Prior to the return of the Peregrine falcons to the Genesee Generating Station in the spring of 2009, Capital Power developed plans to attach satellite transmitters to both adult falcons in an effort to develop a better understanding of their migratory behavior. The data from the transmitter could be used to track the birds’ routes, show where they forage during the summer at Genesee, where they spend their winters, and when they begin their migrations.
To ensure the falcons’ safety during capture, the existing nest box was re-designed to include an access door on the back and a trap door on the front. A high-quality camera was also installed before the box was returned to its location on one of Genesee’s smoke stacks. The nest box was completed by the end of March, and the first peregrine was sighted at the nest box on April 8, 2009.
The newly designed nest box
Safety of the falcons and their eggs was essential. The falcons’ capture was planned for late in the eggs’ incubation period to reduce the chances that the pair would abandon the eggs. Fake eggs were also placed in the box to ensure the real eggs wouldn’t be damaged during the capture.
On May 26, 2009, Geoff Holroyd of the Canadian Wildlife Service and Lisa Burt (Genesee’s wildlife consultant), climbed the smoke stack. They substituted the fake eggs for the real ones, activated the trap door, and waited for the falcons to return to the box.
The male was caught almost immediately. Identification bands were placed around his legs and he was fitted with a 28-gram satellite transmitter. Once released, he flew two kilometres north, but later returned to spend the night on one of the other two smoke stacks.
The female peregrine was caught shortly after the male’s release. She already had bands on her legs, and so was only outfitted with the satellite transmitter. Banding records indicated she had been banded in 2005 in downtown Calgary. Unlike her partner, the female returned to the nest box and spent the night on the nest. Both adults then returned to their normal incubation duties and their real eggs were returned to the nest box on May 28.
While the fake eggs were located in the nest box, the team checked the real eggs. Although all four were viable, on June 4, only three chicks hatched. In late July, all three successfully fledged from the nest.
The Migration Begins
Female migration
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September 15, 2009 - The female began her migration over the Great Plains around 4 a.m and reached southern Texas in ten days.
By October 3, she was 4,000 km south of Genesee Generating Station in Alberta, in the area of Agua Dulce, Mexico, when she removed her transmitter and transmissions of data ended.
She returned to Genesee around April 28, 2010. |
The falcons' journey between Sept. 15 and Oct. 3, 2009 |
Male migration
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September 24, 2009 – The male began his migration south over the mountains. He was spotted September 29 near Denver, Colorado by an air traffic controller at Denver Centennial Airport.
On October 9 he was heading out over the Gulf of Mexico where he spent the night on a ship or structure. Around 4 a.m. on October 10, he was headed back to the gulf coast of Texas (Figure 3).
October 25, 2009 – The male flew to eastern Guatemala and across southern Belize. He stopped five kilometres north of the Guatemala-Honduras border—4,750 kilometres from Genesee (Figure 4). On October 28, he crossed into Nicaragua from Honduras.
November 1, 2009 – The male flew from Costa Rica into Panama. Three days later, he crossed Limon Bay at the Atlantic end of the Panama Canal (Figure 5) before entering Columbia—the tenth country on his voyage (Figure 5).
November 10, 2009 – The male crossed the Andes mountains and heads east. He flew over mountains that reach 4200 metres (nearly 14,000 feet) in elevation. The next day around 12 p.m. local time, he entered Venezuela.
November 15 – April 11, 2010 - Twelve countries, nearly two months of travel and 6630 kilometres later, the male reached his winter destination. His signal was confined to an area of vast grasslands and swamps in central Venezuela (Figure 6).
The male appeared to spend his nights at a centralized location near a small tributary river surrounded by lush forest. During the day he foraged from ten to 70 kilometres way from his roosting site, which is similar to his summer foraging patterns at Genesee. |
Figure 3
Figure 4
Figure 5
Figure 6
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Spring Migration back to Canada
April 12, 2010 – The male headed almost directly north to the coast of Venezuela and travelled only 165 kilometres. The next day, he traveled only 60 kilometres and stopped 25 kilometres east of the town of El Baúl, Venezuela.
April 15, 2010 – He flew across the Tablazo Straight connecting the Gulf of Venezuela and Lake Maracaibo. He followed the northern Colombian coastline and stopped on April 18 just east of the Golfo de Morrosquillo.
April 21, 2010 – He crossed the Golfo de Uraba and continued to rest at high elevations. He was less than half a kilometre from the Panamanian border. On April 24, he spent the night on the edge of Lago Gatun, a man-made lake resulting from the creation of the Panama Canal.
April 26, 2010 – The male increased his pace and flew almost 300 kilometres. He took a 120-kilometre short-cut across the Golfo de los Mosquitos and spent two nights 15 kilometres west of Limon, Costa Rica. Two nights later, he roosted only 20 kilometres from where he spent the night on October 27, 2009.
Both his northern and southern routes through Nicaragua were similar along the eastern shore of the Lago de Nicaragua. The male’s spring pace was fast; he travelled 260 kilometres in one day—a distance he covered in four days in fall.
May 1, 2010 – The male flew 240 km non-stop from El Salvador, over Guatemala, and into the state of Chiapas, Mexico. He rested for the night at an elevation of 430 metres (1200 feet) on a ridge in densely forested biological preserve.
On May 3, he flew north along the coast of Veracruz-Llave and rested within the delta of the Laguna Alvarado, 24 kilometres south of the coastal city of Veracruz.
May 5 & 6, 2010 – The male increased his speed and traveled 500 kilometres north in one day—a distance he covered over eight days in the fall. He stopped overnight in northern Tamaulipas before embarking on his longest flight recorded to date: over 800 kilometres before hew next stopped near Abilene, Texas. He was 140 kilometres west of his fall route.
May 9, 2010 – The male took a route over the Great Plans and rested at the edge of the Black Hills near the Wyoming-South Dakota border. He crossed into Canada on May 12, 2010, 250 kilometres east of his fall route.
May 13, 2010 – The male returned to the nest box at Genesee to join the female, who arrived around April 28.
The male spent 52 days travelling 6600 kilometres to his winter home. He spent 147 days on his wintering grounds in Venezuela and used a foraging area similar in size to his summer home. His journey north took him only 32 days.