Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale
Hawksbill sea turtles (Eretmochelys imbricata) from the Hawaiian archipelago form a small and genetically isolated population, consisting of only a few tens of individuals breeding annually. Most females nest on the island of Hawai'i, but little is known about the demographics of this rookery....
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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The Royal Society
2023-05-01
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| Series: | Royal Society Open Science |
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| Online Access: | https://royalsocietypublishing.org/doi/10.1098/rsos.221547 |
| _version_ | 1827946032104734720 |
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| author | John B. Horne Amy Frey Alexander R. Gaos Summer Martin Peter H. Dutton |
| author_facet | John B. Horne Amy Frey Alexander R. Gaos Summer Martin Peter H. Dutton |
| author_sort | John B. Horne |
| collection | DOAJ |
| description | Hawksbill sea turtles (Eretmochelys imbricata) from the Hawaiian archipelago form a small and genetically isolated population, consisting of only a few tens of individuals breeding annually. Most females nest on the island of Hawai'i, but little is known about the demographics of this rookery. This study used genetic relatedness, inferred from 135 microhaplotype markers, to determine breeding sex-ratios, estimate female nesting frequency and assess relationships between individuals nesting on different beaches. Samples were collected during the 2017 nesting season and final data included 13 nesting females and 1002 unhatched embryos, salvaged from 41 nests, of which 13 had no observed mother. Results show that most females used a single nesting beach laying 1–5 nests each. From female and offspring alleles, the paternal genotypes of 12 breeding males were reconstructed and many showed high relatedness to their mates. Pairwise relatedness of offspring revealed one instance of polygyny but otherwise suggested a 1 : 1 breeding-sex ratio. Relatedness analysis and spatial-autocorrelation of genotypes indicate that turtles from different nesting areas do not regularly interbreed, suggesting that strong natal homing tendencies in both sexes result in non-random mating across the study area. Complexes of nearby nesting beaches also showed unique patterns of inbreeding across loci, further indicating that Hawaiian hawksbill turtles have demographically discontinuous nesting populations separated by only tens of km. |
| first_indexed | 2024-03-13T10:52:58Z |
| format | Article |
| id | doaj.art-1205c4a7d58e43bca530679b7d00fe91 |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-03-13T10:52:58Z |
| publishDate | 2023-05-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-1205c4a7d58e43bca530679b7d00fe912023-05-17T07:27:24ZengThe Royal SocietyRoyal Society Open Science2054-57032023-05-0110510.1098/rsos.221547Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scaleJohn B. Horne0Amy Frey1Alexander R. Gaos2Summer Martin3Peter H. Dutton4Southwest Fisheries Science Center, NOAA-Fisheries, La Jolla, CA, USASouthwest Fisheries Science Center, NOAA-Fisheries, La Jolla, CA, USAPacific Islands Fisheries Science Center, NOAA-Fisheries, Honolulu, HI, USAPacific Islands Fisheries Science Center, NOAA-Fisheries, Honolulu, HI, USASouthwest Fisheries Science Center, NOAA-Fisheries, La Jolla, CA, USAHawksbill sea turtles (Eretmochelys imbricata) from the Hawaiian archipelago form a small and genetically isolated population, consisting of only a few tens of individuals breeding annually. Most females nest on the island of Hawai'i, but little is known about the demographics of this rookery. This study used genetic relatedness, inferred from 135 microhaplotype markers, to determine breeding sex-ratios, estimate female nesting frequency and assess relationships between individuals nesting on different beaches. Samples were collected during the 2017 nesting season and final data included 13 nesting females and 1002 unhatched embryos, salvaged from 41 nests, of which 13 had no observed mother. Results show that most females used a single nesting beach laying 1–5 nests each. From female and offspring alleles, the paternal genotypes of 12 breeding males were reconstructed and many showed high relatedness to their mates. Pairwise relatedness of offspring revealed one instance of polygyny but otherwise suggested a 1 : 1 breeding-sex ratio. Relatedness analysis and spatial-autocorrelation of genotypes indicate that turtles from different nesting areas do not regularly interbreed, suggesting that strong natal homing tendencies in both sexes result in non-random mating across the study area. Complexes of nearby nesting beaches also showed unique patterns of inbreeding across loci, further indicating that Hawaiian hawksbill turtles have demographically discontinuous nesting populations separated by only tens of km.https://royalsocietypublishing.org/doi/10.1098/rsos.221547conservationsea turtlesbreeding sex ratiosnesting frequencyinbreedingPacific Islands |
| spellingShingle | John B. Horne Amy Frey Alexander R. Gaos Summer Martin Peter H. Dutton Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale Royal Society Open Science conservation sea turtles breeding sex ratios nesting frequency inbreeding Pacific Islands |
| title | Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale |
| title_full | Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale |
| title_fullStr | Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale |
| title_full_unstemmed | Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale |
| title_short | Non-random mating within an Island rookery of Hawaiian hawksbill turtles: demographic discontinuity at a small coastline scale |
| title_sort | non random mating within an island rookery of hawaiian hawksbill turtles demographic discontinuity at a small coastline scale |
| topic | conservation sea turtles breeding sex ratios nesting frequency inbreeding Pacific Islands |
| url | https://royalsocietypublishing.org/doi/10.1098/rsos.221547 |
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