M3: Lecture 2 Status of Relict Leopard Frog Pt. 2

In 1990 what was happening to the population of R. onca?

They had continued population losses.

What two general areas were R. onca found in?

Northshore and Black Canyon

What was the third area that did have some R. onca populations? What happened?

Little fields

Greatly declined up to extinction, due to bullfrogs and disease

What was the estimated number of adult frogs from the two areas?

1100 (not counting tadpoles or juveniles)

What site had more than half of the 1100 adult frogs than the other?

Black Canyon

What were the likely factors that implicated with the population decline of R. onca? (5)

1. Habitat loss and fragmentation (probably lived along Colorado river, which similar habitat is very scarce now)

2. Habitat degradation (loss of disturbance regimes)

3. Introduced predators

4. Disease (not considered a potential factor until several years later)

5. Synergistic (a combination of disease and predators)

What were the introduced predators?

Bullfrogs, crayfish, exotic fish

What was the relationship between leopard frogs and these predators?

(-)

What area had habitat loss and fragmentation?

The merging of Lake Mead with the Virgin River (2007)

What kind of habitat degradation was there as a likely factor of R. onca decline?

Overgrowth of emergent vegetation

What was troubling about the overgrowth of emergent vegetation?

It made for a horrible frog habitat

• The type of plant grows very thick, sharp, and tall. It can not be burned effectively as it made too much acidic ash that R. onca does not like.

When was the ‘Voluntary’ Conservation Team formed?

2001

What was the ‘Voluntary’ Conservation Team?

A crew from multiple agencies releasing frogs in Arizona

Why was this Conservation team not exactly voluntary?

It was technically not mandated by USFWS under the ESA to go out and do this, however some people were instructed and/or paid to participate by their agency

When was there a petition to list R. onca under the ESA?

2002

What was the USFWS decision from this petition?

They determined that the listing of R. onca “warranted”, but was prevented by other higher priority species

What kind of species was R. onca deemed as under the ESA from the USFWS’s decision?

A candidate species. Essentially on the the waitlist to be listed as Endangered

When was the Voluntary Conservation Agreement signed and how long was the agreement?

Signed in 2005, a ten year agreement

Who was the ten year agreement signed by?

Federal and state agencies

What were the points that were included in the Voluntary Conservation Agreement? (6)

1. Goals and objectives

2. Existing laws, regulations, provisions

3. Responsibilities of signatory agencies

4. Conservation team

5. Assurances of conservation actions (commitment to conservation)

6. Assessment and Strategy

What did the Conservation Assessment include? (5)

1. Previous research of Taxonomy/systematics

2. Previous research of Natural history and current distribution

3. Speculative causes for decline

4. Population status overall

5. Current threats

What factors were included in the Conservation strategy? (5)

1. Monitor populations

2. Establish additional populations through translocation

3. Enhance or create habitat

4. Manage populations to promote sustainability

5. Investigate species biology and apply findings back into the conservation strategy and enhance this approach

What was the process of head starting and translocation for these frogs starting back in 2002 up to 2026?

1. Collect eggs from wild populations

2. Care to late stage tadpoles or small frogs (take a portion of tadpoles or small frogs)

3. Release frogs to established new sites or increase existing sites

What was the total raised and released tadpoles/frogs from 2002-2026?

27,403 raise in the Relict Leopard Frog Room in the Lake Mead State Fish Hatchery

In translocation attempts how many historical-natural populations were there initially?

Roughly 8

In translocation attempts, how many translocated populations were there?

18

How many failed attempts were included in total translocated populations?

8 failed attempts

How was relative abundance measuring from population monitoring?

Visual Encounter Surveys and Selective mark-recapture

Both counting frogs, predators, and surrounding vegetation