Habitat Considerations for Endangered Species Why conserve habitat? Sinks, sources, and metapopulations Critical Habitat Habitat Conservation Plans

Why Conserve Habitat?

Critical to species’ survival Protection applies to more than just the

species of interest Know more about habitat hot spots and

distribution than about species distributions Know habitat loss and degradation are

major reasons for endangerment

Modern Views of Populations and Habitats Review Sinks, Sources, and Metapopulation

Concepts– ESC 450– Chapter 5 in NRC’s “Science and the ESA”– Pulliam 1988 (if you have not read it--DO SO

TODAY!)• dispersal from source can result in large and

growing sink even given <1

Metapopulation Review

Subpopulations connected by dispersal (Levins 1969)

Good way to describe structure and dynamics of populations scattered across a landscape in spatially isolated patches

– common in managed landscapes Some sub-populations may be sinks and some may be

sources, but this is only a special case of general metapopulation model– core-satellite or simultaneous sink-source may be more

common (Doak and Mills 1994; Doncaster et al. 1997)

Key Messages for Endangered Species Management Extinction of subpopulations in metapopulation is to

be expected Subpopulation dynamics may be controlled by

dynamics of other subpopulations– rescue by dispersal– need to ID sources or cores

Functioning metapopulation may be necessary for species to remain extant– Acorn Woodpeckers in New Mexico

• (Stacey and Taper 1992)

Another Key: Habitat is Not Constant in Space or Time

It is a “shifting mosaic” (Bormann and Likens 1979, Botkin and Sobel 1975)

– habitat composition in landscape changes naturally• usually slowly

• BWCA (continual change at replacement rate every 2-4

centuries from glaciation and succession)– fire has return rate of 20-200 years

– GPP may ~ Respiration at ecosystem scale (steady state), but individual stands change frequently

Management Implications of Shifting Mosaics

Land management usually decreases time between disturbances• may also affect spatial arrangement by increasing edge

Endangered species may need change or may need specific disturbance state– Kirtland’s Warbler and Red-cockaded Woodpecker

Fire Wind

Clear-cutting

Tot

al B

i om

ass

Time (White Mountains, NH; Bormann and Likens 1979)

80

20

Do We Really Know Habitat Needs?

Spring

MalesFemales

Important

% o

f E

ach

Age

/Sex

In

Gro

up

10

Fall

AdultsHatchYear

1020

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AG CN CR CS SS WI

AG CN CR CS SS WI

Van Horne (1983)– abundance quality

Yong et al. (1998)– Wilson’s Warblers in New

Mexico– Habitat needs differ from

spring to fall (breeeding to migration)

• cottonwood not used in spring

– Habitat needs differ from adults to subadults

• ag for juveniles, willow for adults

Critical Habitat Designation A specific geographic area that is essential for the

conservation of a listed species and that may require special management and protection

At listing (after 1978, not retroactive) Takes into account ECONOMIC impacts

– Can be opted out if “non prudent” or not determinable• non-prudent can be for any reason

Numbers of species with critical habitat designated has increased steadily (2010 has 545 designations)

Is Critical Habitat Needed? USFWS argues “no”

– Sect 7 consultations already require fed agencies to avoid jeopardizing the species by modifying habitat

– Sect 9 prohibits take by the public, which has been equated with habitat destruction (Sweet Home)

But regulation of habitat by disallowing take is less absolute than designating Critical Habitat– requires “no likelihood of jeopardy” but critical

habitat cannot by “adversely modified”

Possible Improvements to Critical Habitat “Survival Habitat” (NRC)

– temporary designation at time of listing– habitat needed to support current population or

ensure short-term (25-50 year) survival, whichever is larger

– No economic evaluation goes into it– Allows management options to be preserved

until recovery plan and formal critical habitat is proposed

Habitat Conservation Plans

More likely to be the way habitat is protected on non-federal lands (rather than designation of critical habitat)

Allows non-federal landowners to get incidental take permit (Sect 10(a))– implementation of HCP “will, to the maximum extent

practicable, minimize and mitigate the impacts of such taking” and “not appreciably reduce the likelihood of survival and recovery of the species in the wild”

HCPs as a Solution to a Problem

Services view HCPs as a way to balance a citizen’s right to use their property with the nation’s interest in conserving rare and endangered species

Goal is to create “creative partnerships” between landowners wanting to develop their land and our natural heritage

Increase in HCPs

020406080

100120140160180200

No. of HCPs

90 91 92 93 94 95 96

San Bruno Mtn. Cal (1983) Over 200 in 1997, 200 more in

preparation Range in size

– 1/2 acre lot (Fl. Scrub Jay)– 170,000 acres

• Plum Creek Timber– 100 years, 285listed and unlisted

species

– 1.6 million acres• WA DNR

– 70-100 years, 200 species

The HCP Process (USFWS 1998)

Plan Development– permit application ($25)

– the plan

– document of compliance with NEPA

– implementation agreement

Review– service

– public (published in Federal Register)

Monitoring– service monitors compliance with HCP

Contents of HCP (USFWS 1998)

Species covered (listed and non-listed) Assessment of impacts of take How take will be monitored, minimized, and mitigated Plan for funding the proposed monitoring and

mitigation Alternatives to take and why they are not being

adopted Argument that taking will not reduce the species’

survival and recovery

Criticisms of HCPs (Minett & Cullinan 1997;

Kaiser 1997)

Not based on science– We need to know a lot about management of species to decide on

long-term management strategies

• PVAs of all species in plan

Not Flexible (esp. if “no surprises”)– Adaptive management framework that allows adjustment

as more information comes in• need a carefully designed and well funded scientific

management program for the ecosystem – that can be expensive, but costs are predictable

• Provide public funds for SURPRISES

More Criticisms (Minett & Cullinan 1997;

Kaiser 1997) Separate plans for single landowners results in fragmented

approach to conservation– not a problem if landowners hold large areas– can result in “high grading”

• first HCP gets by with as much as possible• subsequent HCPs have to conserve species given what is already

provided– they may have to provide more expensive habitat or curtain operations to a

greater extent than first planer

• plans rely on particular use of adjoining land– what if it fails?

Multi-owner (regional) HCPs would be better

More Recent HCP Evaluation

The National Center for Ecological Analysis and Synthesis reviewed many HCPs and their results echo those previously mentioned

View their report here to better understand HCPs and evaluate their scientific validity

NCEAS evaluation of HCPs

Kareiva et al. online here

43 focal plans, from 1997 and earlier

Types of Mitigation

How Well Was Each Step Analyzed?

HCPs are not Recovery Plans Another criticism is that HCPs often do little for the

listed species– Requirement is that plan MINIMIZES and MITIGATES take

• they do not have to contribute to RECOVERY

• alternatives easily dismissed

– Rota’s proposed HCP would take 1/2 of Mariana Crow’s habitat!

– Balcones Canyonlands HCP (Texas) provided 12,000 ha, but science report called for 53,000 ha

• black-capped vireo is likely to go locally extinct

Limited Public Participation A serious criticism from environmental organizations

– Years of negotiation between service and landowner prior to review

– Service does not have to use public comments obtained during review when making their final decision

– Too much invested in negotiations to change after public comments

– Environmental organizations are out of loop and don’t like it

Making HCPs Better (Kaiser 1997)

Require plan to boost, not reduce, populations of listed species

Initial plan developed by scientists with no vested interests in planning area

Wait for recovery plan before HCP is approved– allows range-wide coordination of efforts

Allow for adjustment even with “no surprise”– public funding for surprises

– good monitoring and adaptive response

An Example of a “Good Plan” (NRC and Kaiser 1997) California’s Natural Community Conservation

Plan• southern coastal sage

– Regional• provides protection for more than just listed (gnatcatcher)

species so future plans are less likley

– Blueprint drafted by panel of independent scientists• functioned as interim plan• pointed out needs for research on dispersal, demography,

genetics, autecology before final plan

Interim NCCP Directions Slow development (<5% of native landscape) No net loss of habitat VALUE

– Stick to tenets of conservation biology• increase species distribution• large, aggregated, non-fragmented, interconnected, roadless

blocks of habitat are best

– Rank habitat according to tenets• best habitat is managed as reserves• secondary priority is conferred on moderate habitat adjoining

reserves

References Minett, M. and T. Cullinan.1997. A citizen’s guide to HCPs.

National Audubon Society. Washington DC. USFWS. 1998. Www.fws.gov/r9endspp/hcpplan.html Kaiser, J. 1997. When a habitat is not a home. Science 276:1636-

1638. Bormann, FH. And GE Likens. 1979. Catastrophic disturbance

and the steady state in northern hardwood forests. Am. Scientist 67:660-669.

Doncaster, CP, Clobert, J, Doligez, B, Gustafsson, L, and E. Danchin. 1997. Balanced dispersal between spatially varying local populations: an alternative to the source-sink model. Am. Nat. 150:425-445.

More References Levins, R. 1969. Some demographic and genetic consequences

of environmental heterogeneity for environmental control. Bull. Entomol. Soc. Am. 15:237-240.

Stacey, PB. And M. Taper. 1992. Environmental variation and the persistence of small populations. Ecol. Appl. 2:18-29.

Pulliam, HR. 1988. Sources, sinks, and population regulation. Am. Natural. 132:652-661.

Doak, DF and LS Mills. 1994. A useful role for theory in conservation. Ecology 75:615-626.

Botkin, DB. And MJ. Sobel. 1975. Stability in time-varying ecosystems. Am. Nat. 109:625-646.

More References

Yong, W., Finch, DM, Moore, FR, and JF Kelly. 1998. Stopover ecology and habitat use of migratory Wilson’s Warblers. Auk 115:829-842.

Van Horne, B. 1983. Density as a misleading indicator of habitat quality. JWM 47:893-901.