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Variable Roosting Habits of Great Egrets

D.V. Chip Weseloh, Rod Dubois, Bruce Di Labio and Bob Scranton

Great Egret. Photo: Ann Brokelman 30 Birds April 2013 Great Egret. Photo: Ann Brokelman

Introduction young (McCrim mon et al. 2011). The The Great Egret ( Ardea alba , henceforth activities of egrets during the post-breed - egret) is a resident of ing period, from July through November, from approximately late March through are not as well documented but there is November, with stragglers remaining ample evidence that egrets are more wide - into December (James 1991, Sandilands ly distributed across much of southern 2005, Curry 2006). During the first half Ontario during this period than during of this period, up to approximately late the breeding period (Speirs 1985, Sandi - July, most egrets in southern Ontario lands 2005, Curry 2006, Weir 2008, are resident on their breeding colonies Black and Roy 2010). and range only within foraging distance During the period from July to Nov - of it, i.e. approximately 16 km (10 miles) ember, the activities of egrets in south - but occasionally a bit farther (McCrim - ern Ontario would include: dispersal mon et al. 2011). Their activities during from the breeding and natal colony by this period are well known: selecting adults and juveniles, daily foraging in territor ies and mates, nest building, new territory, temporary residence and court ship and copulation, egg laying, roosting within their dispersal area, mig - incubation and brooding, and feeding ratory staging, nutritional prepa ration

Volume 31 Number 1 31 for migration and, finally, southward adjacent locations of (Ont ario) mig ration. However, the details, and and (Qué bec) in 2010 and even the existence of many of these post- 2011. These were two of the three most breed ing activities in Ontario are not intensively monitored egret roos ting known or seldom recognized. For exam - sites in southern Ontario during this ple, it is not known if there is a differen - time with the third being Luther Marsh tial migration chronology (timing) where (DVCW and L. McLaren, un publ. data). adult egrets migrate ahead of juvenile To the best of our knowledge, the types egrets, as there is with many other birds, of questions posed above have not been e.g. shorebirds (Pienkowski and Evans add ressed by any previous studies of 1984, Nol and Blaken 1999). Also, it is Great Egrets (McCrimmon et al. 2011) not known to what extent the egrets in southern Ontario undergo a northward Background post-breeding dispersal as do egrets from In the area of Cornwall, Ontario, Great more southerly areas (McCrimmon et al . Egrets formerly bred at Dickerson Island, 2011). The and southern approximately 10 km downstream (east) Ontario are already at the northern edge from the town site, in the Québec waters of the egret’s breeding range in eastern of the St. Lawrence . They are North America and records to the north known to have bred there from 1984 are rare. (David 1996) to 2003. Ninety-one nests For this paper, we have focused our were counted there in 2003 and (prob - attention, primarily, on the roosting ably due to mammalian predation) they habits of Great Egrets during the post- have not been known to nest there since breeding period in the Cornwall and (L. Harper unpubl. data). In the Corn - Ott a wa River area. Some of the un - wall area, egrets were first noted roosting knowns in this area include: are indivi- in a small backwater section of a large dual roosts used continuously during wetland complex just south of where the July to November period or only Richmond Drive crosses a set of railroad sporadically? How many birds occupy tracks, o n the west side of Cornwall, Ont - given roosts? What is the most common ario, in August 2008 (BS un publ. obs). size of roosts? What is the roosting sub - In the area of Ottawa, Ontario, and strate? Where do they roost? Are the Gatineau (formerly Aylmer) , Qué bec, same roosts used year after year? There Great Egrets are a relatively recent arrival; are many unknowns pertaining to local they were first reported as single birds in movements and roosting habits of egrets the former in 1972 (BD unpubl. obs.) in Ontario (and elsewhere) during the and just east of the latter, at Masson post-breeding season. Here, we describe (QC), in 1973 (RD unpubl. obs.). Rep - the roosting habits of Great Egrets at orts of one to two egrets in Otta wa and two southern Ontario locations, one at east of Gat ineau were received occa - Cornwall, Ontario, and the other at the sionally during the 1980s and 1990s

32 Ontario Birds April 2013 Great Egret. Photo: Ann Brokelman

(RD un publ. obs.). In the early 2000s, Egrets did not breed anywhere near the the number of egrets began to increase; Otta wa/ Gatineau area. In fact, the near- five to eight egrets were noted in Ottawa est col ony was at Dickerson Is land in the autumn (BD unpubl. obs.) and (approx imately 100 km to the SE). up to a dozen egrets were reported just east of Gatineau (RD unpubl. obs.). Methods Egrets were first observed on Conroy At Cornwall, all observations were made Island in 2007 but were not noted to be from the backyard of the house at 5696 roosting there, or anywhere in the area, Richmond Drive by BS and colleagues. until 2010, when more than 30 egrets This yard abuts the extension of the were recorded (BD and RD unpubl. wetland complex where the egrets roost- data). Up to the end of 2011, Great ed (Figure 1). From the backyard, across

Volume 31 Number 1 33 Figure 1. The location of the egret roost off Richmond Drive in Cornwall, Ontario.

Figure 2. The Ottawa/Gatineau study area. Egrets roosted in/near the west side of Shirley’s Bay in 2010 and in the east side in 2011.

the small wetland, to the trees where the side of the River) and at an unconfirmed egrets roosted was approximately 100m. location west of, or at the west end of, In the Ottawa River in 2010, the egrets Shirley’s Bay (in Ottawa) (Figure 2); this roosted, sequentially, at two different exact roost site could not be located. All areas: Conroy Island (on the Gatineau observations of roosting egrets on Conroy

34 Ontario Birds April 2013 Island in Gatineau were made from a from the observation post on the north paved bike path along the Ottawa River side of the river. The east end of the at a distance of approximately 20 0 m by island also was not visible from the RD. From the Ottawa side of the River, Gatineau observation post. How ever, where observations were made by BD, very few egrets were ever observed com - Conroy Island was observed most close - ing to Conroy Island from the east. At ly from the . It Shirley’s Bay in 2010, egrets could only could also be seen more distantly (4 be observed flying to and from (in the km) from the old causeway that direct - evening and morning, respectively) the ly overlooks Shirley’s Bay and from unconfirmed roost farther to the west. which flight lines of egrets going to and In 2011, the roost location, in the shal - from the unconfirmed roost site were low waters of the east side of Shirley’s also visible. In 2011, along the Ott awa Bay (just west of the causeway), was River, egrets roosted sequentially on easily visible. Conroy Island (as in 2010) and at an Occasionally, observations were easily observed location from the cause - made in the morning during the first way on the east side of Shirley’s Bay (a hour of daylight. In these instances, the different location from 2010) and obser - most accurate counts were made by vations were carried out as des cribed waiting for the egrets to disperse out of above. DVCW visited the Cornwall their roost and then counting them (2010 and 2011), Conroy Island (2011) individually. On clear days, egrets usu - and Shirley’s Bay (2012) roost obser - ally start leaving their roost about 10 – vation posts on selected occasions. 15 minutes before official sunrise Most observations at the above sites (DVCW unpubl. obs.). When roost - were made in the evening during the ing in trees or shallow water, egrets may last hour of daylight when either the often be bunched together and it can be total number of egrets at the roost was difficult to get a single accurate count. tallied or egret numbers were tallied as All count data for egrets are pre - the birds flew into the roost. At Corn - sented as the greatest number of egrets wall, the egrets could be observed easi - recorded per week; weeks were defined ly flying and landing in medium-tall by the following dates: week 1=1st-7th, trees (5 – 8m) at the water’s edge. At week 2 = 8th-15th, week 3 = 16th-23rd, Conroy Island, the egrets were clearly week 4 = 24th-31st of the month. visible as they flew to the west end of the island (usually from the west or Results southwest), where they landed in the Cornwal l treetops. Their final roosting location, The pattern of roost occupation and however, was lower down in the vege - the number of egrets present at the tation and/or on the south side of the Richmond Drive roost in Cornwall in island, which was not directly visible 2010 and 2011 are plotted in Figure 3.

Volume 31 Number 1 35 In 2010, observations for roosting egrets number increased to four. The num - at the site were made on 12 dates bers of roosting egrets increased sharply between 17 July and 29 Oc t obe r(approx - throughout August, reaching 51 at the imately once per week). The number of end of the month, and through most of egrets using the roost ranged from zero September and peaked at 73 in early to 34. Egret numbers increased fairly Oct ober. Numbers decreased quickly quickly beginning in the last week of during October; they declined 41% July; no egrets were seen on 17 and 21 during the second week and a further July, but 3, 16 and 21 egrets came in to 45% (of the peak) during the third the roost on 23, 26 and 28 July, respec - week. The last two egrets at the roost tively. Peak numbers were recorded from were recorded during the first week of late August to mid-September. Unfor - November. tunately, there were no ob ser vations At Cornwall, as far as is known, the from mid-September until mid-Octo - egrets only roosted at this one location ber, by which time numbers had de - in 2010 and 2011 and they only roost - clined to only eight. The last egret was ed in medium-tall trees (5-8 m) on the observed at the roost on 20 October. shoreline of a wetland. In 2011, observations for roosting egrets (Figure 3) were made on 26 dates Ottawa/Gatineau between 5 June and 4 November (slight - In 2010, egrets roosted sequentially at ly more than once per week). A single two locations in or near the Ottawa egret was observed at the Cornwall roost River: Conroy Island (at the Deschênes intermittently until 25 July when the Rapids) and the unconfirmed location

80 70 60 2011 50 s

t 2010

e 40 r g e

f 30 o

r e

b 20 m u 10 N 0 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1

Jun Jul Aug Sept Oct Nov Week - Month Figure 3. Number of egrets and periods of occupation at the Cornwall roost, 2010 and 2011.

36 Ontario Birds April 2013 Figure 4. Egrets in the Cornwall roost. Photo: Jacques Bouvier in or near the west end of Shirley’s Bay. Island gave no indication as to where the Counts for roosting egrets at these two egrets had gone. sites were made on 15 dates between 7 At sunrise on 28 August, more than August and 23 September (approxi - a dozen egrets arrived at Shirley’s Bay mately twice per week); the two roost from the west; none came from the east, sites are approximately 4 km apart. Dur - the direction of Conroy Island. This ing the summer, through 7 Aug ust, up strongly suggested that the egrets had to three egrets were obser ved roosting on roosted at some location to the west of, Conroy Island (2010 data not shown). or in the extreme west end of Shirley’s During the second week of August, the Bay and not at Conroy Island to the number rose to 18 and by 21 August east. During the rest of August and early numbers peaked at 30 egrets. After that, September, 10-18 egrets were reported numbers declined very quickly as the foraging in Shirley’s Bay during mid- egrets abandoned this site, perhaps due day. On an evening watch on 6 Sep - to disturbance on the island from fish - tember at Shirley’s Bay, small numbers erman at dusk (RD, pers. obs.). During of individual egrets, eventually totalling 22 – 25 August, numbers fluctuated bet- 33, were observed flying to the west, ween only one to five egrets roosting on towards the back of the Bay approach - Conroy Island. Observations at Conroy ing the Crown Game Preserve.

Volume 31 Number 1 37 35

30

25 Conroy Island 2011 20 s t e r

g 15 Shirley’s e

f Bay o

r 2011

e 10 b m u

N 5

0 1 2 3 4 1 2 2 3 4 3 4 1 2 3 4 1 2 3 4 1 2 3 4 Apr May Jun Jul Aug Sept Oct Week - Month Figure 5. Number of egrets and periods of occupation at the Ottawa River roosts, 2011.

Unfortunately, this was the last obser - roosting activity away from the breeding vation that could be made from this area. colony. No egrets were observed in the During the third week of September, at area of the Conroy Island roost until 9 dusk, a single egret was observed to fly April when a single egret was seen forag - over Conroy Island and continue flying ing in the river. Three days later, a single off to the west (in the direction of egret was observed flying westward past Shirley’s Bay and the Game Preserve). Conroy Island at dusk and continued to Thus, in 2010, the egrets using the the west. Finally, on the evening of 19 Ottawa River appeared to switch roosts April, five egrets were observed to come during the autumn period, first roost - in to roost on the island. At dusk/ dawn ing on Conroy Island and then switch - on 23/24 April, two egrets were observed ing to an unknown specific location roosting on the island. Three egrets were either at the extreme west end of Shirley’s observed on the island in mid-morning Bay or to the west of the Bay, perhaps in on 3 May but it is not known if they the Crown Game Preserve. roosted there or if they possibly bred there. The pattern of roost occupation and Regular observations were not made the number of egrets roosting at Conroy at the Conroy Island site during the rest Island and Shirley’s Bay in 2011 are given of May through early July, although dur - on a weekly basis in Figure 4. Observa - ing 14 – 28 June up to three indivi duals tions were initiated on 4 April, in hopes were observed roosting there, including of documenting the use of these roosts in an egret with the red leg-band, 61J (see spring, a time of little reported or known below). Starting in mid-July, regular and

38 Ontario Birds April 2013 intensive observations were resumed (28 and Britannia Park, e.g. on both 7 and days of observations during 18 July – 14 September, more than 20 egrets 26 Sept ember, nearly three times a week) arriv ed there first thing in the mo rn ing and the number of egrets using the roost from the east, the direction of Conroy on Conroy Island increased slowly from Island. five to seven by early August (Figure 5). On the evening of 17 September, During the third week of August, RD was at the usual observation post in increased numbers of egrets were ob - Gat ineau overlooking Conroy Island served on the Ottawa River during the when 27 egrets came into the roost and day (11 – 16 egrets on 19 August, BD). By settled into the trees. Suddenly, at 1942 the first week of August, the number of hrs, 21 of the egrets flew off to the SW egrets using the roost increased to 15 and towards Shirley’s Bay; six egrets remained then 25; 61J was reported present during at Conroy Island. The following night this entire time period. only a single egret came to Conroy Is land For the next month, observations but it, too, flew off in the direction of were made on a nearly daily basis at Shirley’s Bay. On 22, 23, 24 and 26 Sep - Con roy Island and somewhat less freq - tember, no further egrets came to the uently near Shirley’s Bay. The number of Conroy Island roost. On 23 September, egrets roosting on Conroy Island at 0730hrs, just after sunrise, BD ob - increased to a peak of 32 on 12 Sep t em - served 26 egrets foraging at the back ber; 61J was still present. During this (west end) of Shirley’s Bay. The next time, egrets were observed foraging reg - morning, before sunrise, he observed 28 ularly during the day at Shir ley’s Bay egrets, including 61J, roosting in shallow

A colour-banded Great Egret During the latter half of June 2011, when up to three egrets were observed intermittently at the Conroy Island roost, a colour-banded egret (61J) also was observed (RD pers. obs.). This bird had been banded as a flightless young on 17 July 2009 at Nottawasaga Island (near Collingwood, Ontario) by the Canadian Wildlife Service; hence, when it was observed near Conroy Island it was a two-year old bird. This egret was seen on 11 occasions between late June and 24 September 2011 (3.5 months). It was identified nine times coming in to roost on Conroy Island and twice at Shirley’s Bay. It was foraging there on the morn - ing of 11 September and it was roosting there on the evening of 24 September. It prob - ably also was the banded individual observed roosting at Shirley’s Bay on 18 October 2011 (BD pers. obs.). There were no other reports of this bird between 17 July 2009 and June 2011. This observation illustrates how long some egrets may stay in a given area during the post-breeding period.

Volume 31 Number 1 39 Figure 6. Egrets roosting at the Shirley’s Bay roost, 2011. Photo: Bruce M. Di Labio

water on the eastern side of the Bay. Obvi - ously, this had become their new roost - ing site and they had changed from roost - ing in trees/shrubs on Conroy Is land to roosting here in shallow water. During the period of 26 September to 11 October, the number of egrets roos - ting in the shallow water of Shirley’s Bay declined from 28 individuals to 15 and then to six. Somewhat surprisingly, no egrets came into roost at Shirley’s Bay on the evening of 12 or 13 October; it was assum ed that the last few birds had mig rated. More surprisingly was a post - ing on the ONTBIRDS listserv on 15 October reporting that seven egrets had been observed, that day, at a pond along Sarsaparilla Trail off . (B. McCrea pers. obs.). Based on the assum p tion that if there were still egrets in the immediate Ottawa area, they would roost at Shirley’s Bay, BD went Great Egrets at two widely separated geo - there that evening and as expected, he graphical locations and the switching found seven egrets roosting at Shirley’s from one roosting habitat (live trees on Bay. Over the next three evenings, the a riverine island) to another (shallow numbers went from two to zero and six riverine water) by one of those cohorts. days later there were still no other egrets It also documents the use of two differ - roosting at Shirley’s Bay. It appeared the ent roost sites in successive years by egrets egrets had finally left the area for good. from the same local area. To the best of our knowledge, these features of the Discussion Great Egret’s post-breeding roosting This paper reports on the seasonal use of behaviour have not been the main focus four roosting sites by two cohorts of of any previous study of this species.

40 Ontario Birds April 2013 At Cornwall, the egrets did not appear known to occur at the roost sites at River to use their traditional autumn roost dur - Canard (LaSalle, P. Pratt, pers. comm.) ing their spring migratory period. Rather, Metcalf, Ontario (J. Cooper and S. God- they commenced using their only known oy, pers. comm.) and at The Coves (Lon - Cornwall-area roost site (live trees adja - don, A. Granger, pers. comm.). Loc ating cent to a marsh) in the mid-summer active egret roosts in spring, away from (June-July) and occupied it consistently the breeding colony, is very difficult. Occ- throughout the post-breeding period u pation appears to be brief and sporadic until late October-early November. In and the number of birds involved is small. southern Ontario, roost occ u pation in This spring (2012) at the Luther Marsh the autumn during the post-breeding roost (Grand Valley) the number of egrets period and not in the spring, is also using the roost varied from zero t o 11 on

Volume 31 Number 1 41 16 dates from 13 April to 13 May; in the changing of local roosting sites/su b strates autumn, over 400 egrets roost at that site has been observed elsewhere in Ontario. (L. McLar en, unpubl. data). With many Egrets roosting at Oshawa Second Marsh bird species, the spring migration is often (Oshawa, T. Hoar, pers. comm.), the quite direct with birds spending little or mouth of the Rouge River (Scarborough, no time at staging areas en route to their A. Brokelman and K. Fawthrop, pers. breeding areas. In the autumn, there is comm.), Carroll’s Point (Hamilton, C. often a dispersal period prior to the actu - Hodder, pers. comm.) and the Hespeler al southward migration, where move - Mill Pond (Hespeler/Cambridge, R. ments are quite leisurely and temporary MacIver, pers. comm. and DVCW, pers. residence in local areas is common. obs.) have been ob served to change roost In the Ottawa River, on the other sites from treed shoreline areas to shallow hand, egrets were observed to roost on water/mudflats (or vice versa), as observed Conroy Island in the spring of 2011. Up at Ottawa/ Gatineau. In contrast, there to five individuals were seen from 19 was no indication of roost/substrate April to 3 May. Then, like at Cornwall, switching at Cornwall nor has there been egrets began roosting on Conroy Island at some other Ontario roost sites: Lynde during the post-breeding period in June- Creek (Ajax, DVCW, pers. obs) or Wild - July of both years only to switch to a wood Lake (St. Marys, H. Veenendaal, site (approximately 4 km away) in or pers. comm.). near the west end of Shir ley’s Bay (in Although identifying the factors 2010) and near the causeway at Shirley’s which may control the selection of roost Bay (in 2011). sites by Great Egrets is beyond the scope of this study, a major contributing factor Changing roosting sites and substrates appears to be the presence of water and There can be little doubt that the egrets water levels. Of 42 roost sites identified which were roosting on Conroy Island in to date in the area of southern Ontario, mid-September (on the 12th, 14th and all have been in or very close to water; 26 17th) were at least mostly the same ones were in trees in, or immediately adjacent that began, and continued, roosting at to water; 12 were in very shallow water Shirley’s Bay on 23, 24 and 26 Septem - or on mudflats; and four were in low ber. Three observations support this con - bushes or fallen trees in water (DVCW, clusion; the number of egrets involved unpubl. data). was approximately the same (27-32 vs Concerning water levels, in the 26-28), use of the two sites was mutual - extreme, if a wetland that was used pre - ly exclusive, i.e. they were not occupied viously as a roost site dries up or is drawn simultaneously, and the colour-banded down to dryness, egrets have not returned individual, 61J, was observed roosting to that site. For example , Mays Point at at both sites. Though not reported from Montezuma National Wildlife Refuge other locations in the literature, the and M ohawk Pond at Iroquois Na t ional

42 Ontario Birds April 2013 Wildlife Refuge (both in western New egrets roosting at Shirley’s Bay on 5, 6 York) both had egret roosts in the and 11 October (six to seven) were iden - autumn of 2011. In 2012, they were tical to the number that was seen there drawn down to dryness and neither one on 16 October (seven), it was probably was used as a roost (J. Graves, B. Wat - the same group of egrets that was son a nd C. Mor ien, pers. comm .). involved in both roostings. Hence, we There also seems to be a tendency for appear to have a situation where an entire egrets to move from a tree roost, earlier roosting cohort of egrets abandoned their in the season, to a water/mudflat roost, roost site for two nights, only to return later in the season, e.g . at the Rouge for three nights and then migrate out of Riv er Park (Scarborough), Carroll’s the area. The question remains, howev - Point (Hamilton) and this study. Of er, where did they go, and what prompt - the 12 known egret roosts in water in ed them to do so, when they were not southern Ontario and western New at Shirley’s Bay? York, all of them were in very shallow water, probably less than 10 cm Conclusion (DVCW unpubl. data). These condi - Great Egrets show both great consis - tions probably tend to occur as the tency and great flexibility in their roost - autumn season progresses. It remains to ing habits as exhibited by the two be seen if shallow water and mudflats roos ting situations discussed in this pa - may be the egrets’ preferred roosting per. On the one hand, they will roost substrate but it is generally not avail - consistently at the same site throughout able until later in the autumn period. the post-breeding period and bet ween years (as at Corn wall). On the other Temporary abandonment and hand, they show great flexibility in reoccupation of the roost site switching roost sites, and roosting sub - Late in the post-breeding period, daily strate, during the post-breeding period observations at the roost sites on the as well as roosting at different locations, Ottawa River showed that no egrets at a given locale, from one year to the roosted at either Shirley’s Bay or Conroy next (as at Otta wa/Gat ineau). Neither of Island on 12 and 13 October (2011). It these situations would have been un - appeared that the egrets had abandoned covered had it not been for the dedicated the site and probably migrated. Howev - and persistent roost observations by the er, as it turned out, egrets resumed roost - authors and other volunteers. Roosting ing at Shirley’s Bay on 16, 17 and 18 behaviour and habits of Great Egrets October with seven, two and two indi - may or may not change during the bird’s viduals, respectively. An obvious ques - life cycle in southern Ontario but with - tion is where did the egrets roost or where out the repeated observations at given did they go for the evenings of the 12th sites, we will never know. and 13th? Given that the numbers of

Volume 31 Number 1 43 A practical application of these find - Knezevic, Tyler Hoar and Dave Andrews for ings might suggest caution in using the preparing the maps and figures. Dave Moore presence of an egret roost as a selection also commented on a previous version of the criterion in designating Important Bird manuscript. Areas (IBAs), especially with relatively Literature Cited small-sized roosts. There may be a rela - Black, J. E. and K. J. Roy . [Eds.]. 2010. tionship between the size of the roost, i.e . Niagara Birds: a compendium of articles and the number of birds using it, and its species accounts of the birds of the Nia gara stability. Region in Ontario. Brock University Print - ing and Digital Service, St. Cath ar ines, Ontario. Acknowledgements Curry, R. 2006. Birds of Hamilton and Jacques and Sheila Cadieux, Rob Fry, Dawn surrounding area. Hamilton Naturalists Scranton, Jacques Bouvier and Hans van der Club. Hamilton, Ontario. Zweep assisted with observations at Cornwall. Ben F. Di Labio and Julie-Anne Di Labio David, S. 1996. Great Egret. In J. Gauthier assisted with the observations at Otta wa. We and Y. Aubry [Eds.]. 1996. Atlas of the are grateful to Ms Joan Jarvo who per mitted breeding birds of southern Québec. Associa - us to count and observe egrets from her back - tion Québecoise des Groupes d’Ornitho - yard on Richmond Drive in Cornwall. Also, logues, The Province of Québec Society for we are most appreciative to D a ve Moore, Tina the Pr ot ection of Birds a nd The Canadian WOildlife Service (Environment ). , Québec. Pp. 246-250. James, R.D. 1991. Annotated checklist of the birds of Ontario. 2nd ed. Royal Ontario Museum Life Sciences Miscellaneou s Publication s, Toronto. McCrimmon, D.A ., Jr., J.C. Ogden and 636 Point Pelee Dr. Leamington ON N8H 3V4 G.T. Bancroft . 2011. Great Egret ( Ardea Birding Nature Optics Books Birding• • Nature • Optics • •Books alb a ). In The Birds of North America, No. &DQDGD·VCanada’s/DUJHVW6HO HLargestFWLRQRI% SelectionLQRFXODUVDQ G6FRSHV 57 0 (A . Poole and F. Gill, Eds.). The Birds of Binoculars and Scopes $OODW'LVFRXQW3ULFHV oBf North America, Inc., Philadelphia. ‡6ZDURYVNLBest Prices in Canada Guaranteed Nol, E. and M.S. Blanken . 1999. Semi - ‡.RZDSwarovski ‡Kowa3HQWD[ palmated Plover (C haradrius semipalmatus ). ‡/HLFDZeiss In The Birds of North America, No. 444 ‡1LNRQLeica (A. Poole and F. Gill, Eds.). The Birds of Bushnell ‡6ZLIW Celestron North America, Inc., Philadelphia. ‡%XVKQHOOMinox Pienkowski, M.W. and P.R. Evans. 1984. ‡=HLVVVortex Pentax Migratory Behavior of Shorebirds in the ‡Steiner New Swarovski ‡&HOHVWURQNikon ATX / STX Modular Western Palearctic. Pp 74-124. In Burger, J. Eagle ‡9RUWH[ Spotting Scopes and B.L. Olla [Eds.]. 1984. Shorebirds: )RU)$67 0DLO2UGHU'HOLYHU\RU4XRWH Migration and Foraging Behavior. Behavior VDOHV#SHOHHZLQJVFD of Marine Animals: Current Perspectives in ZZZSHOHHZLQJVFD Research. Vol. 6. Plenum Press, New York.

44 Ontario Birds April 2013 Sandilands, A. 2005. Birds of Ontario: D.V. Chip Weseloh , Canadian Wildlife habitat requirements, limiting factors and Service, Environment Canada, 4905 status. UBC Press, Vancouver, B.C. Dufferin St., Toronto, ON M3H 5T4 E-mail: [email protected] Speirs, J.M. 1985. Birds of Ontario. Natural Heritage/Natural History Inc., Toronto, Rod Dubois ,50 Alexis-Rajotte, Ontario. Gatineau, QC J9H 6Y8 E-mail: [email protected] Weir, R. 2006. Birds of the Kingston Bruce Di Labio ,400 Donald B. Munro Drive, Region, 2nd Edition. Kingston Field Natu - P.O. Box 538, Carp, ON K0A 1L0 ralists, Kingston, Ontario. E-mail: [email protected] Weseloh, D.V.C . 2011. Two small autumn Bob Scranton , 1716 Peter St., roosts of Great Egrets at London and Cornwall, ON K6J 1W8 Metcalf, Ontario. Ontario Birds 29:34-39. E-mail: [email protected]

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