Island Invaders (Invasive Thistle Removal)

Invasive Species: Canada Thistle Removal 

We removed 6 large garbage bags full of invasive “Canada” thistles over the past few days. Considered a “noxious weed” under the BC Weed control act, these perennial (grow back every year) weeds can reproduce through seed and root regeneration. Thought to have been introduced to North America via contaminated crop seed in the 1700’s, this plant is actually native to southeast Europe and Asia. Presumably they were introduced to Race Rocks by a visitor on clothing or equipment, or perhaps by an animal.

They can be a bit laborious to remove, due to their tap root and ability to regenerate through “cloning” (growing back if you leave the root in the ground). Incredibly, the seeds can remain viable for 3-6 years when buried at typical depth, and some up to 21 years (yikes!). Each plant produces an average of 1500 seeds, but can sometimes exceed 5000.

Because of this, we collected them into garbage bags to remove from the island instead of composting them where they would have the opportunity to reproduce. Unfortunately it appeared that these aggressively persistent weeds were whipper snipped in past seasons, allowing the seeds to disperse and roots to regenerate. Hopefully with some attentiveness, they can be eradicated from Race Rocks in the next few years. More information on other introduced plants available in this post from Garry Fletcher, 2006.

Weather: 

  • Sky partly cloudy, some sunshine
  • Visibility 15+ miles (some fog last night)
  • Wind 20-30 knots W
  • Water choppy, whitecaps

Visitors: 

  • Today Laura (Pearson’s marine science teacher), and her class came for a bit for their first trip to Race Rocks! Two more classes will visit in the next couple of days.
  • Less frequent eco-tourism traffic now that the summer tourism has slowed down. They have been getting quite close to the sea lions though, often causing them to climb over each other to get further away from the vessels. Since it has been overcast, we’ve been seeing the use of flash photography much more, which seems to audibly cause quite a stir.

Ecological: 

  • There have been some birds passing through that we don’t often see: western sandpiper, savannah sparrow, song sparrow, and juvenile sandpiper (or possibly sanderling- we have a hard time with bird ID!) Also, we think we spotted a yellow warbler a while back, but it was too speedy for us to snap a photo.
  • The sea lions have continued to haul out- notably, there are typically over 100 animals on the jetty alone.

Christmas Bird Count at RR 2013

Also-Warden’s Report for Dec 28, 2013.
Link to the Index for the past records of the Christmas Bird Counts

2013-12-28songsavan

Song Sparow on the left and Savannah Sparrow on the right of this lichen covered log on the West side of Great race Rocks..

Ecoguardian Alex Fletcher picked up Val George and myself from the Pearson College docks mid- morning and we started our count by water in Pedder Bay, then across Rocky Point, through Eemdyck Channel and then across Race Passage to Race Rocks via West Rocks and Middle Rocks. The following includes only the Race Rocks portion of the census:

Observers:  Val George, Garry Fletcher and Alex Fletcher

2013  Christmas Bird Count – Summary      Date ___Dec28___Area or Sub-Area__Race Rocks Ecological Reserve__
Observers (in field)—3 Leader Garry Fletcher
Temp—-6 Wind NE,  3.5km Time Start__10:30___a.m.   Finish___12:00__a.m.
A.M. Clear,calm partly cloudy Moving water open ocean around
for your entire count team # hours (on foot) 1.5 distance (on foot) .35km, and top of tower
Northwestern Crow 2
Common Raven 2
Thayer’s Gull 200
Canada Goose 6
Black Oystercatcher 30
Black Turnstone 14
Harlequin Duck 10
Bufflehead 8
 Song Sparrow 1
Savannah Sparrow 1
Glaucous-winged Gull 20
 Common Murre 4
Pacific Loon 2
Common Loon 1
Brandt’s Cormorant 80
Double-crested Cormorant 120
Pelagic Cormorant 17
Bald Eagle  (adult) 1
Bald Eagle
(immature
7
Total Number of Birds 528
Total Number of Species 17

Melospiza melodia: Song Sparrow

Aside

Song Sparrow in October, 2007 at Race Rocks. (Photo by David Sacks.)

Song Sparrow from the remote cam 5 (image by Pam Birley March 06)

 

 

 

 

 

 

Song Sparrows are winter visitors to Race Rocks. See the Christmas Bird Count File for other records.

1997 0 1999 0 2001 0 2003 na 2005 1
1998 4 2000 0 2002 3 2004 3 2006 na

On the Ecoreserves.bc.ca website , there are several posts about Song Sparrows. They have been the subject of research on other Ecological reserve Islands in BC.

Domain Eukarya
Kingdom Animalia
Phylum Chordata
Sub-Phylum Vertebrata
Class Aves
Order Passerifomes
Family Passeridae
Genus Melospizia
Species melodia
Common Name: Song Sparrow

Other Members of the Class Aves at Race Rocks 
taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

Garry Fletcher 2006