Ecological Archives A025-094-A1

John W. Pokallus and Jonathan N. Pauli. 2015. Population dynamics of a northern-adapted mammal: disentangling the influence of predation and climate change. Ecological Applications 25:15461556. http://dx.doi.org/10.1890/14-2214.1

Appendix A. Additional data collection methods and results of preliminary analyses for estimating adult porcupine survivorship rates at Sandhill Wildlife Area.

Upon initial capture we immobilized porcupines using either an intramuscalur injection of Telazol (Tiletamine HCL and Zolazepam HCL 7 mg/kg; Hale et al. 1994) or by inhalation of oxygen-carried isoflurane (inducted at 5% concentration and maintained between 1% and 4%). We recorded body mass, gender, mid-sternal chest circumference, body length, and left hind-foot length, and age class (juvenile, yearling, or adult) based on tooth eruption patterns (Dodge 1982). Animals were subcutaneously implanted with a passive integrated transponder (PIT, AVID Norco, CA), and had their posterior region marked with non-toxic enamel spray-paint for visual identification in the field. Recaptured animals were released at the site of capture after the PIT tag was read and the animal’s body mass was quantified. All procedures and protocols were approved by the Institutional Animal Care and Use Committee, University of Wisconsin-Madison (A01483-0-08-11) and were consistent with guidelines approved by the American Society of Mammalogists (Sikes et al. 2011).

We created capture histories for each individual to analyze with Cormack-Jolly-Seber models in Program MARK to obtain estimates of annual adult survivorship. Juvenile (n = 62) and yearling (n = 44) captures were underrepresented in the data set and were excluded from the analysis. Local weather conditions were tabulated annually from November through April in order to account for early-winter effects on adult survivorship. We obtained snowpack depth and winter temperature from Babcock-1 weather station (COOP ID 470456) located 0.9 km south of SWA. We substituted data from nearby locations: Necedah-5 WNW (COOP ID 475790) and Marshfield Municipal Airport, WI weather stations for missing values in the Babcock-1 historical data set. Station-based Hurrell seasonal (December, January, February, March) NAO indices were collected from the National Center for Atmospheric Research (Fig A1).

Table A1. Cormack-Jolly-Seber models analyzed for all adult porcupines (Erethizon dorsatum) in Sandhill Wildlife Area, Wisconsin from1997-2013. Model notation follows Lebreton et al. (1992) with ϕ and P indicating survival and capture probability, respectively. Covariate abbreviations are as follows: f = fisher abundance index, p = porcupine abundance index, s = porcupine sex, NAO = North Atlantic Oscillation index. Models were ranked via ΔAICc and model weight; also provided are the number of model parameters (K) and deviance.

 

Model

ΔAICc

wi

K

Deviance

ϕ(s), P(s)

0.00

0.53

4

547.74

ϕ(s + f), P(s)

1.97

0.20

5

547.64

ϕ(s + p), P(s)

2.02

0.19

5

547.69

ϕ(.), P(s)

6.08

0.03

3

555.88

ϕ(NAO), P(s)

7.24

0.01

4

554.99

ϕ(p), P(s)

8.05

0.01

4

555.79

ϕ(f), P(s)

8.06

0.01

4

555.80

ϕ(f + NAO), P(s)

8.98

0.01

5

554.65

ϕ(p + NAO), P(s)

9.20

0.01

5

554.86

ϕ(p + f), P(s)

9.22

0.01

5

554.89

ϕ(f + NAO +f*NAO), P(s)

9.80

0.00

6

553.38

ϕ(time), P(s)

24.87

0.00

18

542.14

ϕ(s + time), P(s)

47.14

0.00

34

525.31


 

Table A2. Cormack-Jolly-Seber models analyzed for adult porcupines (Erethizon dorsatum) in Sandhill Wildlife Area, Wisconsin captured from 15 January through 31 March from1997-2013 to identify the best-fitting covariate to model P. Model notation follows Lebreton et al. (1992) with ϕ and P indicating survival and capture probability, respectively. Covariate abbreviations are as follows: s = porcupine sex, NAO = North Atlantic Oscillation index. Models were ranked via ΔAICc and model weight; also provided are the number of model parameters (K) and deviance.

Model

ΔAICc

wi

K

Deviance

ϕ(.), P(s)

0.00

0.52

3

535.15

ϕ(.), P(s + snow cover)

1.52

0.24

4

534.63

ϕ(.), P(s + NAO)

1.90

0.20

4

535.00

ϕ(.), P(time)

6.68

0.02

17

511.86

ϕ(.), P(time + snow cover)

6.68

0.02

17

511.86

ϕ(.), P(.)

13.90

< 0.01

2

551.09

ϕ(.), P(snow cover)

15.44

< 0.01

3

550.60

ϕ(.), P(NAO)

15.85

< 0.01

3

551.00

ϕ(.), P(s + time)

19.38

< 0.01

33

486.65

 

Table A3. Cormack-Jolly-Seber models analyzed for adult porcupines (Erethizon dorsatum) in Sandhill Wildlife Area, Wisconsin captured from 15 January through 31 March from 1997-2013 to identify the best-fitting environmental covariate. Model notation follows Lebreton et al. (1992) with ϕ and P indicating survival and capture probability, respectively. Covariate abbreviations are as follows: s = porcupine sex, NAO = North Atlantic Oscillation index. Models were ranked via ΔAICc and model weight; also provided are the number of model parameters (K) and deviance.

Model

ΔAICc

wi

K

Deviance

ϕ(NAO), P(s)

0.00

0.35

4

532.72

ϕ(.), P(s)

0.39

0.29

3

535.15

ϕ(snow depth), P(s)

1.45

0.17

4

534.17

ϕ(temperature), P(s)

2.32

0.11

4

535.04

ϕ(temperature + snow depth), P(s)

2.65

0.09

5

533.30

 

Table A4. Annual Survivorship estimates (ϕ) and capture probabilities (P) for adult porcupines (Erethizon dorsatum) at Sandhill Wildlife Area, Wisconsin from the top ranking Cormack-Jolly-Seber model (Table 1).

Parameteryear

Estimate

SE

95% Confidence Interval

ϕ1

0.83

0.07

0.67–0.93

ϕ2

0.94

0.07

0.63–0.99

ϕ3

0.85

0.07

0.67–0.94

ϕ4

0.57

0.16

0.27–0.82

ϕ5

0.95

0.06

0.67–0.99

ϕ6

0.92

0.04

0.81–0.96

ϕ7

0.93

0.03

0.84–0.97

ϕ8

0.92

0.04

0.82–0.97

ϕ9

0.93

0.04

0.82–0.97

ϕ10

0.75

0.08

0.58–0.87

ϕ11

0.98

0.02

0.90–1.00

ϕ12

0.96

0.03

0.87–0.99

ϕ13

0.93

0.03

0.83–0.97

ϕ14

0.54

0.12

0.32–0.75

ϕ15

0.90

0.04

0.78–0.96

ϕ16

0.99

0.01

0.91–1.00

Pfemale

0.31

0.03

0.26–0.37

Pmale

0.13

0.03

0.08–0.20

 

FigA1

Fig. A1. Average snow (November-March) minimum temperature and total snow depth for March from 1950-2011 at Sandhill Wildlife Area, Wisconsin, USA.


 

Literature Cited

Dodge, W. E. 1982. Porcupine (Erethizon dorsatum). Pages 355–366 in J. A. Chapman, and G. A. Feldhamer. Wild mammals of North America. Johns Hopkins University Press, Baltimore, MD, USA.

Hale, M. B., S. J. Griesemer, and T. K. Fuller. 1994. Immobiliation of porcupines with tiletamine hydrochloride and zolazepam hydrochloride (Telazol®). Journal of Wildlife Diseases 30:429–431.

Lebreton, J. D., K. P. Burnham, J. Colbert, and D. R. Anderson. 1992. Modeling survival and testing biological hypothesis using marked animals: a unified approach with case studies. Ecological Monographs 62:67–118.

Sikes, R. S., W. L. Gannon, and the Animal Care and Use Committee of the American Society of Mammalogists. 2011. Guidelines of the American Society of Mammalogists for the use of wild mammals in research. Journal of Mammalogy 92:235–253.


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