Transcript Document 7223808

Wetland Mammals:
Species and Their Roles
in Aquatic Ecosystems
By Patrick Gaskin
Wetland Fuctions and Values
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Hydrological
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Geochemical
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Natural Filters
Biological
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Help control floodwater and erosion
Contribute to aquifer and groundwater recharge
Provide habitat for fish and wildlife
Socio-economic
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Support timber production
Support shellfish production and aquaculture
Provide water sources for irrigation
Provide recreational opportunities
Aesthetic values
Examples of Various Wetlands
Wetland use by Mammals
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Feeding
Shelter
Source of drinking
water
Importance of Mammals to
Wetlands
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Beaver dams flood
surrounding land
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Enhance habitat for a
variety of wildlife
Reduce water velocity and
erosion
Reduce the peak and
frequency of flooding
Liberates fertile substrate
at the abandonment of
dam or draining of pond
Economic Value of Wetland
Mammals
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Many types of wetland mammals are
harvested
 Sport
hunting (deer, raccoons, etc.)
 Fur-trapping (mink, beaver)
The Origin of Mammals
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Cotylosaurs- Stem reptiles
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Named for their cup-shaped vertebrae
First appeared in the Pennsylvanian Times
Anapsid skull type, with no temporal openings on
side of head
Pelycosauria
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Also of the Pennsylvanian Times
Had a synapsid type of skull
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With one temporal opening on either side of the head
Almost to Mammals
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Therapsida- Mammal-like
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Had many advances over the stem reptiles, closer to
mammals
Double occipital condyles in the skull
 Thecodont-type teeth
 Heterodont dentition
 Vertical posture of limbs
 Secondary palate present
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On to Mammals
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General Characteristics
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Homeothermic
Usually viviparous birth
Young nourished by milk from mother
Vertical limb posture
Often covered with hair/fur
Thecodont teeth with heterodont dentition
Terrestrial and aquatic
One group (bats) can fly
Others have membranes between limbs that allow them to
glide (flying squirrels and sugar gliders)
Classification of Wetland Mammals
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Kingdom- Animalia
Phylum- Cordata
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Sub-phylum- Vertebrata
Class- Mammalia
Orders- Artiodactyla, Insectivora, Rodentia,
Lagomorpha, Carnivora
On to the Representatives
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Order Artiodactyla
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Family Cervidae
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Moose (Alces alces)
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Large North American Ruminant mammal
Very large, flattened antlers
2.5 to 2.7 m in length, stands over 2 m at shoulder
550 to 700 kg
Relatively poor eyesight
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Behavior
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Moose are browsers
Feed on aquatic vegetation (esp. horsetails and pondweed)
 Ruminants
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Four-chambered stomach
Regurgitate swallowed food to be chewed at a later time
Excellent swimmers
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Can swim up to 6 mph
Order Insectivora
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Includes two Families:
Soricidae- the shrews
 Talpidae- the moles
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Family Soricidae
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Arctic shrew, masked shrew, Pacific shrew,
Pacific water shrew, smoky shrew, and water
shrew
Small, mouse-sized insectivores
 Throughout most of North America
 Feed primarily on insects, but also on small
vertebrates
 Prolific breeders
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Up to 3 litters per year with 2 to 10 young
Arctic shrew Sorex arcticus
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10.1 to 12.6 cm
Fairly aquatic
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Lives in swamps, bogs,
marshes, and grass-sedge
meadows
Smaller in size than its
southern counterparts
Masked shrew Sorex cinereus
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7.5 to 11 cm
Semi-aquatic
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Marshes, moist fields,
bogs, moist or dry woods
nocturnal
Pacific shrew Sorex pacificus
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12.9 to 16 cm
More terrestrial
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Lives in spruce and
redwood forests, often
found along the edges of
streams
Pacific water shrew Sorex bendirii
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14.7 to 17.4 cm
Semi-aquatic
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Lives in marshes, along
streams, occasionally in
moist forests
Largest of the shrews
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Can run on surface of
water due to fringed hairs
on toes that give it
buoyancy
Smoky shrew Sorex fumeus
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11 to 12.7 cm
Semi-aquatic
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Lives in various types of
moist wooded areas,
swamps, and along
streams
Will often utilize tunnels
made by other small
insectivorous mammals
(other shrews, moles,
etc.)
Water shrew Sorex palustris
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14.4 to 15.8 cm
Semi-aquatic
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Lives in an around boulders
along mountain streams or
sphagnum moss around lakes
Excellent swimmers, with
webbed 3rd and 4th toes
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All toes have stiff hairs on the
sides to increase swimming
efficiency
Family Talpidae
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Moles
Tiny eyes and no external ears
 Broad spade-like fore feet
 Feed on a variety of insects and other small
invertebrates
 The star-nosed mole is the only member of this
family that is adapted to living in muddy wetland
soils
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Star-nosed mole Condylura cristata
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15.2 to 21.1 cm
Semi-aquatic
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Water-proof fur
Spade-like feet are used as
paddles to swim
Use tail as a rudder
Hunts in stream bottoms or
forages in tunnels
22 tentacle-like fleshy
projections around tip of
nose
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These are used in searching for
prey, probing and navigation
Order Rodentia
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Four families:
Family Zapodidae- meadow mice
 Family Muridae- mice, rats, voles, muskrats, and
lemmings
 Family Capromyidae- nutria
 Family Castoridae- beaver
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Family Zapopidae
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Meadow jumping mouse
Zapus hudsonius
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18.7 to 25.5 cm
Nocturnal
Semi-aquatic
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Lives in moist fields,
marshes, woodlands and
fields with thick vegetation
Omnivorous
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Feeds on invertebrates in
spring, mostly on seeds,
green plants and fungi in
summer and fall
Family Muridae
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Cotton mouse, golden mouse, marsh rice rat, meadow
vole, southern red-backed vole, water vole, muskrat,
southern bog lemming
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Small to medium-sized rodents
Active year-round
Omnivorous
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Feed on fungus, seeds, fruits and vegetation, but also terrestrial and
aquatic invertebrates as well as small bird eggs and young
Number of litters and young vary among species, but
generally is fairly prolific
Cotton mouse Peromysus gossypinus
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15.2 to 20.5 cm
Semi-aquatic
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Swamps, moist
woodlands, beaches,
rocks, and brushlands
Strong swimmers
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Forage and escape
predators in water
Golden mouse Ochrotomys nuttali
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15 to 19 cm
Arboreal, but often lives
in wetland areas
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Swamps, greenbrier
thickets, and rocky
hemlock slopes
Excellent climber, uses
long tail for balance
Prevalent golden
coloration
Marsh rice rat Oryzomys palustris
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18.7 to 30.5 cm
Semi-aquatic
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Lives mostly in marshes
Excellent swimmer, can
submerge
Water repellent fur
Omnivorous
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Subterranean fungus
Endogone is important diet
component
Meadow vole Mircotus pennsylvanicus
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14 to 19.5 cm
Semi-aquatic
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Marshes, swamps, woodland
glades and fields
Good swimmer
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Commonly forages in water
Active day or night
Short tails and small eyes of
lemmings and voles contrasts
with mice and rats
Southern red-backed vole
Clethrionomys gapperi
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12 to 15.8 cm
More terrestrial
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Cool, damp forests,
swamps and bogs
Swims and climbs well
Mostly herbivorous
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Primarily fungi, and
succulent plants
Will forage on
invertebrates
Water vole Arvicola richardsoni
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19.8 to 26.1 cm
Semi-aquatic
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Upland creek and stream banks
and marshes
Strong swimmer
Burrows along stream banks
Lives in colonies
Lives in SE and SW British
Colombia and Alberta, also
in eastern Washington and
Oregon, northern Idaho,
central Utah and western
Wyoming
Southern bog lemming Synaptomys cooperi
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11.8 to 15.4 cm
Mostly terrestrial
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Burrows about 6 inches
below ground, also other
animal burrows
Lives in grassy meadows,
but occasionally bogs,
always in areas with heavy
vegetation
Will forage algae and
other aquatic vegetation
Muskrat Ondatra zibethicus
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40.9 to 62 cm
Marshes, and edges of ponds, lakes,
rivers and streams
Aquatic rodents
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Hind feet partially webbed and
flattened
Long scaly tail used for swimming
Build cone-shaped houses out of
vegetation
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Feed on aquatic vegetation
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May live together communally during
cold weather
Roots and shoots of cattail and other
emergents, but also clover, fruits and
occasionally aquatic invertebrates
Valvular mouth allows them to feed
underwater
Glands near anus produce musky odor
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Water-proof fur, and valuable skins
Muskrats continued…
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Muskrats are
instrumental in the
Marsh-cycle
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As muskrats feed, they
create openings in
marshes with dense,
emergent vegetation
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Create random openings
initially
Can consume most of the
vegetation and return the
marsh to an open state if
left unregulated
Family Capromyidae
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One species: Nutria
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South American rodents, escaped or introduced
Have been introduced in 22 states across the US
 Well-established in areas of the southeast, especially
Louisiana
 Foraging and burrowing activities can have detrimental
effects
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Nutria Myocastor coypus
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67 to 140 cm
Semi-aquatic
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Feeds on aquatic
vegetation
builds nests of vegetation
on the surface of water
Excellent swimmer
Found in marshes,
ponds, swamps, and
lakes
Family Castoridae
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One species: Beaver Castor Canadensis
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Largest living rodents in North America
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Range over most of Canada and the US
Construction of dens often dams rivers and streams,
flooding surrounding land
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Beaver presence can have a huge impact of the state and
stability of a particular wetland
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Can enhance habitat
Herbivorous
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Feed mostly on tree bark and green twigs
Beavers continued…
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88.9 to 131.3 cm
Aquatic
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Webbed feet, rudder-like tail,
nictitating membrane over
eyes, valvular ears, nose and
mouth, fur contains waterrepellent oil
Build stick and mud lodges
that dam rivers and streams
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Used for denning and food
caching
Order Lagomorhpa
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One Family: Leporidae
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Marsh and Swamp rabbits
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Similar to cottontail rabbits, but are associated with
bottomland hardwood forests of the southeast US
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Good swimmers
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Have smaller ears
Will take to the water when threatened
Also forage wetland plants
Restricted to the southeast coast in wet bottomlands and
wetlands
Marsh rabbit Sylvilagus palustris
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35 to 45 cm
Semi-aquatic
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Wet bottomlands, swamps,
hummocks, lake borders and
coastal waterways
Good swimmer, will flee
predators by taking to water
Herbivorous
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Forages on wetland and
terrestrial vegetation
Swamp rabbit Sylvilagus aquaticus
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53 to 54 cm
Semi-aquatic
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Good swimmer
Swamps, marshes, wet
bottomlands and
canebreaks
Can cause damage to
crops near swamps
Order Carnivora
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Two families:
Mustelidae- Mink and Otters
 Procyonidae- Raccoons
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Semi-aquatic
 Forage in and around wetlands for plant and/or animal
matter
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Mink Mustela vison
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49.1 to 72 cm
Semi-aquatic
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Excellent swimmers
Water-proof fur
Forages in water, feeding on
crayfish, frogs, and fish, but
also small mammals and birds
Releases musk from scent
glands in anal region when
agitated
Were the first American
furbearers to be raised in
captivity due to their valuable
furs
River otter Lutra canadensis
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88.9 to 131.3 cm
Semi-aquatic
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Excellent swimmers, catch prey in
water
Webbed feet, stream-lined bodies,
and dense oily underfur
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Carnivorous
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This dense oily underfur limits the
market value of their pelts
Feed on fish, crayfish, herps, and
some vegetation
Sociable
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Often play together, chasing each
other, and repeatedly sliding down
slopes into the water
Family Procyonidae
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Raccoon: Procyon lotor
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61 to 91 cm
Semi-aquatic
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Very intelligent
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Problem solving skills often
allow for detection of traps
Omnivorous
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Excellent swimmers
Slight webbing of toes
Forage in and around water
Fruits, grains, and vegetation,
also fish, shellfish, herps,
small mammals and birds
Can be destructive
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Destroy all or parts of corn
and other crops
Kill poultry and raid nests
Predator-Prey Relations
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Although they are often the predator, raccoons
can find themselves on the prey side of the food
chain
Other mammals
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Other mammals that frequently visit wetlands
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Black bears
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Often wade into streams and lakes to forage on animal
and plant foods
White-tailed deer
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Will forage a variety of aquatic vegetation, as well as seek
cover in wetland areas
Habitat management for wetland
mammals
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Generally directed toward a specific wildlife
species
Can be aimed at increasing the overall
biodiversity of wetlands
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Successful efforts usually increase seed sources,
invertebrate populations, and other wetland mammal
foods