presentation - otter ecology and research description - 2005

8/8/2019 Presentation - Otter Ecology and Research Description - 2005

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Ontogeny & Reproduction

P olygynous

Sexual maturity at 2 years of age Rarely, yearlings may produce young B reeding period: December to A pril

Gestation of 61-63 days Delayed implantation lasting 8-11 months Y oung born between F ebruary and A pril


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Ontogeny & Reproduction

L itter size: 1 to 3 (maximum of 5)

Born fully furred, blind, toothless

W eaning at 12 weeks F emale provides food until 37-38 weeks

L ife expectancy: 13 years in the wild, 25 in captivity


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Ecology

H abitat preferences Permanent watersheds B og lakes B eaver ponds Dense riparian vegetation (evergreen species) Mouths of permanent streams Points of land B anked shores S oils rich in Organic matter


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D en and Resting Sites

D ependence on pre-existing refuge sites: B eaver huts B eaver bank dens F ox & coyote dens

Muskrat burrows W oodchuck burrows Root cavities L ogjams Riparian vegetation S now & ice cavities H ollow logs A bandoned car B oat dock/raft B ridges


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D en and Resting Sites

Non-agonistic coexistence with beavers 3 known accounts of the two species sharing common lodge.

Otters occasionally prey on juvenile beavers.

Unique observation in 1995: construction of natal den by an introduced female in Indiana(USA ).


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D iet

Main diet (up to 80%) Game & non-game fish species

Opportunistic catches: A mphibians (frogs, salamanders) Crustaceans B irds S mall mammals (muskrats)

Reptiles (snakes, lizards) Molluscs Insects

Cooperative fishing occasionally observed


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P redators

H umans T rapping Illegal shootings Road kills A ccidental captures

On-land vulnerability W olves Coyotes Dogs B obcats Cougars

A ccidental deaths Ice flows S hifting rocks

S tarvation (excessive toothdamage)


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Social structure

Basic social units: T he family (adult female + yearlings + juveniles) S olitary males

Casual groupings F amily groups may include helpers (unrelated

individuals) Groups of unrelated adult males Groups of unrelated juveniles


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B ehavior

A ctive year-round Nocturnal in spring, summer and fallDiurnal in winter Resident species (no annual migration)

Non-aggressive territoriality T erritorial marking (latrines) Mutual avoidance Overlapping home ranges H ome range size: 10s to 100s of Km 2

Can travel up to 40 km/day (average: 2 to 5 km/day)


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B ehavior

H ighly intelligent: well developed play behavior S liding Chasing tail S wimming Juggling sticks and pebbles Rolling around W restling

Playing with captured prey or conspecifics

Can be trained to bring back fish, ducks(Middle & F ar-East)


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P arasites

Ectoparasitesa) T icks ( L yme disease)

b) S ucking lice

c) F leas

Endoparasites

d) Nematodese) T rematodesf) Cestodesg) S porozoans

a)

b)

c)

d) e)


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D iseases

Canine distemper Rabies

Urinary infectionRespiratory tract diseaseJaundice

H epatitis Feline panleucopenia

Pneumonia


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V ulnerability to pollution

Mustelids known for their sensitivity to pollution(Mercury and PC B s) L iver and kidney accumulations

Incoordination (neuronal degeneration) A norexia Kit mortality Reproductive failure Paralysis Death

Mercury bioaccumulation


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Part II: Ongoing Research atKouchibouguac National Park

Daniel Gallant

Universit de MonctonMarch 9 th 2004


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I ntroduction

Development of management tools Monitoring and maintenance of ecosystem health.

The indicator species concept

H ighly popular Increasing amount of knowledge about the concept


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Objectives

1) Evaluate the river otters potential as anindicator species: F or the health of riparian habitats A t the regional scale

2) Develop a monitoring protocol Reliable (accurate and precise) L ogistically feasible Economically viable ( L ong term surveys)


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P revious studies

In natural habitats Protected areas

Z ones with minimal levels of human activities

In zones with heavy human perturbations

Environmental catastrophies (ex: Exxon V aldez) H igh human density zones (ex: Europe)


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Shortcomings

Lack of information about:

Effects of human activities on otter populations in ruralsettings

Influence of human activities on adjacent protected areas

A n ideal research setting: Kouchibouguac National Park


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H ypotheses

1) Otter distribution is positively associated toone or more factors associated to non-disturbedareas.

2) Otter distribution is negatively associated toone or more types of humanactivities/perturbations.


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H ypotheses

3) T he most important descriptors of otter distribution are factors of anthropogenic nature.

4) Encounter rates of otters are significantlyhigher in areas of low anthropogenic activity


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Study Area


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W inter Survey Advantages

H igh detection probabilities

Each animal leaves adistinct track, regardlessof age or gender.

Substrate variabilitycovered by snow

Uniform detection probabilities


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W inter Survey Advantages

Tracks linked to all other activity signs

B urrows Resting sites W

ater access holes F aeces (scats)


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Experimental D esign

W inter riparian transects A long the shores of major rivers

A nthropogenic activities

North-S

outh gradient East- W est gradient


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Continuous transects, covering all shores of given rivers, both inside and outside the park.

24 h waiting period after each snowfall (>2cm) or high winds (> 40 km/h).

Rivers sampled in random order after eachsnowfall.


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V ariables measured during transects: Date and hour of beginnings and endings of transects

Coordinates (U T M, meters, beginnings and ends)

General notes on snow condition

T ime elapsed since last snowfall (hours)

Mode de transport (snowshoes, snowmobile)


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Measured V ariables

A spects of variables Otter presence (ex: type of activity, number of tracks)

Ecological (ex: type of vegetation cover, dominantspecies, presence of beaver ponds, etc.)

P hysical (ex: presence of tributaries, type of soil)

Anthropogenic activities (ex: type of activity, proximity)

Geography (ex: latitudes longitudes, orientation of shoreline)


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Measured V ariables

A ssessment of habitat availability

Same variablesmeasured atsampling positionsestablished at 500 mintervals.


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Anticipated Results

I f otters are good indicators of habitat health:

1) T hey should be positively associated with intactriparian habitats.

2) T hey should be negatively associated with certaintypes of human activities/perturbations.

3) F actors of human activities should be the mostimportant factors in describing otter distribution.

4) L ow disturbance zones: ottersH igh disturbance zones: otters


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P reliminary Results

S urvey Number of transects/days

Km of shorecovered

Number of ottersdetected

B eginningdate

Endingdate

Preliminary projectW inter of 2000

10 125 12 28-jan. 05-mar.

Preliminary project

W inter of 2001

19 229 12 2-jan. 04-mar.

Current projectW inter of 2003

32 358 13 15-jan. 11-apr.


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Funding & Support


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T hank Y ou

presentation - otter ecology and research description - 2005

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