loon habitat enhancement whatshan reservoir 2013 1

Enhancement and monitoring of nesting habitat for Common

Loons (Gavia immer) on Whatshan Lake Reservoir and Upper

Arrow Lakes Reservoir

Prepared for BC Hydro Fish and Wildlife Compensation Program ‐ Columbia

Mandy Kellner and Harry van Oort

Kingbird Biological Consultants Ltd.

Revelstoke BC

250‐837‐0820

[email protected]

Dec. 2013

Kingbird Biological Consultants: Loon habitat enhancement and nesting success 2013

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ExecutivesummaryCommon Loons (Gavia immer) are large, piscivorous birds that nest on the shoreline of lakes,

immediately adjacent to the water. At Whatshan Reservoir in southeastern British Columbia,

construction of a dam and flooding of original wetland and riparian habitats has likely led to the

reduction of suitable nesting habitat. Further affecting the productivity of loons at Whatshan, are

disturbance from human development and recreation on the reservoir, and the flooding of nests

through reservoir operations. Floating nest platforms have been used successfully to increase loon

reproductive success in other lakes and reservoirs, and could help mitigate negative impacts of reservoir

operations and encourage the loons to nest away from areas prone to human disturbance. In response

to a low rate of reproductive success documented during previous work, we installed five floating

artificial nest platforms in 2011. The platforms were planted with graminoids, emergent plants, and

shrubs, which grew vigorously and by mid‐summer, they were vegetated enough to appear as riparian

habitat, adding diversity to the reservoir and potentially offering resting, foraging, or cover habitats to

wildlife. No loons nested on the platforms in their year of instalment.

Monitoring for loon usage continued in the 2012 nesting season. However, water levels that were 3‐4m

below norm in spring (mid‐ to late‐May) meant that loons could not access the stranded platforms

during the start of the nesting period. Nevertheless, after the reservoir filled, one of the platforms was

used by loons for nesting. This nest did not succeed, due to either predation of eggs or young shortly

after hatching. Of the four territorial pairs of loons present on the lake, only one pair was successful in

hatching a single chick (1/4 pairs, 25% success). This successful nest was also on a floating platform, an

old dock also used in previous years as a nest site.

Monitoring continued for 2013, and use of the platforms by loons increased dramatically, with three of

four nesting pairs using artificial platforms. Two of these pairs successfully nested and raised young; the

third pair failed to incubate their egg, for reasons unknown. The fourth breeding pair nested on the

shore of an island, and the nest was inundated as the water level rose. Overall, two of the four breeding

pairs reproduced successfully this year (2/4 pairs, 50% success). Perhaps equally as important, the

successful young were hatched around June 12 and June 24, much earlier than hatch dates of successful

nests in the past.

As in previous years, the condition of the floating structures and associated vegetation was

documented. All five platforms survived the winter and remained anchored in their original positions.

However, inspection in April showed variable amounts of damage from mammals and/or ice or wind,

and some significant wear and tear on the original anchoring systems. These problems were addressed

through re‐vegetation and replacement of worn components, but should be considered for future

installations.

New this year was the addition of a floating island nest platform to Montana Slough, near Revelstoke.

This site is frequently used for nesting by loons but often suffers from nest inundation as reservoir levels

rise, similar to at Whatshan Lake. This platform was installed after nesting had begun, and did not

receive any use in 2013.


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KeywordsCommon loon, Gavia immer, reservoir, nesting success, nesting habitat, artificial nesting platform,

Whatshan Lake, Montana Slough, Upper Arrow Lake


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TableofContentsExecutive summary .......................................................................................................................................2 Keywords.......................................................................................................................................................3 Table of Contents..........................................................................................................................................4 List of Figures ................................................................................................................................................4 List of Tables .................................................................................................................................................5 Introduction ..................................................................................................................................................6 Introduction ..................................................................................................................................................6 Study area .....................................................................................................................................................7 Methods........................................................................................................................................................9

Platform installation .............................................................................................................................9 Monitoring of nest platforms and loon reproductive success............................................................10 Data analysis and management..........................................................................................................10

Results.........................................................................................................................................................10 Use of platforms by loons ...................................................................................................................11 Nesting success and timing.................................................................................................................11 Platform condition and maintenance .................................................................................................12 Other wildlife ......................................................................................................................................14

Discussion and management implications..................................................................................................14 Use of platforms and nesting success.................................................................................................14 Platform condition ..............................................................................................................................15 Recommendations ..............................................................................................................................16

Acknowledgements.....................................................................................................................................16 References ..................................................................................................................................................17 Appendix 1. Loon nest information ...........................................................................................................19 Appendix 2. Photo log of platform condition and plant development on platforms during Year 3 ..........21 Appendix 3. Incidental observations of wildlife at Whatshan Lake, 2013..................................................24

ListofFiguresFigure 1. Map showing the location of Whatshan Lake in south‐central British Columbia. ........................8 Figure 2. Map showing the location of Montana Slough on the Upper Arrow Lake Reservoir, near

Revelstoke, in south‐central British Columbia..............................................................................................9 Figure 3. The Montana Slough platform wrapped in wire, prior to planting. ............................................10 Figure 4. Reservoir elevation for Whatshan Lake Reservoir in 2013, minimum water levels prescribed by

the WUP, and the initiation dates for successful and unsuccessful nests. Both successful nests were on

floating platforms; 1 unsuccessful nest was on a platform but not incubated, and one was on shore and

was inundated.............................................................................................................................................12


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Figure 5. The Flicker Lagoon platform in April 2013 (left), showing the loss of buoyancy due to the

removal of matrix material by small mammals. The platform did dry out and support plant growth, and

attracted nesting loons (right). ...................................................................................................................13 Figure 6. The Lagoon platform in late April 2013 (left), showing loss of soil and vegetation, potentially

caused by ice, waves, or mammals. Although not totally vegetated by late June, this platform was re‐

planted and grew some vegetation, and attracted nesting loons (right)...................................................14 Figure 7. Successful nests on Whatshan Lake in 2013: the South End platform nest SE‐1‐13, located on

May15 (left), and the Lagoon platform nest LG‐1‐13, located on May 28 (right). .....................................20 Figure 8. Unsuccessful nests located at Whatshan Lake in 2013: the White Grouse shore nest WG‐1‐13

on May 28 (left) and the Flicker Lagoon platform nest FL‐1‐13 on June 12, which appeared to not be

incubated (right). ........................................................................................................................................20 Figure 9. Flicker Lagoon (FL) platform in late April (left), May (centre), and late June (right). The platform

was excavated by small mammals in the winter, leading to loss of buoyancy. However, it dried out in the

summer and was used for nesting, although the nest failed. ....................................................................21 Figure 10. The Loongoon (LG) platform in late April (left) showing damage from ice or mammals, its use

by loons in May (centre), and its state in late June after the nest hatched (right). ...................................21 Figure 11. The North End (NE) platform in May (left) and at the end of the growing season in August

(right). .........................................................................................................................................................22 Figure 12. The South End (SE) platform still stranded on Apr 28 (left), and being used for nesting in late

May (right). .................................................................................................................................................22 Figure 13. The White Grouse (WG) platform in late April (left), late May (centre), and late June (right). 23 Figure 14. The Montana Slough (MO) platform when first deployed in May (left), after being heavily

grazed by Canada Geese in June (centre), and regrown after Geese moved on, in July (right).................23

ListofTablesTable 1. Start dates for successful nests at Whatshan Lake, year of nest, and substrate used for nesting.

Note early start dates for nests on artificial nest platforms, and paucity of successful shore nests. ........15 Table 2. Location, descriptions, and fates of loon nests on Whatshan Lake and Montana Slough, Upper

Arrow Lake, 2013. .......................................................................................................................................19 Table 3. Incidental wildlife observations, 2013. .........................................................................................24


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IntroductionCommon loons (Gavia immer) nest immediately next to the water’s edge, often amongst emergent

vegetation (Campbell et al 2008), and select diverse micro‐sites such as muskrat mounds, floating or

emergent logs, bare ground, or floating bog mats, with floating mats offering the best chance of nesting

success (McIntyre and Barr 1997). On Whatshan Lake Reservoir (and elsewhere in the Columbia Basin)

much of the higher‐quality nesting habitat along the lakeshore was likely lost with reservoir creation,

and was replaced largely by the steep dry banks that surround much of the reservoir at present (Utzig

and Schmidt 2011). Areas within Whatshan Lake Reservoir that appear to offer suitable nesting habitat

become flooded by rising reservoir levels each spring.

Potentially compounding the impacts from reservoir creation and operations are other factors known to

be detrimental to loon nesting success, such as the waves created by motorized recreation on the

reservoir and the shoreline development along the southern lake. Four years of data on loon

reproductive success and timing of reproduction on Whatshan Lake between 2006 and 2010 have

shown that most pairs of loons do not successfully reproduce and that reproductive rates are low (0 – 50

% of nests are successful per year) (van Oort and Kellner 2007, 2008, Kellner and van Oort 2009, 2011a,

b), compared to the Canadian average of 50% or better (Timmermans and Jones 2002). Over the 4 years

of monitoring 4 or 5 loon pairs each year, 4 nests were confirmed (and others suspected) to have failed

due to rising water levels flooding nests built on shore or on unstable floating substrates (Kellner and

van Oort 2011b). Other causes of nest failure were suspected human disturbance and suspected

predation.

An indirect negative impact to the productivity of loons nesting on Whatshan Lake Reservoir is that

successful nests are commonly initiated near or after the reservoir has reached full pool. This results in

later dates for nest initiation (Kellner and van Oort 2011a,b), compared with other records from the

West Kootenay which document nesting in early‐ to mid‐May (Campbell et al 2008), and also results in

late hatching of young, with potential consequences for winter survival and juvenile recruitment.

Research in other regions has shown that loons readily use artificial floating nest platforms (McIntyre

and Barr 1997, Piper et al 2002), and that reproductive success can increase when nesting platforms are

used (Piper et al 2002). In British Columbia, the use of floating nest platforms has been suggested as a

“management tool” for loon populations on reservoirs (Campbell et al 2008). Any efforts to improve the

nesting success of common loons are especially relevant in light of new research detailing a long‐term

decline in the number of fledged young per breeding pair of loons across southern Canada (Tozer et al.

2013). Several factors make Whatshan Reservoir a suitable site for enhancement using floating nest

platforms. The reservoir has a convoluted shoreline, with secluded lagoons and bays that offer prime

nesting locations. The reservoir also has a relatively small drawdown height, simplifying anchoring

systems. Additionally, data is available on reproductive success, timing of nesting, and causes of nest

failure prior to enhancement, to which the post‐enhancement data can be compared. Five floating nest

platforms were installed at Whatshan Reservoir in 2011. However, nesting was underway at that time


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and the platforms were not used by loons in the initial year (Kellner and van Oort 2011a). In 2012, the

platforms were used by one pair of loons, in spite of the unusual water levels fluctuations in that year.

In 2013, we continued to monitor the use of platforms by loons and the reproductive success of loons

on the reservoir. We documented the durability of the platforms and state of associated vegetation

after two full years of deployment, to assess the suitability, long term durability, and future

maintenance requirements of this technology for enhancement work in Whatshan and other BC

reservoirs. We also expanded the project with the installation of a floating nest platform in Montana

Slough, Upper Arrow Lakes Reservoir, near Revelstoke, in late May 2013, and monitored the use by

loons and the growth of vegetation on this platform.

StudyareaEnhancement work and monitoring was done on Whatshan Lake Reservoir, at 5 locations known to be

within territories of common loons. In 4 cases, the platforms were located at known nesting sites.

Whatshan Lake Reservoir is west of Lower Arrow Lake, immediately north of Hwy 6 at the Needles ferry,

and approximately 55 km southwest of Nakusp, BC (Figure 1. Map showing the location of Whatshan

Lake in south‐central British Columbia..


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Figure 1. Map showing the location of Whatshan Lake in south‐central British Columbia.

The reservoir is approximately 17 km long with a convoluted shoreline and a number of lagoons and

islands. The reservoir supports considerable fish stocks and is valued for its recreational fishery. The

southern end of the reservoir is characterized by high levels of shoreline cottage development and is

used heavily during the summer months for motorized water sports. Water level fluctuations at the

Whatshan Lake Reservoir are controlled throughout the year by the operations of the hydroelectric

power generating plant. These operations are detailed by the Whatshan Lake Reservoir Water Use Plan

(BC Hydro 2005). In this document, it was prescribed that the water levels should be maintained at or

above: 636.5 m during the winter; 639.1 m elevation from May 15th to June 14 th; and, 640.35 m from

June 15 th to October 1st. These target water levels were developed to benefit recreational quality and

fish populations of the reservoir.

Enhancement and monitoring was also done at Montana Slough, Upper Arrow Lakes Reservoir, near a

known nesting site for common loons. Montana Slough is 4 km south of Revelstoke, on the east side of

Upper Arrow Lakes Reservoir (Figure 2). This wetland complex is positioned at ~436 m elevation. The

wetland becomes flooded when the Upper Arrow Lakes Reservoir elevation exceeds 436 m. An

interesting feature of Montana Slough is a floating bog mat that provides riparian habitat as water


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elevations rise, but this mat becomes gradually inundated and has proven to be an unreliable nesting

substrate for loons in previous years (HvO personal observation).

Figure 2. Map showing the location of Montana Slough on the Upper Arrow Lake Reservoir, near Revelstoke, in south‐central

British Columbia.

Methods

PlatforminstallationLoon nesting platforms were pre‐fabricated by Floating Islands West, California

(http://www.floatingislandswest.com). They are approximately 2m X 1.5m in size, and constructed with

durable non‐toxic plastic mesh product that can acts as a rooting substrate for vegetation (Figure 3).

Before planting, the new platform at Montana Slough was entirely wrapped in chicken wire to deter

small mammals from damaging it (Figure 3). Wire cutters were used to create holes for planting, above

each of the planting wells in the original platform. It was then located and planted following the

protocols used for the five platforms at Whatshan Lake (Kellner and van Oort 2011). The exact location

for anchoring was determined by locating the deepest area of Montana Slough from bathymetric maps

(Hawkes et al. 2011), plus considering the location of previous known loon nests.

The platform was anchored with a pulley‐system on each side, to allow the platform to float without

rotating as the reservoir rises, while keeping slack out of the system at lower water levels. Platform

location was chosen so that the water depth (~6 m) at low reservoir elevations exceeded the amount of


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rise needed in the cable to allow the platform to float at full‐pool (~4 m) – thus, the counterweights

should never become grounded, reducing the potential for slack in the lines and possibly entanglement.

Figure 3. The Montana Slough platform wrapped in wire, prior to planting.

MonitoringofnestplatformsandloonreproductivesuccessWe monitored the condition and use of artificial nest platforms and the reproductive success of

Common Loons, from late April to late July, 2013, using the protocol of Kellner and van Oort (2011b).

Monitoring was conducted, weather‐permitting, using a canoe and two observers. If the weather was

not conducive to boating, monitoring occurred from shore where possible. For each of the five platforms

in the territories previously identified on Whatshan Lake (Kellner and van Oort 2011a,b), and for the

Montana territory, we visited nest platforms to assess platform condition and look for use by loons. We

attempted to locate loon pairs, and their nest sites if possible, and determine the number of eggs and

fate of these nests. If loon pairs were accompanied by young, the number, size, colour, and behaviour of

young were recorded (McIntyre and Barr 1997). When a loon or nest was located, a handheld global

positioning system (Garmin Map76CSX) was used to record its location on the reservoir.

DataanalysisandmanagementData from field notebooks were entered in an Excel spreadsheet after each survey. All waypoints were

downloaded and saved on computer, and projected in ArcView to check accuracy of the waypoints and

associated field notes. Data on nest locations and success and the final report are to be submitted to the

Province of BC through the Wildlife Species Inventory submission site. Data on nesting success will also

be submitted to the Canadian Lakes Loon Survey.

We examined observations to estimate dates for nest initiation, start of incubation, and hatching. We

calculated nesting success per year as the number of loon pairs observed with young divided by the

number of territorial loon pairs observed in spring.

Results


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UseofplatformsbyloonsAt Whatshan Lake Reservoir, loons nested on three of the five platforms (South End, Lagoon, and Flicker

Lagoon). A fourth loon pair nested on a rocky shore very near a platform (White Grouse), while in the

fifth territory (North End), we did not observe any loons exhibiting nesting behaviours (paired birds,

localized activity), although a single loon was seen very near the platform. Water levels in 2013 followed

recommendations in the WUP (Figure 4), and although several platforms were still beached in late April,

all were available to loons by our next visit on May 15. At this time, the South End pair was already

incubating their nest on a platform.

At Montana Slough, nesting was underway when the platform was first installed, and no loons used the

platform in 2013.

NestingsuccessandtimingWe located four nests from the four territorial pairs of loons on Whatshan Lake this year. Three were

established on the floating island nest platforms, in the South End, Lagoon, and Flicker territories; these

were first observed with eggs or incubating on May 15, May 28, and June 12, respectively (Figure 4).

One nest, for the White Grouse pair, was not on a floating platform. It was located on May 28 on the

rocky shore of an island just above the water level, and was likely inundated shortly after it was

observed. No re‐nesting attempt was observed after the initial nest site was flooded.

Two of the four breeding pairs on Whatshan Lake Reservoir successfully hatched young in 2013 (50% of

pairs were successful). Two small black young were observed in the South End territory on June 12.

Large, undisturbed eggshell fragments at the Lagoon nest suggested that one young hatched on

approximately June 24. The nest on the platform at Flicker Lagoon appeared to not be incubated and did

not hatch.


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Date

01-Apr 01-May 01-Jun 01-Jul 01-Aug

Re

serv

oir

ele

vatio

n (

m)

634

635

636

637

638

639

640

641

2013 reservoir elevation (m)WUP minimum elevationInitiation date of successful nestsInitiation date of failed nests

Figure 4. Reservoir elevation for Whatshan Lake Reservoir in 2013, minimum water levels prescribed by the WUP, and the

initiation dates for successful and unsuccessful nests. Both successful nests were on floating platforms; 1 unsuccessful nest

was on a platform but not incubated, and one was on shore and was inundated.

At Montana Slough, loons were nesting when the platform was installed on May 28. This nest

subsequently failed by May 27, and the pair re‐nested on the shore in late June when the reservoir was

full. Falling water levels left this nest stranded well above the water’s edge, and it was abandoned in late

July, likely just before hatching. Information on nest locations and fates is detailed in Appendix 1.

PlatformconditionandmaintenanceAll five platforms at Whatshan were still anchored as placed, but required some maintenance for

hardware and vegetation. One anchor cable was worn through (North End platform), and we replaced

that cable and several others that showed signs of wear. These anchors were re‐attached using an

improved system that did not require removing the protective rubber casing from the cables.

As previously, there was some rodent damage (likely from Deer mice (Peromyscus maniculatus)) found

upon first inspection in late April – notably at the North End, Lagoon, and Flicker Lagoon. The damage

constituted of tunnelling through the soft inner matrix. The platforms appeared to suffer some loss of

buoyancy due to removal of this matrix but dried out as the summer progressed (Figure 5. The Flicker


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Lagoon platform in April 2013 (left), showing the loss of buoyancy due to the removal of matrix material

by small mammals. The platform did dry out and support plant growth, and attracted nesting loons

(right). The vegetation on the platforms also showed damage, either from mammals or ice or wave

action. In one case (Lagoon), the damage was fairly extensive and required new soil and re‐planting

(Figure 6. The Lagoon platform in late April 2013 (left), showing loss of soil and vegetation, potentially

caused by ice, waves, or mammals. Although not totally vegetated by late June, this platform was re‐

planted and grew some vegetation, and attracted nesting loons (right).Error! Reference source not

found.). This platform had otter (Lontra canadensis) scat on it, suggesting mustelids may have played a

role in removing the soil and plants.

As in 2012, the vegetation on all platforms looked surprising poor in April and early May, but quickly

became lush, with excellent plant survival and growth as the growing season progressed (Appendix 2). A

wide variety of vegetation continued to grow well on the platforms, including grasses, sedges, rushes,

cattails, various other herbaceous plants, alder, and willow. Platforms were once again left in place for

winter 2013/2014.

Figure 5. The Flicker Lagoon platform in April 2013 (left), showing the loss of buoyancy due to the removal of matrix material

by small mammals. The platform did dry out and support plant growth, and attracted nesting loons (right).


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Figure 6. The Lagoon platform in late April 2013 (left), showing loss of soil and vegetation, potentially caused by ice, waves,

or mammals. Although not totally vegetated by late June, this platform was re‐planted and grew some vegetation, and

attracted nesting loons (right).

OtherwildlifeAt Whatshan Lake, two platform showed signs of fall, winter, or early spring use by otters, based on the

presence of old scat containing fish bones and scales. Three platforms were disturbed by deer mice or

other small mammals, which excavated tunnels into the plastic matrix during the winter months when

the platforms were grounded. As in previous years, after water levels rose, damage from small

mammals ceased. The Montana platform was used extensively by Canada Geese (Branta canadensis) for

resting and grazing. It also housed at least three young Western Toadlets (Bufo boreas) in mid‐summer.

A list of other incidental wildlife observations is included as Appendix 3.

Discussionandmanagementimplications

UseofplatformsandnestingsuccessAs anticipated based on the literature (Piper et al 2002, DeSorbo et al 2007), the use of platforms by

loons increased greatly in 2013, several seasons after being deployed. This is the third summer that the

Whatshan platforms have been in the water, and the loons are obviously familiar with the structures

and find them appealing. The platform at Montana Slough will hopefully attract loons in 2014. The

success of two nests on platforms alleviates concerns about possible increased predation of nests on

platforms. Nevertheless, it seems prudent to ensure that sticks or shrubs remain in place on the

platforms as protection against avian predators.

We documented the platforms at Whatshan and Montana being used by several species other than

loons, including small mammals, otters, Canada Geese, and Western Toads. Use by other species may

have occurred but not been detected. The vegetated islands clearly add to the diversity of habitats

available, and potentially benefit many wildlife species through providing foraging habitat, resting spots,

or cover.


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In previous years of study at Whatshan lake Reservoir, loons used a variety of natural and man‐made

floating structures, as well as sites along the shore, to nest on. Results in 2013 (two successful platform

nests, one flooded shore nest) support the idea that nests on floating platforms are more likely to

succeed than those on shore, in this reservoir (Kellner and van Oort 2011a,b, Kellner and van Oort 2012)

and elsewhere (McIntyre and Barr 1997, Piper et al 2002). This project has succeeded in increasing the

number and relative permanence of available floating structures at Whatshan Lake Reservoir, as well as

locating the available structures farther away from human disturbance.

The floating platforms allowed successful nests to be initiated earlier than if nests were on shore, where

nests can only be initiated successfully once the reservoir is near full pool. The two successful nests in

2013 had very early initiation dates relative to those in previous years (Table 1), even in relation to nests

on other floating substrates (a dock and natural floating platforms such as root balls). Since delayed

nesting is thought to potentially have implications for size at fall migration, juvenile survival, and future

reproduction (Newton and Marquiss 1984, Hochachka 1990, Naef‐Daenzer et al. 2001), hopefully the

early nesting dates at Whatshan increase the chances that juvenile loons survive to adulthood, to be

recruited into the breeding population.

Table 1. Start dates for successful nests at Whatshan Lake, year of nest, and substrate used for nesting. Note early start dates

for nests on artificial nest platforms, and paucity of successful shore nests.

Incubation start date for successful nests Year Nest substrate

May 15 2013 Nest platform

May 19 2011 Natural floating platform

May 28 2013 Nest platform

May 30 2010 Shore

Jun 8 2012 Floating dock

Jun 6 2008 Shore

Jun 6 2008 Natural floating platform

Jun 15 2009 Natural floating platform

Jun 25 2011 Shore

PlatformconditionThe platforms and anchoring systems were generally in good condition after two winters. The main

issues and repairs were:

1. damage by small mammals and/or possibly otters. The new platform at Montana was wrapped

in chicken wire before deploying. The state of the wire will be assessed in spring 2014. There

were concerns that the texture of the wire may deter birds; however, the wire‐wrapped

platform was heavily used by geese, suggesting that it will be ok. Planted platforms cannot be

retro‐fitted with wire. Future installations should consider a wire treatment or discuss options

with the manufacturer.


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2. corrosion and breaking of some anchor cables – these were replaced using a new attachment

system used that does not require stripping of the protective plastic coating, and should

therefore not suffer from corrosion issues. This system will be assessed in 2014.

Entangling of cables, noticed in 2012, was not a problem in the spring of 2013. However, because of the

low water levels in winter and the abundance of stumps and logs in the reservoir, entanglement is likely

always going to be a potential problem at Whatshan. The Montana Slough platform should not suffer

from entanglement, because the water is sufficiently deep to allow counterweights to remove slack

form the anchor system, without the counterweights and lines getting ‘grounded’. This is certainly a

preferable scenario for deploying platforms, but may be relatively rare in areas of reservoirs used as

nesting sites.

Because of these issues, it is important that the anchoring systems and floatation of the platforms

should be checked every spring to ensure that the platforms are correctly positioned and functioning

properly, as recommended in 2012. We continue to agree with the manufacturer that it seems

unnecessary to remove platforms over‐winter, unlike the recommended protocol for conventional cedar

rafts (NALF 2005, DeSorbo et al 2008). This makes Floating Islands attractive for enhancement work

since they do not require scheduled yearly spring installation and fall removal.

RecommendationsBased on the need to do spring maintenance, and the excellent results of increasing platform use in

2013, we recommend another year of monitoring the state and use of platforms and the reproductive

success of loons at Whatshan and Montana Slough. Specifically,

Because of the unusual conditions in 2011/2012, and guidelines suggesting 3 years of monitoring as

appropriate to determine the level of use of platforms (DeSorbo et al 2007), we recommend another

year of monitoring, similar to the previous year, and including:

1. a site visit early spring to ensure that anchoring systems are functioning properly and platforms

are properly buoyant under normal water levels,

2. inspection of all anchor cables for wear and potentially converting them all to the new system, if

the few cables repaired in 2013 have over‐wintered well,

3. monitoring of use of platforms or natural nests by loons in early May and June, with efforts to

determine causes of any nest failures on platforms,

4. monitoring hatching success of loons in July, and

5. write‐up and publishing of results from platform installations as a peer‐reviewed paper,

documenting findings about the platforms and anchoring systems, as well as the use of

platforms by loons and implications on reproductive success.

AcknowledgementsFinancial support was contributed by the Fish and Wildlife Compensation Program‐ Columbia. We are

especially grateful to Irene Manley for her ongoing support and enthusiasm. We are grateful to Cooper


17

Beauchesne and Associates Ltd., who provided information regarding the nest monitored in Montana

Slough as part of the BC Hydro CLBMON‐36 project.

ReferencesBC Hydro. 2005. Whatshan project water use plan: revised for acceptance by the comptroller of water

rights. Accessed at http://www.bchydro.com/etc/medialib/internet/documents/environment/pdf/wup_whatshan_water_use_plan_pdf.Par.0001.File.wup_whatshan_water_use_plan.pdf

Campbell, R.W. M.I. Preston, L.M. Van Damme, D.C. Evers, A. Roberts, and K. Andrews. 2008. Featured

species – Common Loon. Wildlife Afield 5(1): 54‐ 146.

North American Loon Fund. 2005. Instructions for building an artificial nesting platform for loons.

Canadian Lakes Loon Survey/ Bird Studies Canada.

DeSorbo, C., K.M. Taylor, D.E. Kramar, J. Fair, J.H. Cooley, Jr., D. C. Evers, W. Hanson, H.S. Vogel, J.L.

Atwood. 2007. Reproductive advantages for Common Loons using rafts. Journal of Wildlife

Management 71(4): 1206 ‐1213.

DeSorbo, C., J. Fair, K.M. Taylor, W. Hanson, D. C. Evers, H.S. Vogel, J.H. Cooley, Jr. 2008. Guidelines for

constructing and deploying Common Loon Nesting Rafts. Northeastern Naturalist 15(1): 75‐86.

Hawkes, V.C., M.T. Miller, J.D. Fenneman, and N. Winchester. 2011. CLBMON‐11B4 Monitoring Wetland

and Riparian Habitat in Revelstoke Reach in Response to Wildlife Physical Works. Annual Report –

2010. LGL Report EA3232. Unpublished report by LGL Limited environmental research associates,

Sidney, BC, for BC Hydro Generations, Water License Requirements, Burnaby, BC. 76 pp +

Appendices.

Hochachka, W. 1990.Seasonal decline in reproductive performance of Song Sparrows. Ecology 71:1279‐

1288.

Kellner, M. and H. van Oort. 2009. Whatshan project water use plan: Whatshan wildlife monitoring (year

4). Prepared for BC Hydro Water License Requirements, Castlegar BC, by Kingbird Biological

Consultants Ltd., Revelstoke, BC.

Kellner, M. and H. van Oort. 2011b.Whatshan Water Use Plan Monitoring Program: Wildlife Monitoring.

Study Period 2008 – 2010. Fish and Wildlife Compensation Program. 26pp.

Kellner, M. and H. van Oort. 2011a. Enhancement and monitoring of nesting habitat for Common Loons

(Gavia immer) on Whatshan Lake Reservoir. Fish and Wildlife Compensation Program. 23pp.

McCann, N., D. Haskell, M.W. Meyer. 2004. Capturing Common Loon nest predators on 35mm film. The

Passenger Pigeon 66(4): 351‐361.

Loon Preservation Committee. 2012. Loon Preservation Committee Newsletter – summer 2012.

www.loon.org.


18

McIntyre, J.W. and J.F. Barr 1997.Common Loon (Gavia immer); the Birds of North America. The

Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union,

Washington, D.C.

Naef‐Daenzer, B., F. Widmer and M. Nuber. 2001. Differential post‐fledging survival of great and coal tits

in relation to their condition and fledging date. Journal of Animal Ecology 70:730‐738.

Newton, I. and M. Marquiss. 1984. Seasonal trend in the breeding performance of Sparrowhawks.

Journal of Animal Ecology 53: 809‐829.

Piper, W.H., M.W. Meyer. M. Klich, K.B. Tischler, and A. Dolsen. 2002. Floating platforms increase

reproductive success of Common Loons. Biological Conservation 104 (2002) 199–203.

Timmermans, S. and K. Jones. 2002. Canadian Lakes Loon Survey National Report: Western Loons have

higher productivity than eastern Loons. Bird Watch Canada Newsletter:18‐19.

Tozer, D. C., C. M. Falconer, and D. S. Badzinski. 2013. Common Loon reproductive success in Canada:

the west is best but not for long. Avian Conservation and Ecology 8(1): 1.

http://dx.doi.org/10.5751/ACE‐00569‐080101

van Oort, H. and M. Kellner. 2007. Whatshan project water use plan: Whatshan wildlife monitoring (year



van Oort, H. and M. Kellner. 2008. Whatshan project water use plan: Whatshan wildlife monitoring (year



Utzig, G. and D. Scmidt. 2011. Dam footprint impact summary. Fish and Wildlife Compensation Program.

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Kingbird Biological Consultants: Loon habitat enhancement and nesting success 2013 19

Appendix1.Loonnestinformation

Table 2. Location, descriptions, and fates of loon nests on Whatshan Lake and Montana Slough, Upper Arrow Lake, 2013.

Date located Reservoir‐Territory Nest ID UTM_X UTM_Y Description # eggs Fate

15‐May‐13 Whatshan‐ South End SE‐1‐13 419813 5529965 On platform 2 Hatched 2 young approximately 10

Jun.

28‐May‐13 Whatshan‐ Lagoon LG‐1‐13 421590 5535075 On platform. Mud and grass

nest.

2 Hatched 2 young (based on eggshell

fragments) approximately 20 Jun.

28‐May‐13 Whatshan‐ White

Grouse

WG‐1‐13 421255 5539469 Scrape amongst rocks on

shore of island; very close to

floating island.

1 Failed – flooded.

12‐Jun‐13 Whatshan‐ Flicker FL‐1‐13 421934 5536265 On platform. 1 Failed ‐ pair did not incubate.

15‐May‐13 Arrow ‐ Montana MO‐1‐13 418762 5643927 Mud and grass, on natural

floating bog mat.

Unk Failed – flooded.

21‐Jun‐13 Arrow‐ Montana MO‐2‐13 418677 5643988 Grass, on bog mat. 2 Failed – stranded as water levels

dropped.


20

Figure 7. Successful nests on Whatshan Lake in 2013: the South End platform nest SE‐1‐13, located on May15 (left), and the

Lagoon platform nest LG‐1‐13, located on May 28 (right).

Figure 8. Unsuccessful nests located at Whatshan Lake in 2013: the White Grouse shore nest WG‐1‐13 on May 28 (left) and

the Flicker Lagoon platform nest FL‐1‐13 on June 12, which appeared to not be incubated (right).


Appendix2.PhotologofplatformconditionandplantdevelopmentonplatformsduringYear3

Figure 9. Flicker Lagoon (FL) platform in late April (left), May (centre), and late June (right). The platform was excavated by small mammals in the winter, leading to loss of

buoyancy. However, it dried out in the summer and was used for nesting, although the nest failed.

Figure 10. The Loongoon (LG) platform in late April (left) showing damage from ice or mammals, its use by loons in May (centre), and its state in late June after the nest

hatched (right).


Figure 11. The North End (NE) platform in May (left) and at the end of the growing season in August (right).

Figure 12. The South End (SE) platform still stranded on Apr 28 (left), and being used for nesting in late May (right).


Figure 13. The White Grouse (WG) platform in late April (left), late May (centre), and late June (right).

Figure 14. The Montana Slough (MO) platform when first deployed in May (left), after being heavily grazed by Canada Geese in June (centre), and regrown after Geese

moved on, in July (right).


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Appendix3.IncidentalobservationsofwildlifeatWhatshanLake,2013Table 3. Incidental wildlife observations, 2013.

Date Location Species Number Comments

28‐Apr S end mallard 2

28‐Apr S end Canada Geese

28‐Apr S end Varied Thrush

28‐Apr S end Black‐capped chickadee

28‐Apr S end Dark‐eyed junco

28‐Apr S end ruby‐crowned kinglet

28‐Apr S end moose 1 tracks in drawdown zone

28‐Apr Loongoon wolf 1 tracks in drawdown zone

28‐Apr Loongoon otter scat on platform

28‐Apr White Grouse wolf scat in drawdown zone

28‐Apr White Grouse otter scat on platform

28‐Apr S end of N lake kingfisher 1

28‐Apr Flicker kingfisher 3 flying high screeching

28‐Apr N end osprey 1

28‐Apr N end common merganser 2

28‐Apr N end scaup 2

28‐Apr N end S lake common merganser 2

28‐Apr Flicker deer 2 in drawdown zone

28‐Apr Loongoon swallows

28‐Apr Flicker swallows

13‐May S end deju

13‐May S end yrwa

13‐May S end flycatchers

13‐May S end osprey 1 on nest along powerline

13‐May Loongoon nuthatch

13‐May Loongoon osprey

13‐May Loongoon Canada Geese

13‐May Loongoon yrwa

13‐May Loongoon robin

13‐May Loongoon flycatchers

13‐May Flicker red eyed vireos

13‐May White Grouse Canada Geese 4 fluffy yellow young

27‐May Montana Canada Geese not seen, but platform is covered in droppings

28‐May N end swainson's thrush

28‐May N end flycatchers

28‐May S end osprey incubating nest on powerline

26‐Jun S end N lake kingfisher

26‐Jun Middle lake Grebe ‐ eared? Horned?

26‐Jun N end S lake bald eagle

26‐Jun Loongoon violet green swallows

30‐Jun Montana Western Toad 3 toadlets! On platform.

loon habitat enhancement whatshan reservoir 2013 1

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