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Problems with wrens on the bluebird trail (Part 7)In addition to Messages that have appeared in the Bluebird Mailing Lists on this topic, the following are on the Audubon Society of Omaha website:
From: Bet Zimmerman [mailto:ezdz"at"charter.net] Sent: Sunday, June 25, 2006 10:59 AM Subject: RE: wren strikes eggs; should i remove nest? Mike from OH wrote: mr. wren pecked and removed all five eggs. Should i remove the nest and let the EABL pari start anew? Or let it be? Will she lay another clutch? Sorry to hear this Mike! House Wrens can do a lot of damage. Tips on deterring them here: If the House Wren is serious about the box, he may yank out the bluebird nest and use it, or just cover it up with sticks. If it is covered by sticks (usually filled to the top of the box - see photo on right here: http://www.sialis.org/competition.htm ) it is unusable for other birds. The bluebird may start anew with another clutch as long as its not too late in the season. I like to leave a nest (if it's not yucked up with egg goo) as it saves them time. However, the peckage problem may continue. Can you move the box into better territory? (50-300 feet away from brambles, woods etc.)? House Wrens are native, cheery and eat lots of bugs, which is great, but I don't let them use my boxes. If I let them nest once, the following year they spread out. I had one nest get away from me last year and since it had a nestcup I had to leave it. This year, HOWR tore out two TRES nests in the vicinity, one of which is about 225 feet from brambles. Tree Greenwood has had luck with the "keep them busy" technique. Put up a number of wren houses without predator guards in a very small area in prime wren habitat, away from bluebird boxes. Then continually remove the dummy nests. This may keep the males occupied so they don't have time to attack. Boxes should have 15/16" holes. Tree uses 6-20 or more. Bet from CT From: Bet Zimmerman [mailto:ezdz"at"charter.net] Sent: Wednesday, June 28, 2006 8:04 PM Subject: All about House Wrens New webpage with lots o' info: http://www.sialis.org/howrbio.htm A few interesting facts: The Chippewa indians call it O-du-na-mis-sug-ud-da-we-shi, meaning a big noise for its size. HOWR males even make a "Whisper Song" (without opening their bill) while copulating. Diet is 98% animal matter Usually active nests are almost 100 feet apart, up to about 230 feet. Also nests in variety of other crevices or cavities-e.g., in a flower pot, tin can, boot, scarecrow, At fledging, nests may contain >50,000 mites. Egg sacs of predatory jumping spiders are often One researcher developed psittacosis apparently after contracting the bacterium Chlamydia psittaci Dummy nests may have less than 10 or more than 400 sticks. Since incubation begins on the ante/penultimate egg, hatching may be asynchronous, over a 1-4 day Bet from CT PS More house wren nests = more house wrens = likely more predation. House Wrens populations are on Input is always welcome! From: Linda [mailto:linyl"at"alltel.net] Sent: Wednesday, July 05, 2006 2:30 PM Subject: Dealing with house wrens Question for anyone. If you have a purple martin setup, will the martins deter house wrens from invading bluebird houses nearby? Just curious. I haven't been able to have bluebirds because of the house wrens and the bluebirds are around. House wrens invaded my next door neighbor's bluebirds, resulting in bluebirds cries for 2 days, and now wrens are after the ones in the field nearby on the other side of my house. Linda in NW GA. From: Dottie, Hickory Hollow, Brown County, Indiana [mailto:yumyumkatts"at"voyager.net] Sent: Wednesday, July 05, 2006 5:51 PM Subject: Re: Dealing with house wrens Not around here they won't. One Purple Martin man put up gourds around Dottie, Hickory Hollow From: Steve Murphy Home [mailto:thcri"at"qwest.net] Sent: Sunday, July 16, 2006 8:52 AM Subject: WRENS Yesterday I went out to check my 3 nest boxes that I have been getting HOSP in. On top of the mess of nest was about 5 or 6 sticks in 2 of the 3 boxes. I cleaned them out along with the straw or the junk the HOSP put in and came back 5 minutes later and the sticks were back in again. I cleaned them out and then kept the boxes open. I now have WRENs chewing me out. I don't want the wrens. I have never seen a wren around here before and really don't want them to move in. I know it is illegal for me to destroy their nest, but to me it was not a nest yet and them boxes were going to be moved in the fall anyway. One of the boxes is 10 feet away from my BB's. Do I let the wren move in or do I prevent them from moving in. If they can't nest in the box they started will they move on to where my BB's are and destroy the eggs? Not sure what to do. Steve Murphy From: Cher [mailto:bluelist"at"localnet.com] Sent: Sunday, July 16, 2006 9:31 AM Subject: Re: WRENS Steve, the wrens will fill every available nestbox they can find with sticks, even when they have their own nesting site. I don't know how others have handled it, but the two separate years I had wrens trying to nest out in my treeline at the back of the property, they would come into my yard and try to fill up the nestboxes with sticks. I just kept removing the sticks, sometimes four and five times a day. Eventually they got discouraged, and the following year I had no wrens. If you have an active Bluebird nesting going on at the same time, you can try adding a wren guard to the box. Some people have had success with them, others have not - especially with adding one after the wrens have discovered the box. Unfortunately, I don't think anyone's found a sure-fire way of dealing with wrens - we can only discourage them, and place our nestboxes as far away from wooded areas as possible. Cher From: Dottie, Hickory Hollow, Brown County, Indiana [mailto:yumyumkatts"at"voyager.net] Sent: Sunday, July 16, 2006 12:18 PM Subject: Re: WRENS I would put up a gourd for them. You can get a supergourd and put it on Dottie, Hickory Hollow From: Gretchen Cornnell [mailto:gcornnell"at"diocesecpa.org] I have a HOWR who is worrying me to death but that isn't the question. I have been closely observing it for days trying to get a really good look at it with my binoculars. I have been curious because it didn't seem to be able to see as a normal bird would, it seemed to have a dominating eye side. This morning I did get a good look and it looks like one eye is missing and half of it's head (all around the missing eye) is missing feathers. Do you think this is due to a fight or is it some kind of disease? And if it is a disease what about the health of my EABLs? This HOWR steals mealworms out of my mealworm feeder. The EABLs used to be able to frighten it away but now when the HOWR comes the EABLs get the heck out of there. I think the HOWR has a brood and my EABLs have 4 babies about 4 days old. Any thoughts? From: Tree Greenwood [mailto:doctree"at"crosslink.net] Sent: Wednesday, July 26, 2006 11:07 PM Subject: Re: Injured or Diseased Wren Hi, Gretchen and everyone, Perhaps disease, avian conjunctivitis or pox. > And if it is a disease what about the health of my EABLs? This HOWR Keep it clean. I routinely dismantle my tube feeders and run them through the dishwasher on the 'sanitize' setting after washing out the gunk and seed. Wooden feeders get scraped and brushed, then dunked in a 9:1 chlorine solution that I also use to sanitize recycled flower pots for next year. Let the feeders air dry. Some choose to take down feeders after seeing an infected bird. Their justification for doing so was to prevent the spread of the disease. I chose to leave my feeders up because Finches flock and feed together whether at human-provided feeders or a natural food source. So far, I haven't seen any evidence of the diseases spreading due to feeders. Just an occasional bird suffering an infection that will eventually be fatal when the bird becomes completely blind and helpless. I've never seen a substantiated report of EABB with either avian pox or conjunctivitis... but I've never heard of an infected Wren, either. So it's your choice. Clean the feeder often if you continue to feed or put it away until your House Wren heads south or dies. Take care, R J 'Tree' Greenwood From: lviolett [mailto:lviolett"at"earthlink.net] What you describe regarding the House Wren with the "missing" eye could have been caused by an injury, as you mentioned. It could also have been caused by a previous (cured) eye infection rather than an active contagious disease. From: Bet Zimmerman [mailto:ezdz"at"charter.net] See video – quality isn’t great, but you get the picture. http://www.sialis.org/howrattack.htm I wanted to add the Psycho shower scene music but didn’t get around to it. Bet from CT From: Bet Zimmerman [mailto:ezdz"at"charter.net] I checked the box, and there is a second pure white (pointy ended) House Wren egg in the box today, along with one normally pigmented egg. Very bizarre! I usually do not let HOWR nest on my trail, but am going to let this proceed and see what happens…. Photo of first two eggs at http://www.sialis.org/weirdeggs.htm Bet
At http://www.sialis.org/wrens.htm , one of my recommendations on deterring wrens (which are a growing problem on my trail) is: Avoid slot, Gilbertson and Gilwood boxes especially near typical wren habitat. The slot opening makes it easy for House Wrens to bring sticks in, which may make the box more attractive. House Wrens may also be attracted to Gilwood boxes, which have a larger opening. Both the Gilwood and Gilbertson have small interiors. Try boxes with larger floor size, as House Wrens may prefer smaller floors. For those who have a variety of box styles, do you find that House Wrens seem to prefer those with a smaller interior? I've had them try to nest in slots, Gilwood, Gilbertson, sometimes regular NABS boxes, a few dummy nests in Petersons, but I "feel" like I find them more often in the first three. FYI, I continue to hear reports of people generally having good luck with a wren guard. I put a good photo up that I got from Loren Hughes here: http://www.sialis.org/wrens.htm#guard and also have drawings that a friend made. Bet from CT From: Gretchen Hughes [mailto:lghughes"at"
joink.com
]
Sent: Sunday, August 13, 2006 12:16 PM Subject: wren guard Hi all,
I tried a wren guard this year where wrens were so thick, a bluebird didn't have a chance. We decided to experiment with it and it worked. Has anyone else had any experience with it.??? If you don't know what it looks like, Bet Zimmerman has it on her web site. www.sialis.org just click on wren guard. It is on a slot box--- Thanks go to Bet for putting it on.
Would like to know if anyone else has had success with it.
Loren Hughes ,Pres. East Central IL Bluebird Society From: Mary Beth Roen [mailto:mbroen"at"hotmail.com] Sent: Sunday, August 13, 2006 8:14 PM Subject: RE: wren guard Loren and all, I have used wren guards for 3 years now, and also have had good success with them. Ideally, they are put on before a wren shows up so it never sees the hole in the nest box, but I have had good success putting the guards on after a Bluebird claims a box even when the House Wrens are already there. Mary Roen, River Falls, WI From: Paula Ziebarth [mailto:paulaz"at"columbus.rr.com] Melissa wrote: Melissa, This should be easy to remedy next spring by simply moving that nestbox AT LEAST 40 yards (that is 120 feet) away from any stands of trees or brushy areas. If you do this, you are outside of HOWR habitat and they should leave the other nesting bird alone. Ideally, box should be placed in an open mowed grassy area with sparse trees (i.e. lone tree here and there). I have had wonderful success on my Libety Park Trail these past years. It is all mowed grass with no trees within 100 yards of boxes. I hear HOWR in the woods near the trail, but they never venture out to try to use these boxes which are well out in the open (over 40 yards). Paula Z .From: Bet Zimmerman [mailto:ezdz"at"charter.net] Peter wrote: The underlying idea was, how pro-active shall I be in my preventive measures? I don't have many HOSP as I wrote earlier, but if HOSP can kill my box tenants suddenly, then I shall be more pro-active than when HOSP merely harrass my box tenants for some time before they do something real bad. House Wrens (HOWR) generally arrive later in the season here in CT, and they make quite a racket singing. However, they are VERRRRRRRRRY quick to come in and peck eggs - I don't know how much warning you would get. The attack shown in this little video clip (http://www.sialis.org/howrattack.htm) I'm not sure they would wait to evict the current tenants before building a real or dummy nest - House Wrens have also been observed filling a red-naped sapsucker nest with sticks while the sapsucker chicks were still in the nesting cavity. Unlike some other cavity nesters, they WILL clean out a box (even one with sticks in it from a dummy nest used to lure a female) and start over. The two best preventive measures that I know of are: 1. Avoid marginal bluebird habitat (install boxes at least 50 and preferably 200-300 feet away from thickets, brambles etc.) Note that some folks have reported HOWR using boxes over 1,000 feet away from wooded areas. 2. If you are worried about HOWR, try a wren guard http://www.sialis.org/wrens.htm#guard once another birds' egg is laid. In my area, HOWR are so common I don't feel I need to supplement nesting habitat, and do not want multiple boxes "disabled" with dummy nests. (I find if they nest in my boxes, the population and box competition from HOWR increases quite a bit the following year.) But there are probably at least two schools of thought on HOWR. Unlike HOSP, they are native birds, and are beneficial (insect eaters.) Here is another perspective: Bet from CT From: Autumn L. Kruer [mailto:autumnk"at"iglou.com]
I’ve had the cutest pair of Carolina wrens hanging about this winter. They hop around my porch and jump into the plant pots on the porch (maybe eating dried seeds from the now dead plants from last year?) with those funny little tails sticking straight up in the air. Strangely, both my daughter and I have had them get in our houses this year. She had one hanging around her porch that flew in and perched in her Christmas tree and she had to patiently wait with the door open and the dog restrained until it flew out. I had one fly into my laundry room when my husband came in the door and he quickly closed the door to the hall so it wouldn’t get further into the house and then had to shoo it out.
Sent: Thursday, January 18, 2007 9:55 AM Subject: Speaking of wrens Autumn in Kentucky From: Vicki Butler [mailto:butlerrowe"at"sbcglobal.net] Hi Folks: I have the start of a mountain trail at a friends property in the foothills of CA. She has 50 acres with a river running through it, mostly wooded but has a meadow that is probably 200-300 ft across. The property is adjacent on two sides to lots of acres of BLM land and there is Bear scat observed regularly. The older boxes that I replaced were full of twigs, I I just got a call yesterday that she has seen BB's (don't know yet if they are Mountain BB or Western) They are checking out a NABS style that had the HOWR nest last year and a hanging 2 holed mansion that is high in a very large oak that is in the middle of the Do the HOWR utilize higher boxes? The mansion is about 15-20 ft up. Last year they did not fill the hanging mansion with twigs. If the BB's occupy the lower NABS box and then the HOWR return to last year's box, is there any hope for the BB's? I can't imagine a wren guard would help with a box that they already know exists. I've thought of putting up multiple boxes lower to try to occupy the HOWR and protect the upper hanging boxes, but they could potentailly be predated by Bear. This may be my first BB nest in one of "my" boxes so I don't want it to end in mayhem. Any suggestions are appreciated. Vicki Butler From: SCooke [mailto:ncw001"at"nc.rr.com]
Sent: Tuesday, April 10, 2007 9:20 AM Subject: HOWR and Bluebird nestlings In spite of the cold snap here, my neighbor's nestbox has 4 new babies. Last year, HOWR attacked and killed 4 nestlings in the same box about three days after hatching. I haven't seen any HOWR in the neigborhood yet so maybe my concerns are pointless. I've read about wren guards in the archives and wonder if it's too late to put one up. Last year was just heartbreaking and neither my neighbor or I want a repeat. What do you guys think?
Sharon Cooke
Cary, NC
From: Cher [mailto:bluelist"at"localnet.com] From what I've read, this would actually be the BEST time to put one up Cher ~ Finger Lakes region, NY State From: Mary Beth Roen [mailto:mbroen"at"hotmail.com]
Sent: Saturday, April 21, 2007 9:11 PM Subject: RE: Ethical standards, success rates Hi everyone, From: Horace Sher [mailto:hjsher1"at"yahoo.com] To Anyone with upcoming House Wren problems... I posted info about this & my successful experience about preventing House Wren as a predator to the BB boxes or any box for that matter a year or 2 ago. I 1st learned how to do it by reading BLUEBIRD TRAILS (A Guide to Success) by Dorene Scriven on pages 112-115. This method I used successfully for several years with no problems. From: Mary Beth Roen [mailto:mbroen"at"hotmail.com]
Sent: Monday, April 23, 2007 11:13 PM Subject: Start of nesting in Wisconsin Hi everyone, From: Paula Ziebarth [mailto:paulaz"at"columbus.rr.com] Bet, I am very curious as to which wren guard you are using. Are you using the half circle type or the traditional type? Do you have any responses from people using the half circle type? I have three CACH nests on a trail that I cringingly refer to as the House Wren Trail. I monitored the trail last week and heard the HOWR song all around me - a bit like an episode from the Twilight Zone. I installed traditional wren guards on these three boxes. This week I returned to find that two nests have remained undisturbed with female incubating eggs, but the third had the eggs chucked out. The guard was installed too far forward as I mounted it on roof overhang which was fully 5 inches out from front of box. I slapped together these things quickly in the field and did not do that one quite right. One of the CACH nests has a box occupied by HOWR just Thanks, Bet wrote: "The chickadees are the ones that were there first and built a nest. From: Bet Zimmerman [mailto:ezdz"at"charter.net] I have tried the half circle type on several boxes. If it had any effect, it was pretty limited. But I assume timing is important - that the guard go up BEFORE the HOWR tries to claim it. I am going to try out an adjustable guard that Blaine (of the DRST) is working on that uses flexible tin to drop down and position the "cover" part of the guard in front of the entrance hole. I have heard of people successfully using Cheez-it boxes (blah side facing out). Someone reported making one out of wooden paint sticks. Also some folks on the Garden Web Bluebirding Forum are trying wren guards with sides on them, and have had good luck. I am reluctant to put one up before an egg is laid. But I was surprised to see how early HOWR's showed up here in CT. They apparently don't start singing until later, after the females arrive. My HOWR Biology page says "Male arrives first, establishing territory with dummy nests. Male begins constructing nests in empty cavities within a few days if not hours of arriving back from migration. Female selects actual nesting site." Yet that male was at my birdcam checking out the chickadee box over a week ago, and there are no sticks in any of my boxes yet. In terms of distance from the hole, Orthwein recommended that the distance from front to guard should be 2.5" for bluebirds. 2.0 to 2.25" is okay for smaller birds like chickadees. http://www.sialis.org/wrens.htm#guard. Bet from CT From: Bet Zimmerman [mailto:ezdz"at"charter.net]
Sent: Monday, May 07, 2007 9:19 AM Subject: Help on WREN GUARDS I caught a House Wren checking out the chickadee nest again today on the birdcam (6:25 a.m. - waaaaaaaay before I am awake.) No eggs yet though. From: Bet Zimmerman [mailto:ezdz"at"charter.net]
After catching a House Wren on my birdcam checking out the box chickadees have a nest in, I debated about whether to put up a wren guard before an egg was laid. After offlist emails from some folks who had all lost BCCH nests and young to House Wren, and one report from Pam who had a tolerant chickadee pair go on to lay eggs after she put up a wren guard BEFORE the first egg, I decided to put it up at 1:10 p.m., and spent the rest of the day biting my nails.
Sent: Monday, May 07, 2007 8:43 PM Subject: Update on wren guard At 6:58 p.m. the birdcam snapped a shot of the chickadee in the entrance hole (head in at least). PHEW. Now I want chickadee eggs AND no photos of House Wrens going in the box…. Bet from CT
I have a Black-capped Chickadee nesting in another box (away from my house, not the one on the Birdcam). It's a Gilberston (they seem to like them.) Anyway, based on the fact that: Guess what? I would have needed a stopwatch to measure how fast the chickadee accepted the guard! It was less than a minute - it flew right under it, into the box. I will note that this chickadee might be unusual - it's in a homeowners back yard where there is a lot of activity, AND when I came up to the box, it didn't want to leave the box, and was actually almost buzzing me while I installed the guard (never had a BCCH do that before - have had them dee-dee-dee me.) Bet from CT From: Bob Walshaw [mailto:walshaw1"at"cox.net]
Sent: Tuesday, May 08, 2007 8:25 PM Subject: An averted tragedy Because of all of the rain we have had our patio chair cushions have been folded up on the chairs. Yesterday I saw a pair of Carolina Wrens carrying nesting material into the folds of one of the chairs. When I carefully opened the cushion the fold was full of dead grass, oak catkins, etc. There was no cohesiveness to the mass and there was no way that I could put it together anywhere near the chair. Also based on the location and our use of the patio I was not in aa position to let them continue, and the cushions have been blown out of the chairs almost every week by our Oklahoma winds. Fortunately they had not progressed to where eggs were laid. They hopped around the refolded chair for about 5 minutes and then left. They have two wren boxes and a big plantpot to use when they smarten up! Bluebird Bob. From: Bob Walshaw [mailto:walshaw1"at"cox.net]
Sent: Tuesday, May 08, 2007 10:59 PM Subject: House Wrens I haven't seen any this year yet, and until two years ago they were never in this area. Two years ago I had two boxes filled with sticks, and last year eight. (Keith says they are moving north from Texas). Without killing them as they are a protected species, what is the best way to deal with them? Should sticks be removed as soon as they start showing up? Information will be appreciated. Thanks, Bluebird Bob. From: Bet Zimmerman [mailto:ezdz"at"charter.net] I reported on 5/7 that a Black-capped chickadee accepted a wren guard put on a Gilbertson house in less than one minute. On 5/9, after calling out and gently tapping on the side of the box, I opened the box today (the bottom of a regular Gilbertson detaches from the roof) and looked inside and the female was sitting on the nest. I figured she was incubating. I replaced the box, she flew out, and I checked again - 6 eggs. I assume that was why she was "buzzing" me when I put the guard up and why she accepted it so readily. The conventional wisdom is that a wren guard should be placed on a nestbox In the box by my house that has a birdcam, I KNOW there were no eggs. I put up the wren guard before an egg was laid. This morning (two days later) an egg did show up. The birdcam indicates that the chickadee was in the box at Mr. and Mrs. Jammer bluebirds who are incubating eggs in the backyard were back under the wren guard today, checking out the box, which Mr. J trying to jam his head inside again (the box, if you recall, has a 1.25" hole restrictor on the inside.) The good news is, no sign of a House Wren under the guard, although I do hear him singing nearby. Orthwein's concept of a wren guard is very interesting. I don't understand why the House Wrens don't see/look in to the sides, which are typically open (some people are now making wren guards with sides.) Has anyone used a wren guard on a Tree Swallow nest? I would think they might have trouble with it.... Bet from CT From: Bet Zimmerman [mailto:ezdz "at"charter.net]
Sent: Tuesday, May 15, 2007 10:21 AM Subject: There was a young lady who lived in a shoe I spent last week in Hampstead NC (near Wrightsville Beach), where I got to see my first Red-headed Woodpecker. It was bigger than I imagined. They are listed as Endangered in the State of CT. I also got to see my first live Great Crested Flycatcher checking out a bluebird box. It was also bigger and longer than I imagined. A Mockingbird was doing what looked like a mating dance in front of it, prancing around with its wings spread. I saw many House Sparrows nesting in the rafters of a local hardware store porch, but not a single House Sparrow in my mom's (more wooded neighborhood near the inland waterway) about 10 miles away. I saw a starling getting chased away by the House Sparrows. It was either trying to snoop, or nest in the rafters also, or looking for a meal (eggs/young.) I got to see Tufted Titmice the day they fledged (from a box with a 1.5" hole on a baffled pole), and then a pair of bluebirds that moved in to claim the box within hours (but apparently changed their minds two days later.) I also got to see a little Carolina Wren nest in a boot - see http://www.sialis.org/picture.htm. Bet from CT From: wensuz "at"isp.com [mailto:wensuz "at"isp.com] Hi gang; This day started out badly, and it just got worse from there. I awoke to find my birdbath top smashed to bits on the ground. The night before a raccoon had climbed my feeder post and ate what was left of some suet, and tried for one of the hanging feeders, but the Shepard's hook it is on rotates, so it just moved out of it's reach. So last night I brought in all the feeders, only left the Gazebo on the post platform. From: MJ Shearer [mailto:eshearer "at"comcast.net] Yes, Wendy. House Wrens would do that. A HOWR destroyed my six Brown-headed Nuthatch eggs last week, and they had already completed their nest in another box with two other empty nestboxes to choose from. They do not make good neighbors! MJ From: Ellen Lafouge [mailto:elafouge "at"wi.rr.com] I had House Wrens and bluebirds co-exist peacefully in my garden in 2005 and 2006, each raising two broods per season. The nest boxes must have been within the "magic" proximity to each other, about 20 feet, as I never witnessed any HOWR aggression except at the mealworm feeder, when the wrens always showed begrudging deference to the blues. The blues definitely ate first. This year, I added two new nest boxes at the front of my yard, one of which has 6 HOWR eggs as of this evening when I checked. I assume incubation will begin in a day or two even if the female is intent on laying a few more eggs. There is a bluebird pair that comes daily for mealworms, but have nested elsewhere. From their behaviors at the mealworm feeder, I estimate their young have hatched and are about a week old. I'm hoping they may choose to come to my yard for their second brood but that of course is up to them. My question is whether the HOWR would be less aggressive and destructive of bluebirds nesting nearby if they are busy with their own young who will more than likely have hatched by the time the bluebirds would be interested in starting their second brood. The nest box that would be an option, should the bluebirds choose it, is about 50 feet from where the HOWR are nesting. Or should I "retire" the open box for this season and remove it from the bluebirds' Ellen Lafouge From: Bet Zimmerman [mailto:ezdz "at"charter.net] Wow Wendy, you certainly had a rough day! I hope you have raccoon proof predator guard on your boxes - as Cher says, once they find a "Happy Meal" Ellen your experience with House Wrens (HOWR) is interesting. A study by Pribil showed that wren depredation seldom if ever occurs if the other birds' nestbox is closer than 3 to 16 feet of the wren's nest. If you're experiencing egg-pecking, find the wren's nest and either move your nestbox in close to it, or move it out over 130 feet. In some studies, male HOWRs attacked eggs only before pairing, and females only before laying. (Hannon and Cotterill 1998, Kennedy and White 1996, White and Kennedy 1997) However, I have seen a House Wren take out a chickadee nest that was within 10 feet of its box. A list of options for those who wish to deter House Wrens is found here: As I posted earlier, I'm having good luck this year with Wren Guards, which bluebirds readily accept. http://www.sialis.org/wrens.htm#guard. However, if the House Wren has already started adding sticks, they tend to fly right under it. So it's good to get it up early. I was fascinated to watch a HOWR caught on birdcam. He checked out a chickadee nest on several occasions (way before I knew HOWRs were back, as I had not heard them Bet from CT More on HOWR: From: Maynard Sumner [mailto:m-r-sumner "at"juno.com] Most of the time House Wrens only have one nest a year. I think it will be okay for the Bluebirds to nest in your box. Maynard Sumner From: Stephen Gilson [mailto:stephengilson "at"yahoo.com]
Sent: Tuesday, May 22, 2007 11:14 AM Subject: BCCH next empty: Suspect HOWR About a week ago, possibly a few days more than that, I had several BCCH eggs in a NABS nestbox. The pair had been actively building their a few weeks ago nest when a male EABL stopped by to check it out, but moved on within a couple of days.
I have seen the BCCHs and at least one HOWR chasing each other near this box. So, this morning I found the nest empty and a single egg fragment under the box. I suspect that one of several HOWRs who've moved into the neighborhood since I put up my boxes this spring, may have raided the nest and chucked out the eggs. The shell fragment was paper-thin, white with light brown speckles.
Can anyone tell me if BCCHs dispose of shell fragments once the chicks have fledged? There weren't enough egg fragments for me to be able to tell if they'd been attacked or if the chicks hatched.
I cleaned out the box which had a lovely, light, and dry moss nest which was also scattered with slivers of the box intermixed. I'm curious who might occupy it next. There was no sign of any carnage.
I have three boxes up in the back about 50 feet apart in a triangle. Two are currently occupied by HOWRs, the ones closest to the house.
- Stephen, West Boylston, MA
From: plkldf "at"comcast.net [mailto:plkldf "at"comcast.net] Sent: Wednesday, May 23, 2007 6:06 AM Subject: re: re: Marauding House Wrens? Paul Kilduff
trail at Oregon Ridge Park, Cockeysville (Baltimore Co) MD
Hi, Bet,
I read your HOWR summary with interest. The one thing I don't understand is how removing dummy nests is beneficial. I did go to the cited site, and scanned it but not perhaps as thoroughly as I should have. What I did see is that by removing a dummy nest, you may cause another bird to choose the cavity, and the HOWR may then return and re-claim the box. This is my concern about removing dummy nests. I don't see HOWRs giving up because their sticks got removed. But I can imagine a TRES (at Oregon Ridge, TRES are much more frequently victims of HOWR than EABL are) building in a cavity which it thinks is empty, and then Mr HOuse WRen comes back and says, "what are these enemies doing in my cavity?" and cleans out the nest. I have certainly seen sticks get replaced week after week. What's the point of removing dummy nests if they're just going to replace them? Given that something else may nest ! in the cavity in the meantime, isn't this not only futile, but actually harmful?
Thanks, Bet, as always for sialis.org and all, all!, that you do!! :o)
Paul From: Keith & Sandy Kridler [mailto:txbluebirder "at"sbcglobal.net]
Sent: Wednesday, May 23, 2007 7:38 AM Subject: Re: re: Marauding House Wrens? Keith Kridler Mt. Pleasant, Texas
We normally only have the House Wrens down in our area during the winter. They seem to nest along the Red River between Texas and Oklahoma in scattered locations. There are occasional reports of House Wrens in different parts of Texas but very few reports. The last couple of years I have found at least one nestbox along my trail with what appears to be quite a few sticks but these are always covered up with the normal cavity nesters for my area.
I am like Paul on this one and I wonder if for those of you with severe House Wren populations if anyone is leaving about an inch of the Wren sticks in the bottom of these dummy wren nest boxes? I really doubt that the native birds like Tree Swallows or bluebirds ETC. would then be able to see this as possible Wren territory that is already "claimed" BUT is anyone experimenting along these lines? I doubt that natives would know to build with caution in this area if they encountered just a few sticks or would they just build over the tops of these since they are needing a nestbox.
Mortality for small birds is so high that very often other cavity nesters encounter half built nests where the original birds have been killed or abandoned this area or they find nestboxes that have never been cleaned and are forced to build over the tops of old nests.
I have heard of other people that placed old coffee cans and gourds and other containers all through the brushy areas on their property in an effort to try to place more possible nest sites for the male wrens to fill than what the poor wrens have TIME to fill up.
The problem it seems with House Wrens and House Sparrows is that they show up and even when there are multiple empty nestboxes they throw out eggs about the same as when they hit a trail or backyard where EVERY nestbox is filled with native birds.
We probably won't ever know for sure if the House Wrens are doing this because there is a localized food shortage for them even though they do not compete for food with either the Chickadees or Tree Swallows. If we are dealing with House Wrens who have evolved for millions of years that selected the breeding lines for this species we have today by removing any birds that compete with them for nest sites then there is probably nothing we humans can do to change their behavior. KK From: Bet Zimmerman [mailto:ezdz "at"charter.net] Tough question. When a HOWR fills up a box with a dummy nest, they don't use the box but they also make it unavailable for other birds. HOWR are skilled at quickly building a stick nest, and when the female choses a box, she apparently disassembles and reassembles it. I'm not aware that other birds are adept at removing existing nesting material. A downside to leaving some/all sticks would be if another species builds a nest on top of HOWR sticks, their eggs and young will be closer to the entrance hole, increasing the risk of predation. If I were a bird, and recognized how aggressively territorial HOWR are, I would stay away from boxes with sticks in them, but who knows if birds have evolved to figure this out or not. My hope in removing HOWR dummy nests is that they will be encouraged to nest elsewhere, i.e., not on my trail. Sometimes after repeatedly removing sticks they do give up. Other times they do build a nest cup (sometimes sans sticks) and go ahead and lay eggs and then, legally, there is nothing I can do about it. Tree suggested the following last year: Keep them busy: Put up a number of wren houses without predator guards in a very small area in prime wren habitat, away from bluebird boxes. Then continually remove the dummy nests. I think it is a mistake to encourage them to nest, at least in my area. Bet from CT From: plkldf "at"comcast.net [mailto:plkldf "at"comcast.net]
Sent: Thursday, May 24, 2007 6:06 AM Subject: re: re: re: Marauding House Wrens? Bet, Keith, all,
My first thought is that sending messages to birds is not workable. They're absolutely incapable of "getting the idea," in my view. If we can do something that communicates with their genetic programming, such as moving the box away from brush, then that's going to work, while if we try to break their eggs (earlier discussion) or remove their sticks they're going to react as they have evolved to react (sorry, non-believers!).
Trying to see a pattern, I see a bird which has evolved to present the female with a selection of cavities, of which she chooses one. Works for them. I also see a bird which has evolved to compete for nest cavities with fanatic determination. As well, I see a bird which, if it were chicken-size, would make us all afraid to go for a walk in the woods! Tough little buggers!
I don't think we've seen TRES or EABL building over stick nests at Oregon Ridge, for which I'm grateful.
Bet, I also am not aware of a definitive study that shows that the presence in a box of sticks or straws deters other birds from trying to claim a cavity -- does anyone know of such? But it seems logical to me that in a world of secondary cavity nesters, my genes are going to learn quickly that if I, as a species, choose cavities with no recent activity I have a better chance of not having to waste a lot of energy trying to enforce my claim than if I choose cavities which DO show recent activity. Therefore those of my species which DID choose cavities evidencing recent activity, such as a fresh piece of grass or most especially a pile of sticks, will become scarcer and scarcer in the gene pool, unless I'm the toughest SOB in the forest, which, as a TRES or EABL or CACH, I'm generally not.
My guess would be that the HOWR eventually stop putting sticks in the box when the pair have settled on another cavity for their nest, not because he got tired of putting sticks in there. I would even speculate that causing the male HOWR to TAKE MORE TIME to maintain his selection of dummy nests may prolong the dummy nest period -- he can't attract a femal until/unless he has his requisite number of dummy nests to show her. IF that were true, then by removing the sticks we MAY be prolonging the time when this particular HOWR male is removing eggs and babies from surrounding active nests.
(Regarding the close-to-hole-danger argument, don't they generally build to within a certain distance of the hole, rather than putting a certain amount of material into the nest? If they have a shallow cavity, they'll build a shallow nest, if they have a deep cavity they'll build a deep nest, no? If that's true, then building on top of a dummy nest, they'll build up to what they consider (what their genes tell them is) a reasonable distance from the entrance hole and no higher.....?)
What think, folks?
Paul
From: Peter Kwa [mailto:kwapeterca "at"yahoo.ca]
Sent: Thursday, May 24, 2007 7:46 AM Subject: re: Marauding House Wrens? > Tree suggested the following last year: Keep them busy: Put up a number
> of wren houses without predator guards in a very small area in prime wren
> habitat, away from bluebird boxes. Then continually remove the dummy
> nests. This may keep the males occupied so they don't have time to attack.
> Boxes should have 15/16" holes. Tree Greenwood uses 6-20 or more.
I don’t have house wrens, but I find the idea of keeping them busy a good one. I would also automate the idea in that I would install a small (perhaps battery operated) engine to open and close the bottom of the box every hour or whatever the optimum time interval is to deceive the house wren. It’s easy to do with a kit from Radio Shack. You may need only one such box.
It may also help for house sparrow infested boxes, so I might actually try this out myself if the circumstance so requires. Let's nevertheless hope I won't have to try this out. From: Keith & Sandy Kridler [mailto:txbluebirder "at"sbcglobal.net]
Sent: Thursday, May 24, 2007 8:07 AM Subject: Re: re: re: Marauding House Wrens? Keith Kridler Mt. Pleasant, Texas
These are really good posts from Bet and Paul on this subject. They give us lots of stuff to read and think about! If you actually think about it the Wrens, House Sparrows and Bluebirds are actually VERY similar when scouting and looking for potential nest sites.
Male House Wrens seem to inspect every nook and cranny in their territory and then allow the female to chose one.
I have watched male bluebirds basically do the same thing by taking or following their female all over a piece of property looking at all of the potential cavities. I believe this is why sometimes bluebirds will kick out other cavity nesters because they feel they have invaded one of the boxes that is in their territory and this box MIGHT be needed when the bluebirds get done with one brood and or need another nestbox.
House Sparrows also do some of the same stuff. The males will call from a chosen nestbox and try to entice a female to come and use their nestbox. But I have also seen where they would abandon this box and go with the female to look in Martin Houses or other nestboxes. I have also seen them moving from one nestbox in one yard to another yard and then another yard calling from all of the nestboxes up and down a street. Even though they may prefer a certain nestbox or maybe they are forced by competition to a limited territory they will abandon this area if a female comes along that knows where she wants to nest. KK From: Shari Kastner [mailto:smk "at"teamv.com]
Sent: Thursday, May 24, 2007 10:09 AM Subject: RE: re: re: Marauding House Wrens? I only have one year of monitoring a trail under my belt, but I did have a lot of HOWR dummy nests on my trail near the end of the nesting season last year. At first I didn't remove the HOWR nests. After reading about them I started removing all the nests I found without nest cups. No other birds tried to build nests in the boxes that had dummy nests in them. That could have been because it was later in the nesting season or because they had dummy nests in them. What I'm wondering is how large of an area does the HOWR build the dummy nests? My trail is about a mile long and I had dummy nests in boxes throughout along my trail. I know I had one HOWR nesting in a box (that was not part of my trial) on one end and another HOWR that had a nest cup on my trail on the opposite end, so I did not remove the nest. There were dummy nests in several of the boxes in between. Thinking of the mile distance between these two, were these likely to be from the two on each end or from others that were trying to nest on my trail? I never saw the HOWRs by the dummy nests. I did not have any damage to eggs or birds last year. I'm guessing that was because my trail was new and as it becomes established with the birds nesting there each year, that will change due to competition.
Shari Kastner
New Berlin, WI From: Mary Beth Roen [mailto:mbroen "at"hotmail.com]
Sent: Thursday, May 24, 2007 3:58 PM Subject: RE: Marauding House Wrens? Shari and all,
I have had a lot of problems with HOuse WRens in the past. As the habitat around my trail grew up and became more brushy, the HOWRs took over more and more of my nest boxes. I have now moved many of my pairs of boxes along roadsides on neighbor's property. This year so far, I only have 2 active HOWR nests out of 23 pairs of boxes. Unless you move nest boxes out in the open, far from brushy wooded areas, it is almost impossible to keep the number of HOWRs from increasing every year. Mary Roen, River Falls, WI From: FairfieldDoc6 "at"aol.com [mailto:FairfieldDoc6 "at"aol.com]
Sent: Thursday, May 24, 2007 4:57 PM Subject: Second nesting for Carolina Wren Last Wednesday I went to check on a CARW building a nest in my garage (I closed off her last nesting site in my 5th wheel camper) and almost stumbled on a baby BB that evidently had just fledged from some unknown place. It flew up to an overhead branch of our red Maple tree and so I had two things to monitor (admire), the baby BB and the CARW. My garage doors oddly enough were closed but the CARW found a way to slither under the door where the rubber gasket is missing. My wife and I found the nest in a basket on one of the storage shelves in the garage. I think these birds are very intelligent cavity nesters, finding "safer" places out of the rain, predation, etc. Now, someone on the list, I'm sure, will prove me wrong with their story of how dumb these birds are. BTW, the baby BB flew across the street to waiting parents who then had to protect it from a Bluejay on the attack. I think these BB babies fledged from my neighbor's nestbox seen in the distance in their backyard. As to the CARW, we will happily give her plenty of space to raise another brood.
Dean Manning
Cantonment/Pensacola, FL From: Paula Ziebarth [mailto:paulaz "at"columbus.rr.com] I found Paul's comment intriguing. ..."Bet, I also am not aware of a definitive study that shows that the presence in a box of sticks or straws deters other birds from trying to claim a cavity -- does anyone know of such? But it seems logical to me that in a world of secondary cavity nesters, my genes are going to learn quickly that if I, as a species, choose cavities with no recent activity I have a better chance of not having to waste a lot of energy trying to enforce my claim than if I choose cavities which DO show recent activity. Therefore those of my species which DID choose cavities evidencing recent activity, such as a fresh piece of grass or most especially a pile of sticks, will become scarcer and scarcer in the gene pool, unless I'm the toughest SOB in the forest, which, as a TRES or EABL or CACH, I'm generally not." What I have seen over the years is that a HOWR dummy nest generally deters The reason Paul's comment intrigued me is because I see other nest starts as an incentive for some birds to take a box. Specifically, the HOSP seems especially attracted to boxes with nest starts in them. Any grass, moss, or pine needle nest start seems to be an incentive for HOSP interest. I believe a stick nest start is a deterrent to them, however. I think he may like these nestboxes with material best because it cuts down his work load - the nest is already partially complete. I am considering putting my own grass dummy nests into boxes early next spring to experiment and see if this increases HOSP trapping success. EABL, TRES, and CACH seem to respect the nest starts of other birds for the most part. I have never had birds of these species take over the active nest of another bird. For these species, any existing material in a box appears to be a deterrent. For the HOWR, there is no deterrent. If he sees a hole, in he goes. In HOWR habitat, the only deterrent that has worked for me is a HOWR guard placed on active nestboxes. Paula Z From: Bet Zimmerman [mailto:ezdz "at"charter.net] According to what I read somewhere (wish I had noted the source), the size of a House Wren's (HOWR) territory is not known, but may be about 100-230 feet from the nest site (about 1 to 2.3 acres). In terms of nest depth, I see lots of variability. This year one pair of bluebirds built right up the bottom of the entrance hole, another built a shallow nest. Chickadee nests are usually pretty shallow. Tufted Titmouse eggs are very bulky. House Wren nests usually go up to the roof, but they have a tiny cylindrical nest cup. From: plkldf "at"comcast.net [mailto:plkldf "at"comcast.net]
Sent: Saturday, May 26, 2007 2:37 PM Subject: RE: re: re: Marauding House Wrens? Hi, Bet,
I'll do whatever I legally can to discourage HOWR from destroying other birds' nests. However, I don't think it is logical that removing the sticks from a dummy nest works to reduce the amount of depradation which the HOWR cause. I hate it when a viable TRES nest has its eggs removed by a HOWR!
I wonder if the reason why I associate HOWR depradation with TREe Swallow nests much more than with EAstern BLuebird nests is that usually around here (Baltimore MD) the EABL nest first, followed by TRES, followed by HOWR. Therefore the EABL nests tend to be further along than the TRES nests and the HOWR depradate the eggs of the TRES rather than the nestlings of the EABL. Incidentally, this year we are a little screwy because of the weather. Usually the EABL choose the cavity, then the TRES choose from what's left. This year, with its cold spring, it seems the TRES chose their cavities at around the usual time, but the EABL were very late, so the EABL ended up with what cavities were left over. However, the EABL still laid their eggs first -- but the TRES chose their cavities first. I guess the HOWR seldom remove nestlings from the nest because they would have to put up more of a fight with the parents than when t! hey rem ove eggs...?
Paul From: Bet Zimmerman [mailto:ezdz "at"charter.net] I was just thinking about you Paul! Got back from monitoring two of my trails. I removed a dummy nest in one box last week - the House Wrens did not rebuild in that box. I had hoped maybe that large boxes hanging high in trees might deter House Wrens based on something I read. I checked the two-hole mansions boxes on the no-trap Hill trail today and found sticks in two of the boxes - one in the box that the Tufted Titmice had started a nest, which then got taken over by a House Sparrow (I removed the House Sparrow part of the nest). In the other box that the Tufted Titmice had probably moved to (existing nest, no eggs last week, added hole reducers), House Wrens had almost completely filled up that box. There were no sticks in the other two boxes where House Sparrows have attempted to nest. I think House Wrens are more likely to prey on nests during the egg laying period, when the nest is unattended for longer periods of time. It's harder for them to find a window to attack when incubation has begun, although they are quite speedy! In this case, the House Sparrows slowing down the Titmice nesting moved their second nest attempt later in the season, which is when House Wrens become a bigger problem. Birds CAN learn. For example, a Black-capped Chickadee will not reuse a nestbox where they had a failed nesting. House Sparrows and Starlings (perhaps smarter than the average bird) quickly learn to recognize a gun. I think it's possible that birds could learn that sticks = danger and choose to avoid a box that has some in it, even if it's just a dummy nest. Also, again the sticks take up space and make it harder for another bird to build a nest in that box. BTW, I am watching a starling on a nestcam, by my second story window. I saw a House Wren very quietly and quickly sneak inside the box this afternoon to check it out (no eggs yet.) Bet From: Mary Beth Roen [mailto:mbroen "at"hotmail.com]
Sent: Saturday, May 26, 2007 3:30 PM Subject: House Wrens Hi all, From: wensuz "at"isp.com [mailto:wensuz "at"isp.com] From: Bob Walshaw [mailto:walshaw1 "at"cox.net]
Sent: Saturday, May 26, 2007 5:08 PM Subject: Re: House Wrens Mary, you have posted a very significant message. I also have my best success along roadsides, and I think it is because cars stir up and knock down insects. I continually tell people that I help with Bluebirds to get away from thinking only of their yards and to get at least several boxes along the road near their home, partly because it is an excellent location, and because having more than one box reduces the unhappiness when something bad happens to one of their bird families. That way they don't have all of their eggs in one basket! Bluebird Bob. From: Linda Tate [mailto:lamccub "at"ilstu.edu]
Hi,Sent: Saturday, May 26, 2007 6:42 PM Subject: house wrens On Monday, I wrote as a new trail person about my bluebird babies dying. Someone asked that I let them know about the activity after removal of the babies. Well as of today a pair of House Wrens are liking the box. So, I don't know if they had anything to do with it or not.... as there seem to suddenly be lots of house wrens around. At least one box is taken with 5 house wren eggs and another I think is Carolina Wren eggs. I read somewhere that house wrens are federally protected so you are not allowed to remove their active nest sites, but are allowed to remove the "dummy nests". Is this accurate? On the good note. A box that hadn't had any activity before, as of yesterday has a pair of bluebirds claiming it as home. I went back to check today and they are both still there!!!!!! so there is hope again. (It is the box closest to the box with the loss of the babies) (maybe the same parents??) I haven't seen anyone else mention other birds (unrelated to the BB trail) but I was so excited today to find both an Orchard Oriole nest and a Common Yellowthroat nest on the trail today. Again, thanks for all the help and responses on the BB babies. Linda T. Central Illinois |
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