Three month high and low periods (Appendix 2)
Loberia and Malecon follow identical patterns of 3 month high and low periods. In general low periods are early in the year and high periods late in the year.
Oro: Low periods very similar to Loberia and Malecon i.e. early in the year. High periods were late in the years 16/17 and 17/18 but over the next two years, 18/19 ad 19/20 have moved much earlier to April – June.
Hypothesis: There are lower periods on Loberia, Malecon, Mann and Carola in April and June. Could some Sea lions be moving to Oro during April to June>
Los Marinos and Malecon: In the last 2 years the high periods on these beaches are an even closer match to the low periods of Loberia, Malecon, Mann and Carola.
Hypothesis: Sea lions moving from these beaches initially and then more increasingly to Oro i.e. leaving in January/February to Los Marinos and Malecon and then Oro.
Tag Records
Red tag numbers were recorded from 30th August 2019 onwards. 92 different numbers were seen. Of these:
29 recorded just once.
11 recorded twice with 6 on just one beach and the other 5 on two.
15 recorded three times with 9 on one beach, 5 on two beaches and 1 on three beaches.
11 recorded four times with 5 on one beach, 2 on two beaches, 2 on three beaches and 2 on four beaches.
5 recorded five times with 1 on one beach, 2 on two beaches and 2 on three beaches.
8 recorded six times with 5 on one beach, 2 on two beaches and 1 on three beaches.
4 recorded seven times with 2 on one beach and 2 on two beaches.
5 recorded eight times with 4 on one beach and 1 on four beaches.
2 recorded nine times with 1 on one beach and 1 on three beaches.
1 recorded ten times on three beaches.
1 recorded eleven times on two beaches.
Whole beach records for the period where tag numbers were recorded – September to November 2019 - in general show:
Loberia: similar numbers between the three months
Malecon: slight increase in numbers but not many sea lions actually recorded
Armada and Los Marinos: increase in numbers with an approximate doubling in numbers
Mann and Carola: numbers decrease across the months.
When movement of those sea lions that have been seen on more than one beach is analysed it is seen that 30 of the 92 sea lions have moved across 2 or more beaches. The biggest moves are in line with the decreases in Mann and Carola and increases in Armada and Los Marinos. 13 movements are to Los Marinos from Mann or Carola and 5 movements to Armada from the same beaches. 6 other movements are in between Armada and Los Marinos.
Report on Sea Lion numbers on San Cristobal Beaches 2016-2019
0 1 / 1 6 0 2 / 1 6 0 3 / 1 6 0 4 / 1 6 0 5 / 1 6 0 6 / 1 6 0 7 / 1 6 0 8 / 1 6 0 9 / 1 6 1 0 / 1 6 1 1 / 1 6 1 2 / 1 6 0 1 / 1 7 0 2 / 1 7 0 3 / 1 7 0 4 / 1 7 0 5 / 1 7 0 6 / 1 7 0 7 / 1 7 0 8 / 1 7 0 9 / 1 7 1 0 / 1 7 1 1 / 1 7 1 2 / 1 7 0 1 / 1 8 0 2 / 1 8 0 3 / 1 8 0 4 / 1 8 0 5 / 1 8 0 6 / 1 8 0 7 / 1 8 0 8 / 1 8 0 9 / 1 8 1 0 / 1 8 1 1 / 1 8 1 2 / 1 8 0 1 / 1 9 0 2 / 1 9 0 3 / 1 9 0 4 / 1 9 0 5 / 1 9 0 6 / 1 9 0 7 / 1 9 0 8 / 1 9 0 9 / 1 9 1 0 / 1 9 1 1 / 1 9 1 2 / 1 9 Playa Mann Alfa Male 9.7 12.7 5.3 3.5 0.0 1.0 0.8 0.5 0.1 0.0 0.3 1.2 1.3 1.6 1.0 1.0 1.3 1.0 0.8 0.0 0.2 1.3 3.2 1.3 1.9 1.5 1.4 1.0 0.7 0.3 0.5 0.3 0.2 0.5 1.8 1.8 1.3 1.1 2.0 1.1 Sub Adult Male 17.3 25.3 8.0 9.5 5.0 8.0 1.5 0.5 0.3 0.7 0.3 12.8 6.0 4.9 4.5 4.5 1.6 1.0 1.5 0.5 2.6 4.8 4.7 4.8 5.8 3.5 4.5 2.7 1.1 0.4 0.9 1.5 1.3 1.8 11.7 9.1 5.5 4.0 3.8 0.5 Female 54.7 31.0 34.5 35.0 27.0 26.5 28.3 0.5 0.2 0.3 1.0 12.4 28.0 26.7 30.5 21.8 24.3 19.0 10.1 1.4 3.3 2.3 5.7 10.9 23.3 12.3 16.4 15.1 8.7 1.6 1.9 0.5 2.0 2.8 33.8 42.0 44.8 35.6 32.1 9.8 Juvenile 69.7 33.3 36.0 34.0 22.0 11.5 11.8 0.3 0.3 0.7 0.3 24.4 13.3 20.4 23.0 14.2 5.9 8.0 7.3 2.2 5.5 4.2 9.9 19.3 32.9 18.1 22.9 19.2 15.1 1.9 2.8 2.1 4.6 3.8 34.5 45.0 46.3 46.8 46.4 20.6 Puppy 1.3 1.7 1.8 1.0 0.0 5.0 9.3 3.5 1.0 1.3 0.0 7.0 2.0 1.9 4.0 4.2 11.9 17.0 14.2 1.6 0.6 0.3 0.0 0.1 1.4 2.5 5.0 11.7 11.9 3.0 0.4 0.0 0.0 0.0 1.5 5.0 6.8 2.2 3.1 6.3 New Born 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.5 0.1 0.0 0.0 0.0 0.0 0.0 0.5 0.0 3.7 1.0 0.8 0.0 0.0 0.0 0.0 0.0 0.0 0.7 1.0 1.8 0.1 0.0 0.1 0.0 0.0 0.0 0.0 0.2 0.4 0.3 0.2 0.3 Not-identified 10.0 0.7 9.3 0.0 0.0 0.5 0.3 1.0 0.6 3.7 0.7 1.0 0.0 0.9 1.0 0.0 0.0 0.0 0.4 0.8 4.7 2.3 1.6 1.0 1.6 0.8 1.1 1.3 1.3 4.0 5.3 7.4 7.0 2.9 1.5 0.5 0.8 0.0 0.7 0.2 Total 162.7 104.7 94.8 83.0 55.0 52.5 51.8 6.8 2.6 6.7 2.7 58.8 50.7 56.3 64.5 45.7 48.6 47.0 35.1 6.5 16.9 15.2 25.0 37.3 66.8 39.4 52.3 52.6 38.9 11.1 11.9 11.6 15.1 11.6 84.8 103.5 105.6 90.0 88.3 38.7 0 1 / 1 6 0 2 / 1 6 0 3 / 1 6 0 4 / 1 6 0 5 / 1 6 0 6 / 1 6 0 7 / 1 6 0 8 / 1 6 0 9 / 1 6 1 0 / 1 6 1 1 / 1 6 1 2 / 1 6 0 1 / 1 7 0 2 / 1 7 0 3 / 1 7 0 4 / 1 7 0 5 / 1 7 0 6 / 1 7 0 7 / 1 7 0 8 / 1 7 0 9 / 1 7 1 0 / 1 7 1 1 / 1 7 1 2 / 1 7 0 1 / 1 8 0 2 / 1 8 0 3 / 1 8 0 4 / 1 8 0 5 / 1 8 0 6 / 1 8 0 7 / 1 8 0 8 / 1 8 0 9 / 1 8 1 0 / 1 8 1 1 / 1 8 1 2 / 1 8 0 1 / 1 9 0 2 / 1 9 0 3 / 1 9 0 4 / 1 9 0 5 / 1 9 0 6 / 1 9 0 7 / 1 9 0 8 / 1 9 0 9 / 1 9 1 0 / 1 9 1 1 / 1 9 1 2 / 1 9 Carola Alfa Male 7.5 11.0 4.3 6.0 1.0 0.8 0.0 0.0 0.0 0.3 0.0 2.7 2.8 1.5 2.3 2.0 1.0 1.1 0.2 0.1 0.1 5.8 5.5 6.0 3.3 2.1 0.9 1.0 0.0 0.0 0.0 0.0 0.0 2.1 6.0 2.2 1.4 1.7 1.4 Sub Adult Male 14.0 12.7 14.0 13.5 1.5 2.5 0.5 0.1 0.0 0.3 1.6 30.7 21.6 10.0 14.5 4.0 5.0 3.2 0.3 0.2 0.4 15.7 25.3 21.4 12.1 3.6 1.7 2.2 0.1 0.2 0.3 0.1 0.4 20.9 22.6 12.4 9.6 7.1 1.2 Female 25.0 26.0 44.7 53.5 32.0 41.8 6.5 0.4 1.3 1.3 1.2 85.0 61.9 59.5 38.6 66.7 46.0 25.6 0.9 0.5 1.1 21.6 59.2 78.0 56.4 29.7 19.9 20.9 0.1 0.3 0.2 0.3 0.9 36.7 77.2 64.0 71.7 55.4 19.4 Juvenile 14.5 17.0 30.7 31.5 11.0 16.3 2.8 0.3 0.7 0.7 2.4 15.0 37.4 49.0 29.5 9.4 20.0 19.4 3.8 2.5 2.8 19.5 48.5 63.3 52.5 32.9 29.3 18.7 0.9 0.4 1.6 1.6 0.4 19.1 34.0 38.6 43.5 51.1 22.4 Puppy 0.5 0.7 2.7 0.0 5.0 6.3 12.0 3.0 2.3 0.7 0.0 4.3 1.0 5.0 5.5 27.4 49.0 32.2 3.5 0.0 0.0 0.1 2.3 4.0 1.6 2.5 6.0 7.8 0.3 0.0 0.0 0.0 0.0 0.0 1.2 3.9 2.6 3.3 7.3 New Born 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.0 0.0 0.3 0.0 0.0 0.5 7.7 0.0 0.9 0.0 0.0 0.0 0.0 0.0 0.0 2.4 1.9 0.2 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.8 0.4 0.6 0.1 0.4 Not-identified 0.0 3.7 6.7 4.5 2.0 1.0 1.0 1.1 3.3 1.7 0.8 1.7 0.9 3.5 0.0 0.0 0.0 1.1 1.2 3.5 2.4 1.4 1.8 1.4 0.1 0.2 0.9 0.1 0.1 0.5 0.3 0.6 0.0 7.6 0.3 0.3 0.2 0.0 0.5 Total 61.5 71.0 103.0 109.0 52.5 68.5 22.8 5.3 7.7 5.0 6.0 139.7 125.5 128.5 90.7 117.3 121.0 83.5 9.9 6.8 6.8 64.1 142.5 174.1 128.4 72.9 58.9 50.8 1.6 1.3 2.4 2.6 1.6 86.4 142.1 121.9 129.5 118.7 52.4
2016 2017 2018 2019 0.0 5.0 10.0 15.0 20.0 25.0 30.0
total each year N u m b e r
Loberia: Mean
2016 2017 2018 2019 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0
each
N u m b e r
Armada: Mean total
year
2016 2017 2018 2019 0.0 50.0 100.0 150.0 200.0 250.0
N u m b e r
Los Marinos: Mean total each year
2016 2017 2018 2019 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 Malecon:
total each year N u m b e r
Mean
2016 2017 2018 2019 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 Oro: Mean total each year N u m b e r
2016 2017 2018 2019 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0
N u m b e r
Playa Mann: Mean total each year
2016 2017 2018 2019 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0
N u m b e r
Carola: Mean total each year
2016 2017 2018 2019 0.0 100.0 200.0 300.0 400.0 500.0 600.0
N u m b e r
Total on all beaches: Mean total each year
Appendix 2: High and Low 3-month periods
0 4 / 1 6 0 5 / 1 6 0 6 / 1 6 0 7 / 1 6 0 8 / 1 6 0 9 / 1 6 1 0 / 1 6 1 1 / 1 6 1 2 / 1 6 0 1 / 1 7 0 2 / 1 7 0 3 / 1 7 0 4 / 1 7 0 5 / 1 7 0 6 / 1 7 0 7 / 1 7 0 8 / 1 7 0 9 / 1 7 1 0 / 1 7 1 1 / 1 7 1 2 / 1 7 0 2 / 1 8 0 3 / 1 8 0 4 / 1 8 0 5 / 1 8 0 6 / 1 8 0 7 / 1 8 0 8 / 1 8 0 9 / 1 8 1 0 / 1 8 1 1 / 1 8 1 2 / 1 8 0 1 / 1 9 0 2 / 1 9 0 3 / 1 9 0 4 / 1 9 0 5 / 1 9 0 6 / 1 9 0 7 / 1 9 0 8 / 1 9 0 9 / 1 9 1 0 / 1 9 1 1 / 1 9 1 2 / 1 9 Loberia 7.5 44.7 6.3 58.0 2.8 39.9 4.9 Armada 49.3 49.3 141.0 10.3 21.3 143.4 14.5 Los Marinos 128.0 255.0 87.7 416.9 136.2 422.6 115.2 Malecon 14.0 105.0 13.5 139.2 14.5 182.8 8.5 Oro 18.3 51.3 20.7 56.0 21.6 149.5 14.6 128.7 Mann 162.7 2.6 64.5 6.5 66.8 11.1 105.6 Carola 5.0 139.7 6.8 6.8 174.1 1.3 142.1 0 1 / 1 8 166.8
Sealion Data Update 2022
Due to the Covid 19 pandemic no monitoring of sealion numbers took place in 2020 and 2021. Monitoring only started again with any regularity in November 2022. As a consequence, any data uptake could only make comparisons between the data records for Novembers 2016, 2017, 2018, 2019 and 2022.
Key Features:
1. Total Sealion numbers across the seven beaches were very similar in the years 2016-2018 but then increased by 11% between 2018 and 2019 and then by 38% between 2019 and 2022.
2. Carola: Total numbers have tripled (220% increase) in the years between 2019 and 2022. This has involved increases in the numbers of females, juveniles, puppies and new borns.
N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 Carola Alpha Male 1.0 2.0 1.0 1.0 3.0 Los Marinos Alpha Male 6.9 3.0 4.1 4.3 1.5 Sub Adult Male 2.0 4.0 2.0 1.0 2.0 Sub Adult Male 21.7 12.3 34.3 41.7 92.5 Female 42.0 67.0 21.0 19.0 68.0 Female 71.0 61.0 54.0 72.2 43.0 Juvenile 16.0 9.0 19.0 22.0 54.0 Juvenile 54.8 14.7 66.3 69.0 53.2 Puppy 6.0 27.0 8.0 7.0 24.0 Puppy 5.2 33.0 16.4 16.8 5.5 New Born 0.0 8.0 0.0 0.0 13.0 New Born 7.8 4.3 2.1 0.3 4.2 Not-identified 1.0 0.0 0.0 0.0 0.0 Not-identified 3.8 0.0 0.1 0.2 0.0 Total 68.0 117.0 51.0 52.0 165.0 Total 171.2 127.7 177.4 204.5 200.0 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 Mann Alpha Male 0.7 1.3 0.7 1.1 1.8 Malecon Alpha Male 0.4 0.7 0.3 0.9 0.8 Sub Adult Male 1.5 1.6 1.1 0.5 2.0 Sub Adult Male 3.1 2.6 2.9 3.0 3.2 Female 28.2 24.3 8.7 9.8 38.2 Female 2.0 3.1 7.7 10.0 7.8 Juvenile 11.8 5.9 15.1 20.6 35.8 Juvenile 0.7 0.9 8.3 8.7 6.8 Puppy 9.3 11.9 11.9 6.3 10.7 Puppy 0.0 0.0 1.3 0.9 0.5 New Born 0.2 3.7 0.1 0.3 6.2 New Born 0.0 0.0 0.3 0.0 0.2 Not-identified 1.2 0.0 1.3 0.2 0.0 Not-identified 0.8 0.0 0.1 0.2 0.0 Total 51.7 48.6 38.9 38.7 94.7 Total 7.0 7.9 21.0 23.7 19.2 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 Oro Alpha Male 0.9 1.4 1.1 1.2 2.2 Loberia Alpha Male 1.0 1.9 1.4 1.3 1.5 Sub Adult Male 3.4 2.7 6.7 4.1 4.0 Sub Adult Male 1.3 2.3 1.0 1.5 1.8 Female 11.1 18.0 17.1 14.9 29.2 Female 14.7 18.4 12.1 14.6 27.5 Juvenile 8.7 4.0 20.4 14.3 29.8 Juvenile 6.9 3.9 8.9 14.7 16.8 Puppy 0.8 4.6 9.0 5.2 16.0 Puppy 7.9 27.9 14.6 9.3 11.2 New Born 2.6 2.1 0.4 0.3 7.7 New Born 9.4 3.3 0.8 0.6 2.0 Not-identified 2.4 0.0 0.2 0.2 0.5 Not-identified 2.0 0.4 0.4 0.0 0.0 Total 29.9 32.9 55.0 40.1 89.5 Total 43.1 58.0 39.2 42.0 60.8 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 N o v1 6 N o v1 7 N o v1 8 N o v1 9 N o v2 2 Armada Alpha Male 2.7 2.9 2.3 2.0 1.3 All beaches Alpha Male 13.6 13.2 10.9 11.8 12.1 Sub Adult Male 6.5 4.6 4.6 7.5 12.2 Sub Adult Male 39.5 30.1 52.6 59.3 117.7 Female 54.2 55.1 49.1 72.4 61.8 Female 223.2 246.9 169.7 212.9 275.5 Juvenile 40.0 18.0 48.3 53.5 51.8 Juvenile 138.9 56.4 186.3 202.8 248.2 Puppy 5.2 42.1 34.1 45.8 27.5 Puppy 34.4 146.5 95.3 91.3 95.4 New Born 8.5 3.1 4.4 2.3 13.5 New Born 28.5 24.5 8.1 3.8 46.8 Not-identified 3.6 0.0 0.6 0.5 7.2 Not-identified 14.8 0.4 2.7 1.3 7.7 Total 120.7 125.9 143.4 184.0 175.2 Total 491.6 518.0 525.9 585.0 804.4
3. Mann: Similar picture to Carola with an almost 150% increase between 2019 and 2022. Numbers of females showed the biggest increase (290%).
4. Oro: This also shows increases in numbers. 123% increase in total numbers between 2019 and 2022 although the 2019 figures showed a slight drop when compared to 2018. It is clear that there are now more puppies and new born sealions on Playa Oro. It is also interesting to note that more dead sealion pups or new borns were found on Oro when compared to previous years or other beaches.
5. Armada and Malecon: Sealion numbers have remained quite stable between 2019 and 2022. These are the only beaches that seem to have remained similar over time.
6. Los Marinos: This beach shows the most dramatic change in the profile of sealions over time. Although overall numbers have remained similar over the past few years falls in female, puppy and new born numbers have been balanced by a large increase in sub adult males. It is clear that although Los Marinos is known as a bachelor beach this has become even more dramatically the case. This has probably resulted in their being less room for the other sealion groups.
7. Loberia: This beach show a 45% increase in numbers between 209 and 2022 with this being almost totally due to an increase in the number of females (88% increase).
