Geoscience Reference
In-Depth Information
be.more.plastic.than. widely.understood..The.assumption.that.butterlies. have. pre-
dictable.associations.with.the.composition.and.structure.of.vegetation.communities.
(Hermy. and. Cornelis. 2000). can. be. quite. tenuous.. At. a. local. level,. the. larvae. of.
many.species.of.butterlies.are.restricted.to.one.or.a.few.closely.related.species.of.
larval.host.plants,.and.adults.of.some.species.are.linked.closely.with.particular.spe-
cies.of.plants.from.which.they.draw.nectar..Nevertheless,.the.breadth.of.host-plant.
use.and.preferences.for.individual.species.sometimes.differs.dramatically.in.space,.
time,. and. even. among. individuals. in. the. same. population. (Singer. 1983;. Boughton.
1999)..Furthermore,.in.temperate.regions,.let.alone.the.tropics,.the.identities.of.larval.
host.plants.used.by.many.butterlies.still.are.not.known.at.the.species.level,.and.the.
geographic.distribution.of.a.given.butterly.species.typically.is.less.extensive.than.
the.geographic.distribution.of.its.larval.host.plants.and.nectar.sources.(Scott.1986;.
Ehrlich.and.Hanski.2004).
The.feasibility.of.monitoring.a.biological.response.to.climate.change.depends.in.
part.on.the.ease.with.which.the.target.of.monitoring.can.be.measured..Butterlies.
generally.meet.reasonable.standards.of.measurement.tractability—they.are.diurnal,.
colorful,.and.typically.are.readily.detected—but.there.can.be.substantive.caveats..As.
noted.previously,.phenologies.of.butterly.populations.can.vary.dramatically.among.
locations.and.years.and.are.affected.by.short-term.weather.conditions..These.attri-
butes.are.a.challenge.to.conducting,.and.analyzing.data.from,.annual.surveys.of.but-
terly.populations..Estimation.of.population.size.and.emergence.curves.can.require.
intensive.surveys.or.mark-recapture.efforts.by.trained.personnel.(Weiss.et.al..1993;.
Haddad.et.al..2008)..It.is.generally.appreciated.that.targets.of.monitoring.also.should.
be. easy. to. identify.. Certainly. many. species. of. butterlies. can. be. identiied. on. the.
wing.or.in.the.net.by.an.experienced.observer,.but.morphological.similarities.among.
species. in. some. species-rich. genera. (e.g.,.
Speyeria
,.
Euphydryas
,. and.
Euphilotes
).
confound.reliable.identiication,.even.by.seasoned.lepidopterists..In.addition,.many.
small-bodied.species.of.butterlies,.especially.hesperiids.and.lycaenids,.are.dificult.
to.capture.and.handle.without.injuring.the.animals.
Past. assumptions. about. the. elevational. distributions. of. butterly. habitats. and.
about.habitat-area.relationships.may.have.led.to.overestimates.of.the.probability.of.
climate-driven.extirpations.and.underestimates.of.the.ability.of.butterlies.to.adapt.
to. climate. change.. It. often. is. assumed. implicitly,. but. incorrectly. (because. evolu-
tion. occurs. at. the. level. of. the. organism),. that. multiple. plant. species. comprising. a.
vegetation. association. have. synchronous. responses. to. climate.. As. a. result,. projec-
tions.about.shifting.distributions.of.host.plants,.nectar.sources,.or.other.vegetational.
attributes. of. the. habitat. of. butterlies. may. be. erroneous.. For. example,. woodlands.
dominated.by.singleleaf.pinyon.(
Pinus monophylla
).and.Utah.and.western.juniper.
(
Juniperus osteosperma
,.
Juniperus occidentalis
). are. widespread. across. the. Great.
Basin..Researchers,.managers,.and.the.public.often.refer.to.pinyon-juniper.as.a.sin-
gle.unit..Nevertheless,.the.two.conifers.have.different.climatic.tolerances.and.resil-
iencies.to.disturbances.such.as.ire..Thus.the.compositional.stability.of.vegetation.
across.the.region.is.uncertain.
In.addition,.for.computational.simplicity,.it.is.common.to.assume.that.elevational.
boundaries.of.vegetation.associations.are.homogeneous.in.space..Previous.work.cited.
2300-2800.m.(Murphy.and.Weiss.1992).or.2300-2700.m.(Boggs.and.Murphy.1997).
