PROPERTY ASSESSMENT – OWL HABITAT AND USE PROPOSED … · 2013. 7. 30. · Dossier 06.0245 PROPERTY ASSESSMENT FOR OWL HABITAT AND USE PROPOSED DEVELOPMENT PROPERTY ECHO HEIGHTS,

PROPERTY ASSESSMENT – OWL HABITAT AND USE PROPOSED DEVELOPMENT PROPERTY ECHO HEIGHTS, CHEMAINUS, BC for: The Corporation of the District of North Cowichan Box 278, 7030 Trans Canada Highway Duncan, BC, V9L 3X4 by: Lea Menzies, B.Sc., B.I.T. MADRONE ENVIRONMENTAL SERVICES LTD. 1081 Canada Avenue, Duncan, BC V9L 1V2 July 31, 2007 Doss ie r 06 .0245

M A D R O N Eenvi ronmental services l td.

D o s s i e r 0 6 . 0 2 4 5 M A D R O N E

e n v i r o n m ent a l s e r v i c e s l t d.

TABLE OF CONTENTS

1.0 INTRODUCTION.................................................................... 1

2.0 SURVEY METHODOLOGY ..................................................... 1 2.1 Owl Surveys .......................................................................... 2 2.2 Weather Data ........................................................................ 3

3.0 RESULTS AND RECOMMENDATIONS ................................... 5 3.1 Surveys .................................................................................. 5 3.2 Habitat .................................................................................. 5

4.0 REFERENCES ............................................................................. 7

D o s s i e r 0 6 . 0 2 4 5

PROPERTY ASSESSMENT FOR OWL HABITAT AND USE PROPOSED DEVELOPMENT PROPERTY ECHO HEIGHTS, CHEMAINUS, BC

1.0 INTRODUCTION

As part of the Ecological Assessment for a proposed development at Echo Heights in Chemainus, the Municipality of North Cowichan (the Client) requested that Madrone Environmental Services Ltd. (Madrone) conduct owl surveys, as per the recommendations in the Echo Heights Ecological and Biophysical Assessment Report (Reid et al. 2006). The focus of the wildlife field surveys conducted for the Ecological and Biophysical Report (Reid et al. 2006) was to assess the area for wildlife values and to identify the presence of suitable habitat for rare species (federally or provincially listed). Because the field work was conducted outside of the optimal survey time for owls, Reid et al (2006) recommended that owl surveys be conducted during the following spring during the breeding season when owls are most vocal (Hausleitner, 2006). Three rare owl species (Western Screech-, Northern Pygmy and Barn Owls) have the potential to occur in this area. Table 1 shows all owl species that have the may be present in the Echo Heights area. Federal and Provincial Ratings systems can be found in Appendix I. The Barn Owl was not surveyed for as its forgaing and nesting habitat requirements would not be met on the assessment property. The Barn Owl forgages mainly in open fields and nests in old barns and buildings and in tree hollows (Johnsgard, 1988).


District of North Cowichan Page 2

Echo Heights – Owl Survey July 31, 2007

D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


No fields or barns are present on the assessment property. However, fields do occur on the properties that border Echo Heights and Barn Owls may occasionally roost in the forested area of Echo Heights.

Table 1. Owl species that may occur in the Echo Heights area.

Common Name Latin Name Federal Status Provincial Status

Western Screech-owl Megascops kennicottii kennicottii Special Concern Blue

Northern Pygmy Owl Glaucidium gnoma swarthi Not listed Blue

Barn Owl* Tyto alba Special Concern Blue

Northern Saw-whet Owl Aegolius acadicus Not listed Yellow

Barred Owl Strix varia Not listed Yellow

Great Horned Owl Bubo virginianus Not listed Yellow

*No surveys were conducted for the Barn Owl.

2.0 SURVEY METHODOLOGY

2.1 Owl Surveys

Biologists with Madrone conducted call play back surveys in accordance with the Resource Inventory Standards Committee (RISC) methodology (Hausleitner, 2006) during two survey sessions. Large and small surveys were conducted on different nights for three primary reasons: 1. Large owls, particularly Barred Owls, are thought to predate on small owls

(Cannings and Angell, 2001). 2. Broadcasting large owl calls may also decrease the likelihood of small owl’s

responding to the call play back. 3. Playing small and then large owl calls in the same night may increase the risk

of predation on small owls.



D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


The large (Barred and Great Horned) owl surveys were conducted on April 3, 2007 by Lea Menzies and Guillermo Pérez. Guillermo Pérez also conducted the Northern Pygmy and small (Western Screech - and Northern Sawwhet) owl surveys on April 18, 2007. Northern Pygmy Owl surveys were conducted prior to sunset to maximize the optimal period of activity. Unlike other small owls in the area, the Northern Pygmy Owl is active in the day with peak activity periods at dawn (sunrise) and dusk (sunset) (Johnsgard, 1988). This behaviour is known as crepuscular. Three call stations were established to maximize coverage of the 21-hectare (52 acre) property. Hausleitner (2006) recommends that the maximum inter-station distance should be 500 m. Owl call play back stations at Echo Heights were approximately 300 to 400 m apart (Figure 1). All surveys were conducted during the optimal time for activity and breeding times for owl detections (both time of day and time of year) (Hausleitner, 2006). All surveys were initiated with a two minute listening period to allow for detection of spontaneous calling owls (Hausleitner, 2006). A total of four call bouts for each target species were broadcast at the station using a CD player and megaphone. At the end of the call broadcast, observers listened for an additional five minutes. 2.2 Weather Data

At the beginning and end of each survey session temperature, cloud cover, precipitation, wind (using the Beaufort scale) and noise level were recorded. If wind, rain, or noise interferes with the ability to detect owl calls then the survey is typically cancelled or the observers wait until conditions improve to a level acceptable to the RISC standards (Hausleitner, 2006).

³±EH1

³±EH2

³±EH3

[b

[b

[b

ASH RD.

CHANNEL VIEW BLVD.

SUNSET DRIVE

30m

Recommended Wildlife Reserve

ECHO HEIGHTS

- Figure 1: Echo Heights Owl Survey Locations & Detections -DOSSIER NO:06.0245

DRAWN BY:J.Thomson

CLIENT:District of North Cowichan

MAP REVISION DATE:July 17, 2007

ASSESSED BY:Lea Menzies, B.Sc., B.I.T.

MAP SCALE:1:2,500

0 25 50 75 10012.5 Meters

Owl Survey StationBard Owl DetectionGreat Horned Owl DetectionPorter CreekDitchHigh Water MarkRecreational TrailRecommended Wildlife ReserveSensitive EcosystemProperty BoundaryRiparian Buffer (30m)Sensitive Ecosystems Buffer (15m)

´MAP LEGEND

[b

[b

³±EH#



D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


3.0 RESULTS AND RECOMMENDATIONS

3.1 Surveys

The surveys conducted at Echo Heights resulted in the detection of one Great Horned Owl and one Barred Owl. A Great Horned Owl was detected in the farmer’s field to the south of the property during large owl surveys. As we walked west through the property, the owl continued to call and flew over towards us when we proceeded to Station EH2. The Barred Owl was detected at Station EH3 during the Northern Pygmy Owl surveys. No small owls were detected during the surveys. Figure 1 displays all three broadcast stations as well as the estimated owl detection locations (i.e., the distance and direction of the owl detection is recorded and is later projected on the map, estimating the detection location). 3.2 Habitat

The forest along the western portion of the property that was classified as a Recommended Wildlife Reserve in the Echo Heights Ecological Assessment (Reid et al. 2006) contains numerous trees that are suitable roosting and nesting habitat for owls. Large snags (> 80 cm dbh) and other significant trees throughout the assessment area should be retained to maintain use by owls, bats, and other cavity users. Large, live trees also provide wildlife nesting habitat, as they often contain natural cavities and hollows. The large Bigleaf maple (Acer macrophyllum) and Western redcedar (Thuja plicata) that occur throughout the property (most frequently in the recommended wildlife reserve) will likely provide roosting habitat for bats and nesting opportunities for cavity-nesting birds. Care should be taken when construction activities are undertaken during the breeding season (February 1-August 1). If a worker observes a stick nest or chicks during the breeding season, a biologist should be consulted for identification and to locate the nest tree if possible. Section 34 of the Wildlife Act states: “A person commits an offence if the person, except as provided by regulation, possesses, takes, injures, molests or destroys:

a) a bird or its egg



D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


b) the nest of an eagle, peregrine falcon, gyrfalcon, osprey, heron or burrowing owl.

c) the nest of a bird not referred to in paragraph when the nest is occupied by a bird or its egg.”

Variation in owl breeding activities exists. For example, the Great Horned Owl nests earlier in the season with breeding activity beginning as early at February 1 (Hausleitner, 2006). The Northern Pygmy Owl typically nests later in the spring with egg laying occurring between February and June and fleding occurring as late as early August (Darling, 2003). The overall breeding season, to include all owls occurring in the area, is between February 1 and August 1. No activity should occur during this time. In summary, the following recommendations should be adhered during the construction phase at Echo Heights: • All trees greater than 80 cm dbh should be retained where possible. • All wildlife trees and trees containing cavities should be retained where

ever possible. • If an owl or raptor nest or chicks are seen during the construction process,

a biologist should be consulted. Should you have any questions please do not hesitate to contact our office. Prepared by: Reviewed by:

Lea Menzies B.Sc., B.I.T. Guillermo Pérez, M.Sc., R.P.Bio.



D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


4.0 REFERENCES

Cannings, R. J., and T. Angell. 2001. Western Screech-Owl (Otus kennicottii). In The Birds of North America, No. 597 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Darling, L.M. 2003. Status of the Vancouver Island Northern Pygmy-Owl

(Glaucidium gnoma swarthi) in British Columbia, BC Minist. Sustainable Resour. Manage., Conservation Data Centre, and BC Minist. Water, Land and Air Protection, Biodiversity Branch, Victoria, BC Wildl. Bull. No B-113. 14 pp

Hausleitner, D. 2006. Inventory Methods for Owl Surveys. Prepared for

Ecosystems Branch of the Min. of Environ., Resources Information Standards Committee.

Johnsgard, P. 1988. North American Owls: Biology and Natural History.

Smithsonian Press, Washington D.C. Reid, H., L. Menzies, T. Willmott, B. Simonsen and G.Butt. 2006. Ecological and

biophysical assessment, Proposed Development Property, Echo Heights, Chemainus, BC.

D o s s i e r 0 6 . 0 2 4 5

APPENDIX I

PERTINENT LEGISLATION




D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


APPENDIX I. Pertinent Legislation Concerning Rare Species.

Federal Species at Risk Act (SARA)

SARA is federal legislation that aims to protect species at risk from becoming extinct or lost from the wild. It covers all wildlife species listed as being at risk nationally (including critical habitats) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Compliance to the act generally applies to Federal Lands, although compliance of private properties is applicable in some cases. Volunteer compliance is encouraged. G1, N1, S1: Critically Imperiled on a global (G), national (N) or provincial (S) scale. Especially susceptible to extirpation or extinction. Occurrences: 5 or less. G2, N2, S2: Imperiled. Very susceptible to extirpation or extinction. Occurrences: 6-20. G3, N3, S3: Vulnerable. Found only in a restricted range (even if abundant at some locations), or susceptible to extirpation or extinction. Occurrences: 21 to 100. G4, N4, S4: Apparently Secure. Uncommon but not rare, and usually widespread in the province. Occurrences: more than 100 existing. Federal Ranking System

COSEWIC assesses the status of wild species in Canada. The application of ranking criteria by COSEWIC describes the relative condition of a particular species and gives some indication as to the likelihood of extinction. For example, a species that is “Endangered” faces imminent extirpation or extinction; a species that is “Threatened” is likely to become endangered if limiting factors are not reversed (Table A). Species ranked as G1 are considered of greatest risk for global extinction, and are therefore of highest management priority.



D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


Table A. Federal Species at Risk Ranking and Definitions.

Rank Description X – Extinct Species no longer exists.

XT - Extirpated Species no longer exists in Canada, but it still occurs elsewhere.

E - Endangered Species is facing imminent extirpation or extinction.

T - Threatened Species is likely to become endangered if limiting factors are not reversed

SC - Special Concern Species that are sensitive to human activities and natural events, but are not considered to be; Endangered or Threatened.

DD - Data Deficient Species with inadequate information to make direct / indirect assessment.

NAR - Not at Risk Species that have been evaluated, but are considered not to be at risk.

Provincial Rare Element Ranking

Rare and endangered plants, plant communities, and animals in British Columbia have been rated by both provincial and federal classifications. The B.C. system uses three “lists”, associated with a colour, to indicate degree of rarity. The Red List includes any indigenous native species, subspecies, or element (e.g., plant community) considered to be extirpated, endangered, or threatened in B.C. Extirpated species no longer exist in the wild in B.C., but do occur elsewhere. Endangered species are extremely rare, facing imminent extirpation or extinction. Threatened species are likely to become endangered if limiting factors are not reversed. The Blue List includes any rare indigenous species or subspecies (taxa) considered to be of special concern (vulnerable) in British Columbia. Taxa are of special concern because of characteristics that make them particularly sensitive to human activities or natural events. Blue-listed taxa are at risk, but are not extirpated, endangered or threatened. The Blue list also includes species that are generally suspected as being vulnerable, but for which information is too limited to allow designation in another category. The Yellow list includes species that are apparently secure and not at risk of extinction. Unless otherwise indicated as Blue or Red, a plant is considered to be on the Yellow list.



D o s s i e r 0 6 . 0 2 4 5 M A D R O N E


Provincial Ranking System

Within BC, the Conservation Data Centre (CDC) is responsible for assigning provincial status of indigenous species. The CDC is a branch of the Ministry of Water, Land and Air Protection (MWLAP). The coding is by colour, with red indicating species at greatest risk (threatened and endangered species), and yellow indicating the lowest level of risk (Table B).

Table B. Provincial Ranking System and Definitions.

Rank Description Yellow List Indigenous species, subspecies and natural plant communities deemed not to

currently be at risk in B.C. Blue List Indigenous species, subspecies and natural plant communities of Special Concern in

B.C. Red List Indigenous species, subspecies and natural plant communities that are extirpated,

endangered or threatened in B.C. These species either have, or are candidates for, official extirpated, endangered, or threatened status in B.C.

Documents

PROPERTY ASSESSMENT – OWL HABITAT AND USE PROPOSED … · 2013. 7. 30. · Dossier 06.0245 PROPERTY ASSESSMENT FOR OWL HABITAT AND USE PROPOSED DEVELOPMENT PROPERTY ECHO HEIGHTS,