets of Japan and Taiwan [26,27]. Annual fishing effort was calculated from monthly reported fishing effort dataPLOS ONE | www.plosone.orgDifferential Susceptibility to Bycatchs refers to state dependency in proportion, breeding (denoted as b), success (denoted as c), encounter (denoted as p) and state determination (denoted as d) probabilities, and superscript t refers to time. To test for linear and quadratic temporal trends over time in initial proportions of individuals in observable states we fitted models where the initial proportion varied according to a quadratic (or linear) trend on a logit scale as: pt log log it(pt ) azb|Tt zc|Tt2 1{pt.