By Raeth J. Morgan

What are the factors that have changed the seasonal migration of the Southern Oregon stock. Chemical composition of nearby breeding ponds?

Predator avoidance?

Dramatic climate change?

One of the most abundant Salamander species in the Pacific Northwest.

Only two subspecies exist. Ssp Granulosa and Mazamae (only found in Crater Lake, Oregon).

Often referred to as “Orange Bellied Newt” or “Oregon Newt”.

Two stages of life: Aquatic and Terrestrial.

Adult size ranges from 3 ½” to 8” total length

Medium sized lunged salamander with dry granular skin with no coastal groves.

The most toxic Newt in North America.

The rough skinned newts generally breed in every month except November. Lower elevations: tend to breed February to May.

Higher elevations : breed late spring to early fall.

Mating generally occurs in the water.

Eggs are laid 5-10cm under the water surface.

Directed to breeding ponds by a built in directional “homing” sense.

Migration toward breeding waters triggered by first seasonal rains.

Temperatures : 60°-70°F summer, 40°-50°F

Require low to moderate Ph levels

Several studies have been conducted with conflicting results.

The consensus is that the Southern Oregon Newt displays a unusual migration.

Copyright © 2008 Richard Cameron

Newt samples were collected along Eel Lake in Tugman State Park Oregon.

EEL LAKE

William Tugman

State Park, Oregon

Large deep coastal lake located at the mouth of the Umpqua river.

Surface elevation: 16m.

Surface Area: 141 ha.

Volume 17,554,100 m(cubed)

Depth: 20.9 m

Population counts were conducted from October 2009 to November 2009.

Newts were caught by hand and lengths recorded.

Capture sites were ¼ in circumference and sites were ½ mile(approx) away from previous sites.

In September 2001 DEQ found the lake to be anoxic at the deepest part.

In October 2009 Algae Bloom advisory

Water sample was taken in mid November 2009. Ph levels greater than 8.8

Ammonia .50 ppm

Nitrate/Nitrite 0.0 ppm

Rough Skinned Newt(Taricha granulosa ).

Yellow-spotted Millipede ( Harpaphe haydeniana).

Pacific Banana Slug (Ariolimax Columsianus).

Unidentified Beetle species.

Common Garter snake (Thamnophis Butleri).

Rough Skinned Newt-135

Yellow Spotted Millipied-40

Pacific Banana Slug-63

Beetle-43

Common Garter Snake-1

Species abundance

-10

0

10

20

30

40

50

60

70

80

50° 52° 55° 60° 66°

beetle Rough scale Newt Bannanna Slug Yellow spot Millipide

The rough Skinned Newt was more active during temperatures ranging from 52°to 62°.

All sampled Newt species were heading away from breeding grounds.

None of sample were in “breeding” mode.

High Ph levels. Chemical run off from residential fertilizers.

Containments from recreational fishing.

Toxic algae blooms.

Predator avoidance. The Rough Skinned Newts have only one natural predator: The common Garter Snake.

Climate change. Seasonal rains late in season.

Cooler temperatures earlier in season.

Drop in water level.

Possible anoxic conditions.

Study was preliminary in nature, Further more long term, in depth studies needed to narrow down possibilities.

Rough Skinned Newts are affected by biotic conditions.

Results show correlation between the absence of predators and Newt abundance.