LAKE UMBAGOG NATIONAL WILDLIFE REFUGE

ECOSYSTEM STUDY

LOON FAMILY DISTURBANCE PILOT

DRAFT FINAL REPORT

JULY 2006

Prepared by

Carol R. Foss, Ph.D.

Audubon Society of

LAKE UMBAGOG NATIONAL WILDLIFE REFUGE LOON FAMILY DISTURBANCE PILOT STUDY

Introduction

The Lake Umbagog National Wildlife Refuge Ecosystem Study is a multi-year, multi-disciplinary investigation intended to address two over-arching questions:

. What are the critical factors that influence abundance, distribution, and productivity of focal species within the Lake Umbagog NWR?

. How can management actions affect critical factors to benefit populations of focal species on the Lake Umbagog NWR?

The study design includes the following components:

Public Use Component . Baseline use . Human Dimensions . Impacts on Wildlife

System Analysis Component . Water characteristics . Focal species population dynamics . Food resources . Habitat composition . Interspecies disturbance

Contaminants . Analysis of archived eggs . Analysis of waters and sediments . Analysis of food chain tissue samples

The Common Loon is a focal species on the Refuge, and family disturbance, particularly during the first 10 days after hatching, can reduce chick survival rates and lower overall productivity. Such disturbance may result from the activities of humans, other wildlife species, or interactions of the two.

Loon chick mortality may result from starvation (submissive chicks), sibling-inflicted injury, trauma from collisions with boats and water skiers, infections, parasite infestations (nematodes and cestodes), and predation (McIntyre and Barr 1997). Known predators of loon chicks that occur in the Lake Umbagog ecosystem include Bald Eagle (Haliaeetus leucocephalus), gulls (Larus spp.), and snapping turtle (Chelydra serpentina) (McIntyre and Barr 1997). Bass (Micropterus sp.), Pickerel (Esox niger), Bullfrog (Rana catesbeiana), Mink (Mustela vison), and Great Horned Owl (Bubo virginianus) are known predators of ducklings (Eadie et al. 1995, Hepp and Bellrose 1995, Hohman and Eberhardt 1998, Longcore et al. 2000, Mallory and Metz, 1999, Mobray et al. 2002), and may predate recently hatched loon chicks. Breeding loons are known to defend their nesting territory against beaver (Castor canadensis), otter (Lutra canadensis), raccoon, coyote (Canis latrans), and waterfowl, providing additional opportunities for interspecies disturbance (McIntyre and Barr 1997).

Extensive literature documents impacts of human disturbance on loon productivity (Titus and Vandruff 1981, Smith 1981, Heimberger et al. 1983, Valley 1987, McIntyre 1988, Jung 1991, Caron and Robinson 1994, Kelly 1992, Weeber 1999, Mills 2000). While incubation is the period of greatest vulnerability, human activity can pose risks to chicks as well. Boating activity can separate chicks from their parents, increasing their vulnerability to predation, and injuries from boat propellers and jet skis are known agents of chick mortality (McIntyre and Barr 1997). Education of recreationists, particularly through personal contact at boat ramps, is the primary management tool available to address human disturbance of family groups (Kelly 1992, Hamann et al. 1999).

The research priority with respect to family disturbance of Common Loons at the Lake Umbagog National Wildlife Refuge is to better understand the frequency, extent, and effects of disturbance to loon families from human or other wildlife activity during the post-hatching period. Thus, the objectives of this pilot study were to . field test study protocols and logistics . collect preliminary data on types and frequencies of potential disturbance incidents, and . collect preliminary data on behavioral responses of loon families to potential disturbance agents. This project addresses both public use (impacts on wildlife) and systems analysis (focal species population dynamics and interspecies disturbance) components of the Ecosystem Study’s research plan.

Study area

The study area included major water bodies within the Lake Umbagog National Wildlife Refuge, including Lake Umbagog; the and associated wetlands between the Route 16 bridge in Magalloway Plantation, , and the in New Hampshire; and the Androscoggin River and associated wetlands between Lake Umbagog and the Errol Dam in Errol, New Hampshire (Figure 1). Pilot observations focused on five Common Loon territories, which were located along the Magalloway River (Upper Magalloway), at the confluence of Lake Umbagog and the Androscoggin and Magalloway rivers (River Junction), in the northwest corner of Lake Umbagog (Leonard Marsh), and in large coves on the northeast (Glassby Cove) and southeast (Stateline Cove) sides of Lake Umbagog, respectively (Figure 2).

Methods

Field Observations Weather permitting, field staff surveyed each active territory approximately once every two days, rotating visits among morning (6-10:30 a.m.), mid-day (10:30 a.m.-3 p.m.), and afternoon (3-7:30 p.m.) observation periods. Observation periods were increased from 15 minutes during 20-23 June to 1 hour during 24 June – 18 July and 3 hours during 20 July – 5 September. Observation periods were occasionally truncated by threatening weather conditions.

Field staff conducted family observations for a total of 143.6 hours on 45 days from 20 June through 7 September (Table 1). Unsuccessful attempts to locate a given family during four additional observation periods accounted for another 5.41 hours of field time.

Table 1. Observation effort for five Common Loon families on Lake Umbagog National Wildlife Refuge during the 2005 breeding season.

Loon Terrritory Observation Observation Time frame of Hours Days observations Glassby Cove 18.961 141 20 June – 4 August Leonard Marsh 66.89 19 18 July – 7 September River Junction 8.00 6 11 – 26 July Stateline Cove 39.63 22 20 June – 9 August Upper Magalloway 33.13 22 20 June – 15 August

1 Includes 5.41 hours of unsuccessful searching for family on 4 observation days.

On entering a loon territory, field staff documented the time, UTM coordinates (with GPS), and any boats currently within 200 m of the loon family. Observations were conducted from watercraft (motor boats and kayaks) located > 200 m from loon families. While initially locating the family, staff occasionally approached within 200 m, particularly when family members were somewhat separated on the open lake. Staff documented time of first sighting for each adult and chick and time of any significant change in location; time, type, and activity of all boats within and exceeding 200 m distance from the loon family during the observation period; and time and activity of any potential chick predators within 200 m of the family. Maps were used to document locations and movements of loons, boats, and potential predators.

Observed watercraft and wildlife were categorized as within or exceeding 200 m from the loon family, and those within 200 m were considered potential intrusions. Loon behavior during the approach of a potential intruder was categorized as response to the intrusion or non-response. Behaviors considered to be responses include vocalizations, aggressive or defensive postures or actions, and leaving the vicinity of the intrusion. Behaviors considered to be non-responses include continuation of whatever activities were occurring prior to the potential intrusion.

Analysis We categorized human intrusions as motor boat, paddle craft (canoes and kayaks), fishing, or other (which included swimmers, a low-flying floatplane, and a swimming dog; and wildlife intrusions as Bald Eagle, Common Loon, or other (which included moose, Canada geese, and Northern Harrier). We used Mann-Whitney U tests to evaluate whether intrusion rates differed significantly between human and wildlife intrusions and whether total intrusion rates differed significantly among families. We used chi square goodness of fit tests to evaluate whether response rates differed significantly between human and wildlife intrusions.

Results

Field staff observed 65 human intrusions, eliciting 20 responses, and 18 wildlife intrusions, eliciting 15 responses, during the 161.03 hours of observations. Both human and wildlife intrusion rates were highest for the River Junction family (2.13/hr, 0.25/hr respectively). The Glassby Cove family experienced the lowest human (0.07/hr) and the State Line Cove family the lowest wildlife (0.025/hr) intrusion rate (see Table 2). Human intrusion rates averaged 0.40/hr over the five families; both Upper Magalloway and River Junction rates were above the average. Wildlife intrusion rates averaged 0.11/hr; only the Stateline Cove rate was below this average. (If Stateline Cove’s extremely low rate is ignored, rates for the other four sites averaged 0.17/hr; only River Junction exceeded this rate.)

Table 2. Total observation time, numbers and (hourly rates) of human and wildlife intrusions, and response numbers and (rates per intrusion) for 5 Common Loon families in the Lake Umbagog National Wildlife Refuge during the 2005 breeding season.

Loon Terrritory Observation Human Wildlife Hours1 Intrusions Responses Intrusions Responses Glassby Cove 14.59 1 (0.07) 0 (0) 2(0.14) 2(1.0) Leonard Inlet 66.89 11 (0.15) 4 (0.36) 8(0.12) 6(0.75) River Junction 8.00 17 (2.13) 3 (0.18) 2(0.25) 2(1.0) Stateline Cove 39.63 10 (0.25) 4 (0.40) 1(0.025) 0(0) Upper Magalloway 31.92 26 (0.91) 9 (0.35) 5(0.16) 5(1.0) Total (mean) 161.03 65(0.40) 20(0.31) 18(0.11) 15(0.83)

1 Includes only time during which family was in view. Motorboats created the highest observed human intrusion rates overall (0.24/hr) and the highest intrusion rates for the Leonard Inlet, River Junction, and Upper Magalloway families; paddlers created the highest rate for Stateline Cove. Bald Eagles and other adult loons created similar intrusion rates overall (0.050/hr and 0.043/hr, respectively) and for individual families.

Table 3. Numbers and (hourly rates) for four categories of human and three categories of wildlife intrusions for five Common Loon families in the Lake Umbagog National Wildlife Refuge during the 2005 breeding season.

Glassby Leonard River Stateline Upper Total Disturbance Inlet Junction Cove Magalloway Human Fishing 1 (.068) 0 4(0.50) 4(0.07) 0 9(0.055) Motorboat 0 9(0.13) 11(1.38) 1(0.03) 17(0.53) 38(0.24) Paddlers 0 1(0.01) 2(0.25) 4(0.10) 7(0.22) 14(0.087) Other 0 1(0.01) 0 1(0.03) 2(0.06) 4(0.025) Subtotal 1(0.068) 11(0.16) 17(2.13) 10(0.25) 26(0.81) 65(0.40) Wildlife Bald Eagle 1(0.068) 2(0.030) 1(0.125) 1(0.025) 3(0.094) 8(0.050) Loon(s) 1(0.068) 3(0.045) 1(0.125) 0 2(0.063) 7(0.043) Other 0 3(0.045) 0 0 0 3(0.019) Subtotal 2(0.14) 8(0.12) 2(0.25) 1(0.025) 5(0.16) 18(0.11) Total 3(0.21) 19(0.28) 19(2.38) 11(0.28) 31(0.97) 83(0.51)

Although the overall human intrusion rate (0.40/hour) was nearly four times the overall wildlife intrusion rate (p=11/hr), the Mann-Whitney U test failed to find statistical significance (p=0.446). Similarly, overall intrusion rates for the five families ranged from 0.21/hr to 2.38/hr, but these differences were not statistically significant. The chi square goodness of fit test indicated a significant difference in response rates between human and wildlife intrusions (p=0.000).

Glassby Cove

The family moved out of Glassby Cove soon after hatch and spent much of their time in mid-lake, where they were difficult to locate and monitor. A summary of observations follows.

20 June, 1015-1040 hrs: One adult in Glassby Cove; one adult and chick in Spillman Cove. No intrusions to either site.

24 June, 1130-1230 hrs: One adult located on south side of B Brook Cove, became agitated at Bald Eagle flyover. Other adult and chick not located.

25 June, 0945-1030 hrs: Unsuccessful attempt to locate family.

26 June, 1535-1638 hrs: Pair and chick in mid-lake. Six boats >200 m from family.

27 June, 850-950 hrs: Family together in mid-lake. No obvious response to fisherman <200 m from family.

1 July, 1035-1240 hrs: Unsuccessful attempt to locate family.

3 July, 1625-1725 hrs: Family in open lake off Pine Point. Four boats >200 m from family.

6 July, 1125-1225 hrs: Both adults observed in Glassby Cove near nesting island, chick not located (stashed in vegetation?). No intrusions.

7 July, 1640-1745 hrs: Family in open lake off Moll’s Rock. Two boats and 3 kayaks >200 m from family.

11 July, 1045-1147 hrs: Family in open lake off Moll’s Rock. Six boats >200 m from family.

13 July, 915-1015 hrs: Female and chick off point between Glassby and Spillman coves; male off Glassby Cove. Bald Eagle soars over River Junction (>> 200 m away), male approaches female and chick. Four boats on opposite side of lake heading north.

26 July, 1505-1805 hrs: One adult and chick off Moll’s Rock, one adult toward Pine Point. In addition, one adult leaving Glassby Cove, 2 adults off B Brook Cove, 4-loon confrontation mid-lake between Pine Point and Leonard Pond. Four outboards and 3 pontoon boats >200 m from family. Jet-ski passes between family and Moll’s Rock. No observed response.

2 August, 1215-1315 hrs: Unsuccessful attempt to locate family.

4 August, 1030-1330 hrs: One adult and chick about 300 m off Pine Point; additional pair near mouth of Glassby Cove. Pair approaches and confronts adult with chick. Chick vocalizes during confrontation, becomes separated from adult, moves to mid-lake, reunited with adult 2.75 hrs after onset of confrontation.

9 August, 1230-1405 hrs: Unsuccessful attempt to locate family.

Leonard Marsh

18 July, 1215-1330 hrs: Pair and two chicks together just outside Leonard Marsh Inlet. One pontoon boat > 200m from family.

20 July, 1200-1500 hrs: Family together near mouth of Leonard marsh inlet. Two boats >200 m away in middle of lake. Adults and chicks hug shore when boat follows shoreline of Leonard Marsh.

21 July, 1617-1915 hrs: Pair and one chick near Leonard Marsh shoreline south of inlet. No intrusions.

22 July, 0935-1335 hrs: Initially one adult and chick off Leonard Marsh Inlet, second adult soon joins from south. Chick climbs onto adult’s back shortly after immature Bald Eagle flyover. Male gives distress call when 5 kayaks approach family. Male charges intruder adult loon that approaches family.

23 July, 0805-1105 hrs: Pair and one chick just south of Leonard Marsh Inlet. Male yodels, dives, and bill-dips when intruder adult loon approaches family. Pair wails when Bald Eagle soars overhead.

25 July, 0930-1230 hrs: Pair and one chick off Leonard Marsh Inlet. No obvious response to boat following Leonard Marsh shoreline about 100 m from family.

26 July, 1215-1515 hrs: One adult and one chick observed. No obvious response to moose swimming offshore for about 15 minutes.

1 August, 1400-1700 hrs: Pair and chick together off Leonard Marsh north of Inlet. No intrusions.

3 August, 1050-1350 hrs: Pair and chick in lake northeast of Leonard Marsh Inlet. No intrusions.

6 August, 1130-1430 hrs: Pair and chick off Leonard Marsh south of inlet. No intrusions.

8 August, 0840-1140 hrs: Pair and chick off Leonard Marsh near inlet. No obvious response to boat travelling along shore.

15 August, 1200-1530 hrs: Pair and chick located off Leonard Marsh nearly 2 hours into observation period. Prior to location, 2 kayaks travel along shore of Leonard Marsh and 2 jets fly low over north end of lake. Subsequent to location no obvious response to float plane flight low over north end of lake.

18 August, 1300-1600 hrs: Adults and chick in open lake well off Leonard Marsh. No intrusions; fishing Osprey, 4 Canada Geese in distance.

25 August, 1430-1730 hrs: Pair and chick initially in open lake between Pine Point and south end of Leonard Marsh. Intruding adult loon approaches family, subsequent hooting, subsequent movement toward Leonard Pond and north along Leonard Marsh shoreline toward inlet. No obvious response to boat, Northern Harrier, and Great Blue Heron all >200 m from family.

26 August, 1230-1530 hrs: One adult with chick near shore of Leonard Marsh. No obvious response to 2 small motorboats within 30 ft. Chick moves towards shore when intruding adult loon wing-rows towards and then away from family. Adult subsequently calls to and reunites with chick. Second adult later joins family. No obvious response to motorboat within 50 ft of family. No obvious response to immature Bald Eagle soaring over Pine Point.

30 August, 1220-1520 hrs: One adult and chick off Leonard Marsh. No obvious response to Northern Harrier foraging over Leonard Marsh.

1 September, 1140-1440 hrs: One adult and chick off Leonard Marsh. Adult calls in response to observer arrival. No obvious response to high-flying jet. No response to 2 kayaks >200 m away, adult loon flying over north end of lake, Osprey foraging over Leonard Marsh shoreline, female mallard flying over Leonard Marsh, immature Bald Eagle perched in north end of Leonard Marsh.

5 September, 1315-1615 hrs: One adult off River Junction; chick alone and preening off Leonard Marsh, no obvious reaction to Osprey flyover; second adult calls from north end of marsh, sees observer, calls to and moves toward chick; no obvious response to jet ski passing > 200 m away or motor boat that passes <200 m from loons.

7 September, 1240-1550 hrs: Pair and chick off Leonard Marsh near inlet. No response to motor boat > 200 m away, 4 Canada Geese on Leonard Marsh shore very close to loons.

River Junction

11 July, 1205-1305 hrs: Family together in lake south of channel markers. No obvious response to 3 motorboats traveling in channel and one canoe between the family and the shoreline of River Junction islands.

12 July, 1605-1705 hrs: Family together in lake off Chewonki Marsh. No obvious response to 3 boats travelling in channel. Male yodels and approaches boat fishing near Chewonki Marsh.

13 July, 0915-1015 hrs: Family together in lake off Leonard Pond islands. No obvious response to 2 boats travelling in channel or boat fishing near channel markers.

14 July, 1400-1500 hrs: Family together in lake north of channel markers. Male yodels at group of people talking loudly while passing nearby in 5 canoes and 3 kayaks, female wails, chick gets on female’s back; male yodels at boat passing full speed approximately 20 m from family.

15 July, 0710-0810 hrs: Family initially together in lake off nesting area, subsequently moves toward open lake, one adult leaves, chick moves alone to Chewonki Marsh. No obvious response to 3 boats fishing at lake and river fringes.

26 July, 0500-0800 hrs: Pair and chick off Chewonki Marsh. Male yodels at immature Bald Eagle flyover. Male tremulos twice after chick becomes separated from adults in fog; chick hoots and joins parents. Adults stash chick in emergent vegetation of Chewonki Marsh to confront approaching Sweatt Meadow loon pair. No obvious response to 2 boats travelling in channel.

Stateline Cove

20 July, 0945-1005 hrs: One adult and 2 chicks at back of Stateline Cove. One boat near shore south of cove >200 m away. Family joins second adult near northern edge of cove towards end of observation period.

23 June, 1030-1100 hrs: Pair and 1 chick in north arm of Stateline Cove. Beaver in south arm of cove. No obvious response to approaching pontoon boat.

24 June, 1310-1355 hrs: One adult and 1 chick at back of Stateline Cove. One boat in lake beyond islands at mouth of cove, >200 m from family.

25 June, 0830-0930 hrs: Pair and chick near back of Stateline Cove. Fisherman works area near loons, they move to Tyler Cove.

26 June, 1649-1750 hrs: One adult and chick in north arm of Stateline Cove. No obvious response to campers on island (site #35).

27 June, 1100-1200 hrs: Pair and chick just inside second island in Stateline Cove. Campers approaching in canoe agreed to stay away from loon family.

28 June, 1030-1135 hrs: One adult and chick in north arm of Stateline Cove, second adult near mouth of cove. Campers present on island (site #35).

1 July, 1203-1303 hrs: One adult and chick in Tyler Cove, other adult between Tyler and Stateline coves yodeling. Four motorboats and two kayaks enter Tyler Cove. Adult with chick leave Tyler Cove to join other adult near island between coves.

3 July, 1520-1620 hrs: Pair and chick near island between Stateline and Tyler coves. Four motorboats in Tyler Cove and one motorboat enters Stateline Cove, all >200 m from family.

4 July, 1110-1210 hrs: One adult Stateline Cove, vocalizing in apparent response to fishing boat in Cove. Other adult in Tyler Cove. Campers at Tyler Cove site. Unsuccessful in locating chick.

6 July, 1018-1115 hrs: Pair and chick near second island in Stateline Cove. No intrusions.

7 July, 1525-1625 hrs: Adult with chick off north shore of Tyler Cove. Other adult between island with campsite and Island. Voices audible from beach in Tyler Cove >200 m from family.

14 July, 1105-1205 hrs: Family in northern portion of Stateline Cove. Campers at site #35. No intrusions.

21 July, 1145-1445 hrs: Pair with chick near island in back of Stateline Cove. Campers on Blake Island and on shore of Tyler Cove. Fisherman follows loon family at distance >200 m. Family moves into Tyler Cove. One kayaker in Tyler Cove. One adult moves into open lake, other adult and chick remain in Tyler Cove. Eventually fishing boat departs, adult and chick move back towards original location, second adult joins family, wind picks up, and group moves to area between Blake islands.

25 July, 0930-1230: One adult with chick near beach in Tyler Cove, other adult off shore south of Stateline Cove. No intrusions.

28 July, 1300-1600 hrs: Pair with chick off shore south of Stateline Cove. No obvious response to Bald Eagle flyover, passing motorboat >200 m away.

30 July, 1300-1600 hrs: Pair with chick near mouth of Stateline Cove. Two motorboats pass from south toward Tyler Cove >>200 m away.

1 August, 1030-1330 hrs: Pair and chick near small island in back of Stateline Cove. No obvious response to fishing boat and 2 canoes in cove.

3 August, 1320-1630 hrs: One adult and chick near shore between Tyler and Stateline coves. No intrusions. High winds with large waves.

6 August, 1615-1915 hrs: One adult and chick off north shore of mouth of Stateline Cove. No obvious response to 2 kayaks following shoreline.

9 August, 1420-1720 hrs: One adult and chick near small island in back of Stateline Cove. Two motorboats >200 m.

Upper Magalloway

24 June, 1630-1730 hrs: One adult with chick at back of Horseshoe Pond. No obvious response to single boat on Magalloway River.

25 June, 0700-0802 hrs: Family together in main river channel. No obvious response to 2 boats travelling Magalloway River.

27 June, 1218-1318 hrs: One adult and chick in emergent vegetation on west side of Upper Magalloway logan; second adult enters logan from river. No intrusions.

30 June, 1705-1810 hrs: One adult and chick in Horseshoe Pond; second adult enters pond from river. No obvious response to 3 boats travelling Magalloway River.

1 July, 0842-0915 hrs: Pair with chick in Horseshoe Pond. No obvious response to 3 boats travelling Magalloway River.

2 July, 1045-1200 hrs: Pair with chick on southwest side of Upper Magalloway logan. No obvious response to 4 boats travelling Magalloway River. Adults wailed and hooted when 2 kayaks in logan.

3 July, 1730-1830 hrs: Family together in Pulpit Rock logan. No obvious response to 14 boats travelling Magalloway River.

4 July, 1547-1650 hrs: Family together in Pulpit Rock logan. No obvious response to 3 boats travelling Magalloway River.

6 July, 1736-1840 hrs: Family together in back of Upper Magalloway logan near nest site. Male yodels at immature Bald Eagle flyover; family then relocates to Horseshoe Pond.

8 July, 0545-0700 hrs: Family together at mouth of Upper Magalloway logan. No intrusions.

11 July, 1050-1150 hrs: Unsuccessful attempt to locate family.

12 July, 1550-1650 hrs: Family foraging in mouth of Upper Magalloway logan. No obvious response to 6 boats travelling Magalloway River. Adults vocalize and chick dives when immature eagle swoops at chick. Pontoon boat with photographer makes close approach to family; adults vocalize while moving chick upriver to Pulpit Rock logan with pontoon boat following closely.

25 July, 1745-2045 hrs: Family together in main channel of Magalloway River. Male yodels when boat approaches closely; family soon moves to Horseshoe Pond. No obvious response to subsequent boat travelling upriver and back on Magalloway.

28 July, 0830-1110 hrs: Family in Upper Magalloway logan. No obvious response to 4 kayaks travelling Magalloway River. Mail wails when refuge boat (“baby cat”) travels up and down river. Pair stashes chick in emergent vegetation and confronts unbanded loon pair that enter logan and remain for 12 minutes.

30 July, 1500-1800 hrs: Family together in Horseshoe Pond. No obvious response to 11 boats on Magalloway River, including one fishing at mouth of Horseshoe Pond, 2 playing loud music, and 3 travelling full-speed through no-wake zone. Male yodels at return trip of one boat and tremulos at return trip of another.

2 August, 1510-1740 hrs: One adult in river at Parson’s Landing, one adult with chick in Tepee Campground logan. No obvious response to motorboat and 2 kayaks travelling Magalloway River. Adult with chick eventually move to river at Parson’s Landing.

4 August, 1530-1830 hrs: Family in Magalloway River in vicinity of Parson’s Landing. No obvious response to 4 kayaks travelling river. Adult tremulos at passage of Marine Patrol. Family moves downriver when dog leaps from canoe to chase nearby Mallards. Male yodels and chick hides in emergent vegetation in response to intruding loon.

8 August, 1115-1415 hrs: Family moves from Upper Magalloway logan into and out of Horseshoe Pond and downriver during observation period. While in logan, no obvious response to 4 kayaks traveling Magalloway River (>200 m from family). While in Horseshoe Pond, adult vocalizes with 3 wails and one tremulo when boat enters pond. Adult moves chick downriver from Horseshoe Pond when canoe lands just upriver from pond and canoeists are jumping off rock and being loud. While moving downriver, no obvious response to passing canoe (< 200 m).

15 August, 1200-1500 hrs: One adult with chick in Upper Magalloway logan. No obvious response to 3 boats and 2 kayaks. No obvious response to arrival of BRI boat and removal of tree stand, but male gives tremulo when boat leaves cove. Chick wails at immature Bald eagle flyover.

Discussion, Evaluation, and Recommendations

This preliminary data suggests that human intrusions into loon family territories are more frequent (but not significantly so) than those by wildlife. However, intrusions by Bald Eagles and other adult loons provoke behavior indicative of disturbance significantly more often than human intruders. Considerably larger sample sizes will be needed to draw meaningful conclusions from study of loon family disturbance.

Field Season and Observation Periods Administrative complications resulted in a late start for pilot observations, and some chicks had been hatched for some time when observations began. If loon family disturbance studies are continued in future years, observations need to begin as soon as possible after hatch on each territory and continue until chicks are at least 10 days old. Observation periods should be 2-3 hours in length and rotate between morning and afternoon, if not among finer divisions of the day (e.g., early morning, mid-day, late afternoon). Using consistent time blocks for observations could enable use of observation periods, rather than territories, as samples. Stratification across times of day and weekdays vs. weekends as well as territories should be important considerations in study design.

Observation sites Because the loon families are mobile once the chicks have hatched, observers also need to maintain mobility. The resulting necessity of using boats as observation platforms adds to the risk of observer influenced on loon behavior. However, observations during the pilot study suggest that, at least in most cases, boat-based observations can be conducted successfully from distances adequate to avoid influence on loon behavior.

Data collection Judging distances between loons and potential intruders can be problematic, particularly for families on large expanses of open water. Field use of maps on which distances between key points have been noted (as measured using Terrain Navigator or similar software) and access to GIS software could alleviate this problem to some degree. It may be worthwhile to add a second band of distance for documenting human and wildlife activity (e.g., 200 – 500 m), but this would complicate the distance estimation issue even further.

Locating loons on the open lake can be very difficult, particularly under windy conditions. This may limit the potential for observing families at greatest risk from high- speed boats.

Data analysis Analysis options will continue to be limited by sample size, particularly if numbers of successful nests remain low. It may be worth considering observations of failed pairs as well as pairs with chicks to gain insight into human and wildlife activity levels within the various territories. Such observations would also provide an opportunity to evaluate differences in response behavior between adults with and without chicks.

Summary The family disturbance study presents many challenges absent from documentation of nest disturbance. Future study of family disturbance will require careful consideration of objectives, logistics, feasibility, and study design. A comparative review of historical failure rates during the incubation and chick-rearing periods may help elucidate the relative priority of investigating nest disturbance vs. family disturbance.

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