Wildlife Management- Exam 2

Woodlot Management

• Managed forests (public)- fiber production important consideration

• Woodlot- small (<100 ha) forest fragment in area converted to other land use (private ownership)

• Wildlife generally main objective for most woodlot owners

General Woodlot Considerations

• Interior spp seldom occur in woodlots unless adjacent to larger forest tracts

• Management of woodlots = management for edge spp (edge effect often extends throughout woodlot)

• $ for management often limited

• Woodlot should be viewed as part of surrounding area

• Avoid invasive spp- invasive spp of concern include:

  • Buckthorn

  • Garlic mustard

  • Spotted knapweed

General Mgmt Treatments that Benefit Wildlife in Many Woodlots

• Selected tree harvest to release best mast trees & shrubs

• Creating snags and logs

• Plantings (game mixes, apple trees, alfalfa, etc.)

• Construction of a farm pond

• Exclusion of cattle

• Creating openings for forbs/grasses (if woodlot big enough)

Inventory and Planning in Woodlots

Existing Habitat Inventory

• Types and amount of each available

• Wildlife spp (densities) supported by each

• Spp (densities) desired

• Can existing habitat be improved/modified to meet goals?

Develop Plan- completed should include:

• Landowner objectives

• Inventory and arrangement of plants (important individuals), plant communities, wildlife spp

• List of any plants needed for plantings and procedures for planting and maintenance

• Timber harvest methods and improvements

• Plant to protect from/deal with livestock grazing, fire, insects, disease, etc.

  • Ex. Oak Wilt

    • No cutting/wounding Apr 15 - 1 Oct

    • Trenching around infected stands

    • Removing infected stands

• Other treatment required- burning, lime, etc.

Divide Woodlot

• Woodlot divided into compartments (similar veg spp/age classes, soil types, topography, etc.)

• Should have easily identified or marked boundaries

• Inventory records and management prescriptions should be maintained by compartment

Covert

Junction of 3 or more desirable habitat types- best provide food, water, and cover

• Coverts should be provided in plan

  • 2 habitat types generally there by default

  • 2 age classes of trees bordering field = covert

  • Field, pond/stream, woodlot = covert

Woodlot Cutting Considerations

• Small area may mean no cutting is best

• $ return may be low

• Wildlife improvement nature of the cut should be indicated in contract (selection cuts)- local DNR/conservation district forester can help

• General Guidelines

Woodlot Cutting Considerations: General Guidelines

• Shelterwood cuts best 0.04-0.4 ha (double height of trees)

• Border trees should be left

• Leave stumps and allow sprouting

• Establish patchwork of age/spp classes

• No cutting in riparian areas

Additional Woodlot “Pieces”

Evergreens/Conifers- provide thermal cover

• 0.8-2 ha (clumped)/40 hectares of deciduous trees

• Planted along edge of field

• Shade tolerant spp can be underplanted

Mast Trees- should be maintained and “freed” from competition for sunlight

• Oak, hickory, beech, walnut, cheery, ash, butternut

  • Red/Black oaks produce acorns every 2 years, white oaks every year (less tannins)

• Aspen, birch, hazel, alder produce catkins

• Additional mast producing spp

  • Rubus spp (raspberry)

  • Blueberry

  • Grapes (female)

  • Elder berry

  • Spice bush

  • Etc.

Food Plots

• Need dependent on woodlot and surrounding area

• Veg spp composition depends on wildlife spp desired

• Unharvested strips in ag fields adjacent woodlot work well

• Many ag crops beneficial to wildlife

• Strips maximize edge

• Many commercial mixes available

“Special” Forest Features

• Openings

• Course Woody Debris (CWD)

“Special” Forest Features: Openings

• Natural- permanent

• Constructed- permanent or temporary

• Maintain 1-5% of forest in openings dependent on wildlife spp desired and size of forest (not needed <100 ha)

• Opening <10% trees and <30% brush, mainly grass and forbs

• Forb- herbaceous flowering plant that is not a graminoid (grass, sedge, etc.), normally broad-leafed

• Creating/Maintaining Openings

  • Maximize location

  • Minimize creation effort

  • Minimize maintenance effort

    • Mowing

    • Herbicide

    • Grazing/Browsing

    • Fertilizing

“Special” Forest Features: Course Woody Debris (CWD)

Dead logs, limbs, bark, etc on forest floor

• Important to various spp of wildlife

  • Marten

  • Grouse

  • Herps

  • Small mammals

• Amount needed and type varies

  • Maintain approx what would occur in “natural” setting

  • Removal of too much decreases habitat quality

  • Leaving too much increases fuel load for fire

Components of Developing Stand Prescriptions (Mgmt Plans)

• Species Background 

  • Plant and animal spp intended for this stand/property

  • Habitat needs of these spp

  • Over what scale must habitat needs be met (nesting sites, foraging patches, home ranges, etc.)

• Current Stand Conditions- habitat conditions for species of interest

  • Tree and shrub spp composition

  • Stocking rates (dbh, density of trees, etc.)

  • Site index (soil quality, growing conditions, etc.)

  • Existing/Future regeneration

  • Estimate/Quantification of habitat suitability

  • Factors limiting habitat suitability for spp of interest

• Desired Future Conditions

  • Be specific (spp composition, stocking rates, age classes, etc.)

• Management Actions to Achieve Desired Conditions

  • Be specific (should be a “cookbook”)

  • How long will it take?

  • How long will it last?

  • Cost?

• Monitoring Plans- what will you measure/how will you measure it to evaluate plan success?

• Budget- cost of implementation and monitoring plan

• Schedule/Timeline- when will management and monitoring actions take place?

• References- provide context of why decisions were made

Management Plan Case Study: Species Background

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• RC Woodpecker- associated with old yellow pine forests with abundant red heart disease (fungal)

  • 25-100ha home range based around nest tree

  • Clan social structure with nest helpers

  • Diet- insects and fruit

  • Forage in trees >60 years old and >25cm dbh

  • Nest trees >100 years old and >100cm dbh

  • Nest in live trees (avoid snags)

  • Make shallow excavations around nest cavity opening → sticky resin ring → rat snake barrier

  • Stand around nest tree dominated by pine (mean 16m sq ba) with a few (1.1m sq ba) midstory pines

  • Clan size, density, and productivity related to ground cover composition and pine regeneration

    • Productive ground layer, minimal pine regen (local fire history maintains)

• Bachman’s Sparrow- associated with mature pine woodlands- well-spaced pines, open midstory, dense grass/forb understory (ground nester)

  • Burning initiates/maintains grass/forb understory

  • Pops disappear 4-5 years after burn

• Brown-headed Nuthatch- associated with pine stands

  • 3 ha home range

  • Nest in cavities in pine snags >20cm dbh

  • Forage on live pines

  • Most often found in open, mature, old-growth pine forest with snags where natural fire patterns exist

Management Plan Case Study: Current Stand Conditions

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• Has shrub layer, but little overstory regen

• Hardwoods indicate no recent burns

• Adequate fuel load for a fire?

• Potential foraging site for RCWP

• Not nesting site- stocking too high, hardwoods in midstory, trees not old enough for heart rot

• Too little grass forb layer for BS

• Good BHNH habitat (especially if snags present)

Management Plan Case Study: Desired Future Condition

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• Trees >100 yo (disease)

• 16 ≤m² BA (grass/forb understory)

• A few mid story pines, no hardwoods

• Reestablish longleaf pine (LLP)

• Presence of snags

Management Plan Case Study: Management Actions 2015 - 2035

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• Group selection (LLP) stands or irregular shelterwood (loblolly - shortleaf pine stands (SLP)) cuts

• 2015- Irregular Shelterwood Cut

  • Leave 25 loblolly pines/ha (8m²/ha), cut all hardwoods

  • Site prep- cool winter burn

  • Plant 250 LLP seedlings/ha

  • Allows natural regen of loblolly and SLP

  • After 3-5 years begin spring burns every 2-3 years to control hardwood, SLP regen, and brownspot disease

    • LLP resistant to low intensity burns

• 2025- basal area lower than pre 2015 (LLP regen)

  • 20 mature pines/ha (future nest trees) and high density pine regen

  • Burning- increased BS habitat

  • 5 snags/ha- BHNH nesting trees

  • Maintain burning regime

• 2035- overstory loblolly and regenerating LLP showing increased growth

  • RCW foraging habitat, BS, BHNH habitat

  • Potential need for light overstory thinning (10% canopy removal) and/or precommercial thinning of saplings, seedlings…

Management Plan Case Study: Management Actions 2045 - 2065

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• 2045- if regen of LLP not adequate (BA/density?), create gaps and plant seedlings, maintain BS habitat

• 2055- Precommercial Trimming

  • Remove 25-50% of regenerating pines to maintain grass forb layer and provide growing space for pine seedlings

• 2065

Management Plan Case Study: Management Actions 2075 - 2125

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• 2075- begin group selection cuts (10-15 year cycle) to maintain trees in all age classes

  • Maintain old/”original” loblolly pine (now old/large enough for RCWP nests)

• 2125- BA nearly target of 16m²/ha

  • LLP- 80% (density), 50% (ba)

  • Original loblolly pines >60cm dbh, >150 yo

  • Grass forb layers persists due to burning

  • Natural snags adequate for BHNH nesting

Management Plan Case Study: Monitoring Plans

7 ha pine stand, management for red cockaded woodpecker USFS in LA

• Implementation

  • Were unmarked trees harvested?

  • Were burns conducted in the correct season?

  • Were cuts conducted in the right cycle?

• Effectiveness

  • Vegetation Growth, Survival, Structure, etc.

    • 10-20 random circular plots to monitor seedling survival for first 5 years

    • 10-20 permanent plots (fixed or variable radius) to monitor tree growth, ba, density, species composition, snags, understory

    • Monitor every 5-10 years

  • Wildlife Use

    • RCWP nest tree survey every 5 years (search for resin marks on trees)

    • Bird point counts every 5 years

    • 3-5 survey points, visit 5 times early mornings in breeding season

    • Record all birds heard or see with estimate of distance to bird

    • Potential nest searches for BS and BHNH

Dead Wood Management

• Trees (snags) continually decay

• Different age trees and snags provide habitat elements for different species

• Continuous supply of “new” snags must be available

• Up to 40% of bird species in forests are cavity nesters

3 Broad Types of Dead Wood “Users”

• Primary Cavity Users

• Secondary Cavity Users

• Log Users

Primary Cavity Users

Excavators, create cavities

• Almost always excavate fungi softened areas of trees

• Generally excavate in ≥ 10cm/4in dbh

• Generally excavate new nest cavity each year

• May excavate cavities for roost/rest

• Most feed on woodboring insect larvae

• Biggest/most important group in MI is woodpeckers

Secondary Cavity Users

Cavities from natural decay or primary excavators

• Opportunistic Cavity Users- benefit from cavities

  • Ex. Black bears, raccoons, peromyscus, invertebrates, some bat spp

• Obligate Cavity Users- require cavities as a resource for something (reproduction, thermal cover through winter, etc.)

  • Ex. Wood duck, tufted titmouse, flying squirrels

Log Users

Cavities, space underneath & between bark and wood in logs provide cover, nesting, foraging, display sites

• Interior of hollow logs and area under them provide stable, moist microclimate (important for herps)

• Importance of Log Size

  • Area/Volume available (4in min)

  • Persistence

  • Size of cavities/spaces beneath

Number of Cavities Used

• Number used by individual varies widely by spp

  • Most bird species use new cavity for each clutch/brood

  • Mammals often use multiple cavities in a breeding season or year

  • Cavity may be used by multiple individuals at diff times

Other Factors Influencing Value of Logs to Wildlife

• Piece Size and Decay State

  • Wildlife species prefer different sizes & decay states

  • Longer pieces provide connectivity

• Successional Stage in Which Log Occurs

  • More valuable when scarce

  • Suppression mortality → most dead trees 50% (but similar length) dbh of dominant trees

Dead Wood Recruitment

Driven by:

• Suppression Mortality (Competition)

  • Increases after stand initiation, then declines

• Disturbance

  • Big pulse, drop off then slight recovery as trees age

Species of Tree Influences Density of Snags and Rate of Decay

• Conifer stands → more snags than hardwood

• Hardwoods (generally) decay slower than conifers

  • Aspen may live 125 years, stand as a snag for 35, exist as log for 35

  • Oak may live for 300 years, stand as a snag for 75, exist as log for 75

• Fall rates vary- 10 year fall rates for some snag species of snag >50%

Management of Cavities and Dead Wood

Two approaches:

• Maintain Conditions Within Historical Range of Variability (HRV)

  • Density, size, decay conditions, etc. of snags, logs, etc. maintained at “normal” levels

  • Conduct at larger scale than stand level- at least forest compartment level

• Establish/Estimate functional relationships between animals and dead wood → manage for levels that meet wildlife needs

Steps in Management Process

(Don’t need to memorize)

Live Tree Cavity Management

• Managing for primary cavity users generally doesn’t provide enough cavities for secondary cavity users

  • Some larger than primary users

  • More species → often occur at higher density

  • Nest boxes offer short term (expensive) solution

• Managing live tree cavity abundance is more challenging than dead wood

  • Harder to inventory

  • Rate of gain/loss unpredictable

  • Generally larger trees with signs of injury (limb loss) more likely to have cavities

• Arrangement/Distribution of dead wood/cavity trees should also be considered

  • May not mesh with most efficient harvest methods

• Monitoring should be conducted just like in any other aspect of management

Woody Vegetation/Brush Removal

• Change structure

• Remove species (often invasive)

• Grassland/Opening creation/maintenance

Physical Removal Techniques

• Hand Cutting- usually requires herbicide treatment for deciduous species; usually small scale

• Bulldozing- tends to pull roots up so no suckering, can be bad for soil

• Masticator/Forestry Mulcher

Herbicide

• Various regulations on commercial application (vary by location)

• Two Main Types

  • Glysophate (Roundup)- both herbaceous and woody

  • Triclopyr (Garlon, Element, etc.)- woody

Herbicide Oil Mixes

Both herbicide types normally (necessary for basal bark spray) mixed with oil to promote sticking to surface of treated plant

• Nuclear Options- work well but bad for environment

  • Diesel

  • Kerosene

• More Environmentally Friendly Options

  • Bark oil

  • Vegetable oil

  • Mineral oil

  • Methylated seed oil

  • Crop oil concentrate

Herbicide Application Methods and Sprayer

• Application Methods

  • Foliar spraying

  • Basal bark/band spraying

  • Stump treating

  • Drill and fill- hack and squirt

• Sprayers

  • Backpack

  • Hand

  • Daubers

Basal Bark/Band Spraying

• Target tree size- <6 in dbh

• Bark thickness is the more critical issue

  • Smooth, thin bark = easier to penetrate

  • Ridged, plat park = tougher to penetrate

Extreme Trees Diseases in MI

• Beech Bark Disease

• Emerald Ash Borer

• Hemlock Woolly Adelgid

• Oak Wilt

Beech Bark Disease

• Initial infection by Cryptococcus fagisuga- sap feeding insect

• Allows infection by Nectria coccinia- fungus that girdles tree

  • Gets into vascular tissue (xylem and phloem)

• Insects can be treated with insecticide- only small scale (time and effort)

• 3% of beech trees are resistant

  • Can use these trees to (re)populate stands

• 32 millions beech trees, 2.5 million killed

Emerald Ash Borer

• Invasive wood-boring beetle whose larvae burrow in and feed on phloem and girdles tree

• Larva leave D-shaped holes in tree

• Don’t spread widely on their own

  • Spread(usually in larval stage) through wood products

• Kill the main trunk but roots still viable so sprout can occur

Hemlock Woolly Adelgid

• Invasive aphid-like, sap feeding insects drain tree nutrients and preventing the production of new buds/needles 

• White fuzz = waxy wool-like protective masses secreted by females for both adults and eggs

• Tree death in 4-10 years

• Natural and human spread

• Can be treated with insecticide- only small scale (time and effort)

Oak Wilt

• Fungal disease that clogs vascular tissue, functionally girdling the tree from the inside

• Spread by sap-feeding/picnic beetles, which are attracted by fresh wounds

  • Also spread by grafted roots of infected trees

• Once it gets under the bark, the fungal matt begins and girdles tree

Potential Diseases

In the US but not in MI

• Asian Longhorn Beetle

• Thousand Cankers Disease

• Spotted Lanternfly

Asian Longhorn Beetle

• Kills maple trees by boring deep tunnels through the wood and destroying vascular tissue/structural integrity

  • 1.5 billion maples in state- so would be very bad

Thousand Cankers Disease

• Kills walnut trees through walnut twig beetles tunneling into bark to feed/reproduce and transmitting fungus that infects phloem

• Fungus creates small localized cankers around each beetle entry and exit hole

Spotted Lanternfly

• Infects various ag crops and tree species

• Damage from feeding and mold growth on feces

  • Promotes fungal infection

• Has been detected a few times in MI

• Love tree of heaven

Values of Wetlands

• Biologically productive and heavily used by wildlife

• Required component of many vert and invert life cycles

  • Waterfowl- game species (= funding) 

  • Amphibians

  • Invertebrates- provide food for all sorts of spp

• Economic value to humans

  • ⅔ of fish and shellfish spp commercially harvested associated with wetlands of some sort

  • Reduce flooding- help buffer when flood happens, absorbing much of the water

    • Riparian zones, floodplains, mangrove swamps

  • Improve water quality

  • Provide recreation sites- good for $ (hunting/fishing)

55 Technical Types of Wetlands

Based on below classification scheme (categories and subcategories)

• Wetland Categories

  • Marine

  • Estuarine

  • Riverine

  • Lacustrine

  • Palustrine

• Wetland Subcategories- based on:

  • Hydrologic Regime- when, how deep, variability

  • Substrate Type- soil

  • Water Chemistry

  • Vegetation

Marine

Open ocean

Estuarine

Semi-enclosed by land, but influenced by open ocean (river mouth, etc.)

• Where freshwater and ocean water mix

Riverine

Within channel generally along river/stream

Lacustrine

In depression or damned river channel (lakes)

Palustrine

Stereotypical wetland (marshes, swamps)

Common Wetland Categories Used by MI DNR

Each type of wetland potentially supports diff wildlife spp and needs diff management strategies

• Marshes

• Swamps

• Bogs

• Fens

Marshes

Standing water < an inch to several feet deep, can fluctuate seasonally or from year to year

• “Flooded grasslands”

• Dominated by herbaceous veg- might be some trees/woody veg but not lots

• Common Veg- cattails, grasses, sedges, rushes, arrowhead, pickerel weed, and smartweed

• Common Wildlife- fish (not always, need year round standing water), water birds (ducks, geese, herons, cranes, rails), song birds (marsh wren and yellow warbler), frog species, reptiles (turtles, water snakes), muskrats (like open water), beaver (less common), like woody veg), and otter (also less common)

  • Some spp more general, other more keyed in to specific habitat

Swamps

Flooded woodlands or shrublands, more likely to be flooded year round

• Dominated by shrubs in MI but all swamps are dominated by woody spp- some herbaceous but only flood-tolerant adapted

• Common Veg- red and silver maple, cedar, balsam, willow, alder, black ash, elm, and dogwood

• Common Wildlife- wood frogs, gray treefrogs, salamanders, barred owls, waterthrushes, prothonotary warblers, water shrews (big back feet with hair, can run across still water), and raccoons

  • Some spp more general, other more keyed in to specific habitat

Bogs

Accumulations of decaying veg form mats that fill in old ponds or kettle lakes

• Rare = species here are of high conservation concern

• Open water may be surrounded by floating veg, others are totally grown over and consist of spongy, waterlogged peaty soil covered by sphagnum moss

• Bog soils are usually highly acidic, and oxygen and nutrient deficient- leads to distinct veg community

  • High acidity = low decay rate = wet dead veg mat = more acidic

• Common Veg- labrador tea, poison sumac, tamarack and black spruce, orchids, insect eating sundews and pitcher plants (carnivorous plants)

• Common Wildlife- spotted turtle, southern bog lemming

Fens

Bogs that are less acidic (calcium soils)

• Rarest 

• Common Veg- prairie plants- prairie white fringed orchid, sweet grass, the bluestems, and blazing star

• Common Wildlife- EMR, butterflies such as Mitchell’s satyr and the Powesheik skipper

Functioning of wetland from wildlife perspective based on 3 components:

• Hydrology- amount and timing of water determine nearly everything else

• Vegetation- food and cover (for wildlife and invertebrates)

• Macroinvertebrates- food especially for young animals

  • Abundance/Diversity primarily determined by hydrologic cycle, veg, and water chemistry/quality

Wetland Management

Requires understanding interrelationships among habitats and resources needed by wetland wildlife to survive and reproduce

• Wetland function

• Requirements of spp being managed

• Successfully managed wetland mimics naturally occurring wetlands

• Natural wetlands are often best managed passively

  • Passively = monitoring, maybe invasive species or brush removal (depending on goals)

• Since so little natural wetland remains, much management deals with wetland restoration

Wetland Restoration: MI Figures

• Originally 11 million acres of wetland (⅓ of state)

• Currently 35% lost statewide- losses in southern MI greater, some counties > 75% lost

3 Requirements of a Wetland

• Hydrology

• Hydric Soils

• Wetland Vegetation

Requirements of a Wetland: Hydrology

Water at or near surface during at least part of the year (saturated soil or above ground, standing H2O)

• Returning water to area is most common method of wetland restoration

Requirements of a Wetland: Hydric Soils

Developed under saturated conditions

• Hold water for at least part of year

• Difficult to artificially create and take long periods to develop → wetland restorations only feasible in areas with hydric soils

  • Can return water but won’t work if soil isn’t holding it → no water for veg

Requirements of a Wetland: Wetland Vegetation

Adapted to grow in wet soils/water

• Seeds of many wetland plants are viable for decades

USFWS Partners for Fish and Wildlife Program

• Technical expertise and some funding for habitat improvement on private (and tribal) lands

• “Assist with projects in all habitat types which conserve or restore native veg, hydrology, and soils associated with imperiled ecosystems”

  • “Imperiled ecosystems” usually = wetlands

• Federally funded- funding probably cut

Michigan Wetlands Reserve Program

“To provide a wide diversity of high quality wetland, and associated upland as habitat for migratory birds and wildlife”

• Provides some funds for restorations, may pay farmers to convert (restore) marginal cropland into wetland

• Emphasizes partnerships- encourage donations and work with land owners and communities

• Easements and Restorations

Easement

Piece of language attached to a deed or property that adds a condition/restriction/privilege

• Attached to deed- legally binding forever (cannot be changed by new owner)

• Protects management decisions outside of actual property owned or if sold

• Owner may get $ or lower property tax

• Ex. Can’t develop certain area on property (left as wetland/“wild”)

  • “Can’t develop”- usually best practice

  • Land owners responsible

  • Org that put easement must monitor yearly

Mitigated Wetland

Restored wetland that was restored to compensate for the loss/degraded of another wetland

Drain Tiles

Structures that collect rain and routes it to drainage ditches which flow to stream/river; largely how wetlands drain

• In a restoration, need to be broken/removed so water starts to accumulate again

• Effort to remove/break depends on tile amount/depth, etc.

• Usually have to be found by probing the earth

Reservoir/Impoundment Management (Waterfowl)

• Water level management yearly and within year (seasons)

• Nesting area management

  • Meet water level, cover, and food populations for various waterfowl spp

• Invasive spp control

  • If herbicide gets into water then it gets into whole wetland system- must use specific formulations, etc

• Which areas open to hunting

  • Accessibility for hunters

  • Zones → # hunters in a zone

• Crop damage control

Reservoir/Impoundment Management (Waterfowl): Water Level Management

• Accomplished using water control structures that allow control of water levels in reservoirs throughout the year

• Build up of decaying aquatic veg leads to flocculant bottom → nutrients tied up → difficult for new veg to get established

  • Flocculant bottom- muck of partially decayed organic material that is not yet soil

• Drawing down water lets bottom dry out and decay (get firmer) → releases nutrients → flush of new veg

  • Provides mud flats used heavily for feeding

Reservoir/Impoundment Management (Waterfowl): Crop Damage Control

• Creation of mud flats and pulse of vegetation growth aids in lessening crop damage

• “Lure” Fields- planted by management agency to keep birds out of farm fields (essentially food plots)

• Noise Makers- propane cannons

  • Other hazing methodologies also employed

  • Try to scare birds out

  • Only effective short term

Water and Wildlife: Impacts (of Precipitation) on Reproduction

• Cottontails higher March and September → lower hunter harvest that year (Applegate and Trout 76)

• 50% of North American waterfowl produced in prairie pothole region → most ponds are ephemeral

  • Drier years mean less ponds for breeding- July Pond Index (Crissey 1969) used to estimate amount of breeding habitat for ducks

• Bobwhite quail “boom or bust” years determined by amount of late-spring early summer rainfall (more is better- Stanford 72)

• Wild turkey egg production influenced by preceding late summer/fall precipitation in TX (Pattee 80)

• Early spring rainfall reduces most gallinaceous spp chick survival

• Mechanisms are generally either direct (starvation, reduced growth, etc.) or evolutionary

  • Energy invested in laying/incubation is wasted if there is insufficient food for chicks