Low ecological differentiation in leopard subspecies

It is now out in bioRxiv the preprint resulting from the part II project of Sidney Leedham:

Sidney Leedham, Johanna L. A. Paijmans, Andrea Manica, Michela Leonardi
Niche conservatism in a generalist felid: low differentiation of the climatic niche among subspecies of the leopard (Panthera pardus)
bioRxiv 2023.01.26.525491

The leopard (Panthera pardus) is a generalist species with a very wide geographic range: it can be found in most of Africa and part of Eurasia. It is subdivided into one African and eight Asian subspecies, which are the result of an ancient expansion from Africa.

We collected published observations of leopards across the entire historical range to see if the Asian subspecies live in the same climate as the African one, or if, in their expansion, they adapted to new climatic conditions.

We visualised the niche occupied by each subspecies in the climate space and compared them to see how much the Asian subspecies diverged from the African one. In most cases, there is great or total overlap, with the exception of the Persian leopard which suggests niche expansion.

This is supported by the fact that, when modelling the range of the species using only African presences, only the most northern part of the distribution is not retrieved.

These results help us better understand how the ecology of the leopard varies across its range, a knowledge that is vital for the effective conservation of its most distinct and vulnerable populations.

Preprint

Abstract

Aim Species distribution modelling can be used to reveal if the ecology of a species varies across its range, to investigate if range expansions entailed niche shifts, and to help assess ecological differentiation: the answers to such questions are vital for effective conservation. The leopard (Panthera pardus spp.) is a generalist species composed of one African and eight Asian subspecies, reflecting dispersal from an ancestral African range. This study uses species distribution models to compare the niches of leopard subspecies, to investigate if they conserved their niches when moving into new territories or adapted to local conditions and shifted niche.

Location Africa and Eurasia

Methods We assembled a database of P. pardus spp. presences. We then associated them with bioclimatic variables to identify which are relevant in predicting the distribution of the leopard. We then constructed a species distribution model and compared the distribution predicted from models based on presences from all subspecies versus the ones built only using African leopards. Finally, we used multivariate analysis to visualise the niche occupied by each subspecies in the climate space, and to compare niche overlaps to assess ecological differentiation.

Results Niche comparisons and model predictions suggest a general lack of niche separation between all subspecies. Most Asian subspecies have overlapping niches and occupy subsets of the niche of the African leopard. Nevertheless, we found the Persian leopard Panthera pardus saxicolor to have the most distinct niche, giving some evidence for niche expansion in more Northern Asian subspecies.

Main conclusions These results suggest little ecological differentiation among leopard subspecies and a lack of adaptation to novel climates after dispersal from Africa. This finding complements recent genetic studies in implying that the taxonomy of Asian leopards may not reflect biological differentiation, an issue that is important to resolve due to its relevance for the conservation of the species.