Nest Replacements or Lack Thereof and mites.

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Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

I have a confession to make, in our 49 gourd school colony I haven't changed a nest since 2013, or cleaned out a gourd either :oops:

The old nesting material is breaking down inside the gourds into almost a soil-like consistency.

The thing is, up until I could keep checking last week, nary a single swarming mite outbreak anywhere in the colony, even though all but one of the gourds are occupied with active nests. This despite our wet spring. Tiny mite-sized insects (springtails?) can be seen in moderate numbers.

Likewise, in informal trials of clean/no-clean in previous years we saw no difference in the number of mite outbreaks.

I'm wondering given the enormous quantities of mite eggs that are probably laid in just an average purple martin's nest, if there isn't some organism or fungus in these old nests that preys upon these mite eggs and hatching mites.

Mike
Last edited by Scully on Fri Jun 12, 2015 6:20 pm, edited 1 time in total.
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
Matt F.
Posts: 3895
Joined: Mon Feb 28, 2005 9:48 am
Location: Houston, TX

Mike,
I have often wondered the exact same thing.
I wondered if there was another type of bug that lived in old nests, that preyed on the bird mites, in turn controlling their numbers.
I've searched for scientific studies, and have not found much (I did find a small article sometime back about mite numbers in starling nests were old nests were reused, as opposed to new nests, but the article was incomplete :roll:)
I had not thought of some type anti-mite fungus, prior to your post.
Intriguing subject.
Last edited by Matt F. on Fri Jun 12, 2015 9:15 pm, edited 2 times in total.
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

I rarely admit it but I.... um.... actually have a Master's Degree in Entomology... :oops:

...from a certain Texas "World Class University" yet....

..and OMG, there are certain types of "entomophagous fungi" straight out of a horror movie.... :shock:

http://herbarium.usu.edu/fungi/funfacts/ant_fung.htm

Image

Imagine getting a case of athlete's foot and the next thing you know you have a fatal case of mushrooms growing out of your head.

The next thing to do would be to figure out a way of showing said fungus was present in old bird's nests.

Mike
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
GeneP
Posts: 523
Joined: Mon Jul 23, 2007 7:35 am
Location: Kansas, Lawrence
Martin Colony History: 1 gourd rack with 24 gourd capacity. 2018, my 11th year hosting martins.
18 pair in 2017.

The older I get the more I think I'm going to miss out on some great discoveries. Interesting stuff.
PMCA Member, Single Gourd Rack, 2019 marks 12 years hosting martins.
Ed Svetich-WI
Posts: 798
Joined: Tue Jan 13, 2004 10:05 pm
Location: Brooks, Wi (McGinnis Lake)
Martin Colony History: 24 Super and Excluder Gourds on two gourd racks, all SREH. Full occupancy. My philosophy is to maximize fledge % with existing cavities rather than adding gourds to grow colony, thus providing opportunities for new colony expansion. Fledge over 100 nestlings yearly from 24 gourds. Band nestlings in cooperation with state university. 2019 Adendum: Reduced colony size to 12 gourds to focus on more intensive management regimen.

Mike,

Since we are into honesty, I have question . What perecentage of the eggs laid in your 49 gourds have fledged? Your lack of nest changes or even gourd cleanouts flies in the face of current colony management.Secondly, what circumstances led you to abandon nest changes as a management tool? Would a smaller number of gourds allow you to conduct the recomended nest replacements or was this an experiment?

Thanks,

Ed
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

Ed,

Would a smaller number of gourds allow you to conduct the recomended nest replacements or was this an experiment?

Are you asking could I have found the time to clean out the gourds? Um, yes.

What percentage of the eggs laid in your 49 gourds have fledged?

I'm not looking at the data right now but no, there have been no discernible changes in clutch losses or nestling survival. Certainly, over the past thirteen years of records, this has been one of our better years.

Two of 49 clutches failed to hatch, a normal failure rate here it seems.

Overall success this year, including these failed clutches, has been an average of 4.2 nestlings successfully fledged per nesting attempt. A "nesting attempt" being defined as beginning when one or more eggs actually appears in a gourd.

"Four point something" fledges per nesting attempt is about as high as our colony gets.

This is the first year of any I can recall with NO mite problems, and also only the second time all the martins came back to old nests.

What drives purple martin success in this part of the world is rainfall, pure and simple. The critical window appears to be the last two weeks when the martin nestlings are large and their food requirements greatest.

I have watched them many times through an entire foraging flight. Around here in this urban environment, leaving the colony they climb steeply into the prevailing breeze until they are high up and hard to see, they then actively forage, darting around and drifting downwind, before returning to the colony in a series of steep dives.

If they cannot do this about every two or three minutes during peak foraging times, returning with large insects each time, they will lose nestlings.

Hence our colony success depends on the number of large insects passing high overhead in a window of sky over the colony perhaps as much as a mile across.

This is a good year so nestling losses have been minimal.

In contrast the drought year of 2011 was our worst year when almost NO nestlings survived among 47 nests.

Secondly, what circumstances led you to abandon nest changes as a management tool?

We are a high school and I am a science teacher so so EVERYTHING is an experiment.

Probably the last four or five years I have left some old nests in, the reason being simple curiosity and a sound knowledge of ecology (actually, both my degrees are in entomology - insects, my MS is from Texas A&M and my BS is from the College of Environmental Science and Forestry, Syracuse NY). Only an idiot brags on their college education, I post those just to indicate I'm grounded in the principles.

Why some gourds develop mite problems and others to not, even when all started identically clean, seems a mystery.

I do keep shredded cypress bark mulch on hand and would have switched out a nest in a heartbeat had mites been a problem.

Next year I'll formalize this and do half and half, equally interspersed through our four gourd pole locations.

Anyhow, this is what our colony looks like from the outside, here's a couple of photos I snapped just yesterday at dusk. Probably half the broods are already gone by this point...

Our Gemini...

Image


..and our old Carrol pole, which just bent this year in a windstorm and so will need replacing. Fortunately it still lowers enough that with a step ladder we can still access the gourds.

Image

This is our S&K pole in the fenced-in school garden out back, I'll admit some of the arms are a tad droopy, a tendency of the design...

Image

Our fourth pole is an SS with 17 gourds attached.

Mike
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
Ed Svetich-WI
Posts: 798
Joined: Tue Jan 13, 2004 10:05 pm
Location: Brooks, Wi (McGinnis Lake)
Martin Colony History: 24 Super and Excluder Gourds on two gourd racks, all SREH. Full occupancy. My philosophy is to maximize fledge % with existing cavities rather than adding gourds to grow colony, thus providing opportunities for new colony expansion. Fledge over 100 nestlings yearly from 24 gourds. Band nestlings in cooperation with state university. 2019 Adendum: Reduced colony size to 12 gourds to focus on more intensive management regimen.

Scully,

Your results from a control of allowing nest contents to remain vs nest changes would be of interest. One aspect of such a comparison might be how the weight of nestlings varies between the two arms. I have noticed a difference in body weight between nestlings impacted by blow flies and those in cavities blow fly free. Again, why one cavity is impacted and another is blow fly free is an unknown. At times, the larval pupulation is huge. An appreciable weight gain can be noticed once the feeding blow fly larvae are removed. Do you use any chemical means to control vermin in these cavities or have you simply gone hands off.

Vermin controlling fungi would certainly exist in nature, especially in wooden cavities in trees or even aged wooden bird houses. Several years ago I conversed with an Entomology professor in the NW who stated that wild birds had evolved along with their insect pests and we should not be as concerned about stringent control methods. It may be that the flora in natural cavities controls pests naturally reducing the impact on nestlings to some extent.In contrast, artificial cavities have a relatively sterile environment, since we usually clean them yearly.

Ed
tlragsdale
Posts: 218
Joined: Wed Jul 24, 2013 12:22 pm
Location: Wisconsin/New Richmond

Hey Mike….interesting reading. Of a different note, did you fashion (or purchase) the owl guard-arms, seen on your Gemini rack? Don't currently have any such protection on our Gemini, and need to add something.
Terry & Michelle
New Richmond, WI

2005 - 2014 Hard luck stories
2015 - 2 pair, 12 eggs/12 fledglings
2016 - 6 pair, 35 eggs/35 fledged
2017 - 18 pair, 88 eggs / 85 fledged.
2018 - 23 pair, 119 eggs/115 fledged.
2019 - 31 pair, 137 eggs/133 fledged
Craig Dyer
Posts: 500
Joined: Fri May 13, 2005 2:24 pm
Location: Nevada, TX
Martin Colony History: Area is rural. Offer 28 compartments...metal housing (Lonestar Goliad) & Supergourds all w/crescent entrance holes. Purple martins are abundant here and eager for quality, well maintained, safe housing. Expect near 100% occupancy this season.

Nor have I observed a mite infestation this season. Haven't seen any mites. Very strange in light of the mite explosions I have experienced in the past. I finally applied sevin dust last weekend as a precaution, as my colony is at a point where nest checks are becoming problematic (premature fledging/multiple nests in one housing unit).
Craig Dyer
Craig Dyer
Posts: 500
Joined: Fri May 13, 2005 2:24 pm
Location: Nevada, TX
Martin Colony History: Area is rural. Offer 28 compartments...metal housing (Lonestar Goliad) & Supergourds all w/crescent entrance holes. Purple martins are abundant here and eager for quality, well maintained, safe housing. Expect near 100% occupancy this season.

P.S.
I thoroughly clean out my gourds and housing at each season's end.
Craig Dyer
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

I have noticed a difference in body weight between nestlings impacted by blow flies and those in cavities blow fly free. Again, why one cavity is impacted and another is blow fly free is an unknown. At times, the larval pupulation is huge. An appreciable weight gain can be noticed once the feeding blow fly larvae are removed. Do you use any chemical means to control vermin in these cavities or have you simply gone hands off.
I should have specified, blow flies (blood-sucking nest maggots) are a whole 'nother ballgame.

Surprisingly, we do not have them here, I believe this includes much of the south.

We have always weighed our nestlings, just for the data, and two underweight nestlings were not included in our fledgling estimate as it seems they are unlikely to survive. Part of the weighing process is because these last few years I have been sub-permitted to band them.

Most times over the years we have just started with bare gourds and for years I routinely did nest replacements on all the gourds at the time of weighing.

I do not believe Sevin dust does any harm and it will knock back mites but I have not used it.

I think part of what biases my outlook down here is how much time I have spent looking at average martin housing sites around here. We located more than 200 housing sites within a four mile radius, and monitored occupation rates for at least five years. For three years I was even able to do nest checks on four neglected housing sites in public places.

What seems readily apparent to me is almost ALL the martins in eastern North America in any given year must be nesting in more or less neglected housing yet the martin remains a common bird across the South at least.

I believe up north, just as drought hammers us here, so cold weather early in the season absolutely hammers northern populations. I believe even the PMCA would have lost their Edinburg colony without developing supplemental feeding methods. Given that the great majority of people jut buy a house and put it up, the effect of weather up north must be enormous.

Mike
[/quote]
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

Hey Mike….interesting reading. Of a different note, did you fashion (or purchase) the owl guard-arms, seen on your Gemini rack? Don't currently have any such protection on our Gemini, and need to add something.
The story on those is back in 2010 I wrote a $10,000 grant proposal for our school re: martins. I sent it off to four sources and three said yes :shock:

I ended up with $27,000 .Two elementary school, one middle school, six high schools and two universities now have top-of the line Gemini set-ups thanks to us :grin:

As part of all this money I HAD to spend specifically as per the grants I had a whole bunch of owl guards made. This even though the manufacturer no longer makes them, feeling that the deep gourd designs like the Troyer Horizontal are sufficient.

Anyways, I still got a whole box full sitting in my storage room. How many do you need? I can send them for the cost of shipping.

MIke

[/quote]
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
tlragsdale
Posts: 218
Joined: Wed Jul 24, 2013 12:22 pm
Location: Wisconsin/New Richmond

Hey, Mike---

We have 24 Troyer gourds on our Gemini. You let me know how much $$, and where to mail it----I would run (OK, drive at the top-end of the speed limit) to the post-office.

What a kind and generous act.....
Terry & Michelle
New Richmond, WI

2005 - 2014 Hard luck stories
2015 - 2 pair, 12 eggs/12 fledglings
2016 - 6 pair, 35 eggs/35 fledged
2017 - 18 pair, 88 eggs / 85 fledged.
2018 - 23 pair, 119 eggs/115 fledged.
2019 - 31 pair, 137 eggs/133 fledged
4th Gen Martin Fan
Posts: 1483
Joined: Thu Jul 04, 2013 1:19 pm
Location: TN/Collierville
Martin Colony History: I have been exposed to purple martin sounds in utero when my mother went out to get my father away from his martin colony.
I played around the martin colony every summer and watched as my father maintained his colony. In the late 50's until the 70's he did not notice European Starlings in south Texas.
When old enough, I helped maintain his colony. My primary task was eliminating English House Sparrows with a 1956 Benjamin 317 .177 air rifle.
When I settled into my own home, I started my first colony with an original Trio Castle and Trio Grandpa. When I moved again, I did not put up any martin houses. Frustration with European Starlings in the Southeast US was overwhelming.
Found PMCA Forum and learned about modern enlarged compartments and SREHs.
Inherited my father's last martin house, a Trio Grandma, modified it to modern specifications and have had good results since then.

Mike,
My sister in Seguin, TX has a K-Series Gourd Rack with 18 Troyer Horizontal Gourds. She is very actively managing her colony and it is thriving with a full gourd rack after only 2 seasons.
She is concerned about hawks and owls on her THGs.
I would gladly send you any cost to provide enough for her 18 THGs.
Mark.
Last edited by 4th Gen Martin Fan on Mon Jun 15, 2015 10:33 pm, edited 2 times in total.
Mark.
Firm believer in HOSP/EUST Control, Enlarged Compartments, SREHs, Pole Predator Guards, Owl/Hawk Guards, Mite/Parasite Control, Housing Insulation, and Vents for Compartment Cooling.
PMCA Member.
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

I'll go in there and get a count next week, but because of travel plans it will be two weeks before I can act on this.

You'll be doing me a favor, storage space is so tight I was actually considering having them recycled :???:

Mike
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
William A
Posts: 173
Joined: Sun Feb 23, 2014 11:35 am
Location: AL/Marion

Good Morning Mike, very nice setup at the schools and what a wonderful experience for the students. I would sure like to have 24 of those owl guards for my gemini pole if you have any left. Please email me at ralph.avery@roadrunner.com Thank you so very much
PMCA Member
Emil Pampell-Tx
Posts: 6743
Joined: Tue Nov 11, 2003 1:26 pm
Location: Tx, Richmond (SW of Houston)
Martin Colony History: First started in Gretna, La in 1969 with a small homemade house, have had martins ever since at 2 different homes in Texas

I too am surprised with all the rain that we have gotten, but have not seen a single mite. I rinse out the old gourds but leave the larger sticks, shake out as much small stuff as I can. The martins spent very little time building nests this year, seems like they like the old nests the best. Before I hang the gourds, I do add about 1/4 teaspoon of sevin dust, and have not used any since initially hanging the gourds.
PMCA Member, 250 gourds, 6 poles, 2traps
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Mike,

I am seeing few if any mites this year in our two personal martin colonies. I did dust my gourds/houses with 5% Sevin at the beginning of the season. Bob didn't dust any of his and he does not clean out the old nests.

I often leave "good" old nests intact and just dump out any loose dried fecal matter if necessary. The martins simply add some leaves, sticks or grass stems to the old nest and that works just fine. If I find an old nest that is almost entirely dried fecal matter/dirt, I will clean it out though I try to leave any nest foundation. I still will add "new" pine straw to many of my old nest foundations.

Martins seem to prefer cavities with nests already there and those nests can be rather dirty!

Steve
PMCA Member
300+ pairs of martins each season
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

We have 24 Troyer gourds on our Gemini. You let me know how much $$, and where to mail it----I would run (OK, drive at the top-end of the speed limit) to the post-office.
Private messaging has been disabled on these boards

Since your need is apparently immediate, I have the owl guards, if you can get me an address I can maybe get them out tomorrow (Tuesday 6/16).

I can be reached at mike.scully@nisd.net

Also I recall now that the manufacturer, Creative Universe Enterprises, when they did make them, did not make owl guards to fit Troyer Horizontals. Some I straightened in a vise to extend over the TH entrances as can be seen in the photo. This is a simple and easy task.

Image

Originally that pole only had a few Troyer Horizontals but I had to "call in" all our Troyers from around the district a couple of years back when we were trapping adult martins in cooperation with a university study (Troyer has a very good trap mechanism). Since we have never had owl problems I did not bother to bend the other owl guards where you see the TH entrance projecting past the guards.

Mike
Last edited by Scully on Mon Jun 15, 2015 9:01 am, edited 1 time in total.
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
Scully
Posts: 2008
Joined: Mon Jan 26, 2004 5:35 pm
Location: Texas/San Antonio

4th Gen Martin Fan wrote:Mike,
My sister in Seguin, TX has a K-Series Gourd Rack with 18 Troyer Horizontal Gourds. She is very actively managing her colony and it is thriving with a full gourd rack after only 2 seasons.
She is concerned about hawks and owls on her THGs.
I would gladly send you any cost to provide enough for her 18 THGs.
I can be reached at mvlasak@bellsouth.net.
If it is not feasible, then I understand.
Mark.

I'll send you a set of 24, but I cannot act on it until after July 12th unless you just want to meet me here in town tomorrow to pick them up in person, my email is mike.scully@nisd.net . No charge of course.


Mike
Last edited by Scully on Mon Jun 15, 2015 9:07 am, edited 3 times in total.
...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them. Canasatego 1744
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