Seal review 2016

The Farne Islands are home to thousands of grey seals, and each autumn hundreds of pups are born here.

Recent trends suggested that 2016 might be the year that Grey Seal Halichoerus grypus pup production would surpass 2000 for the first time since the 1971, but expectations were exceeded as the previous island record of 2,041 (set in 1971) was well and truly smashed. The season started late, with the first pup spotted on Longstone End on 8th October. Unfortunately due to the exposed nature of the island, the pup didn’t survive long. The prolonged spell of easterly winds in early October eventually died down, and the rangers finally made it out for a first count on 21st October. It took a few more weeks for things to get going, then in a 10 days period from 8th November, over half the total seals pups were born.

 

IF

WW

KR

Staple

BR

NW

SW

BH

NH

LG

LE

8th Oct

0

0

0

0

0

0

0

0

0

0

1

21st Oct

0

0

0

3

3

22

10

0

2

0

0

25th Oct

0

0

0

8

8

10

19

0

0

0

0

29th Oct

0

0

0

42

28

18

34

0

0

0

0

4th Nov

0

0

0

90

108

35

61

0

1

0

0

8th Nov

0

3

0

70

131

0

0

0

5

0

0

13th Nov

0

16

6

105

190

43

75

0

6

0

0

18th Nov

5

34

36

85

164

12

45

2

1

0

0

24th  Nov

1

32

23

50

167

0

0

0

0

0

0

25th Nov

0

0

0

0

0

20

45

1

3

0

0

28th Nov

1

0

0

56

68

3

13

1

4

1

0

29th Nov

0

29

25

0

0

0

0

0

0

0

0

3rd Dec

5

34

17

18

54

6

12

2

10

0

0

15th Dec

12

6

5

21

13

0

0

0

0

0

0

Total

Total

24

154

112

548

934

169

314

6

32

1

1

2295

This year saw another huge rise in the number of seals using Brownsman as a rookery, as the pup production rose from 655 to 934. Interestingly the population remained relatively stable on Staple dropping by 18 pups, suggesting that Brownsman could be the preference for a prospecting cow seal. These two islands account for 65% of total pup production, exactly the same as last year.

There was also a big jump in the number of seals using the Inner Group of the islands, where mortality was much lower than in the outer group, reflecting their more sheltered position. As recently as 2012, just 44 pups were born across the Inner Group, representing just 2.7% of the total. This year, 290 pups were born there, representing 12.6% of the total.

Mortality

Mortality was slightly higher than average for the previous 5 years, at 29% (26%). This may well be due to the large Northerly storm that blew through in November which undoubtable took out a few pups and probably accounts for the high number that went missing. As usual, mortality on the Inner Group was much lower at just 8%, compared to 32% for the outer group.

2016

2015

2014

2013

2012

2011

Total Pups Born

2,295

1,876

1,740

1,575

1,603

1,555

Surviving

1629

1,360

1.419

1,165

1,166

1,077

Unsprayed Dead

96

139

71

55

54

62

Sprayed Dead

88

79

66

78

71

61

“Missing”

482

298

184

277

312

355

Mortality

29%

27.5%

18%

26%

27.2%

30.7%

 

Elsewhere on the East Coast

The crown for largest east coast colony was a closer run thing this year than it was last. Despite the boom in pups on the islands, Blakeney Point NT in Norfolk remained the largest colony, with a total of 2,366 pups born. In recent years their colony has stabilised after the seals pupped there for the first time just 17 years ago. Just down the Norfolk coast at Horsey a whopping 1,422 pups were born, a new site record, and at Donna Nook 1,957 pups were born, also a site record.

References

http://www.lincstrust.org.uk/donna-nook/weekly-update - Accessed 19/01/17

http://friendsofhorseyseals.co.uk/weekly-seal-count-results/ - Access 19/01/17