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Wildlife Book (2003) - Bolen and Robinson
Updated 16 November 2009
Wildlife Biology - Chapter 11- Wildlife and Water
water -- 97% in ocean
2% in glaciers
<1% in aquifers, rivers, lakes
some properties of water:
- high heat capacity - can absorb lots of heat without getting much warmer (only liquid
ammonia has a greater heat capacity - so ammonia-based compounds are often used
in refrigerators, air conditioners
- water comprises high percent of body weight - helps to stabilize body temperature
- water is universal solvent
some other fun facts about water:
- water may affect carrying capacity of environment; too many/too few nutrients; raise/lower
water table; carry diseases, pollutants
- closed watershed - salt builds up especially when evaporation exceeds precipitation (Great
Salt Lake- Utah; Dead Sea of Israel) (Kenya- when the traditional breeding area flooded,
moved to Lake Magadi – this shallow lake with no outlet caused salt rings to form around legs of
young flamingos (see page 201 for picture)
Some Ecological Influences of Water
light penetration into water influences aquatic vegetation (erosion, wave action, water depth,
water clarity are involved)
high turbidity - may affect vegetation (carp contribute to turbidity)
water - cuts valleys, produces oxbow lakes (see page 203)
mountains - rain on one side; dry on other (called a “rainshadow” on dry side)
glaciers - contributed to making many prairie potholes (waterfowl breeding habitat)
sedimentation - builds up deltas - waters are usually very nutrient-rich
Water, Distributions, and Isolation
Wallace’s Line - zoogeographical boundary coinciding with a deep trench in the seabed between
islands of Bali and Lombok in East Indies (page 205) faunal barrier even when
sea levels were lowered during glacial ages of Pleistocene
some waterways prevent faunal dispersal, others allow dispersal; animals sometimes “raft” to
other areas; ice bridges - allow dispersal (Isle Royale - wolves came across Lake Superior- prey on
resident moose population- L.David Mech is famous for his research on this)
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isolating mechanisms (such as water) - can lead to “adaptive radiation” - e.g., Darwin’s finches
Water and Wildlife Populations
prairie potholes - produce about 50% of the ducks available for hunting; water is sometimes
seasonal - may become dry during a drought - results in fewer offspring-- the
July Pond Index assesses the availability of prime breeding habitat for ducks
(plot # breeding ducks against July ponds available the previous year)
bobwhite quail - (famous studies by Stoddard 1931; Klimstra and Roseberry 1975) - seem to
be sensitive to rainfall; drought-fewer birds (see page 208 for details) (other
things may also be involved - studies with several kinds of quail - higher
temperatures associated with drought may also be involved)
wild turkeys, jackrabbits - also affected by rainfall
Physiological and Behavioral Responses
drought - quail - carotene (precursor to Vitamin A) is usually found in green foliage;
drought - less carotene - no trigger for reproduction
phytoestrogens - food in plants that grow in drought conditions - can inhibit reproduction in
California quail
Australia - seasonal flooding - stimulates fish breeding (temperature is also involved);
grey teal - breeding occurs in response to rising water levels
Africa - wildebeest - major movements of herds go towards areas of rainfall (they think they
see the dark cloud columns and follow them)
ways to conserve water:
- metabolic water (kangaroo rats)
- efficient kidneys
- behavioral patterns (sand grouse males carry water to young with specialized abdominal
feathers)
- some sea birds - nasal glands get rid of salt
snow - can influence range, movements, altitude, etc. of many species (caribou, moose)
ice - influences reproduction in harp seals
Water, Disasters, and Hard Times
winter drought - deer die-off
deep snow - ungulates die - too hard to get through snow to new food supplies; condition of snow
may also be factor (fluffy - hard to walk through while wet snow may develop a crust
- can walk along the top)
Reservoir Effect - in newly flood areas, impounded waters may be enriched by the sudden
incorporation of plant and soil nutrients- production at all trophic levels
usually increases
- happens in prairie potholes; seasonal flooding of riverbottom forests
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Reservoir Effect and Management
drawdown objectives- Robert L. Meeks (1969)
1. increase breeding habitat
2. control succession; increase emergents
3. provides mudflat for seeding of emergents
4. controls carp
5. can restrict muskrats
6. tends to release colloids in water - logged soil (analogous to nutrients from burn)
7. create emergent habitat that attracts ducks going South in winter (duck hunting)
new impoundments - usually lots of fish
wetland “drawdown” - seasonal drying of wetlands – used for controlling succession, producing
waterfowl food and cover plants, and interspersion of vegetation in
wetland (do some of this up at Lake Erie at Winous Point Hunting Preserve)
visual isolation – the more shore inlets – the better for breeding
Beaver, Water, and Wildlife - beavers make dams, flood area, and trees dieproduces nest cavities, fungi, wood-boring insects
- reservoir effect can increase fish populations
- beaver impoundments – often produce waterfowl nesting habitat
- old dams might be removed so as to allow new ones to be madesort of like a “drawdown”- allows nutrients to “recycle” - new
dam will produce a pond with higher productivity
Alligators and Marsh Ecology - once alligators dominated southern marshes; prominent in Everglades
- “gator holes” - overlie natural depressions in limestone floor of
Everglades; alligators clear vegetation from depression and
move debris to make a rim - this allows other kinds of plants to
grow in this higher area - increases plant diversity
- gator holes are small refuges of fresh water during dry winter
season - crustaceans, fish congregate here- establishes a food chain;
- congregation of food here supplies the wood stork with food for
its breeding season in the dry winter
- very interesting reading - pages 221-223
Oil, Water, and Birds Do Not Mix –
pollutants - agricultural chemicals, heavy metals, industrial wastes (polychlorinated biphenyls - PCB’s)
oil spills - size of spill, location, time of year all determine damage
- surface-active species like diving ducks or penguins are especially adversely affected
- kills birds - feathers lose insulative properties- get cold- increases metabolismstarvation; ingest oil during preening - toxic;
- also affects reproduction even if bird lives
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Water and Raw Sewage raw sewage - causes BOD (biological oxygen demand) to increase;
- DO (dissolved oxygen) decreases
- both caused by demands of an immense bacterial population
- stream usually recovers downstream
water treatment lagoons - often become waterfowl habitat (G. Maxson MS Thesis in Grand
Forks, ND); areas can be toxic if detergents accumulate, avian diseases are carried in etc.
Acid Rain - A Changing Environment
combustion of fossil fuels (especially coal) leads to chemical reactions in atmosphere-- acid forms
when sulfur dioxide (SO2 and nitrogen oxides (NOx) released from smelters, power plants, etc.
combine with atmospheric moisture
acid rain - lowers pH (neutral is pH 7; acid is <7, alkaline is >7; pH measures H+ concentration
- many lakes in Canada, Adirondack Mountains in NY, and northern Europe have been affected
- affects all levels of the food chain, but especially affects fish (e.g., brown trout)
- in fish, causes poor reproduction, reduced numbers and size, and demineralized fish
skeletons – results in deformities
- may change invertebrate species of a lake; thus affects waterfowl which feed on the
invertebrates
Water Developments and Wildlife irrigation - may displace birds adapted to semi-arid conditions and replace them with birds
adapted to agricultural conditions (starlings, sparrows)
reclaim wetlands - draining wetlands - especially prairie potholes - lose lots waterfowl breeding habitat
- Everglades
channelization - straighten out streambeds to reduce floods -- lose riparian habitat along the
banks
Welland Canal - (enlarged in 1932) - allowed sea lampreys access into the Great Lakes - sea lampreys
are parasitic on fish and devastated the lake trout fishing industry in the Great Lakes
Operation Gwamba - animals stranded by water from closing the Afobaka Dam in Surinam were
rescued and taken to shore
flood prevention lakes - make new waterfowl habitat; but in private ownership, so many are not
managed to their full potential
stock ponds - give some waterfowl habitat, but again, not usually managed for waterfowl
(increasing amount of shoreline, keep from freezing, better grazing practices - all
give better habitat)
wells, seeps, collecting aprons for wildlife water
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Wildlife and Water (Continued) - Wetland and Waterfowl Ecology
(these notes are not in your textbook)
wetlands - land where water table is at, near, or above the surface long enough each year to
promote growth of hydrophytes and the formation of hydric soil
hydrophyte - plant that lives in soil that is deficient in O2 because of the water level
xerophyte - plant rooted in substrate that will dry to the wilting coefficient at frequent intervals
(in desert areas)
mesophytes - plants which survive in conditions somewhere between those required for
hydrophytes and xerophytes
Ecological Systems:
1. marine (salt water) - major water bodies outside coastal regions with unobstructed access to open
ocean
2. estuarine - intertidal region where salt water meets fresh water (mixing of water)
3. riverine - fresh water rivers, streams (running water)
4. lacustrine - lakes
- open water greater than 20 acres
- rocky or hard shores (usually wave action to keep hydrophytes back;
no hydrophytes along the rocky shore)
5. palustrine - ponds (with marsh)
- no channel or wave-formed shore
- has floating and emergent vegetation
- less than 20 acres of open water
- substrate periodically exposed
Habitat Classes:
1. forested wetlands = swamp (wetlands with trees)
2. shrub wetlands - wetlands with shrubs (woody bushes)
3. emergent wetlands - wetlands with cattails, bulrushes, etc.
(herbaceous vegetation above the water level)
4. floating-leaved beds - wetlands with water lilies, floating-leaved pondweeds
swamp - wooded wetland
marsh - wetlands where hydrophytes are not woody plants: mainly submergent and emergent
aquatic plants: 6” to 3 feet of water- may or may not be there year around: can be very
dry at times: usually fibrous mat of roots and rhizomes in shallow areas
Major Flyways: Atlantic, Mississippi, Central, Pacific (see attached sheet)
(migratory paths for waterfowl)
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Wildlife in Wetlands:
1. Mammals - deer, bear, muskrats, beaver, mink, opossum, raccoons
2. Birds - ducks, geese, swans, shore birds, herons, bitterns, gulls
Class Aves = birds
Order Anseriformes = Waterfowl
Family Anatidae = ducks, swans, geese
Subfamilies:
a. Cygninae = swans
b. Anserinae = geese
c. Anatinae = surface-feeding ducks (dabbling ducks)
d. Dendrocygninae = tree ducks
e. Aythyinae = bay ducks and sea ducks (diving ducks)
f. Oxyurinae = stiff-tailed ducks
g. Merginae = mergansers
A few details about some important waterfowl species:
Surface-feeding ducks- dabble in shallows of fresh and salt-water marshes: are surface-feeders
and most do not dive: agile fliers that take off nearly vertically: male and female
have different plumages: most have a bright distinctive rectangle of color (the
speculum) on the hind edge of each wing: chiefly vegetarians- eat some
mollusks, insects, and small fish
e.g., mallard, black duck, pintail, gadwall, American widgeon, shoveler,
blue-winged teal, cinnamon teal, green-winged teal, wood duck
Diving ducks (bay ducks) - they dive from surface and swim underwater: heavy birds that run
along the surface as they take off: they eat more animal food than surface-feeding
ducks: often winter in protected coastal bays and river mouths.
e.g., redhead, canvasback, ring-necked duck, lesser scaup, common goldeneye,
bufflehead
Stiff-tailed ducks - small and stubby, with a short thick neck: in swimming, the tail is often held
up at a jaunty angle: they dive and sometimes sink slowly, as grebes do.
e.g., ruddy duck
Mergansers - fish-eating diving ducks with a long thin bill serrated on both sides: flight is rapid
with body held very straight and horizontal: all 3 N. American species have a white
wing patch, and all except the male Common show a crest.
e.g., common merganser, red-breasted merganser, hooded merganser