Tuesday 21 March 2017

marsh volunteers building a new j-trap


We would be lost without volunteers Rachelle and Sylvain to the rescue !!!



So what is a "j trap you might ask?   It is a trap which has "j" shaped funnels to allow the birds to get into the trap. The birds are attracted by food and with the door left open they can come and go as they please but once the door is shut it allows us to capture birds in a way that does not harm them..  The  species we really are targeting in this trap are red winged blackbirds and common grackles. Sadly since the 1990's Red winged blackbird numbers have been in decline by about 2% per year which does not sound like a lot but is really substantial when one thinks about sheer numbers of birds, We have been tracking these  birds  with the use of a j trap but two winters ago our trap built by past terra students did  not survive the winter  so with the help of  Sylvain and Rachelle Plante  we will have a trap ready for the arrival of  blackbirds which is very soon.


Rachelle and Sylvain taking a forced break by an insistent photographer


The trap design we are using was designed by David Okines from Prince Edward Point bird observatory. Dave is a master trap designer  and with the addition of some new plastic mesh we will soon be able to hopefully capture some good number of returning birds. Every year we catch birds that we have banded  before the oldest grackle we have re-trapped was 10 years old and the oldest red-winged blackbird so far was 8 years old.

Rachelle and Sylvain with the trap



  Blackbirds have a lot of survival issues including poisoning and being shot. Blackbirds are not protected by the migratory convention act and are at risk during the migration. one reason is that farmers need some way to protect their crops from large flocks  and ironically in places like Georgia one of their favouite crops  to eat are  sunflowers which are specifically grown for bird seed!!!


Our hope at the marsh is that we can continue to track their  population. Red winged blackbirds and grackles both favor wetlands . Red wings are more wetland dependent than grackles requiring cattails to nest in. Our numbers have been pretty consistent over the years  ,


      year    red winged  grackle
2016 244 57
2015 229 50
2014 281 45
2013 147 35
2012 128 24
2011 292 57
2010 126 45
2009 167 58
2008 272 91
2007 159 67
2006 230 138
2005 196 66
2004 104 84
2003 208 52
2002 200 88
2001 72 57
2000 143 63
ave  170 ave   55.2
total 3246 total   431


So that is the story of the J trap we are so lucky that Rachelle and Sylvain have been able to take on the project  and I certainly cannot wait until we can try it out .  The trap is being assembled in sections so we can put it together in the field .  Apparently I am allergic to hammers and all sorts of tools but I will not be able to cry sick when it comes time to carry it out to where it will start to catch birds . I am looking forward to continuing the saga of the j trap.... more to come !!!!!