A comparison of population estimation techniques for individually unidentifiable free-roaming dogs
Abstract Background Measuring the size of free roaming dog populations quickly and accurately is critical in the implementation of numerous preventive health and population control interventions. However, few studies have investigated the relative performance of population size assessment tools when...
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| Format: | Article |
| Language: | English |
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BMC
2019-06-01
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| Series: | BMC Veterinary Research |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s12917-019-1938-1 |
| _version_ | 1819019289479348224 |
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| author | N. V. Meunier A. D. Gibson J. Corfmat S. Mazeri I. G. Handel L. Gamble B Mde C Bronsvoort R. J. Mellanby |
| author_facet | N. V. Meunier A. D. Gibson J. Corfmat S. Mazeri I. G. Handel L. Gamble B Mde C Bronsvoort R. J. Mellanby |
| author_sort | N. V. Meunier |
| collection | DOAJ |
| description | Abstract Background Measuring the size of free roaming dog populations quickly and accurately is critical in the implementation of numerous preventive health and population control interventions. However, few studies have investigated the relative performance of population size assessment tools when applied to dogs. The aim of this study was to compare the commonly used mark-resight methodology with distance sampling methods, which are less resource intensive, to estimate free-roaming dog abundance in Goa, India. Twenty-six working zones were surveyed along all roads twice by the same surveyor at the same time of day, following a vaccination campaign which included marking of vaccinated dogs with a coloured paint. The Chapman estimate was then used to evaluate the mark-resight abundance. Additionally, the number of dogs and perpendicular distance from the road for all dogs sighted was recorded. This was used to estimate dog density and abundance using distance sampling methods. The detection function was fitted based on goodness-of-fit and AIC. Results The Chapman abundance estimate for the entire study area was 5202 dogs (95%CI 4733.8–5671.0), and the distance sampling method abundance estimate was 5067 dogs (95%CI 4454.3–5764.2). For individual working zones, after taking other factors into account in a mixed effects model, the average distance sampling estimate was 35% higher (95%CI 20–53%) than the Chapman estimate. There was also evidence of a difference in estimates between surveyors of 21% (95%CI 7–37%) and between days (22% lower on day 2, 95%CI 8–38%) for individual working zones. Conclusion Our study demonstrated that the distance sampling estimates were comparable overall to the Chapman method of abundance estimation of free roaming dogs across the entire study region but there was noticeable variation between the two methods when individual zones were compared. Consequently, distance sampling methods may be suitable to enumerate dogs over large areas in a more time efficient manner than the widely used mark-resight approach. |
| first_indexed | 2024-12-21T03:32:57Z |
| format | Article |
| id | doaj.art-a41bae740f0040fb8c1bb7aad6d9bd08 |
| institution | Directory Open Access Journal |
| issn | 1746-6148 |
| language | English |
| last_indexed | 2024-12-21T03:32:57Z |
| publishDate | 2019-06-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Veterinary Research |
| spelling | doaj.art-a41bae740f0040fb8c1bb7aad6d9bd082022-12-21T19:17:25ZengBMCBMC Veterinary Research1746-61482019-06-0115111010.1186/s12917-019-1938-1A comparison of population estimation techniques for individually unidentifiable free-roaming dogsN. V. Meunier0A. D. Gibson1J. Corfmat2S. Mazeri3I. G. Handel4L. Gamble5B Mde C Bronsvoort6R. J. Mellanby7The Royal (Dick) School of Veterinary Studies (R(D)SVS) and the Roslin Institute, Hospital for Small Animals, Easter Bush Veterinary CentreMission RabiesMission RabiesMission RabiesThe Royal (Dick) School of Veterinary Studies (R(D)SVS) and the Roslin Institute, Hospital for Small Animals, Easter Bush Veterinary CentreMission RabiesThe Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute and the Royal (Dick) School of Veterinary Studies (R(D)SVS)The Royal (Dick) School of Veterinary Studies (R(D)SVS) and the Roslin Institute, Hospital for Small Animals, Easter Bush Veterinary CentreAbstract Background Measuring the size of free roaming dog populations quickly and accurately is critical in the implementation of numerous preventive health and population control interventions. However, few studies have investigated the relative performance of population size assessment tools when applied to dogs. The aim of this study was to compare the commonly used mark-resight methodology with distance sampling methods, which are less resource intensive, to estimate free-roaming dog abundance in Goa, India. Twenty-six working zones were surveyed along all roads twice by the same surveyor at the same time of day, following a vaccination campaign which included marking of vaccinated dogs with a coloured paint. The Chapman estimate was then used to evaluate the mark-resight abundance. Additionally, the number of dogs and perpendicular distance from the road for all dogs sighted was recorded. This was used to estimate dog density and abundance using distance sampling methods. The detection function was fitted based on goodness-of-fit and AIC. Results The Chapman abundance estimate for the entire study area was 5202 dogs (95%CI 4733.8–5671.0), and the distance sampling method abundance estimate was 5067 dogs (95%CI 4454.3–5764.2). For individual working zones, after taking other factors into account in a mixed effects model, the average distance sampling estimate was 35% higher (95%CI 20–53%) than the Chapman estimate. There was also evidence of a difference in estimates between surveyors of 21% (95%CI 7–37%) and between days (22% lower on day 2, 95%CI 8–38%) for individual working zones. Conclusion Our study demonstrated that the distance sampling estimates were comparable overall to the Chapman method of abundance estimation of free roaming dogs across the entire study region but there was noticeable variation between the two methods when individual zones were compared. Consequently, distance sampling methods may be suitable to enumerate dogs over large areas in a more time efficient manner than the widely used mark-resight approach.http://link.springer.com/article/10.1186/s12917-019-1938-1Population estimationDog abundanceFree-roaming dogsMark resight |
| spellingShingle | N. V. Meunier A. D. Gibson J. Corfmat S. Mazeri I. G. Handel L. Gamble B Mde C Bronsvoort R. J. Mellanby A comparison of population estimation techniques for individually unidentifiable free-roaming dogs BMC Veterinary Research Population estimation Dog abundance Free-roaming dogs Mark resight |
| title | A comparison of population estimation techniques for individually unidentifiable free-roaming dogs |
| title_full | A comparison of population estimation techniques for individually unidentifiable free-roaming dogs |
| title_fullStr | A comparison of population estimation techniques for individually unidentifiable free-roaming dogs |
| title_full_unstemmed | A comparison of population estimation techniques for individually unidentifiable free-roaming dogs |
| title_short | A comparison of population estimation techniques for individually unidentifiable free-roaming dogs |
| title_sort | comparison of population estimation techniques for individually unidentifiable free roaming dogs |
| topic | Population estimation Dog abundance Free-roaming dogs Mark resight |
| url | http://link.springer.com/article/10.1186/s12917-019-1938-1 |
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