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Concurrent threats and extinction risk in a long-lived, highly fecund vertebrate with parental care.
- Source :
-
Ecological applications : a publication of the Ecological Society of America [Ecol Appl] 2024 Mar; Vol. 34 (2), pp. e2946. Date of Electronic Publication: 2024 Feb 01. - Publication Year :
- 2024
-
Abstract
- Detecting declines and quantifying extinction risk of long-lived, highly fecund vertebrates, including fishes, reptiles, and amphibians, can be challenging. In addition to the false notion that large clutches always buffer against population declines, the imperiled status of long-lived species can often be masked by extinction debt, wherein adults persist on the landscape for several years after populations cease to be viable. Here we develop a demographic model for the eastern hellbender (Cryptobranchus alleganiensis), an imperiled aquatic salamander with paternal care. We examined the individual and interactive effects of three of the leading threats hypothesized to contribute to the species' demise: habitat loss due to siltation, high rates of nest failure, and excess adult mortality caused by fishing and harvest. We parameterized the model using data on their life history and reproductive ecology to model the fates of individual nests and address multiple sources of density-dependent mortality under both deterministic and stochastic environmental conditions. Our model suggests that high rates of nest failure observed in the field are sufficient to drive hellbender populations toward a geriatric age distribution and eventually to localized extinction but that this process takes decades. Moreover, the combination of limited nest site availability due to siltation, nest failure, and stochastic adult mortality can interact to increase the likelihood and pace of extinction, which was particularly evident under stochastic scenarios. Density dependence in larval survival and recruitment can severely hamper a population's ability to recover from declines. Our model helps to identify tipping points beyond which extinction becomes certain and management interventions become necessary. Our approach can be generalized to understand the interactive effects of various threats to the extinction risk of other long-lived vertebrates. As we face unprecedented rates of environmental change, holistic approaches incorporating multiple concurrent threats and their impacts on different aspects of life history will be necessary to proactively conserve long-lived species.<br /> (© 2024 The Ecological Society of America.)
- Subjects :
- Animals
Ecosystem
Amphibians
Urodela
Extinction, Biological
Vertebrates
Subjects
Details
- Language :
- English
- ISSN :
- 1051-0761
- Volume :
- 34
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Ecological applications : a publication of the Ecological Society of America
- Publication Type :
- Academic Journal
- Accession number :
- 38303165
- Full Text :
- https://doi.org/10.1002/eap.2946