Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed - - PDF document

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Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed - - PDF document

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Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed Salamander Workshop 2009 Santa Cruz Long-Toed Salamander Field Studies Santa Cruz Long-Toed Salamander Field Studies 1998-2009 Outline 1998-2009 I) Seascape Uplands Preserve III)

slide-1
SLIDE 1

Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed Salamander Workshop 2009 David Laabs, presenter 1

Santa Cruz Long-Toed Salamander Field Studies 1998-2009

David Laabs David Laabs Biosearch Associates & Biosearch Associates & Center for Natural Lands Management Center for Natural Lands Management

Santa Cruz Long-Toed Salamander Field Studies 1998-2009 Outline

I) Seascape Uplands Preserve a. History b. Monitoring Program c. Seascape Uplands Pond 1 d. Bonita Pond (Pond 3) e. Uplands Pond 2 II) Studies at Other Breeding Sites a. Valencia Lagoon b. Buena Vista Pond c. Millsap Pond d. Tucker Pond e. McClusky Slough f. Zmudwoski Pond III) Upland Trapping a. Seascape Uplands b. Willow Canyon IV) Management and Monitoring Implications

Santa Cruz Long Santa Cruz Long-

  • Toed Salamander

Toed Salamander

Santa Cruz Long-Toed Salamander Range

♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦

Seascape Uplands Pond

Seascape Uplands Pond

  • SCLTS discovered in

1974 in permanent stock pond; catfish & bullfrogs present

  • Berm breached in 1975-

76, creating seasonal pond

  • Ruth Study 1986-87;

Adult population estimate = 1,468 ± 60

  • HCP Approved; CNLM

takes title in 1998

  • Two mitigation ponds;

road tunnels built in 1999

  • Long-Term SCLTS

Monitoring 1998-Present

Seascape Uplands SCLTS Long-Term Monitoring

  • Track Adult

Population Trends

  • Measure Larval

Growth & Abundance

  • Minimize

impacts of study on SCLTS & other species

  • Minimize Cost
  • Regularly spaced

fencing around pond (~75% enclosure)

  • Traps open only

during rains & 1 night following

  • Traps opened 1st

Fall rains through April

  • Pond 1 monitored

1998-2008; Pond 3 monitored 2002- 2008

  • Study Design

Considerations

  • Drift-Fence/Pitfall

Trapping

  • Aquatic

Sampling

  • Sample every 2

weeks between mid-April and July

  • Measure 25 larvae
  • n each occasion
  • Quantify larvae on

100 ft2 plots

  • Level of effort

reduced after 6 years to presence/ absence

slide-2
SLIDE 2

Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed Salamander Workshop 2009 David Laabs, presenter 2

Seascape Uplands Pond SCLTS Adult Activity

  • Data from 2001-02

– typical of adult SCLTS activity pattern

  • Males arrive prior to

females; depart later

  • No SCLTS activity

past mid-March, even with rains

  • Fewer outbound

adults than inbound – consistent with

  • ther studies
  • 100
  • 50

50 100 150 200 10/1/01 11/1/01 12/1/01 1/1/02 2/1/02 3/1/02 4/1/02 Date # SCLTS Captured Inbound Females (+) Inbound Males (+) Outbound Females (-) Outbound Males (-) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 10/1/01 11/1/01 12/1/01 1/1/02 2/1/02 3/1/02 4/1/02 Precipitation (in.) 10 20 30 40 50 60 70 80 90 100 Temperature (F) Precipitation Maximum Temperature Minimum Temerature

Seascape Uplands Pond SCLTS Adult Activity 1998-2008

  • Males Arrive Prior

to Females

  • Males active at

pond for longer period (Males Avg. 34 days; Females

  • Avg. = 17 days

(Ruth 1989)

  • Most SCLTS

activity at pond was between 1 December – 15 March

50 100 150 200 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May # Adult SCLTS Captured Inbound Females Outbound Females 50 100 150 200 250 300 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May # Adult SCLTS Captured Inbound Males Outbound Males

Seascape Uplands Pond Population Monitoring 1998-2008

250 500 750 1000 1250 1500 1750 2000 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 Breeding Season Estimated SCLTS Breeding Population Females Males Error Bars indicate 95 Confidence Interval

Seascape Uplands Pond - Effect of Rainfall

  • n Female Migration

5 10 15 20 25 30 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 Breeding Season Precipitation Non-Jan (in) 500 1000 1500 2000 Estimated # Adult Female SCLTS Precipitation Nov-Jan Adult Female SCLTS

  • Rainfall between

November and January most critical for SCLTS breeding migration

Seascape Uplands Pond SCLTS Measurement Data - Inbound Versus Outbound Adults

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 1998-1999 1999-2000 2000-2001 2001-2002 2002-2003 2003-2004 Breeding Season Average Weight (g) Inbound Females Outbound Females Inbound Males Outbound Males Bars indicate 1 standard deviation

  • Both sexes lose

significant mass while at pond; especially females

  • Effect is

consistent year to year

  • Need to

distinguish when providing measurement data

Seascape Uplands SCLTS Measurement Data 1998-2008

  • Little year-to-year

change in mass (or length) of inbound adults

  • Significant year-to-

year variation in mass (and length) of emerging juveniles

  • Effects on

survivorship?

  • Years with lowest

juvenile mass were years with highest numbers of juveniles

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 1998- 1999 1999- 2000 2000- 2001 2001- 2002 2002- 2003 2003- 2004 2004- 2005 2005- 2006 2006- 2007 2007- 2008 Weight (g) Inbound Females Inbound Males Bars indicate 1 standard deviation 0.0 1.0 2.0 3.0 4.0 5.0 1998- 1999 1999- 2000 2000- 2001 2001- 2002 2002- 2003 2003- 2004 2004- 2005 2005- 2006 2006- 2007 2007- 2008 Weight (g) Outbound Juveniles Bars indicate 1 standard deviation

slide-3
SLIDE 3

Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed Salamander Workshop 2009 David Laabs, presenter 3

SCLTS Larval Monitoring Seascape Uplands Pond

Larval SCLTS Development at Seascape Uplands Pond, 1999-2003 5 10 15 20 25 30 35 40 45 50 60 90 120 150 180 210 Day of Year Average Snout-Vent Length (mm) 1999 2000 2001 2002 2003

  • Larvae transform

at 35-40 mm SVL

  • Larvae can persist

through July if water available; but usually transform by end

  • f June

SCLTS Larval Monitoring Seascape Uplands Pond

  • Larval density

greatest in April & May

  • Vegetation

changes on plots problematic

  • Strong correlation

between maximum larval abundance and # juveniles following season

  • Limited value in

comparing site to site

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 90 120 150 180 210 240 Day of Year Average # SCLTS Larvae/100 sq ft Plot 1999 2000 2002 2003

Bonita Pond (Uplands Pond 3)

  • Constructed 1999
  • Designed to be

ephemeral; holds water year-round

  • Colonized by SCLTS

2000

  • Estimated population

increased steadily from 311 ± 50 in 2002-03 to 1,242 ± 186 in 2007-08

  • Adjacent high-quality
  • ver-summering

habitat

  • Bonita Road source of

mortality

Uplands Pond 2

  • Built 1999
  • Designed to be

seasonal; holds water year-round

  • SCLTS first bred

in 2002

  • Population

estimate in 2007- 08 was 351 + 124

  • Relatively low

larval abundance – some unhealthy

Valencia Lagoon

  • Type locality for

subspecies (1954)

  • Population estimate

in 1977-78 (Reed 1979) was 2,583 ± 120

  • Population estimate

in 2007-08 (Biosearch 2008) was 734 ± 149

  • SCLTS breeding in

both mitigation pond and drainage channel

  • Highway 1 barrier to

movements; Bonita Road source of mortality

Millsap Pond

Millsap Pond

  • In Calabasas

Complex

  • Population

Estimate 2000- 2001 = 197 ± 16

  • Suitable Uplands

in Vicinity

  • Pond size is

limiting factor

  • California red-

legged frog also present

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SLIDE 4

Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed Salamander Workshop 2009 David Laabs, presenter 4 Tucker Pond

  • In Calabasas Complex
  • Population Estimate

(Bland 2001) 1,062 ± 38

  • HCP approved 2007
  • Conservation Easement

granted to CNLM

  • Population estimate to

be conducted Years 1, 5 and 10

  • No SCLTS larvae

present in 2007 (goldfish) or 2008 (?)

  • Bullfrogs & rough-

skinned newts present

Buena Vista Pond

  • In Ellicott-Buena Vista

Complex

  • California tiger

salamander also present

  • 2008-09 SCLTS

Breeding Adult Population Estimate was 775 ± 380

  • Below-average rainfall

in December and January; pond did not hold water until late February

McClusky Slough

  • Only southern

perimeter of slough trapped –not comparable to other sites.

  • 2001-2002: 33 adult &

53 juvenile SCLTS trapped; few recaptures

  • Adults significantly

smaller than other populations

  • Upland habitat is

limiting factor

  • California red-legged

frog also present

Zmudowski Pond

  • 2001-2002: 10 adult

& 6 juvenile SCLTS trapped; no recaptures

  • Most trapped in

southeast corner near only available willow habitat

  • Adults significantly

smaller than other populations

  • Upland habitat is

limiting factor

  • Salinity 0.5 ppt

Upland Trapping - Seascape Uplands

  • New road built

across known migratory route – source of take

  • 6 tunnels built -

untested for SCLTS

  • Migrating SCLTS

marked along fence in 2000-01

  • Only 4 of 44 (9%)

marked adults passed through tunnels

  • Need to test again

to see if population has adapted

Tunnel 6 Tunnel 5 Drift-fence

Upland Trapping - Willow Canyon

Trap 1 Trap 17

  • Drift-fence ¼ mile from

Seascape Uplands Pond

  • Willow Canyon Upland

Fence 2001-2002 Estimated Adult Population = 886 ± 51

  • Seascape Uplands

Pond 2001-2002 Estimated Adult Population = 2,927 ± 289

  • ~ 26- 36 % of Seascape

Uplands Pond Adults Migrated from/to Willow Canyon in 2001-2002

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SLIDE 5

Elkhorn Slough Coastal Training Program Santa Cruz Long-Toed Salamander Workshop 2009 David Laabs, presenter 5

Valencia-Seascape Complex

Valencia Lagoon Willow Canyon Seascape Uplands

Santa Cruz Long-Toed Salamander Population Studies - Laabs & Allaback 1998-2009 Summary

Breeding Complex Breeding Trap # # Peak Arrival Peak Arrival

  • Est. #

95% Sex Ratio % Deform. Breeding Pond Season Period Nights Traps Male Female Adults CI M:F Adults Valencia-Seascape Complex Valencia Lagoon 2007-08 10 Oct - 15 Apr 55 196 4-Jan 26-Jan 734 149 0.67 1.8 Seascape Uplands Pond 1998-99 15 Oct - 30 Mar 49 32 19-Jan 20-Jan 1833 131 1.26 Seascape Uplands Pond 1999-00 15 Oct - 15 Mar 58 32 18-Jan 24-Jan 2041 193 1.24 0.7 Seascape Uplands Pond 2000-01 30 Sep - 30 Apr 51 32 11-Jan 24-Jan 2310 310 2.39 0.1 Seascape Uplands Pond 2001-02 25 Sept - 30 Mar 69 32 6-Dec 29-Dec 2927 289 1.05 Seascape Uplands Pond 2002-03 15 Oct - 2 Apr 51 40 14-Dec 28-Dec 2234 178 1.27 0.7 Seascape Uplands Pond 2003-04 30 Nov - 30 Mar 50 40 20-Dec 30-Dec 1983 214 1.42 0.7 Seascape Uplands Pond 2004-05 1 Dec - 15 Mar 35 40 9-Dec 31-Dec 1794 195 1.64 0.1 Seascape Uplands Pond 2005-06 1 Dec - 15 Mar 41 40 19-Dec 23-Dec 1683 290 1.25 0.1 Seascape Uplands Pond 2006-07 27 Nov - 30 Mar 34 40 13-Dec 11-Feb 950 152 3.09 0.7 Seascape Uplands Pond 2007-08 1 Dec - 15 Mar 41 40 4-Jan 26-Jan 2074 204 0.88 0.3 Bonita Pond 2002-03 15 Oct- 2 Apr 51 48 14-Dec 10-Jan 311 50 1.03 Bonita Pond 2003-04 30 Nov - 30 Mar 50 48 20-Dec 30-Dec 399 76 1.64 0.8 Bonita Pond 2004-05 1 Dec - 15 Mar 35 48 9-Dec 1-Jan 597 105 1.54 0.6 Bonita Pond 2005-06 1 Dec - 15 Mar 41 48 19-Dec 23-Dec 686 122 1.83 0.0 Bonita Pond 2006-07 27 Nov - 30 Mar 34 48 13-Dec 27-Dec 674 135 1.45 0.3 Bonita Pond 2007-08 1 Dec - 15 Mar 41 48 4-Jan 4-Jan 1242 186 1.09 0.2 Uplands Pond 2 2007-08 1 Dec - 15 Mar 41 30 4-Jan 26-Jan 351 124 1.60 0.0 Willow Canyon ^ 2001-02 20 Nov - 31 Mar 61 34 2-Dec 2-Dec 886 51 0.87 Calabasas Complex Millsap Pond 2000-01 14 Nov - 7 Apr 40 32 11-Jan 11-Feb 98 16 1.65 1.2 Ellicott-Buena Vista Complex Buena Vista Pond 2008-09 15 Oct - 15 Mar 60 60 22-Jan 16-Feb 775 380 0.85 2.0 McClusky Slough Complex McClusky Slough

#

2001-02 15 Oct - 1 Apr 54 50 na na 32* na 1.00 2.3 Zmudowski Pond 2001-02 15 Oct - 1 Apr 54 60 na na 10* na 0.67 2.3 ^ - Traps in upland 1/4 mile from Seascape Pond

# - Ony small percentage of pond perimiter sampled; not comparable to other studies

* - Insufficient recaptures to allow for population estimate

Santa Cruz Long-Toed Salamander Field Studies 1998-2009

Management and Monitoring Implications Management and Monitoring Implications 1. 1. Both aquatic and upland habitats need protection Both aquatic and upland habitats need protection 2. 2. Variety of upland habitats used; large Variety of upland habitats used; large-

  • scale movements across

scale movements across grassland & scrub habitats grassland & scrub habitats 3. 3. Variety of aquatic habitats used; Permanent ponds used but Variety of aquatic habitats used; Permanent ponds used but potential for introduced predators & other factors potential for introduced predators & other factors 4. 4. Natural variability in population size Natural variability in population size -

  • Seascape Uplands Pond

Seascape Uplands Pond SCLTS population ranged between ~1,000 and ~3,000 breeding SCLTS population ranged between ~1,000 and ~3,000 breeding adults over 10 adults over 10-

  • year period

year period 5. 5. Rainfall total important, but timing equally important; November Rainfall total important, but timing equally important; November to to January critical January critical 6. 6. Pitfall trapping studies should extend from 1 December to 15 Mar Pitfall trapping studies should extend from 1 December to 15 March ch 7. 7. Any quantitative larval sampling effort affected by vegetation Any quantitative larval sampling effort affected by vegetation – – between between-

  • site comparisons difficult

site comparisons difficult