Vancouver Bald Eagle Report 2013

Transcription

1 Vancouver Bald Eagle Report 2013 August 2013 Eagle perches unabashedly despite approaching gull Photo by: Martin Passchier Stanley Park Ecology Society has monitored bald eagle nests during the breeding and fledging seasons throughout Vancouver with the assistance of volunteer monitors and in partnership with the Lower Mainland Wildlife Tree Stewardship program (WiTS) since Eagle numbers in Vancouver have increased since the 1960 s when there were only one or two pairs (Hancock, 2006), demonstrating that some eagles are adapting to urban environments. While 2013 was not a stellar year for eagles, a new nest in Stanley Park near Third Beach deceived monitors into thinking that the nesting pair at Merilees Trail had moved. However, it was soon confirmed that two separate pairs were nesting in quite close proximity (see bald eagle nest map on page 8). Results of 2013 Monitoring Of the seventeen nests observed in 2013, twelve nests were active, meaning at some point in the season they had a breeding pair of eagles on the nest. Of those twelve nests, nine were successful, having at least one chick fledge (depart from the nest) successfully. Since 2007, the number of active nests has remained relatively stable year to year, and the same goes for the number of successful nests (Table 1). However, 2013 saw a dip in the number of fledges produced. Connecting People With Nature

2 Productivity Nesting Success Page 2 Table 1 Nest productivity data for bald eagle pairs in City of Vancouver from Total number of nests observed Number of active nests Total number of successful nests Number of fledges The number of fledges produced per successful nest has varied year to year but has never exceeded two (Figure 1). In comparison 2011 and 2012 were particularly better years for productivity (1.89 and 1.90 respectively) while 2013 saw a reduction that fell within a normal range of previous years (1.33). However, the rate of nest success was comparable to rates in 2011 and Productivity (# of fledges per successful nest) Nesting success (% of active nests that produced a fledge) % 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Figure 1 Productivity and Nesting Success in bald eagle nests in Vancouver from The drop in the number of fledges produced in 2013 may be concerning, however it will take more years to show whether this is a trend or just an anomaly. For more detail on each nest please review the following pages. A very special thanks to our volunteer nest monitors who make this program possible!

3 Page 3 Adopt an Eagle Nest To support SPES ongoing volunteer eagle nest monitoring program, please consider making a donation through our adopt-an-eagle nest program. Call or sponsors@stanleyparkecology.ca Merilees Trail, Stanley Park One chick - The Merilees eagle pair played a trick on us this year: We thought they had moved down the trail and set up a new nest site near Third Beach, but it turns out the Third Beach nest is a new and separate eagle pair. One chick has been spotted at the Merilees Trail nest in the old Douglas-fir tree. This chick fledged in late July. Jericho Park Strathcona Park Two chicks - For a third year in a row, this pair had an early start and the two chicks were the first to fledge at the end of June. This pair used the nest that was built in 2012, and the chicks were in good condition when they fledged. One chick - The eagle pair nesting in a mature Douglas-fir tree on a platform installed by the Vancouver Park Board had some bad luck this year. One of the chicks fell from the nest and because it broke its wing badly, the Orphaned Wildlife Rehabilitation Society (OWL) had to humanely euthanize it. The nesting platform was installed in 2011 because this nest has had problems falling from the tree in previous years. Third Beach, Stanley Park One chick Just one has been spotted at the new Third Beach nest. This chick fledged in late July. Cathedral Trail, Stanley Park One chick Heron feathers have been found underneath this nest, meaning this pair is likely preying on the eggs and chicks of the nearby heron colony. One large chick was spotted by volunteer monitors and was audible in the nest until the end of July.

4 Page 4 Vanier Park Two chicks - For a fourth year in a row, this nest had seemingly produced two chicks. However, very late in the season, after the chicks had learned to fly, eagle monitors observed that one of the eaglets disappeared suddenly. Hancock Wildlife Foundation got permission from Ministry of Environment and the help from a movie company to use a lift to take a look in the nest. As it turned out, no deceased chicks were found, suggesting that both had fledged successfully. Hastings St. Two chicks These eaglets fledged by mid-july. The eagle pair at this nest was observed drinking and bathing at the small pond in Hastings Park. The nest tree is on City of Vancouver land, at the edge of a large parking lot at the corner of Renfrew and Hastings St. Brockton, Stanley Park One chick - This is the nest of the pair of eagles which used to occupy the nest by Malkin Bowl in Stanley Park. In 2010 they moved location to this site above the Brockton Oval. One chick was heard at the nest until late July, suggesting a successful fledge.

5 Page 5 Active nests Monument (PAC), Musqueam, Botanical. These eagle pairs have been observed near their nest sites, but due to the low visibility of the locations, chicks were not confirmed. Inactive Nests Southlands, Kerrisdale (49 th and Larch), Botanical, SW Marine (at Angus) - These nests were active early in the season but no chicks were produced. Imperial No activity was observed Towers and Pandora These nests have been inactive for several years. It is likely that that they are secondary nests for some of the eagle pairs. Pipeline Road - Although active earlier in the season, this nest seems to have fallen down. Adopt a Nest For more information on the program see:

6 Page 6 Wall St. (LaFarge) One chick - This highly visible nest can be seen through a Hancock Wildlife Foundation webcam ( After an exceptional last year s nesting season at Wall Street nest, when a pair of bald eagles brought up 3 fledglings, the recent season turned out to be more modest but nonetheless a successful nesting year. Even though it all started with the same scenario as the previous year when 3 eaglets hatched from 3 laid eggs, only the first born was lucky enough to make it to the sky. The laws of nature might appear cruel sometimes but everything happens for a reason and the unfortunate deaths of 2 younger siblings allowed the first born and the strongest chick to get as much attention and care from its parents as was necessary to bring up a strong and a healthy individual. Thanks to the webcam installed by Lafarge Canada Inc. and the Hancock Wildlife Foundation we were able to monitor these precious birds of prey more intensively and witness their fight for survival from really close distance. -Michal Belanik, Wall St. eagle nest volunteer monitor. Wall St. Nesting Timeline as seen through the Hancock Wildlife Foundation webcam (screenshots courtesy of Age: 2 days. Female adult feeding the first born chick, there is a freshly hatched 2 nd eaglet and the 3 rd egg is still un-hatched, April 21 st Age: nearly 3 weeks. Male adult in the nest, both parents were providing a shadow to the eaglet during hot sunny days, May 9 th

7 Page 7 Age: 4 weeks. Female adult feeding eaglet a juvenile gull. The prey consisted mainly of birds like gulls and crows as well as some fish, May 19th Age: 5.5 weeks. Both parents were providing a shelter for the eaglet during heavy rains, May 28th Age: 10 weeks. The eaglet flapping its fully evolved wings exercising its flying muscles, June 30 th Age: 13 weeks. The eaglet eating prey parts brought by adults on its own, July 20 th Photo 1. Site photo showing an adult sitting on an artificial post. The eagles are mostly using it as a lookout point, May 31 st Photo 2. The fledgling practicing a flight, preparing for migration July 31 st

8 Vancouver Bald Eagle Nests Page 8 Bald eagle nests and the trees they reside in are protected under Section 34 of the Wildlife Act. If you have concerns about the safety of a nest in your area, please contact your regional BC Ministry of Environment office. Written by: Dan Straker Photos by: Martin Passchier More information: Contact: urbanwildlife@stanleyparkecology.ca or