Intertwined Fates: Opportunities and Challenges in the Linked Recovery of Two Rare Species

Dunwiddie, Peter W.; Haan, Nathan L.; Linders, Mary J.; Bakker, Jonathan D.; Fimbel, Cheryl; Thomas, Theodore B.

doi:10.3375/043.036.0214

Cited by 14 publications

(27 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Castilleja levisecta is federally listed as threatened in the USA (FWS ), but has been the target of focused recovery efforts, and is now locally common in relict and restored native grasslands in western Washington (Dunwiddie et al. ). Castilleja and several related genera produce iridoid glycosides (IGs hereafter), bitter secondary compounds thought to deter generalist herbivores (Bowers , Marko and Stermitz ).…”

Section: Methodsmentioning

confidence: 99%

Hemiparasites can transmit indirect effects from their host plants to herbivores

Haan

Bakker

Bowers

2017

Ecology

Self Cite

View full text Add to dashboard Cite

Parasitic plants can serve as critical intermediaries between their hosts and other organisms; however these relationships are not well understood. To investigate the relative importance of plant traits in such interactions, we studied the role of the root hemiparasite, Castilleja levisecta (Orobanchaceae), as a mediator of interactions between the host plants it parasitizes and the lepidopteran herbivore Euphydryas editha (Nymphalidae), whose caterpillars feed on Castilleja and sequester iridoid glycosides from it. We tested whether the hemiparasite's size, leaf N concentration, and iridoid glycoside concentrations were influenced by the identity of its host plant, and then whether these traits influenced outcomes for the herbivore. We found that the hemiparasite's size and leaf N depended on the host it parasitized, and these traits in turn affected outcomes for E. editha. Specifically, Euphydryas editha survival increased with hemiparasite size and caterpillar mass increased with leaf N; caterpillars with greater mass were more likely to survive during diapause. We also found preliminary evidence that host identity influenced iridoid glycoside sequestration by the herbivore. Mean iridoid glycoside concentrations in caterpillars ranged from 1-12% depending on the host being parasitized by Castilleja. This study demonstrates that root parasitism can result in strong indirect effects on higher trophic levels, influencing organisms' survival, growth, and chemical interactions.

show abstract

Section: Methodsmentioning

confidence: 99%

Hemiparasites can transmit indirect effects from their host plants to herbivores

Haan

Bakker

Bowers

2017

Ecology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Adult checkerspots oviposit on all three species, although they mostly interact with P. lanceolata and C. hispida (Dunwiddie et al, 2016). Adult checkerspots oviposit on all three species, although they mostly interact with P. lanceolata and C. hispida (Dunwiddie et al, 2016).…”

Section: Study Systemmentioning

confidence: 92%

“…Adult checkerspots oviposit on all three species, although they mostly interact with P. lanceolata and C. hispida (Dunwiddie et al, 2016). As many E. e. taylori populations now depend on P. lanceolata exclusively, land managers have found themselves in the interesting position of removing exotic species that threaten butterfly habitat while also preserving or planting the exotic P. lanceolata (Severns & Warren, 2008;Dunwiddie et al, 2016). In fact, records of E. e. taylori populations feeding on P. lanceolata go back to the late 19th century (Danby, 1890).…”

Section: Study Systemmentioning

confidence: 98%

“…As many E. e. taylori populations now depend on P. lanceolata exclusively, land managers have found themselves in the interesting position of removing exotic species that threaten butterfly habitat while also preserving or planting the exotic P. lanceolata (Severns & Warren, 2008;Dunwiddie et al, 2016). Land managers have established large C. levisecta populations at several sites, which could also be used for E. e. taylori recovery if C. levisecta were a suitable host (Dunwiddie et al, 2016). It is used frequently where butterflies have access to it.…”

Section: Study Systemmentioning

confidence: 99%

“…Euphydryas e. taylori is the focus of coordinated recovery efforts, but we know relatively little about its relationship to its host plants (Dunwiddie et al, 2016). We tested the effects of host plant variation, both within and among species, on survival of Euphydryas editha ssp.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Instar‐specific effects of host plants on survival of endangered butterfly larvae

Haan

Bakker

Dunwiddie

et al. 2018

Ecological Entomology

Self Cite

View full text Add to dashboard Cite

1. Outcomes for butterfly conservation can hinge on interactions with host plants during early larval instars. Ontogenetic changes in larvae may cause predictors of survival to shift quickly over time.2. Survival from instar to instar was measured for an endangered oligophagous butterfly, Euphydryas editha ssp. taylori (Taylor's checkerspot), which was experimentally released in the field on three host plants: Castilleja levisecta, Castilleja hispida, and Plantago lanceolata. Survival rates were quantified, from hatching to the second instar, from the second to the third instar, and from the third to the fourth instar.3. This study tested whether host plant characteristics (degree of senescence and anthocyanin pigmentation) affected survival during each instar; the effects of oviposition timing and larval group size on survival were also tested, as these vary by group and could affect outcomes for larvae differently on different hosts. 4. Survival rates depended on the host species being consumed, mostly because of a disparity in survival during the transition from the second to the third instar. Survival was lowest on C. levisecta, intermediate on C. hispida, and highest on P. lanceolata.5. Plant senescence, oviposition timing, and group size were predictors of survival, but their relevance depended on both the host plant being used and the instar being considered.6. Host plant suitability can vary strongly both within and among species, changing quickly with caterpillar ontogeny during early instars.

show abstract

Mechanism matters: the cause of fluctuations in boom–bust populations governs optimal habitat restoration strategy

Boor

Schultz

Crone

et al. 2018

Ecological Applications

View full text Add to dashboard Cite

Many populations exhibit boom-bust dynamics in which abundance fluctuates dramatically over time. Past research has focused on identifying whether the cause of fluctuations is primarily exogenous, e.g., environmental stochasticity coupled with weak density dependence, or endogenous, e.g., over-compensatory density dependence. Far fewer studies have addressed whether the mechanism responsible for boom-bust dynamics matters with respect to at-risk species management. Here, we ask whether the best strategy for restoring habitat across a landscape differs under exogenously vs. endogenously driven boom-bust dynamics. We used spatially explicit individual-based models to assess how butterfly populations governed by the two mechanisms would respond to habitat restoration strategies that varied in the level of resource patchiness, from a single large patch to multiple patches spaced at different distances. Our models showed that the restoration strategy that minimized extinction risk and boom-bust dynamics would be markedly different depending on the governing mechanism. Exogenously governed populations fared best in a single large habitat patch, whereas for endogenously driven populations, boom-bust dynamics were dampened and extinction risk declined when the total restored area was split into multiple patches with low to moderate inter-patch spacing. Adding environmental stochasticity to the endogenous model did not alter this result. Habitat fragmentation lowered extinction risk in the endogenously driven populations by reducing their growth rate, precluding both "boom" phases and, more importantly, "bust" phases. Our findings suggest that (1) successful restoration will depend on understanding the causes of fluctuations in at-risk populations, (2) the level and pattern of spatiotemporal environmental heterogeneity will also affect the ideal management approach, and (3) counterintuitively, for at-risk species with endogenously governed boom-bust dynamics, lowering the intrinsic population growth rate may decrease extinction risk.

show abstract

Intertwined Fates: Opportunities and Challenges in the Linked Recovery of Two Rare Species

Cited by 14 publications

References 22 publications

Hemiparasites can transmit indirect effects from their host plants to herbivores

Hemiparasites can transmit indirect effects from their host plants to herbivores

Instar‐specific effects of host plants on survival of endangered butterfly larvae

Mechanism matters: the cause of fluctuations in boom–bust populations governs optimal habitat restoration strategy

Contact Info

Product

Resources

About