Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California
Avian eggshell thickness is an important life history metric in birds and has broad applications across disciplines ranging from animal behavior to toxicology. Empirical eggshell thickness values for songbirds (Order Passeriformes) are under-represented in the literature due to the difficulty of mea...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Resilience Alliance
2024-03-01
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| Series: | Journal of Field Ornithology |
| Subjects: | |
| Online Access: | https://journal.afonet.org/vol95/iss1/art3 |
| _version_ | 1797234721801895936 |
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| author | Carley R. Schacter Sarah H. Peterson C. Alex Hartman Mark P. Herzog Joshua T. Ackerman |
| author_facet | Carley R. Schacter Sarah H. Peterson C. Alex Hartman Mark P. Herzog Joshua T. Ackerman |
| author_sort | Carley R. Schacter |
| collection | DOAJ |
| description | Avian eggshell thickness is an important life history metric in birds and has broad applications across disciplines ranging from animal behavior to toxicology. Empirical eggshell thickness values for songbirds (Order Passeriformes) are under-represented in the literature due to the difficulty of measuring smaller eggs using traditional methods. We used a Hall-effect thickness gauge to measure eggs of five focal songbird species from California’s Central Valley: House Wren ( Troglodytes aedon ; n = 567), Tree Swallow ( Tachycineta bicolor ; n = 297), Ash-throated Flycatcher ( Myiarchus cinerascens ; n = 21), Western Bluebird ( Sialia mexicana ; n = 13), and Bewick’s Wren ( Thryomanes bewickii ; n = 5). We compared minimum eggshell thickness measurements at the equator and sharp pole, and we related eggshell thickness to other egg morphometrics and adult body mass. Eggshell thickness at the equator was 5.6% thicker in Ash-throated Flycatchers and 3.5% thinner in Tree Swallows compared with eggshell thickness at the sharp pole. Among species, eggshell thickness at the sharp pole was greater in species with larger eggs, whereas, within species, larger eggs were thinner at the sharp pole. Eggshells were 8% and 11% thinner in late incubation eggs (≥75% of total incubation duration) than early incubation (≤10% of total incubation duration) for House Wren and Tree Swallow eggs, respectively. Whenever possible, it is preferable to use empirical eggshell thickness data that are specific to the species and geographic region being studied, and a relatively new method used in this study allows accurate measurement of small eggs without having to compromise the integrity of preserved eggshell specimens. |
| first_indexed | 2024-04-24T16:36:34Z |
| format | Article |
| id | doaj.art-f10d6f71a7784c89ae45756ea234b32f |
| institution | Directory Open Access Journal |
| issn | 1557-9263 |
| language | English |
| last_indexed | 2024-04-24T16:36:34Z |
| publishDate | 2024-03-01 |
| publisher | Resilience Alliance |
| record_format | Article |
| series | Journal of Field Ornithology |
| spelling | doaj.art-f10d6f71a7784c89ae45756ea234b32f2024-03-29T16:27:37ZengResilience AllianceJournal of Field Ornithology1557-92632024-03-01951310.5751/JFO-00410-950103410Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, CaliforniaCarley R. Schacter0Sarah H. Peterson1C. Alex Hartman2Mark P. Herzog3Joshua T. Ackerman4U.S. Geological Survey, Western Ecological Research Center, Dixon Field StationU.S. Geological Survey, Western Ecological Research Center, Dixon Field StationU.S. Geological Survey, Western Ecological Research Center, Dixon Field StationU.S. Geological Survey, Western Ecological Research Center, Dixon Field StationU.S. Geological Survey, Western Ecological Research Center, Dixon Field StationAvian eggshell thickness is an important life history metric in birds and has broad applications across disciplines ranging from animal behavior to toxicology. Empirical eggshell thickness values for songbirds (Order Passeriformes) are under-represented in the literature due to the difficulty of measuring smaller eggs using traditional methods. We used a Hall-effect thickness gauge to measure eggs of five focal songbird species from California’s Central Valley: House Wren ( Troglodytes aedon ; n = 567), Tree Swallow ( Tachycineta bicolor ; n = 297), Ash-throated Flycatcher ( Myiarchus cinerascens ; n = 21), Western Bluebird ( Sialia mexicana ; n = 13), and Bewick’s Wren ( Thryomanes bewickii ; n = 5). We compared minimum eggshell thickness measurements at the equator and sharp pole, and we related eggshell thickness to other egg morphometrics and adult body mass. Eggshell thickness at the equator was 5.6% thicker in Ash-throated Flycatchers and 3.5% thinner in Tree Swallows compared with eggshell thickness at the sharp pole. Among species, eggshell thickness at the sharp pole was greater in species with larger eggs, whereas, within species, larger eggs were thinner at the sharp pole. Eggshells were 8% and 11% thinner in late incubation eggs (≥75% of total incubation duration) than early incubation (≤10% of total incubation duration) for House Wren and Tree Swallow eggs, respectively. Whenever possible, it is preferable to use empirical eggshell thickness data that are specific to the species and geographic region being studied, and a relatively new method used in this study allows accurate measurement of small eggs without having to compromise the integrity of preserved eggshell specimens.https://journal.afonet.org/vol95/iss1/art3egg morphometricseggshell thicknesseggshell thinningembryonic developmentpasseriformespasserinesongbird |
| spellingShingle | Carley R. Schacter Sarah H. Peterson C. Alex Hartman Mark P. Herzog Joshua T. Ackerman Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California Journal of Field Ornithology egg morphometrics eggshell thickness eggshell thinning embryonic development passeriformes passerine songbird |
| title | Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California |
| title_full | Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California |
| title_fullStr | Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California |
| title_full_unstemmed | Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California |
| title_short | Eggshell thickness and egg morphometrics in five songbird species from the Central Valley, California |
| title_sort | eggshell thickness and egg morphometrics in five songbird species from the central valley california |
| topic | egg morphometrics eggshell thickness eggshell thinning embryonic development passeriformes passerine songbird |
| url | https://journal.afonet.org/vol95/iss1/art3 |
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