Microhabitat Selection of the Endangered Five-Lined Skink

Elizabeth Vincer • University of Waterloo • Department of Environment and Resource Studies • lizvincer@hotmail.com

Introduction

Objectives

Methodology

Results Discussion and Conclusions

Literature Cited

Many species are at risk of extinction globally, and Canada is home to six species of lizards designated to be at risk. The only lizard species in Ontario, the Five-lined skink [Plestiodon fasciatus, Linnaeus 1758] has experienced declines in abundance in Southern Ontario. P. fasciatus is listed as Endangered by the Committee On the Status of Endangered Wildlife In Canada (COSEWIC) as of April 2007and as Special Concern by the Ontario Endangered Species Act in 2007. Populations are at risk because of theconversion of suitable habitat to agricultural land and urban land, used for commercial and recreational purposes (Hecnar and McCloskey 1998).

Identify and measure important microhabitat features used by individuals of P. fasciatus late in the active season at Rondeau

Provincial Park in order to contribute to the fundamental knowledge of habitat use by this endangered lizard species.

Populations of P. fasciatus at Rondeau Provincial Park are at risk from microhabitat destruction, collection for the pet trade, predation and road mortality. Currently, data on the life history and microhabitat preferences for P. fasciatus are lacking. In order to strengthen the

Recovery Strategy that will be prepared by the federal government, more information needs to be collected on the life history of this small lizard.

1) I created a grid overlay on a map of Rondeau of 100m x 100m squares

2) I randomly chose 5 squares that represented different skink habitat types (beach, forest, built-up, dune, prescribed burn forest)

3) I searched each plot for 1hr flipping over all potential cover items looking for skinks

4) When a skink was sighted I measured a number of habitat variables including cover type and dimensions, canopy cover, distance to water, soil type etc.

5) I measured variables at 4 randomly chosen control sites at the end of my field season

6) I performed a Principle Components Analysis (PCA) and Analysis of Variance (ANOVA) on the microhabitat data

A total of 8 observations of P. fasciatus were made on 7 visits to Rondeau Provincial Park between September 18 – October 19, 2008. After this date, the weather became colder and no more individuals were seen so hibernation was assumed. The most common cover object where skinks were found was woody debris; a wooden plank and cinder block were also utilized.

The Principle Components Analysis reduced the 11 measured habitat variables to 3 main components that explained a total of 72% of the variance in the data

Obser1

Obser2

Obser3

Obser4

Obser5

Obser6

Obser7

Obser8

Obser 9Obser10

Obser11

Obser12

Obser13

Obser14

Principle Components Analysis

Axis 1

Axi

s 2

These components were compared using ANOVA between measurements taken at sites with skinks and measurements taken at sites where skinks were not found. 4 of the 11 microhabitat variables differed significantly (P <0.05): cover length, cover width, air temperature and soil temperature. The results of this test are shown below.

Variable MS F P

Length 9.18 4.23 <0.05

Width 9.96 4.48 < 0.05

Air Temperature 21.45 16.71 < 0.001

Soil Temperature 18.37 13.90 < 0.001

Table 1. Analysis of variance of responses of five lined skink to environmental and

structural variables. Analysis was performed using log + 1 transformed data (for

homoscedasicity). Only significant effects are reported.

Figure 1. Ontario range of P. fasciatus (Oldham and Weller 2001)

Beach along Rondeau’s southeast shoreline showing woody debris microhabitat

Top: Moderately decayed woody debris coverBottom: wooden plank

Pile of woody debris on dune habitat

Howes, BJ; Lougheed, SC. 2004. The importance of cover rock in northern populations of the five-lined skink (Eumeces fasciatus). HERPETOLOGICA60(3): 287-294

Oldham, MJ; Weller, WF. 2000. Ontario Herpetofaunal Atlas. Natural Heritage Information Centre, Ontario Ministry of Natural Resources.

Quirt, KC; Blouin-Demers, G; Howes, BJ; Lougheed, SC. 2006. Microhabitat selection of the five-lined skinks in northern peripheral populations. JOURNAL OF HERPETOLOGY 40 (3): 335-342

Rutherford, PL; Gregory, PT. 2003. Habitat use and movement patterns of northern alligator lizards (Elgaria coerulea) and western skinks (Eumeces skiltonianus) in southeastern British Columbia. JOURNAL OF HERPETOLOGY 37 (1): pp 98-106

Acknowledgements

I would like to thank Dr. Stephen Murphy for his advice and comments; Emily Slavikand Sandy Dobbyn for their permission to conduct this research; and Paul Grant for his assistance collecting the data and moral support

Late in the active season, individuals of P. fasciatus at RondeauProvincial Park prefer cover objects that are at least 0.09m wide and between 0.40-2.00m long.

On warmer days both the air and soil temperature are higher which increases the probability of use of the cover objects measured in this study.

Cover items are likely the most important structural aspects leading to microhabitat choice by P. fasciatus as they allow the lizards to reach their optimal body temperature.

There are many implications from this study that suggest a variety of different aspects to examine in future studies:• Examine daily and seasonal use of microhabitats• Examine the factors behind microhabitat choice (predation, foraging, basking, breeding etc.)• Create a spatial map of all existing cover objects to examine if they are being removed by the park’s public visitors• Conduct genetic studies for inbreeding• Attempt to quantify impacts of climate change on phenology(emergence and hibernation timing) and other life aspects

In conclusion, effective conservation management can be best achieved when detailed knowledge is available on a species’ life history, abundance, distribution and habitat requirements. Understanding the factors behind these requirements is also critically important. This study represents an important first step towards gathering more detailed information on the biological requirements of P. fasciatus at Rondeau Provincial Park.

Figure 2. Principle Components Analysis of microhabitat variables