Stanley Park Owls - Statistics

Barred Owl nest cavity with adult and young

Stanley Park Owls - Statistics

The table below shows the number of (Barred) owlets fledged by each breeding pair in the years for which I have any reliable data. Note that in the very early years I was not fully aware of the multiple territories and hence was not visiting all the areas.

The last major update this page was in 2009, with the latest data added in 2018. In that time I continued monitoring the owls, but with fewer other people. This does mean that statistically speaking I have a smaller observational set of data, so there is a strong possibility that I am missing more activity in this (final) report. In fact it now seems likely that I missed an entire territory for many years - to the east of the Aquarium (around Brockton Point) - a "far east" territory?

That said, it does seem that there has been a general decline in owls in the park over that period. Whether this is due to human activity it is hard to say. Certainly the human presence in the park's "off trail" areas has grown, especially in the Northern owl territory. But the terrain has also undergone some natural changes - especially after the storm of late 2006. It was after that storm (in 2007) that I conducted a systematic survey and found three nest sites.

Between 2011 and 2018 there have been no young recorded in the Northern territory. However, we did continue to see the occasional single (?) adult owl in that area. It also seems that the Western pair have expanded to the north. But there have been changes in the west too - in 2014 the adult female died after the pair successfully raised three young. That was from natural causes - a disease carried by pigeons (on which the owls preyed).

Of course, given the lifespan of wild Barred Owls it is obvious that more than one pairing must have changed over the 18 years I studied them. The only nest site that may have remained unchanged (since 2007) is that of the Eastern pair - somewhere north of Beaver Lake and fortunately (for the owls) still quite hard to access (for humans).


Year East North West South Total
2001 2 1? n/a n/a 2-3
2002 1 2 n/a n/a 3
2003 ? 3 n/a n/a 3 ?
2004 ? 2 n/a n/a 2 ?
2005 1 1 n/a n/a 2
2006 1 ? 1 3 n/a 5 ?
2007 2 ? 2 1 n/a 5 ?
2008 0 1 2 n/a 3
2009 0 2 1 0 3
2010 2 1 2 n/a 5
2011 1 - 2 0 1 ? n/a 0 - 3
2012 2 o 1 n/a 3
2013 1 0 1 n/a 2
2014 2 0 3 n/a 5
2015 3 0 1 ? n/a 3 - 4
2016 3 0 1 ? n/a 3 - 4
2017 3 0 1 ? n/a 3 - 4
2018 1 ?        

2001 - I saw adults in all territories, but was not active in the Western or Southern areas. There may have been more than one juvenile in the North. First year I was aware of juveniles (photo records).

2002 - The Northern young were to the south of their territory. Is it possible that there was no north-west/south split prior to this? The Eastern owls were seen most often around the Miniature Railway.

2003 - This may have been the year that I observed a territorial dispute between Northern and Western owls (of whose existence I remained unaware for another year). My records are "sketchy" on the actual year of the encounter!

2004 - At the time I was not aware of the existence of a Western territory, so was not monitoring the area.

2005 - The Eastern owlet was found dead near Beaver Lake on June 30th.

2006 - The first year that I was fully aware of the Western territory. Additional people were monitoring that year.

2007 - Early in the season 2 juveniles were observed in the east, but later only one, then it was found dead near Beaver Lake on October 5th. The body was taken to the Ecology Society and initial examination revealed malnutrition.

2008 - The Northern juvenile was rescued after a fledging accident. Later released and observed feeding. Only the occasional adult was seen in the east - suggesting breeding failure (or none tried).

2009 - There were 3 healthy owlets in the park (August 19) - actively hunting for themselves yet still being fed by parents. The owls at the Southern (new) and Eastern sites appear to have fledged no young this year. Also, the Southern pair did not last long - one owl was hit by traffic.

2010 - An excellent year for Barred Owls. There were also 2 Great Horned Owls in the Northern area for Spring and Summer, but they have not been seen since. Though individual owls are reported most years - post breading dispersal?

2011 - Observations were scarce this year.

2012 - Only an adult seen in the North this year. The other territories did OK.

2013 - A relatively poor year for breeding success.

2014 - A good year but unfortunately one adult (Western pair) died late in the season.

2015 - The Western male appears to have found a new mate, but at a new nest site? One of the Eastern owlets was found dead near Beaver Lake, July 18. It had been seen with its siblings the previous day - all flying well. Possibly hit by a bicycle?

2016 - The Western owlet was not seen until very late in the season (August 29).

2017 - The Western owlet was not seen until very late in the season (august 27). I only have photographic records of 2 in the East but my notes indicate 3.

2018 - Not much monitoring this year. I heard owlets call the first week of June (Beaver Lake / Eastern territory) but could not locate them. A sighting was reported to the Nature House on June 12. My first sighting was July 5 (later than usual). An owlet was also seen to the east of the Aquarium - later confirmed to be a different family. So this represents a new territory (confirmation of one around Brockton Point). This probably existed for many years prior, so not really "new", just unmonitored.

2019 - I have no formal records for this year (I moved from Vancouver to Victoria in August) but owlets were seen around Beaver Lake (Eastern territory) and to the east of the Aquarium ("far east" territory). A changing landscape.

I welcome any observations from others that could augment (or correct) these statistics.