"I come into the peace of wild things who do not tax their lives with forethought of grief.
For a time I rest in the grace of the world, and am free." ~Wendell Berry


Showing posts with label Great Horned Owl. Show all posts
Showing posts with label Great Horned Owl. Show all posts

Wednesday, February 10, 2021

Building an Owl Excluder for Purple Martin Systems

 

This year will be my 7th year having to deal with a Great Horned Owl and a Barred Owl here on Gobbler's Knob. The first couple of years were tough and we almost threw in the towel. But, with lots of support from other landlords who have 'been there, done that, got the t-shirt', we have reached an (un)-easy alliance with the owls.
Since many landlords either are in the same situation, or soon will be, I decided to make a video describing exactly how we built the cages that protect our purple martin systems. I've listed the materials and I also address some of the most common questions that we commonly receive each year about the cages.
 
Here are a few of the many videos I've recorded of the GHO attacking my colony. I did not arrive at deciding upon this solution easily - it was difficult and a lot of work.  If anything else would have worked, I would have done that first. But this was ultimately the only solution that saved my colony.
 
 
GHO attacks Trendsetter and gourd rack: https://youtu.be/RexdpWmqgLY

Building an Owl Excluder for Purple Martin Systems


 

 
 
 
 

Sunday, June 3, 2018

Nest Checks, New Hatchlings and Nets

My last nest check revealed I have 73 pair so far, with a total of 84 gourds offered.  I continue to be amazed at the resiliency of the purple martin, especially since the Great Horned Owl persists with her attacks.  As an added challenge this year, I've also had a problem now with the Barred Owl attacking my tree swallow and bluebird housing.
But for now, back to my GHO update.  On the morning of April 30th, I became quite alarmed to see the GHO has, after 3 years with these cages, now figured out how to get up and inside to perch on the inside arms of the rack.
After 2 days or mourning and feeling sorry for myself, I decided to cowgirl-up and my husband and I designed a "cargo net" style bottom which would balance the need of the purple martins to both exit quickly when a hawk attacked as well as serve to keep the GHO out. With the mandatory requirement of it being "quick release" so that I could continue with nest checks, we purchased some polypropylene rope, zip ties, quick release clips and some garden stakes.  The first 'net' picture you see below has 14x12" holes in it - I can always adjust the size of these holes if the owl gets through, but since the owl's wingspan ranges from 36"-60", I'm hoping I don't have to change these.  The 4 long ropes are crossed by 6 shorter ropes, tied together using zip ties at each crossing.
I've put together the video below to show other landlords how the netting is connected to the cages and how it quick releases for nest checks.  I made a mistake in the video - the rope is called, "polypropylene".  :)


For the round racks, a different approach was used to the the netting.

While the owl has definitely made my nest checks a little more time-consuming, my husband has always helped me come up with ideas to enable me to keep doing them. Given the heat & humidity we experience here in Missouri during the summer, it's imperative that I know the ages of the kids, because inevitably, I will have a few nestlings that will either get knocked off porches or they will jump and I need to know in which nest to put them back.
New "pinkies"!
Photo taken by my friend, Lu Ann Coons at her colony site here in Missouri.
It was very apparent the nest in the video below had just started hatching.  While it's tempting to help remove the shells from the little, adorable nestlings, because their skin is still so delicate and could be still attached to the shell, I never 'help'. I let Nature take its course - the baby will be stronger for it and I avoid damaging him/her.




Tuesday, May 31, 2016

Nest Check Season Begins and Sub-Adults Swarm Missouri


For the last three weeks, I have been swarmed by sub-adult purple martins as they flooded into my site, harassing the already-established pairs.  We must have had a banner year last year and the happy, carefree calls and antics from the sub-adult males as they try to find a mate puts a grin on my face and tears in my eyes as I stop to enjoy the sounds and raw nature of these birds as they focus on their single goal.  Last Saturday afternoon, May 21st, I decided it was the perfect weather to do my first nest check of the season.  With the temperatures being so cold during the prior week and having to feed almost 160 martins, I was dreading nest checks, but I had to know.
As I gathered my tools, the persistent cheeping of the baby bluebirds begging for food from their exhausted parents made it easy to spot this little fellow in the yard.  Unfortunately, I had found feathers from one of his brothers/sisters nearby, indicating the owl had caught one of them.  But this one's a survivor and I was about to discover how my colony was surviving too.
Bob bought a new tool belt for me to hold all the new equipment I now need for my nest checks inside the wire cages.  It has a belt clip on the back to hook over a belt or the waistband of your pants.  It has plenty of small pouches around the outside with a few clips too, and even a magnetized patch for holding screws, nuts or gourd clips.  It has loops inside the main pouch which will hold things in place and a large opening inside for holding bigger items. I've added wire cutters to quickly cut zip ties that hold the wire cage panels on the frame, 3 different sizes of zip ties for various applications, a marker for refreshing gourd numbers, needle nose pliers for pulling the stubborn zip ties tighter, and I put the zip tie discards in the middle open pouch.  As my nestlings get older, I'll safety pin a plastic bag to the side containing an index card.  The index card will be an easy, quick reference list of nest cavities with the older nestlings whose nest needs to be plugged.  This thing has room for much, much more - as long as my pants don't slide down from all the weight.

A picture of my old tool belt (things fell out of it too easily) and tool box.  I still use the tool box to carry all my nest plugs (used for plugging cavities with older nestlings), a bag full of alcohol wipes, and it also makes a nice step stool for the upper gourd levels.
The martins know what's coming when I enter the yard with my tool belt, my tool box, and my white hat, while smelling like Vanilla extract. The old-timers don't mind - they hang out on the cages and perches, awaiting their turn, while the new sub-adults flush and scream to alert everyone that surely, the Vanilla extract I'm wearing will be used create some tasty dish out of all of them.
The martins in the middle rack await their turn.  They know what's coming. But first, I have to remove the ties that hold each panel to the next, so I can slip inside.
I also use a voice recorder for all my nest checks that I pin to my shirt for easy access.  This helps keep my hands free and I don't have to deal with keeping track of a pen & paper in all the chaos too.  I've had this little thing for the last 6 years and it just keeps going & going.  With 84 cavities to check, it is just another tool that helps expedite the process.
Sony voice recorder.
With some dark days behind us with the cool weather and repeated, Great Horned Owl attacks every night, my heart pounded and I could hear the blood rushing through my veins, unsure of what I would find. 

To my delight, I found 54 pair of nesting purple martins, which is 8 pair ahead of last year around the same part of May, along with 264 eggs and 10 young nestlings.  Still, I didn't know which way my numbers were trending, so I waited another week before breathing a sigh of relief with another nest check completed this past Saturday, May 28th.  I am so excited to report my total pair number increased to 71 pair, 306 eggs and 40 young.  YIPPEEEE!!! 
Since adding the roof over the top of the house cage and extending the bottom of the wire, the owl has been visiting less frequently. I've also been going out just before complete dark and shooing the sub-adults off the porches.
In 2014 and 2015, I had 76 total pair each year and this year, I'm on track for the same total, if not more this year.  Despite the best efforts of the GHO, my martins are surging ahead with their work.  Establishing nests, finding mates and supplying food to the ever-growing number of nestlings.  During the day, you would never know what terrors they have experienced.  They may not forget the night before, but they're moving on quickly & efficiently with their lives, obviously enjoying this moment - the present.  I think I need to be more like my purple martins too - enjoy this moment, for today, we are still the survivors.

Monday, May 2, 2016

Purple Martin Sub-Adult Arrivals and an Old Friend Visits

When purple martin landlord, John Miller from St. Louis (who also manages a few public sites in Forest Park), reported a sighting of a sub-adult male on 4/22/2016, I thought he was kidding around.  But no, he was serious.  And because it was John, I knew he knew what he was talking about.  Check out his post here:
https://www.purplemartin.org/forum/viewtopic.php?f=2&t=31644&p=258054#p258054
Turns out, this is his earliest sub-adult arrival ever.  I searched my colony on 4/28 and identified a rowdy, reckless sub-adult male also, along with 5 ASY banded males whose bands need to be read too!  Not my earliest arrival, but close!  On the night of 4/28, I anxiously watched as the sun sank in the western sky and 12-13 young sub-adult males and females tried desperately to find an open nest cavity.
An ASY male - banded - number to be identified (see his lower right leg).  He patiently waits as his mate-to-be inspects his new housing.
One of the sub-adult females obviously has some leucistic genes, displaying some white splotches on her head.  You can tell it's a female by her bright white undertail coverts.  The loving gaze she's receiving from all the males surrounding her is also a dead giveaway.  I've never noticed a bird with pink legs before and I wonder if that's due to the leucistic genes in her bloodline?
A sub-adult female is checked out by the eager males.  Note the white splotches on her head and her legs are an unusual pink color that I've never seen before.  I shall call her Betty Boop for her "pink stockings". 
Another sub-adult female sits nearby with perfect posture, very lady-like.  Note the very white undertail coverts on her also.  She was somebody's baby last year.
ASY male and SY female.
No group of sub-adult pictures would be complete without one of the very eager, clumsy SY males also fluttering about trying to impress the females.  Note the coloring in his undertail coverts and the purple feather splotches above his right leg and around his throat & chin.  Definitely a young male, about to take a whomping from the ASY males in the Trendsetter whose females he's trying to steal.
SY male - note the splotches of purple feathers already showing.  He will be very easy to identify and track this season.
The reason I was so anxious the night of 4/28 was because earlier in the week, the morning of 4/24/2016 an old friend had returned.  I have mixed feelings about seeing her on my game camera again.  For one thing, I was hoping she would leave us alone this year.  It is encouraging in the video that she is not actually attacking any of the housing, but simply looking like she is using the perches for hunting.

For all I know, she has been using the tops of the gourd racks for hunting most of the year, but since I don't keep the game cameras running all year due to the obvious high cost of batteries, I don't know what she's been up to.  She does look very healthy - downright fat, even.
On the other hand, it is a bit comforting, knowing I have done everything I can to protect my martins and the only way she can get to them now is if they decide to flush out of their housing.  For that, there's nothing I can do and they are on their own.  I have already found a few feathers of one bird about 100' away from my colony.  I can only hope that was from the Sharp-shinned hawk that has now moved out of the area and that was the only loss I'll see this year.  Yeah, let's just say that.
Regarding the video, I watched the ones before & after the GHO left and the patterned shadows on the video look oddly like another owl's feathers, but I cannot for the life of me, figure out how they would be spread out like that.  But they weren't there before the owl appeared or after she left.  So, is there another owl, perhaps her mate, traveling with her?  I'm not sure, but I've setup my main monitoring system now to try to watch the overall colony. Take a look and let me know your thoughts in the comments below regarding what you think the ghost shape is.

The first wave of sub-adults has definitely arrived, so I hope you have your housing open and if you're wanting to expand your colony this year, now is a good time to add more housing or gourds!



Tuesday, March 29, 2016

New Season, More Changes

On Saturday, 3/26 it reached 69 degrees on Gobbler's Knob. But with the ever-present Spring wind, it felt a bit cooler - maybe 68 degrees.  Heh! Oh, but it was so beautiful and there was absolutely no way, I was going to stay indoors.  I was quite surprised when I flushed my martins - it appears my 84 cavity colony is already 1/2 full!  I've never been that full by this time of year before.
My first priority was to finish up my owl cages on my Deluxe gourd racks.  My jerry-rigged, owl interference didn't work as well on those racks last year and I've no doubt that I'll be seeing my Great Horned Owl again this year and possibly, my Barred Owl as well.
I would have caged these 2 racks last year, however, I could never come up with an idea that would work, both because these racks had no place to mount homemade supports for the wire and there were also weight considerations (it's windy here in the spring!).  In summer of 2015, we figured out what we needed to do.  I ordered the same stainless steel arms for these racks from the original manufacturer, only the length of these arms would be changed to 36" and they would have the same gourd mounting holes as the originals.  I ordered 8 arms per rack as that would be enough to support the type of wire cage I needed to build.
Here's what my racks looked like last year, just using garden stakes as a 'cage' to interfere with any owl messing with them.

I decided that I would use 4 panels of 4 foot-high welded-mesh wire fencing, per rack.  Each panel is cut to 56" wide, allowing me to bow them out almost 10" from the front of each gourd.  I was surprised how light the 4 panels were, as I gathered them up and carried them out to the first rack.  The top of each panel is mounted on a stainless steel rod and I added the heavy duty garden stakes along the top in between the new stainless rods, to add more support.
Note the two new, extra long stainless rods. Each panel is cinched together with a heavy duty zip tie, tightening it down on the rod.
Heavy duty zip ties hold together the edges of each panel in place on the rods.  The inside white zip tie is there only to keep the yellow tie & wire from sliding inward.
A smaller zip tie was added inside on just the rod (not holding anything), but will help keep the outside yellow zip tie from sliding inward.
The tops of the panels are all zip-tied to the garden stakes and the top wire 'ceiling' along the way, closing all the gaps at the top.  All I have to do is cut the 3 zip ties holding each panel to the next at the seam, leaving the zip ties at the top that hold it to the extra heavy rods on the top, lift the panel up and walk in.
Each rectangle is 2" wide - you can see the cage is at least 10" out in front of each gourd entrance.

As with my other rack that I enclosed a couple of years ago, I will need to work a little more slowly and be more cognizant of where my face is at all times, since some martins tend to flush out of the gourd at the very last second.
The fencing is 48" high so it drops below the most bottom gourds about 6".  I will have to monitor to see if that's going to be sufficient
East Rack - 3/26/2016

Mid Rack - 3/26/2016

Each cage took 35 - 40 minutes to install and I was really glad that I made the changes early in the day, since it took the colony some time to adjust to their new surroundings. So, 38 feet of mesh wire fencing, a couple of packs of zip ties, some heavy duty stainless steel rods, 24 feet of undersill trim to make some nice, 4"x4" landing spots, a handy pair of wire cutters and a good pair of leather work gloves and I'll be able to better sleep at night.  I think my most stressful time last year was when the new fledges came home late in the evening and hunkered down on the inside gourd arms.  I knew those 'easy catches' were going to attract the owl and I spent many hours & nights outside with them, trying to gently encourage them inside or leave the site. With these new cages, they can safely roost on the arms if they want and stick their tongues out at the GHO when she comes.
Some were initially frightened by the changes, fluttering around and around the outside of the cages, while others flew under and straight up to their gourd without missing a beat.  Some ended up hanging upside down on the cage, and some landed on top and dropped right through to their gourd.  Some of the territorial fighting resumed, with the males quickly reclaiming their gourds as their competitors dropped through the top of the wire in full battle mode, proving that each of these birds have their own character and personality as unique as we humans.
I had a really hard time not laughing out loud (and I can laugh really loud) at some of the antics in this video.  Enjoy!

Thursday, June 25, 2015

Ellie Mae Gets a Makeover for Her 2015 Deployment

I woke up at 3:40 AM Monday morning and decided while I was up anyway, I would check on my purple martins before snuggling back in.  With our new extremely bright LED spotlights shining on the colony, I could see every rack very clearly.  Lo and behold, there was the mighty Giselda, sitting tall and pretty, very proud of herself, on my West Gourd rack.  I watched her for a couple of minutes, then went out to scare her away.  When I checked the videos from the game cards and my Foscam camera Monday afternoon, I found that she had been here quite a while - from around 12:35 AM until I ran her off at 3:40 AM.


I had quite a few of what I thought were 'false triggers' on my game cameras, but in viewing the video from the Foscam camera, I now know why.  Giselda had been a very busy girl for those 3+ hours.  On Sunday, since I have many nestlings that will be fledging over the next week or so, the hawk attacks are increasing, I deployed a lot more decoys.  When my GHO came to hunt, apparently, she thought the decoys were making the noises she was drawn to, and she was attacking them, just out of range of my game cameras.  The 'false triggers' weren't false at all - she was just too fast for the cameras to capture her as she launched her assaults.
In this video, she had just tried a grab on the decoys by my game cameras, failed and landed up there to reevaluate her prey.
Then I found a video that made my stomach turn over and my heart skip a beat.  I watched it over & over to make sure I wasn't making it all up in my head, since the quality is not that great.  She was now attacking my housing and gourds from underneath.  After hitting the house - in the video below, it appears she tried to unsuccessfully land on the predator guard on that pole.  She flapped about, but could not gain footing on it, then fell into the yard.  She roamed around on the ground for about 4-5 minutes, then, after moving about 10' away from the East gourd rack (rack on the far left), she launched an assault under the rods that protect the gourds and attempted to grab one of the gourds.

Luckily, I let my gourds swing freely - moving back & forth with the wind, so, along with the rods interfering with her flapping wings, she could not get a grip on the swinging gourd and attempt to tear off the tunnel.  Even if the martins inside had flushed at that moment, she was still in such a precarious position that she could not grab one of them.  Still....it had to be sheer terror for the martins inside.

But the most surprising video of the night?  The one where she launched herself from the top of a gourd rack, flew past my camera and into the porch area where the new, bright LED lights had attracted a bazillion bugs.  I'm not sharing the video here as it's blurry when she flies by both times and of no use here.  She spent over 5 minutes under there - my guess is she was chasing a mouse or some of the large bugs, but the video only shows her entering and leaving the area.  Nope - this girl is not bashful of any lights!
Ellie Mae is now officially back on duty.  Stuffed with balloons to make her lighter and hanging on my shepherd's hook.  I attached a helium-filled balloon to also help drag her around and keep her moving on the hook, and that's working really well.  I'm moving her around the yard, so my GHO doesn't get too comfortable.
So far, no sightings since 3:40 AM Monday morning.  I'm hoping we can get through the next couple of weeks with this simple tactic.  Much to my husband's dismay, after seeing the grainy video and the low-quality video of her fly-in to the porch, I started talking about another camera.  He's praying the owl will leave before I solidify that plan.  Me too.

Tuesday, May 19, 2015

Giselda - My Varmit-Eating GHO

This year, I decided that I wanted a wide-angle view of my entire colony at night, from a general monitoring viewpoint, allowing me to also see what may be skittering around my yard.  So, Bob did some research and found a reasonably priced Foscam security camera and hooked it up about a week ago.  We've been struggling with the range of the IR (60') and really not wanting to run power out into the yard to get the camera closer to the racks.  In my last post, I also mentioned that I was trying out a motion detection light and thought that may help scare the owl away if he ever came into the colony and triggered it on.  But since 4/18, I hadn't seen the owl and couldn't prove my new tool was working.  In fact, I was beginning to think he was filling up on my neighbor's guineas, whose numbers have gone from 20+ to 3 or 4 now.  I hear they taste like chicken.  That's the word I'm spreading anyway - 'EAT MOR GUINEAS'.
Yesterday (5/18) I pulled my game card cameras for review and found this video date / time stamped at 5/15/2015 -2:35 AM.  It was a bit alarming and given the perspective of the camera, I couldn't tell what mischief  Giselda had been engaged in before she landed on top of that pole.



The videos recorded through the Foscam camera were taking too long to scan, so I hadn't reviewed them in a couple of days and besides, the IR range and lack of illumination issues were bumming me out.  But somehow, on this night, the stars aligned, the winds were perfect, there was no rain, glowing eyes aided in tracking and the lovely glowing cobwebs added just enough annoying creepiness to make the video below quite interesting.  And I now have confirmation that a motion detection light is spectacularly useless in helping to scare a GHO away from your colony.  But it does provide some nice lighting for recording what she's up to.

I've done some cropping in the video to remove a total of almost 4 minutes of the owl turning his head away, because you really can't see anything when his glowing eyes are not looking towards the camera.  I also removed the first 2 minutes of the video where he entered stage-right, landing on the ground about 15' west of the most west rack.  I saw his glowing eyes through the noise on that side of the frame and thought for a bit that it must be a cat, a racoon or a coyote.  That is, until I got to the 2:23 minute mark and all doubt was removed - (at the 2:23 minute mark - watch the top of the leftmost gourd rack).  You have to watch the video at full-screen and watch along the right hand side - you'll see his glowing eyes periodically and her movement as she apparently glides (I don't think a GHO would run) along the ground.
This video served to provide me with a lot of relief - JOY!  Apparently, on this night anyway, she wasn't there to hunt for martins.  She was there chasing or hunting voles, moles, mice or snakes that were creeping along the ground.  Whew!  What a relief!  She can have all those varmits that she can catch!  That $79 camera just paid for itself in saving me a lot of worry & sleepless nights.  For now, my guards are still working and she seems to be ignoring us.
So, new plan - I'm putting my scarecrow back in the yard (she was inside that night, due to expected rain) and we're installing bright spotlights that will aid in video monitoring.  Enough fooling around.  The cages are working - I just need to know what she's doing.  Maybe "want to know" is a better description.
Sssssshhhhhhh, be very, very quiet, my lovely darlings, for ye know not what lurks beneath.  Or above.

Wednesday, January 14, 2015

Monitoring Your Purple Martin Colony With Game Cameras - A Browning Trail Camera Review

Last year I learned a hard lesson.  Never say, "never" when it comes to owls, snakes, racoons, and other predators that could prey on your purple martins.  Never.  As I learned, you don't really know what's going on with your purple martin colony unless you are either sitting outside all night or you have positioned multiple game cameras around your site.  If you ignore the possibility, then you could end up with lots of dead martins and even lose your entire colony.
Sitting in my yard all night was just not realistic for me, so I chose the latter option.   I quickly shopped for game cameras after noticing that my Trendsetter was not filling up like it had in years past and finding a GHO feather in my driveway escalated my sense of urgency.  After reading the reviews for multiple brands and shootout results (good site to see all trail camera reviews here), I decided to try out a Browning Trail Camera - Recon Force XR Series (BTC-2XR).  It has some nice features, including long detection range and the ability to record video.
My purple martin gourd rack - 7-2-2014- 8:20 PM.

My first impression when I opened the box is that the camera is small and compact and the casing has a high-quality, heavy duty plastic feel.  My second impression was, "whoa - this takes a LOT (8) of batteries!".
The Recon Trail Camera User Interface
After loading it with batteries and an SD card, I was able to poke around the very user-friendly buttons and quickly setup the date and time.  I had read about all the features while shopping, but I hadn't realized there were features within features.  Read on to see what features I find most attractive in this game camera.
Features
The camera has 4 capture modes: Trail Cam, TimeLapse, TimeLapse+ and Video Mode.
...

Sunday, November 2, 2014

The Freeze Owl Block (FOB)

Finally!  For a couple months now, the weather has been too hot to go out and start the cleanup of all the gourds and housing.  This past week has been much cooler and, feeling more secure that the mites and other creepy crawlies have drifted into their winter slumber, I ventured out to start the cleaning process.  With dirty gourds removed, Mr. Freeze is now more willing to help with the implementation of the new owl block whose plan has been changed countless times and under much discussion for months.
Mr. Freeze's 5 points of resistance were:
1. Wind.  Well, we do get lots of it here in Missouri.  My response was, the materials are lightweight and plenty of holes (ie, minimal surface area to catch wind).
2. Weight.  My response was again, the materials are lightweight and it's a 3" pole.
3. Our view.  We bought this property specifically because of its fantastic view to the south and who wants big cages permanently mounted in their direct line of sight?  My response, ok, we won't put them all the way up to the top, permanently mounted.  We can't really reach that high anyway.
4. Cost.  My response was, I've spent a lot of , ahem, a few bucks on these rigs to host purple martins and by comparison, it's not going to be that bad.
5. Why now?  Well, because Mr. Freeze, I don't want to go out in the February / March freezing temps and snow to try to measure & figure out the proper configuration for my racks.  Besides, you don't want to be out there then either, freezing off your wee knees right?
Thanks to Aprils Owl Guard pictures and a few emails back and forth with April, we were able to come up with a plan.  We found aluminum angle iron (36" long and 6' long pieces) at the local Lowe's store and the 2"x4" welded wire fencing (4' high) at our local farm store.
The 36" angle arm pieces were cut to 18" each then marked so they could be drilled to fit the already pre-drilled angle arms.  Since the angle arms are 1/8" thicker, we also purchased more bolts that were 1/8" longer to accommodate both the gourd arm, the original angle arm and the new one in the inner-most hole.  I thought we were being so smart to think of that.  But after drilling all the arms, I realized that I hadn't allowed enough room on the inside / underside of the new angle arm for the nut. So I had to move the small gourd arm to the outside and put the nut on the outside.  I can't think of a reason why that's bad...just aesthetically, it would have been better inside I guess.
2 pieces of fencing temporarily hung to ensure sizing is correct and the gourd won't be too close to the fencing.
The nut would not go on the inside as the hole was too close.  Every other vertical will be cut out to make 4"x4" openings.
Out at the opposite end of the arm, we drilled 2, 1/4" holes just in a bit from the end so that we can run #9 wire through the top and middle of the fencing to stiffen it, then bend the end of the wires downward so they can drop through these holes.  This will also allow me to remove the fence panels if needed during the season.
The #9 wire has not been weaved through the fencing yet.  Hung only temporary here to ensure proper sizing.
Right now, until I see how this is going to work in practice, I also plan to use the full height of the wire fencing - 4', hoping that will help discourage the owl from trying to fly up under it.  Once I wind the gourd rack down, I'll still be inside the cage and since I'm so short, I can move from section to section without removing the panels, unless I really need to.
I'll also be cutting out every other vertical wire to make the holes 4"x4".  I really wish I could find some pre-fabricated wire of that size that is made of this same light-weight material, but my searches have yielded nothing.
The 6' long piece of angle iron at the top will be used for support and to have something to which I can secure the top layer of fencing.
The 4' height of the fence may be too much, but I will leave it for now.
Lastly 4, 6' pieces of angle iron will be added across each set of arms at the top to support the welded wire fencing that will need to be spread across the top of the openings, so that my favorite Great Horned Owl can't just drop in for dinner from above.  Right now, there are no plans to enclose the bottom.  I'll monitor the rack and if he ever does decide to try to fly up into the cage, I'll deal with it then.  My preference though for now is to allow the martins an open bottom through which they can fly out and if the owl lands on top - which I'm sure he probably will - if they do panic & fly out, I don't want to find a bunch of birds hung up in the fencing in the morning.  Construction and ideas continue.  I will post more pictures as it develops.
(see Part 2 here: http://kathyfreeze.blogspot.com/2014/11/the-fob-part-2.html
see Part 3 here: http://kathyfreeze.blogspot.com/2015/01/the-fob-part-3.html)
The top will be enclosed with the fencing.  It will be secured to the 6' length of angle iron.

Friday, July 18, 2014

Not Quite Yet

As of today, I only have 5 nests with young that have not fledged.  It has been getting pretty quiet around here during the day.  About 90% of my colony has left to start their migration.  I've been very surprised during the evenings when 6-7 nests of newly-fledged martins return with their parents to stay the night.  I counted at least 30 birds coming in tonight, with 7 new fledges cramming themselves into one gourd.  Hopefully, they've been told the stories and will keep the partying to a minimum tonight.

I have been fortunate this year with only 2 or 3 jumpers.  Without banding it's difficult to tell whether it's the same guy.  Actually, I don't know that I should call him a "jumper" so much as a "failed launch".  I had to chase him around the gourd pole twice in the rain and by then we were both soaked, so I put him in the garage until he dried. The rental price for anyone staying in my garage is to hold still while I take a photo.  He looks stubborn.  Almost defiant. Good.

With all the owl trouble and fledging going on, I haven't had much of a chance to keep up with nest checks and really thought everyone had at least left the Trendsetter.  So, when I saw an ASY male & ASY female martin entering house cavity #1 yesterday, I was surprised to find these four darling, 7-day old nestlings that will not fledge until around 8/5 to 8/9.  The mom & dad of these kiddos deserve medals for courage and bravery.  You've all seen the nighttime videos.  They lived it, yet they hung in there when the beast was shaking and beating his giant wings against their home, threatening to make a meal out of them, yet here they are feeding 4 little winged wonders!  Hooray! 
Speaking of my Great Horned Owl, we have not had an attack for 8 nights now.  Yes, a full 8 nights.  I can't even begin to express to you how happy it makes me to pull the cards out of the game cameras every day and find...nothing.  Nothing except normal, delightful daytime photos & videos of my martins flitting around trying to get their stubborn children to fledge.  Normal!  I do enjoy normal!


I'm not sure if the addition of Ellie Mae to my yard along with the radio & bright lights has kept him away, or my random visits at night with Ellie Mae, or just the fact that the noise level has significantly dwindled here over the last 8 days has caused him to avoid us or lose interest.

Whatever it is, I'll take it, but I can't really breathe a sigh of relief until the 4 darlings pictured above are winging south with their parents.  Until then, Ellie Mae and I will continue to be vigilant.  August sure seems like a long way away right now.

Sunday, July 13, 2014

Playing Chess Instead of Checkers

Make no mistake over this writing - I am extremely distressed over this issue, but this is how I deal with my distress - I write to make myself feel better. When I was a small child, my grandfather taught me to play checkers.  As I matured, he taught me to play chess and it was obvious that chess required a lot more thought, planning and strategy in order to win.  I loved it, especially the knights and bishops pieces as their moves were the more complicated and aggressive on the board.  I never became a pro at the game, but I learned a lot from it that I now apply to real life.

If someone or something presents a smart move to you, make a smarter move in return.  That's the way I feel about my dealings with this owl.  I'm still not 100% sure, but believe my owl to be a Great Horned Owl - one of the most aggressive owls around.  In chess, the best games are played against a knowledgeable, respectable challenger.  Well, I think I have met quite a respectable foe in my current battle to protect my martins.  They don't call them "wise, old owls" for nothing.
Great Horned Owl image: National Geographic Online
From the All About Birds site:
Renowned for ferocity, Great Horned Owls kill and eat small to medium mammals of many kinds, especially hares and rabbits. They eat mice, rats, squirrels, opossums, woodchucks, bats, weasels, and the occasional domestic cat. Great-Horned Owls also eat skunks, which are sometimes such a prominent part of the diet that both bird and nest may smell of musk. Although mammalian prey typically comprise more than three quarters of the diet, more than fifty species of birds have been recorded as prey. In addition to hunting small songbirds, Great Horned Owls have been known to eat large birds such as grouse, herons, ducks, Canada Geese, hawks (including Red-tailed), and even other species of owl. A woodland with resident Great Horned Owls usually lacks any other raptors in the immediate vicinity.
Well, that may explain what has happened to some of the feral cats that have been roaming around here lately.  If I were an owl, I would prefer a larger return for the amount of effort required to hunt - a meal such as a cat or rabbit rather than a scrawny little songbird.  What is it about my purple martins that makes him want to come after them so aggressively anyway?  Do they taste like lobster or some other special delicacy?
My first moves in response to the owl were to put up the wire fencing around my Trendsetter and the array of garden stakes around my gourd racks.  We had multiple days where the owl did not make an appearance, then when he did show up, the game camera pictures showed him using the tops of the racks as perches from which he was hunting for ground-dwelling prey.


Then one night, he upped the ante - I found a bent garden stake in front of 2 gourds, which I replaced with an even thicker stake. As the stake he grabbed was just out of view of the game camera, I was unable to see what had happened, but I did verify that the martins in those 2 gourds were safe & still feeding their young.  In response to his move, I decided to stand watch and wait for him and hopefully give him a good scare.  He flew through my yard at 9:10 PM on 7/4, circled to some trees and at 9:25 PM, he returned to perch on the perching post, 20' from my martin housing.  I flipped on all the lights, including my million-watt spotlight and ran at him, screaming a lot of words that probably shouldn't be printed here on my blog.  Regardless, he left in a hurry.  Despite my feeling of victory in the battle that night, I knew that the war was not yet over, but I still hoped I had provided him with something to think about before he landed here again.
As most of you know, he upped the ante again on the nights of 7/7 and 7/9, challenging the integrity of my wire cage on the Trendsetter and flushing out several martins.
http://kathyfreeze.blogspot.com/2014/07/caught-in-act.html

While these videos have indeed been alarming to me, I saw his increased aggression as another challenge to which I needed to rise and hopefully, respond with something even better which will perplex and discourage him.  As of yesterday, we had 3 peaceful nights with no owl attacks, but knowing that he is probably not done with me or my martins yet., I built a scarecrow and christened her, "Ellie Mae" before sticking her out in the yard to stand guard duty last night.
As I sat with Ellie Mae in the yard last night, I saw a large bird with a large pair of wings silhouetted against the southern horizon moving steadily northward toward my colony.  "Holy Moley - he's bigger than I thought - not tonight - you will NOT eat martins tonight!", I thought.  Grabbing my spotlight as I rose and tensing in preparation to start my own running, screaming, scary attack, I stopped mid-step as my eyes identified my attacker - and I allowed the Great Blue Heron to pass, unmolested by my colorful words and lights.  I did find it odd though that after flying another 5 seconds north of my house, the heron suddenly turned 180 degrees, emitted her own alarm calls, and flew back southward.  What had scared her?  Had she spotted my owl perched in a tree north of the house and changed course?  I'll never know.
All the game cameras confirmed today that we have now been 4 nights without any night visitors.
Whether Ellie Mae is helping or not is yet to be determined.  I'll move her around the yard to different spots, keep playing the radio and keep the lights on all night.  If anything does happen, I'm sure I'll be dismayed, saddened, alarmed and very, very upset again.  But I will regroup and deal with it.
For now though; "Dear Mr. Owl - Your Move". 

Thursday, July 10, 2014

Caught in the Act

I've been monitoring my colony pretty closely and even ran the owl off the perches on Friday, 7/4.  I had to leave for a business trip last Sunday however, so my husband was leaving the radio and porch lights on to try to keep him frightened away.  Upon returning today I pulled the game cards out of my cameras and was quite alarmed to find these two new videos of the owl attacking my Trendsetter.  I've had a lot of fledging going on this week, so I suspect he was after the new fledges that often hang out on these porches at night.  He obviously left empty-clawed but, he's definitely shaking up the tenants of the house.

This one happened early in the evening on 7/7/2014.  You can click on the YouTube icon in the picture and embiggen them for better viewing.

This one happened 2 nights later.

Looks like I'll be staying up late in the evenings until all the martins are gone now.