high park

Observation Hours

Observing hours have remained relatively constant since the year 2000. 1994 data have been excluded from trending graphs because the number of observing hours was very low. 1994 data is used in the timing graphs.

Back

Relative Bird Abundance

The relative abundance of birds has changed over the course of the study. In the 1990s the abundance graph is like this.

Back

(The commonest bird is assigned the value of 100 and all other birds have values calculated relative to their numbers as compared to the commonest bird.)

In the 2000s it looks like this.

Migration at a Glance

The table gives for each species the date range when 90% of the birds are seen and details of the maximum count seen since the beginning of the study as well as totals for recent years.

Back

Migrating Numbers
Trends

The numbers of birds migrating over the site are changing according to the daily graphs for individual species shown below. It remains an issue, though, to determine whether the apparent increases or decreases are real or not. Only some of the graphs show a trend line that is statistically significant at the 99% level of confidence using a Chi Square test and at least one of these is suspect.

The Broad-winged Hawk migrates in such a narrow time corridor each year that we are nervous about making trend statments based on our observations to date. It appears to be too easy to miss significant numbers of migrating birds in any given year.

Back

Birds with rising trend

These rising trends are significant at the 99% level.

These rising trends are not statistically significant because the numbers are too low but there nevertheless appears to be a rising trend.

Bald Eagle
Golden Eagle
Peregrine Falcon

Birds with falling trend

These falling trends are significant at the 99% level.

Birds with no apparent trend

Osprey
Northern Harrier
Cooper’s Hawk
Northern Goshawk
Red-shouldered Hawk
Rough-legged Hawk
Merlin

Weather and Time Effects

In the graphs in this section, the number of birds seen has been divided by the number of hours observing so that the resulting counts are expressed in “birds-per-hour”.

It is clearly best to view migrating raptors when the wind is from the North or the North West.

More birds are seen when the barometer is rising.

Overall, based on total birds seen, the data suggest that the best time to see the largest number of raptors is when the winds are from the north or north west and the barometer is rising.

More birds are seen around noon.

High Park is a 164 hectare park in southcentral Toronto and is characterised by a dominant Black Oak Savannah. Hawk Hill is located at the centre of the park on a small knoll just north of the Grenadier Restaurant at an elevation of 38 metres above Lake Ontario, 1.25 kilometres to the south. The co–ordinates are 17623746 E and 4833730 N. Hawk Hill benefits from the size and the quality of the surrounding parkland habitat and also the encouragement and support of the Toronto Parks Department.

Observers in High Park are seeing autumn raptor migration which consists of southbound birds which, on meeting the obstacle of Lake Ontario, turn westward and follow the Lake Ontario shoreline.

The location of distinct incoming raptors is often described by their position over the background of the downtown Toronto office towers and minutes later by their position over the tall Oaks and Pines of High Park. High Park has the distinction of being one of the very few major raptor monitoring sites operating in the centre of a large urban environment. Access is recommended by subway, streetcar or automobile with every–day entrance off Bloor Street and week–day access off Parkside Drive.

While the primary objective of the hawk watch is to enjoy and monitor the fall raptor migration, there is a public participation element which is encouraged and respected. In all years there has been an enthusiastic group of observers contributing to the spotting, identification and counting of incoming raptors. The High Park Hawk Watch welcomes all visitors and active participants to what has become a very popular destination in High Park.

Weekly totals throughout the season are posted on the ONTBIRDS listserv. Monthly species daily totals which meet the Toronto Ornithological Club reporting guidelines are forwarded to the Records Committee for inclusion in their database.