Jac's Wildlife Blog: The Carden Alvar

I've finally arrived in Carden, home of the critically endangered migratory predatory songbird, the Eastern loggerhead shrike or ELOSH (Lanius ludovicianus migrans).

(ELSOH - image from the Nature conservancy of Canada)

Crickets, mice, other birds and even snakes are all on the menu for these feisty passerines. Since they lack the talons of other predatory birds they must impale their prey on something sharp and as a result they tend to seek out habitat with hawthorn and black thorn. Their eating habits are locally well-known especially by farmers with barbed wire fencing,

The reason for the decline of this species is uncertain but is likely a combination of habitat destruction, use of pesticides and collisions with cars. Monitoring and conserving a migrating species is notoriously difficult. The wild ELOSH in Carden have spent the last 6 months in the Southern US where there are only a few places left where this species of shrike are known to breed.

The Carden plain is on an alvar, a unique and rare habitat consisting of limestone bedrock and a thin soil cover. Since large trees can't get a stronghold here, the majority of the trees are hawthorn, red cedar and poplar. Characterised also by it's grasses that are kept short by cattle grazed on the land by local farmers. The Couchiching Conservancy work hard to conserve the alvar through controlling invasive species and recruiting volunteers. Visit their site here to find out more about the alvar, it's rare ecosystems and the work being done to help protect it.

The ELOSH I'll be working with a part of a captive breeding and release programme, my job will be to take care of 6 pairs this field season in purpose built captive breeding aviaries.

So here it is, my new office. The breeding cages are hidden by the tree line at the back of the field. Soon we will be joined by grazing cows that will help to keep the grass down playing a critical role in helping the shrike spot their rodent prey in the short grass.

For more information on the recovery programme get clicking here.

Firstly we must prepare for the birds to arrive from their overwinter facilities. This involves cleaning out their old field aviaries, taking out old branches, fixing anything that has worn out over the winter and then furnishing the cages with fresh branches, nesting cups and hawthorn branches for them to impale their prey upon.

Here is our stick transporting device and wheel-barrow for tools. Unfortunately 3 days after buying this new barrow (that took half an hour to set up) we got a hawthorn induced flat tyre. This minor set back and a few other minor set backs mean it will be tight for time getting the cages ready before the shrikes arrive in a few days time!

So when the birds arrive I will begin observing their behaviour. To start off the males and female will be in separate enclosures but able to see each other, once I observe the pair courting, the door between their enclosures gets opened they get introduced and hopefully get busy building a nest.

So until I have some shrike pictures to post, here are some other wildlife I've pulled over to get pictures of whilst driving to and from the field site.