Bill Looks Back

Comparison 1996 and 2017 Nov.-Dec. hawk flights -

 

Continuing my comparison of the 1996 and 2017 late season hawk flights, this post will feature November and December statistics. In my experience, late season hawk flights in southeast Tennessee depend on very cold, icy, snowy conditions to our north. These conditions make it difficult for hawks to procure food. If those conditions don’t exist during November and early December, there is no reason for large numbers of late season migrants to come as far south as Soddy Mountain. They either stay where they are as long as conditions allow, or they migrate a shorter distance, stopping well north of our hawk lookout. I find the following statistics very informative and interesting. They also point out why I grew to love the late season hawk migration. Has a warming climate, both here and in states north of us during November and December contributed to recent poor hawk flights at Soddy Mountain? During most of this period in 2017, temperatures were 10-20 F above the norm in those states north of us, with very little snow. I’ll let the numbers speak for themselves.

 

I realize my format yesterday didn’t come out well on the blog, so will use a little different format this time around. Once again, I focused only on Sharp-shinned and Red-tailed Hawks, as they are the two prominent players in the late season flights. Turkey Vultures, another late season migrant, were not included here. I have included the date, starting temperatures and SS and RT records for each year. I will start with 1996.

 

11/3/96, start temp. 37 F: SS 2, RT 30 (2 dark phase!)

11/4/96, start temp. 47 F: SS 4, RT 23

11/8/96, start temp. 40 F: SS 5, RT 15

11/9/96, start temp. 28 F: SS 3, RT 18

11/10/96, start temp. 27 F: SS 3, RT 21

11/12/96, start temp. 37 F: SS 1, RT 21

11/16/96, start temp. 31 F: SS 4, RT 31

11/17/96, start temp. 41 F: SS 5, RT 12

11/19/96, start temp. 58 F: SS 2, RT 18

11/22/96, start temp. 34 F: SS 8, RT 63

11/23/96, start temp. 34 F: SS 5, RT 24

11/24/96, start temp. 40 F: SS 12, RT 22

11/26/96, start temp. 37 F: SS 0, RT 4

11/27/96, start temp. 38 F: SS 1, RT 8

11/28/96, start temp. 40 F: SS 2, RT 25

11/29/96, start temp. 36 F: SS 0, RT 0

12/2/96, start temp. 36 F: SS 3, RT 33

12/7/96, start temp. 45 F: SS 2, RT 8

12/8/96, start temp. 32 F: SS 2, RT 4

12/9/96, start temp. 31 F: SS 1 RT 11

10/10/96, start temp. 33 F: SS 2, RT 7

 

1996 Total: SS 67, RT 398

 

1996 Nov. Dec. days starting temp. was in 20’s: 2

1996 Nov.-Dec. days starting temp. was in 30’s: 12

1996 Nov.-Dec. days starting temp. was in 40’s: 6

1996 Nov.-Dec. days starting temp. was in 50’s: 1

 

Now we’ll skip forward to the recently-completed fall 2017 statistics.

 

11/2/17, start temp. 72 F: SS 5, RT 0

11/9/17, start temp. 59 F: SS 1, RT 2

11/10/17, start temp. 48 F: SS 0, RT 2

11/11/17, start temp. 40 F: SS 1, RT 5

11/12/17, start temp. 54 F: SS 0, RT 0

11/13/17, start temp. 51 F: SS 0, RT 2

11/14/17, start temp. 50 F: SS 1, RT 4

11/16/17, start temp. 56 F: SS 0, RT 2

11/17/17, start temp. 49 F: SS 0, RT 4

11/19/17, start temp. 49 F: SS 0, RT 2

11/22/17, start temp. 52 F: SS 0, RT 2

11/23/17, start temp. 37 F: SS 0, RT 0

11/30/17, start temp. 41 F: SS 0, RT 0

 

2017 Total:  SS 8, RT 24

 

2017 Nov.-Dec. days starting temp. was in 20’s: 0

2017 Nov.-Dec. days starting temp. was in 30’s: 1

2017 Nov.-Dec. days starting temp. was in 40’s: 5

2017 Nov.-Dec. days starting temp. was in 50’s: 6

2017 Nov.-Dec. days starting temp. was in 60’s: 0

2017 Nov.-Dec. days starting temp. was in 70’s: 1

 

RED-TAILED HAWK: Numbers for the two years are drastically different, as are the starting temperatures. Note that the highest daily RT total of 2017 was 5. The season total was less than 30. On only 3 out of 21 days of coverage in 1996 did we count LESS Red-tailed Hawks than our highest 2017 total, and 4 daily totals exceeded our entire 2017 season total, one more than doubling it!  

 

SHARP-SHINNED HAWK: In 1996, Sharp-shinned Hawks were counted on 19 of 21 days, continuing into December. In 2017 they were counted on only 4 of 13 days, with the last one counted on Nov. 14.

 

Is it possible I may have missed major flight days in 2017? Yes. Is it possible we missed major flight days in 1996. Probably. You ALWAYS wonder what is coming past when you aren’t there. I didn’t have as much coverage during this period in 2017 as I would have liked. I still work and can only man the lookout when I have days off. I was there as much as I could be, and I manned the lookout by myself for this entire period. You’ll note a lot of 0 totals when I was there. If good numbers of hawks had been flying, as they did in 1996, I would have definitely  had more hours of coverage, but probably not more days.

 

I welcome any comments about these past few posts that speculate about the link between a warming climate and hawk migration. Any theories expressed here are mine alone, and a result of my 27 years of hawk watching.

 

Reporting: Bill Haley

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It might also be interesting to take a look at just the last 5 years, and see the latest trend. I love that there are so many ways to look at the numbers. and wonder about how what happens this year or last will affect our environment overall.  Will Hawks loose out if they change their migration patterns?  A long study helps to provide the answers as time goes by. We must always keep asking the questions.

 

KEEP LOOKING UP!!!!!