### Abstract

Population viability analyses for butterflies typically use metapopulation models, but for endemic species with no redundancy among subpopulations, we need to understand local population dynamics. However, little is known about the sensitivity of butterfly population vital rates and viability to disturbances such as fire. We fit quadratic models to monthly butterfly count data (1999–2014) to estimate an annual population density index that represents density during peak abundance each year. Relative population growth rate was estimated using a time series of the population density index, and population dynamics parameters r_{0} and K were estimated by fitting relative growth rates (RGRs) to density independent and dependent models that include the effects of fire. Population models were simulated 20 and 100 years into the future to evaluate the sensitivity of extinction probability to density dependent dynamics and fire. Although the density independent model had the highest relative likelihood, density dependent models produced population trajectories with behavior more congruent with data from the Anaea troglodyta floridalis population. The absence of fire increased sensitivity of RGR to density, and the occurrence of fire buffered this sensitivity by increasing carrying capacity. Extinction risk was most sensitive to the inclusion of density dependent dynamics. Density dependent models provided a more optimistic outlook relative to density independent models (8 vs. 66 % probability of extinction in 20 years). Our simulations suggest that improving carrying capacity would provide the best buffer to extinction for this endangered endemic butterfly.

Original language | English (US) |
---|---|

Pages (from-to) | 1589-1608 |

Number of pages | 20 |

Journal | Biodiversity and Conservation |

Volume | 24 |

Issue number | 7 |

DOIs | |

State | Published - Jul 22 2015 |

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### Keywords

- Anaea troglodyta floridalis
- Endemism
- Everglades National Park
- Leafwing butterflies
- Pine rocklands
- Stochastic disturbance

### ASJC Scopus subject areas

- Ecology, Evolution, Behavior and Systematics
- Ecology
- Nature and Landscape Conservation

### Cite this

*Biodiversity and Conservation*,

*24*(7), 1589-1608. https://doi.org/10.1007/s10531-015-0877-9

**Population viability models for an endangered endemic subtropical butterfly : effects of density and fire on population dynamics and risk of extinction.** / McElderry, Robert M.; Salvato, Mark H.; Horvitz, Carol C.

Research output: Contribution to journal › Article

*Biodiversity and Conservation*, vol. 24, no. 7, pp. 1589-1608. https://doi.org/10.1007/s10531-015-0877-9

}

TY - JOUR

T1 - Population viability models for an endangered endemic subtropical butterfly

T2 - effects of density and fire on population dynamics and risk of extinction

AU - McElderry, Robert M.

AU - Salvato, Mark H.

AU - Horvitz, Carol C

PY - 2015/7/22

Y1 - 2015/7/22

N2 - Population viability analyses for butterflies typically use metapopulation models, but for endemic species with no redundancy among subpopulations, we need to understand local population dynamics. However, little is known about the sensitivity of butterfly population vital rates and viability to disturbances such as fire. We fit quadratic models to monthly butterfly count data (1999–2014) to estimate an annual population density index that represents density during peak abundance each year. Relative population growth rate was estimated using a time series of the population density index, and population dynamics parameters r0 and K were estimated by fitting relative growth rates (RGRs) to density independent and dependent models that include the effects of fire. Population models were simulated 20 and 100 years into the future to evaluate the sensitivity of extinction probability to density dependent dynamics and fire. Although the density independent model had the highest relative likelihood, density dependent models produced population trajectories with behavior more congruent with data from the Anaea troglodyta floridalis population. The absence of fire increased sensitivity of RGR to density, and the occurrence of fire buffered this sensitivity by increasing carrying capacity. Extinction risk was most sensitive to the inclusion of density dependent dynamics. Density dependent models provided a more optimistic outlook relative to density independent models (8 vs. 66 % probability of extinction in 20 years). Our simulations suggest that improving carrying capacity would provide the best buffer to extinction for this endangered endemic butterfly.

AB - Population viability analyses for butterflies typically use metapopulation models, but for endemic species with no redundancy among subpopulations, we need to understand local population dynamics. However, little is known about the sensitivity of butterfly population vital rates and viability to disturbances such as fire. We fit quadratic models to monthly butterfly count data (1999–2014) to estimate an annual population density index that represents density during peak abundance each year. Relative population growth rate was estimated using a time series of the population density index, and population dynamics parameters r0 and K were estimated by fitting relative growth rates (RGRs) to density independent and dependent models that include the effects of fire. Population models were simulated 20 and 100 years into the future to evaluate the sensitivity of extinction probability to density dependent dynamics and fire. Although the density independent model had the highest relative likelihood, density dependent models produced population trajectories with behavior more congruent with data from the Anaea troglodyta floridalis population. The absence of fire increased sensitivity of RGR to density, and the occurrence of fire buffered this sensitivity by increasing carrying capacity. Extinction risk was most sensitive to the inclusion of density dependent dynamics. Density dependent models provided a more optimistic outlook relative to density independent models (8 vs. 66 % probability of extinction in 20 years). Our simulations suggest that improving carrying capacity would provide the best buffer to extinction for this endangered endemic butterfly.

KW - Anaea troglodyta floridalis

KW - Endemism

KW - Everglades National Park

KW - Leafwing butterflies

KW - Pine rocklands

KW - Stochastic disturbance

UR - http://www.scopus.com/inward/record.url?scp=84931559893&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84931559893&partnerID=8YFLogxK

U2 - 10.1007/s10531-015-0877-9

DO - 10.1007/s10531-015-0877-9

M3 - Article

AN - SCOPUS:84931559893

VL - 24

SP - 1589

EP - 1608

JO - Biodiversity and Conservation

JF - Biodiversity and Conservation

SN - 0960-3115

IS - 7

ER -