Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity?
Abstract Investigating the drivers of diet quality is a key issue in wildlife ecology and conservation. Fecal near infrared reflectance spectroscopy (f‐NIRS) is widely used to assess dietary quality since it allows for noninvasive, rapid, and low‐cost analysis of nutrients. Samples for f‐NIRS can be...
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| Format: | Article |
| Language: | English |
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Wiley
2020-06-01
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| Series: | Ecology and Evolution |
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| Online Access: | https://doi.org/10.1002/ece3.6354 |
| _version_ | 1818964212114784256 |
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| author | Luca Corlatti |
| author_facet | Luca Corlatti |
| author_sort | Luca Corlatti |
| collection | DOAJ |
| description | Abstract Investigating the drivers of diet quality is a key issue in wildlife ecology and conservation. Fecal near infrared reflectance spectroscopy (f‐NIRS) is widely used to assess dietary quality since it allows for noninvasive, rapid, and low‐cost analysis of nutrients. Samples for f‐NIRS can be collected and analyzed with or without knowledge of animal identities. While anonymous sampling allows to reduce the costs of individual identification, as it neither requires physical captures nor DNA genotyping, it neglects the potential effects of individual variation. As a consequence, regression models fitted to investigate the drivers of dietary quality may suffer severe issues of pseudoreplication. I investigated the relationship between crude protein and ecological predictors at different time periods to assess the level of individual heterogeneity in diet quality of 22 marked chamois Rupicapra rupicapra monitored over 2 years. Models with and without individual grouping effect were fitted to simulate identifiable and anonymous fecal sampling, and model estimates were compared to evaluate the consequences of anonymizing data collection and analysis. The variance explained by the individual random effect and the value of diet repeatability varied with seasons and peaked in winter. Despite the occurrence of individual variation in dietary quality, ecological parameter estimates under identifiable or anonymous sampling were consistently similar. This study suggests that anonymous fecal sampling may provide robust estimates of the relationship between dietary quality and ecological correlates. However, since the level of individual heterogeneity in dietary quality may vary with species‐ or study‐specific features, inconsequential pseudoreplication should not be assumed in other taxa. When individual differences are known to be inconsequential, anonymous sampling allows to optimize the trade‐off between sampling intensity and representativeness. When pseudoreplication is consequential, however, no conclusive remedy exists to effectively resolve nonindependence. |
| first_indexed | 2024-12-20T12:57:31Z |
| format | Article |
| id | doaj.art-667884ca998048949c8367eff83f51a9 |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-12-20T12:57:31Z |
| publishDate | 2020-06-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-667884ca998048949c8367eff83f51a92022-12-21T19:40:02ZengWileyEcology and Evolution2045-77582020-06-0110126089609610.1002/ece3.6354Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity?Luca Corlatti0Chair of Wildlife Ecology and Management University of Freiburg Freiburg GermanyAbstract Investigating the drivers of diet quality is a key issue in wildlife ecology and conservation. Fecal near infrared reflectance spectroscopy (f‐NIRS) is widely used to assess dietary quality since it allows for noninvasive, rapid, and low‐cost analysis of nutrients. Samples for f‐NIRS can be collected and analyzed with or without knowledge of animal identities. While anonymous sampling allows to reduce the costs of individual identification, as it neither requires physical captures nor DNA genotyping, it neglects the potential effects of individual variation. As a consequence, regression models fitted to investigate the drivers of dietary quality may suffer severe issues of pseudoreplication. I investigated the relationship between crude protein and ecological predictors at different time periods to assess the level of individual heterogeneity in diet quality of 22 marked chamois Rupicapra rupicapra monitored over 2 years. Models with and without individual grouping effect were fitted to simulate identifiable and anonymous fecal sampling, and model estimates were compared to evaluate the consequences of anonymizing data collection and analysis. The variance explained by the individual random effect and the value of diet repeatability varied with seasons and peaked in winter. Despite the occurrence of individual variation in dietary quality, ecological parameter estimates under identifiable or anonymous sampling were consistently similar. This study suggests that anonymous fecal sampling may provide robust estimates of the relationship between dietary quality and ecological correlates. However, since the level of individual heterogeneity in dietary quality may vary with species‐ or study‐specific features, inconsequential pseudoreplication should not be assumed in other taxa. When individual differences are known to be inconsequential, anonymous sampling allows to optimize the trade‐off between sampling intensity and representativeness. When pseudoreplication is consequential, however, no conclusive remedy exists to effectively resolve nonindependence.https://doi.org/10.1002/ece3.6354chamoisindividual heterogeneityinfrared spectroscopynonindependencepseudoreplicationrepeatability |
| spellingShingle | Luca Corlatti Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity? Ecology and Evolution chamois individual heterogeneity infrared spectroscopy nonindependence pseudoreplication repeatability |
| title | Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity? |
| title_full | Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity? |
| title_fullStr | Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity? |
| title_full_unstemmed | Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity? |
| title_short | Anonymous fecal sampling and NIRS studies of diet quality: Problem or opportunity? |
| title_sort | anonymous fecal sampling and nirs studies of diet quality problem or opportunity |
| topic | chamois individual heterogeneity infrared spectroscopy nonindependence pseudoreplication repeatability |
| url | https://doi.org/10.1002/ece3.6354 |
| work_keys_str_mv | AT lucacorlatti anonymousfecalsamplingandnirsstudiesofdietqualityproblemoropportunity |