Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana

Abstract Background Animal track surveys can enable rapid population monitoring for conservation, contingent on a suitable substrate and highly skilled trackers. The Formozov–Malyshev–Pereleshin (FMP) formula converts track counts along transects into absolute population density estimates, using the...

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Main Authors: Marie-Charlotte Gielen, Alessandro Araldi, Marie Jardeaux, Seitshiro Pule, Senxwai Mosololo, Xee Fire Seganaphohu, Duela Seganaphofu, Tebelelo Gabaikanye, Pogiso Ithuteng, Derek Keeping, Nicolas Schtickzelle
Format: Article
Language:English
Published: BMC 2025-07-01
Series:Movement Ecology
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Online Access:https://doi.org/10.1186/s40462-025-00582-1
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author Marie-Charlotte Gielen
Alessandro Araldi
Marie Jardeaux
Seitshiro Pule
Senxwai Mosololo
Xee Fire Seganaphohu
Duela Seganaphofu
Tebelelo Gabaikanye
Pogiso Ithuteng
Derek Keeping
Nicolas Schtickzelle
author_facet Marie-Charlotte Gielen
Alessandro Araldi
Marie Jardeaux
Seitshiro Pule
Senxwai Mosololo
Xee Fire Seganaphohu
Duela Seganaphofu
Tebelelo Gabaikanye
Pogiso Ithuteng
Derek Keeping
Nicolas Schtickzelle
author_sort Marie-Charlotte Gielen
collection DOAJ
description Abstract Background Animal track surveys can enable rapid population monitoring for conservation, contingent on a suitable substrate and highly skilled trackers. The Formozov–Malyshev–Pereleshin (FMP) formula converts track counts along transects into absolute population density estimates, using the species' average daily travel distance estimate ( $$\widehat{\text{M}}$$ M ^ ). Its main limitation lies in accurately estimating $$\widehat{\text{M}}$$ M ^ relevant to the survey’s specific time period and location. If empirical $$\widehat{\text{M}}$$ M ^ from the study region is not available, $$\widehat{\text{M}}$$ M ^ can be estimated allometrically, but less accurately, through body mass- $$\widehat{\text{M}}$$ M ^ scaling rules. This study aims to improve the accuracy of FMP-derived density estimates by refining both empirical and allometric $$\widehat{\text{M}}$$ M ^ estimations. Methods We tested a cost-effective forward trailing technique to collect high-quality empirical $$\widehat{\text{M}}$$ M ^ for large herbivore species with local certified trackers, in Khutse Game Reserve and Central Kalahari Game Reserve, Botswana. Since allometric $$\widehat{\text{M}}$$ M ^ values are underestimated in the Kalahari, we calibrated them using empirical $$\widehat{\text{M}}$$ M ^ from this study and the literature. Finally, we integrated our findings to estimate densities of 11 herbivore species using track surveys and the FMP formula. Results Through trailing, we provided empirical $$\widehat{\text{M}}$$ M ^ for five herbivore species, which previously lacked data for the area, and confirmed the temporal stability of daily travel distance values within the study season. We derived two separate coefficients to directly correct allometric $$\widehat{\text{M}}$$ M ^ for Kalahari species based on their foraging strategies. Based on our interpretation of the animal density estimates obtained via the FPM, we discuss the importance of the accuracy of $$\widehat{\text{M}}$$ M ^ , transect design, and survey effort for population monitoring. Conclusion Our research demonstrates the effectiveness of the forward trailing technique for accurately estimating $$\widehat{\text{M}}$$ M ^ of large herbivores in sandy substrates. It also provides coefficients to directly correct allometric $$\widehat{\text{M}}$$ M ^ for Kalahari species and delivers density estimates for multiple herbivores species across 2800 km2 of protected areas. These new elements strengthen the use of track data for wildlife monitoring in low-density environments, although we encourage further research to assess the need of time-specific $$\widehat{\text{M}}$$ M ^ . We also highlight opportunities to integrate Indigenous knowledge with modern technology in research, fostering collaboration with local communities for mutual benefit.
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issn 2051-3933
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spelling doaj-art-49eaa2222b134f588e1945d4f883ba7b2025-08-20T03:46:12ZengBMCMovement Ecology2051-39332025-07-0113111610.1186/s40462-025-00582-1Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, BotswanaMarie-Charlotte Gielen0Alessandro Araldi1Marie Jardeaux2Seitshiro Pule3Senxwai Mosololo4Xee Fire Seganaphohu5Duela Seganaphofu6Tebelelo Gabaikanye7Pogiso Ithuteng8Derek Keeping9Nicolas Schtickzelle10Earth and Life Institute, Université Catholique de LouvainResearch Department, Leopard Ecology & ConservationEarth and Life Institute, Université Catholique de LouvainResearch Department, Leopard Ecology & ConservationResearch Department, Leopard Ecology & ConservationResearch Department, Leopard Ecology & ConservationResearch Department, Leopard Ecology & ConservationResearch Department, Leopard Ecology & ConservationResearch Department, Leopard Ecology & ConservationOkavango Research Institute, University of BotswanaEarth and Life Institute, Université Catholique de LouvainAbstract Background Animal track surveys can enable rapid population monitoring for conservation, contingent on a suitable substrate and highly skilled trackers. The Formozov–Malyshev–Pereleshin (FMP) formula converts track counts along transects into absolute population density estimates, using the species' average daily travel distance estimate ( $$\widehat{\text{M}}$$ M ^ ). Its main limitation lies in accurately estimating $$\widehat{\text{M}}$$ M ^ relevant to the survey’s specific time period and location. If empirical $$\widehat{\text{M}}$$ M ^ from the study region is not available, $$\widehat{\text{M}}$$ M ^ can be estimated allometrically, but less accurately, through body mass- $$\widehat{\text{M}}$$ M ^ scaling rules. This study aims to improve the accuracy of FMP-derived density estimates by refining both empirical and allometric $$\widehat{\text{M}}$$ M ^ estimations. Methods We tested a cost-effective forward trailing technique to collect high-quality empirical $$\widehat{\text{M}}$$ M ^ for large herbivore species with local certified trackers, in Khutse Game Reserve and Central Kalahari Game Reserve, Botswana. Since allometric $$\widehat{\text{M}}$$ M ^ values are underestimated in the Kalahari, we calibrated them using empirical $$\widehat{\text{M}}$$ M ^ from this study and the literature. Finally, we integrated our findings to estimate densities of 11 herbivore species using track surveys and the FMP formula. Results Through trailing, we provided empirical $$\widehat{\text{M}}$$ M ^ for five herbivore species, which previously lacked data for the area, and confirmed the temporal stability of daily travel distance values within the study season. We derived two separate coefficients to directly correct allometric $$\widehat{\text{M}}$$ M ^ for Kalahari species based on their foraging strategies. Based on our interpretation of the animal density estimates obtained via the FPM, we discuss the importance of the accuracy of $$\widehat{\text{M}}$$ M ^ , transect design, and survey effort for population monitoring. Conclusion Our research demonstrates the effectiveness of the forward trailing technique for accurately estimating $$\widehat{\text{M}}$$ M ^ of large herbivores in sandy substrates. It also provides coefficients to directly correct allometric $$\widehat{\text{M}}$$ M ^ for Kalahari species and delivers density estimates for multiple herbivores species across 2800 km2 of protected areas. These new elements strengthen the use of track data for wildlife monitoring in low-density environments, although we encourage further research to assess the need of time-specific $$\widehat{\text{M}}$$ M ^ . We also highlight opportunities to integrate Indigenous knowledge with modern technology in research, fostering collaboration with local communities for mutual benefit.https://doi.org/10.1186/s40462-025-00582-1Daily movementsTrack surveyIndigenous knowledgeWildlife abundanceFormozov–Malyshev–Pereleshin formulaCyberTracker
spellingShingle Marie-Charlotte Gielen
Alessandro Araldi
Marie Jardeaux
Seitshiro Pule
Senxwai Mosololo
Xee Fire Seganaphohu
Duela Seganaphofu
Tebelelo Gabaikanye
Pogiso Ithuteng
Derek Keeping
Nicolas Schtickzelle
Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana
Movement Ecology
Daily movements
Track survey
Indigenous knowledge
Wildlife abundance
Formozov–Malyshev–Pereleshin formula
CyberTracker
title Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana
title_full Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana
title_fullStr Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana
title_full_unstemmed Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana
title_short Refining population density estimation from track counts: improving daily travel distance estimates through trailing of large herbivores in the Kalahari, Botswana
title_sort refining population density estimation from track counts improving daily travel distance estimates through trailing of large herbivores in the kalahari botswana
topic Daily movements
Track survey
Indigenous knowledge
Wildlife abundance
Formozov–Malyshev–Pereleshin formula
CyberTracker
url https://doi.org/10.1186/s40462-025-00582-1
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