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Many African large carnivore populations are declining due to decline of the herbivore populations on which they depend. We recently noted that the densities of true apex carnivores like the lion and spotted hyena correlate strongly with prey density, but competitively subordinate carnivores like the African wild dog benefit from competitive release when density of apex carnivores is low, so the expected effect of a simultaneous decrease in resources and dominant competitors is not obvious. We found that when prey density drops below a tipping point, the relationship of wild dog density to prey density changes sign, and wild dog density declines. We also noted that ‘prey depletion provides a mechanistically direct explanation of patterns in wild dog dynamics that have been attributed to climate change’ (Creel et al., 2023). Woodroffe et al. concur that prey depletion is an important threat, but suggest that we fail to understand the logic of their assertion that “climate change is likely to cause population collapse” (Rabaiotti et al., 2022), because the “identification of climate change as a threat is not based upon observed temporal trends in wild dog demography”. This statement misses our fundamental point. The data that Woodroffe et al. analyzed were collected over a period with rising temperatures and declining prey populations, so whether or not one tests for a time trend in demography, the data themselves are affected by two patterns:
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Relaunching the African Pollen Database: Abrupt change in climate and ecosystems
African ecosystems hold enormous ecological and economic value due to high biodiversity (Myers et al. 2000) and valuable ecosystem services provided to urban and agrarian populations (Wangai et al. 2016). However, these services are vulnerable to land use and climate change (Niang et al. 2014). Long paleoecological records from Africa provide iconic examples of abrupt environmental change, offering critical evidence for tipping points in the Earth system. Datasets in the region are notoriously difficult to access with the African Pollen Database (APD) largely unsupported for the last decade. Poor data accessibility has been a community complaint.
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- Award ID(s):
- 1929563
- PAR ID:
- 10426876
- Date Published:
- Journal Name:
- Past Global Changes Magazine
- Volume:
- 28
- Issue:
- 1
- ISSN:
- 2411-605X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.22498/pages.28.1.26
