I learned the hard way in IA with my bluebird trails that both House Sparrows and House Wrens are notorious for killing Eastern Bluebirds and other birds in nest boxes. If you run a bluebird box trail in a state east of CO (perhaps in eastern CO also), you have to pull out House Sparrow (not protected) nests weekly and House Wren sticks (pulling out sticks only that the male puts into several houses prior to nest building is legal). Never put up a bluebird box anywhere near trees or the House Wrens will move in; keep the boxes in the grasslands. The wrens drive the bluebirds out of the box and build sticks and a nest on top of the now cold eggs. And they also will pitch out bluebird eggs, nestlings, and kill nestlings in the boxes. Then they stuff the house with sticks right over the bluebird nest and the female wren builds a grass nest in the sticks. As shown in this thread, wrens do the same thing to other species unfortunately.
We had many bluebird predators in IA! When I moved to CO, I was amazed that our bluebird trail in Elk Meadow in Evergreen rarely had trouble with any predators. A very pleasant trail to care for! I tried putting up lots of boxes on my pine mt property above Evergreen to try to keep the wren pair happy and accommodate the Mountain Chickadees and Pygmy Nuthatches. That worked. So, maybe more boxes might be a solution. Kay Kayleen A. Niyo, Ph.D. Niyo Scientific Communications 5651 Garnet St. Golden, CO 80403 303.679.6646 k...@kayniyo.com; www.KayNiyo.com From: cobirds@googlegroups.com [mailto:cobirds@googlegroups.com] On Behalf Of markcha...@comcast.net Sent: Monday, July 13, 2015 6:38 PM To: gmlu...@comcast.net Cc: cobirds@googlegroups.com Subject: Re: [cobirds] Wren fatalities We had a situation happen this spring with this kind of behavior. We were thrilled to have Red-breasted Nuthatches nesting in one of our boxes here in Lakewood. I watched the activity as the birds went in and out of the box for nearly two weeks. One morning, I heard the male calling over and over outside of the box. The next day I noticed the wrens were inspecting the nest. I grabbed a ladder and looked inside to find three pierced nestlings. The nuthatches moved on and the wrens took over the box. We also had Flickers nesting in a box to find their nestlings thrown about the yard and Starlings in the box. We sealed up the hole with popsicle sticks to keep the Starlings out. After much persistence the Starlings gave up but the Flickers never returned. Nature is cruel!! Mark Chavez Lakewood-Green Mtn http://jaeger29.smugmug.com/ ----- Original Message ----- From: Luger <gmlu...@comcast.net> To: cobirds@googlegroups.com Sent: Mon, 13 Jul 2015 21:34:21 -0000 (UTC) Subject: [cobirds] Wren fatalities CObirders, I'm puzzled. Last month we hung a Wren box and got a tenant almost immediately. This week for two days I watched a wren bugging and carrying insects back to the box. Then yesterday I found a wriggling hatchling in death throws on the ground beneath the box and another hatchling dead a little further away on the ground covered with ants. The dead bird, though further from the box, still had the shell with the body. Just above my head there was a wren watching me from the house opening. The one still alive had a tiny bloody hole on the back of its head that looked like a beak pinch mark from where it was tossed from the box. What the heck happened? Did the parent kill the hatchlings? Has anyone seen this happen before? There is still a Wren coming and going but not with food. Perplexed, Myrna Luger Across from Horsetooth Mtn Pk -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To post to this group, send email to cobirds@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/B2530B46-BED1-461D-AC66-3C55340E37F1%40comcast.net. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To post to this group, send email to cobirds@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/28946447.4786564.1436834296505.JavaMail.zimbra%40comcast.net <https://groups.google.com/d/msgid/cobirds/28946447.4786564.1436834296505.JavaMail.zimbra%40comcast.net?utm_medium=email&utm_source=footer> . For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To post to this group, send email to cobirds@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/05a001d0bdda%248b13b870%24a13b2950%24%40com. For more options, visit https://groups.google.com/d/optout.
