Mesoscale movement and recursion behaviors of Namibian black rhinos

Dana Paige Seidel; Wayne L Linklater; Werner Kilian; Pierre du Preez; Wayne M Getz

doi:10.1186/s40462-019-0176-2

Mesoscale movement and recursion behaviors of Namibian black rhinos

Mov Ecol. 2019 Nov 9:7:34. doi: 10.1186/s40462-019-0176-2. eCollection 2019.

Authors

Dana Paige Seidel¹, Wayne L Linklater^{1

2

3}, Werner Kilian⁴, Pierre du Preez⁴, Wayne M Getz^{1

5}

Affiliations

¹ 1Department of Environmental Science, Policy, and Management, University of California, Berkeley, Mulford Hall, Berkeley, CA, USA.
² 2Centre for Biodiversity and Restoration Ecology, Victoria University of Wellington, P.O. Box 600, Wellington, 6140 New Zealand.
³ 3Centre for African Conservation Ecology, Nelson Mandela University, Port Elizabeth, South Africa.
⁴ Etosha National Park, PO Box 6, Okaukuejo via Outjo, Namibia.
⁵ 5School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa.

Abstract

Background: Understanding rhino movement behavior, especially their recursive movements, holds significant promise for enhancing rhino conservation efforts, and protecting their habitats and the biodiversity they support. Here we investigate the daily, biweekly, and seasonal recursion behavior of rhinos, to aid conservation applications and increase our foundational knowledge about these important ecosystem engineers.

Methods: Using relocation data from 59 rhinos across northern Namibia and 8 years of sampling efforts, we investigated patterns in 24-h displacement at dawn, dusk, midday, and midnight to examine movement behaviors at an intermediate scale and across daily behavioral modes of foraging and resting. To understand recursion patterns across animals' short and long-term ranges, we built T-LoCoH time use grids to estimate recursive movement by each individual. Comparing these grids to contemporaneous MODIS imagery, we investigated productivity's influence on short-term space use and recursion. Finally, we investigated patterns of recursion within a year's home range, measuring the time to return to the most intensively used patches.

Results: Twenty four-hour displacements at dawn were frequently smaller than 24-h displacements at dusk or at midday and midnight resting periods. Recursion analyses demonstrated that short-term recursion was most common in areas of median rather than maximum NDVI values. Investigated across a full year, recursion analysis showed rhinos most frequently returned to areas within 8-21 days, though visits were also seen separated by months likely suggesting seasonality in range use.

Conclusions: Our results indicate that rhinos may frequently stay within the same area of their home ranges for days at a time, and possibly return to the same general area days in a row especially during morning foraging bouts. Recursion across larger time scales is also evident, and likely a contributing mechanism for maintaining open landscapes and browsing lawns of the savanna.

Keywords: Animal movement; Black rhino; Diceros bicornis; Displacement; Home range; NDVI; Recursion; T-LoCoH.