Jun 29 2012

Musings on Peregrine Mortality

Published by at 8:26 am under Peregrines

To put things into perspective… yesterday’s news about Blue’s death was sad but not unusual.

Juvenile peregrine falcon mortality is high.  Nearly two thirds don’t live to be one year old.  Their often quoted mortality rate is 62.5%.

Scientific research bears this out.  Marcel Gabhauer published his doctoral thesis on peregrine falcons in 2008 having studied urban and rural, wild-born and hacked birds in Ontario since 1995.  His findings showed that nest survival from hatching to fledging is high (95.8%) but first year survival is dramatically lower.  Of the chicks he was able to track for a year, only 36.5% of the wild-born birds and 31.6% of the hacked birds survived to their first birthday.  Only one out of three makes it.

My experience with the Cathedral of Learning peregrines is similar though I’m unable to track them for a year.  Each summer since 2008 at least one juvenile Pitt peregrine has died in Pittsburgh.  Interestingly, I didn’t begin to hear of the Pitt peregrines’ deaths until 2008 when my blog made me known as The Peregrine Lady.

Monitoring juvenile peregrines is a roller coaster experience. Dorothy and E2 know this much better than I do.  Yesterday evening I found them where I expected them to be – on the Cathedral of Learning on the side facing the scene of Blue’s accident.  E2 was gazing in that direction. Dorothy was in her mourning nook, a place she only uses just after one of her youngsters has died.

This dip in our roller coaster won’t last long.  The demands of the remaining juveniles will perk up Dorothy and E2.  The Pitt peregrines’ success stories will keep us going with Dorothy’s “kids” across the eastern U.S:

 

(photo of Smolder by Chris Saladin)

 

4 responses so far

4 Responses to “Musings on Peregrine Mortality”

  1. Paton 29 Jun 2012 at 10:04 am

    The part where you talk about Dorothy and E2 brought a tear to my eyes.

  2. Kate St. Johnon 29 Jun 2012 at 11:08 am

    This morning on my way to work I saw one juvenile perched on the Heinz Chapel steeple. Things are picking up.

  3. Anne Marieon 29 Jun 2012 at 2:10 pm

    I was trying to reason with myself about peregrine mortality on my way to work today – so your blog is timely, as usual. I had also read the 62% statistic before (probably when Green Boy died and I was devastated because he was part of my ‘freshman’ year of peregrine watching). I thought I had evolved and made peace with Blue’s death and then I read this.. had same reaction as Pat! Why can’t our peregrine family beat the odds just one year?! (btw I also saw a juvie last night on Heinz)

  4. Kate St. Johnon 29 Jun 2012 at 2:16 pm

    Good news at 2pm. Dorothy left the mourning nook & moved to 32 northeast to stay cool. I also saw a juvie in a nook on 32 east. It’s HOT out there!

Comments RSS

Leave a Reply

Bird Stories from OnQ