First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia

Abstract The Luangwa giraffe (Giraffa tippelskirchi thornicrofti), a subspecies of the Masai giraffe endemic to the Luangwa Valley of northeastern Zambia, inhabits an increasingly human-modified landscape. Accurate and current population estimates are critical to evaluating their status and identify...

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Main Authors: Catherine Sun, Frederike Otten, Rigardt Hoffman, Courtney Marneweck, Howard Maimbo, Charles-Albert Petre, Dusty Joubert, Tom Riffel, Matthew S. Becker, Stephanie Fennessy, Julian Fennessy, Michael B. Brown
Format: Article
Language:English
Published: Nature Portfolio 2025-05-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-00306-w
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author Catherine Sun
Frederike Otten
Rigardt Hoffman
Courtney Marneweck
Howard Maimbo
Charles-Albert Petre
Dusty Joubert
Tom Riffel
Matthew S. Becker
Stephanie Fennessy
Julian Fennessy
Michael B. Brown
author_facet Catherine Sun
Frederike Otten
Rigardt Hoffman
Courtney Marneweck
Howard Maimbo
Charles-Albert Petre
Dusty Joubert
Tom Riffel
Matthew S. Becker
Stephanie Fennessy
Julian Fennessy
Michael B. Brown
author_sort Catherine Sun
collection DOAJ
description Abstract The Luangwa giraffe (Giraffa tippelskirchi thornicrofti), a subspecies of the Masai giraffe endemic to the Luangwa Valley of northeastern Zambia, inhabits an increasingly human-modified landscape. Accurate and current population estimates are critical to evaluating their status and identifying effective conservation strategies. However, sparse monitoring since the early 1900s has limited inferences about population size, structure, and range. To address this, we conducted the most spatially extensive and systematic survey to date of Luangwa giraffe across its distribution, extending survey effort 120 km south of their officially recognized extent. Using spatial capture recapture modeling, we estimated 651–890 giraffe and an overall density of 0.04–0.05 giraffe/km2. Density decreased to nought beyond 7.5 km from permanent rivers, consistent with preferred forage concentrated in riparian areas. Increasing giraffe density estimates up to a threshold of the Human Footprint Index suggested that limited human presence may have negligible consequences on movement and resource selection. This was likely due to suitable habitat and minimal conflict despite human presence. However, without mitigating land-use planning, rapid land conversion threatens human-giraffe coexistence. An even sex ratio and small proportion of subadults implied a stable population, but sex-biased and temporal dynamics in space use, impacts of predation, and stochastic risks necessitate continued monitoring. This study highlights the value of systematic large-scale monitoring and opportunities for data integration across long-term monitoring programs to evaluate factors driving Luangwa giraffe dynamics and to inform science-based conservation of this unique and isolated population.
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spelling doaj-art-5e82997e05274b579fa991c1bd9bb2d52025-08-20T03:53:58ZengNature PortfolioScientific Reports2045-23222025-05-0115111210.1038/s41598-025-00306-wFirst rangewide density estimate of the endemic and isolated Luangwa giraffe in ZambiaCatherine Sun0Frederike Otten1Rigardt Hoffman2Courtney Marneweck3Howard Maimbo4Charles-Albert Petre5Dusty Joubert6Tom Riffel7Matthew S. Becker8Stephanie Fennessy9Julian Fennessy10Michael B. Brown11Zambian Carnivore ProgrammeZambian Carnivore ProgrammeGiraffe Conservation FoundationGiraffe Conservation FoundationZambian Carnivore ProgrammeBiocarbon PartnersNyamvu SafarisNsanga ConservationZambian Carnivore ProgrammeGiraffe Conservation FoundationGiraffe Conservation FoundationGiraffe Conservation FoundationAbstract The Luangwa giraffe (Giraffa tippelskirchi thornicrofti), a subspecies of the Masai giraffe endemic to the Luangwa Valley of northeastern Zambia, inhabits an increasingly human-modified landscape. Accurate and current population estimates are critical to evaluating their status and identifying effective conservation strategies. However, sparse monitoring since the early 1900s has limited inferences about population size, structure, and range. To address this, we conducted the most spatially extensive and systematic survey to date of Luangwa giraffe across its distribution, extending survey effort 120 km south of their officially recognized extent. Using spatial capture recapture modeling, we estimated 651–890 giraffe and an overall density of 0.04–0.05 giraffe/km2. Density decreased to nought beyond 7.5 km from permanent rivers, consistent with preferred forage concentrated in riparian areas. Increasing giraffe density estimates up to a threshold of the Human Footprint Index suggested that limited human presence may have negligible consequences on movement and resource selection. This was likely due to suitable habitat and minimal conflict despite human presence. However, without mitigating land-use planning, rapid land conversion threatens human-giraffe coexistence. An even sex ratio and small proportion of subadults implied a stable population, but sex-biased and temporal dynamics in space use, impacts of predation, and stochastic risks necessitate continued monitoring. This study highlights the value of systematic large-scale monitoring and opportunities for data integration across long-term monitoring programs to evaluate factors driving Luangwa giraffe dynamics and to inform science-based conservation of this unique and isolated population.https://doi.org/10.1038/s41598-025-00306-wHuman footprint indexMasai giraffePopulation estimateRoad surveySpatial capture-recaptureSearch and encounter
spellingShingle Catherine Sun
Frederike Otten
Rigardt Hoffman
Courtney Marneweck
Howard Maimbo
Charles-Albert Petre
Dusty Joubert
Tom Riffel
Matthew S. Becker
Stephanie Fennessy
Julian Fennessy
Michael B. Brown
First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia
Scientific Reports
Human footprint index
Masai giraffe
Population estimate
Road survey
Spatial capture-recapture
Search and encounter
title First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia
title_full First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia
title_fullStr First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia
title_full_unstemmed First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia
title_short First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia
title_sort first rangewide density estimate of the endemic and isolated luangwa giraffe in zambia
topic Human footprint index
Masai giraffe
Population estimate
Road survey
Spatial capture-recapture
Search and encounter
url https://doi.org/10.1038/s41598-025-00306-w
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