Can wet nest kill young ?

[Matt@atx]

I know its not good to have it. I did nest changes yesterday and found 5 dead Martin babies between 2 gourds. 3 in one gourd which loses the entire clutch, my first total clutch loss... and 2 in another gourd reducing the baby count to 3.
Thing is, all 5 babies where at least 18 days or older, fully feathered, well fed and without any injuries that I could find or see. 2 of these 5 would have fledged in a week or less, the older 3 in approx. 10 days.
No struggle looked apparent. They just died in place like in their sleep.

One gourd that lost 3 was damp ( I think ) but the gourd that lost 2 was very very damp. I was VERY surprised how wet it was. These gourds could have been wet since our first major rain which was 05/12/11. If so, this would mean they were in a wet nest for almost 2 weeks before they died.
It was 101 degrees here yesterday so maybe the heat? and moisture combined?
I figured if it was the heat, the babies would jump which is usually what they do especially those this old. (?) Either this or they got sick from something which I hope is not the case.
Other young around 10 days old or so, appear red on their skin where not covered with feathers yet including thier stomachs. My mom noticed this and commented if that was normal. (?) Im not sure
Anyone has an ideas about how these young birds may have died or whats going on?

[John Miller]

Matt

You may never know the exact cause, but wet nests will kill nestlings, especially younger ones. It may have taken its toll over several days on these older babies. Even older babies tend to have few feathers on their abdomens.

Consider ways to keep future nests more dry, and do frequent nest checks on remaining nests, changing out the nest materal if needed. Maybe there's water getting in, or a drainage problem with water getting out.

A generous bed of white pine needles works well in some gourds -- the needles don't retain moisture. I find the needles stay in place best in gourds with a deep bowl, but may get pushed aside in shallow gourds or house cavities sometimes. But do what you can to keep the nests dry.

John M

[Matt@atx]

John,

Thank you for your reply and ideas for nesting keeping. In 2008 and 2009, we had to modify our nature line gourds with extended tunnel porches with SREH entrances and (get this) port entrances since my step dad is old school and makes the best or upgrades something if it needs it instead of buying again.. You know how this is ... hahahaha
. They had nothing but elongated entrances so we couldn't even look in them.
They were sold to us this way as a Natureline 16 gourd lowering rack system with nylon rope only. (No winches). After I hand lowered them, I couldn't even look in em. I did not know better at the time but soon learned.
I stepped in as complete non bird person who decided to try and help my step dad get Martins which he had been trying to do unsuccessfully for 28 years. All of us together purchased this system for him for a Birthday present we put up in March 2008. That same month, we got 3 pairs

Since then, I have modified (upgraded) this system to include, steel cable, winche, and 8 GOOD gourds that should be used as bought.
Since Natureline gourds have to be snapped together like a kid's toy, they leak. I have sealed, resealed, and resealed, and resealed to stop this.
I thought I got it this year and I should have checked some gourds after that first good rain.
Im not sure this is the reason but if not, it would mean something worse. Im not sure what to do to correct it since Im not sure why they died.
I have ever encountered so many problems as I have this season.
thanks for your input again John

[Scott D.- La]

In 2007, I lost 25 babies to wet nest and aspergillus poisoning. I vowed it would never happen again, and it has not. I am a fanatic about waterproof housing and gourds and will stop at nothing to get them waterproof. Along with waterproofing, venting is the next critical aspect as this allows the moisture to dry up that the parent birds may bring in during rain shower's. Both houses and gourds can be made waterproof so there is no reason to tolerate it. Course, wet nest have become the least of my concern because we cannot seem to get rain in my area anymore.

[Emil Pampell-Tx]

Scott, I agree with you. I might add that I always add extra drain holes to any plastic gourds, ventilate them well, and put drain holes into the tunnels as water can enter them at the entrances. Also, pine needles seem to stay drier than many other nesting materials. I also give the martins an option to use small sticks, which helps them get the nests up higher.

However, when we have excessive rain, the nests will get damp, and I see no way to prevent that. Nest changes may be in order if they get too damp... A taller nest seems to stay much drier.

[e p jones]

We have been very successful adding nest "trays" to the 24 Natureline gourds in our (now) 73-cavity colony.

Over 3 years, we have gone from 79, to 175, to 256 eggs (when 56 cavities) at the Grand Valley Preserve in eastern Cincinnati.

The trays are made of 1/4" galvanized hardware cloth, cut circular--about 9 1/2".

Suggest making a thin cardboard template to try optimizing the size for your gourd--either plastic or natural.

We added either folded electricians or Duct tape to the edges just for ease of handling and to eliminate sharp points.

To install, the "tray" is folded (like a taco) and slipped thru the entrance.

It is secured with a tie wire thru the floor drain holes to make it more concave & to prevent it becoming an entrance blocker with fighting PMs (@ Louise's suggestion).

The initially-installed pine straw is then kept off the floor of the gourd, and drastically improves air circulation results.

Advantages to this approach include: exceptionally light weight, no corrosion, no insect infestation, does not soak up moisture, improves foot traction for all birds, & easy to install & remove each season for nest cleanout.

If interested, I will try to send pix.

[John Miller]

EP

Would love to have the photo. There's a public colony in the Land Between the Lakes in western Kentucky. I've consulted with them a little on their setups -- Natureline gourds -- but I bet their nests get wet. Would like to send them the photo. Maybe they could add these next season. Post here or email me with a PM for my direct email.

John Miller

[Matt@atx]

HI e.p.,

I would like to see the specs and photos on this as well. Please do post.
thanks to all for the reply. I wish I could just replace them with Troyer hangers. I noticed my excluders and Troyer Horizons weren't damp at all.
Scott, John, Emil... does my situation sound like it probably would be wet nest that killed these babies though they were adult sized and feathered?

[Emil Pampell-Tx]

its hard to say whether wet nests killed the adult sized babies. I am thinking that maybe it could be excessive heat (we set another record yesterday at 98deg). How are they vented, and how many drain holes? Or it could be a combination of heat and wet nests which caused an oxygen problem...I really don't know, but high humidity and high temps make me feel much hotter than normal, (and hotter than low humidity & high temps)

[e p jones]

Don't know of any scientific research on the effects of high heat and humidity on Purple Martins.

However, intuitively, take a look at a globe/map.

Almost all of Brazil is between the Equator to maybe 15-degrees South.

Take a look at the degrees North of your individual colony.

I wonder if we are too concerned about heat and humidity; believe drought--creating a food shortage--is probably a much bigger factor in PM mortality?

Wet nest with very young hatchlings is a whole separate issue.

[Scully]

We have looked at heat inside gourds extensively, and IIRC it can be eight degrees warmer inside a gourd than outside, this mostly a function of the intensity of the sunlight.



This is greatest at midday, but fortunately daily highs do not generally hit until around 2 to 4pm on account of heat radiating off of the ground. By this time sunlight intensity is already abating. A good thing too, else we might lose all our nestlings every year.

Needless to say however, six degrees over 98 F at 2pm can still stress nestlings.

The effects of humidity with heat I dunno, but one ameliorating factor (and probably another lifesaver for martins) is that humid air takes longer to warm up, so humid days are often a bit less hot, all else beng equal.

Most years in San Antonio we barely slip by under probable lethal levels (~105 F inside the gourds) for most of the season. A few years back it did hit 104 here in May and we had some jumpers.

I would agree that drought has hammered us here in San Antonio far more often than heat.

Mike Scully

[Scully]

In 2007, I lost 25 babies to wet nest and aspergillus poisoning.

Scott,

Aspergillus (fungus) poisoning is a new one on me, how did you determine that?

In regards to the general issue of wet nests, we have lost nestlings in gourds that faced the direction of violent thunderstorms that had passed through, in those cases I believe the nestlings were directly bombarded through the opening with cold rain, enough to cause them to lose body heat I'd imagine.

Standing water in the bottom of a gourd would of course be lethal even at warm temperatures. Given the high normal temperatures of birds, even "warm" water would give them hypothermia.

Otherwise, while a wet nest is hardly a good thing, I expect that if martins were not somewhat tolerant at least they'd have gone extinct a long time ago Certainly damp nests are frequent in our colony in wet years, but then in those years we generally have excellent nestling survival.

Mike Scully

[Scott D.- La]

Scully,
The babies I lost were all due to fledge very soon as these were all older babies. A black molded substance was in the gourds. I took pictures and posted them here and several folk's believed it was Aspergillus. I researched it and the conditions seemed to fit perfectly. Filthy wet nest combined with fecal matter can produce Aspergillus. I was instructed to send a baby in for testing but did not. The babies were in those conditions for several days before I caught it between nest checks. Once I caught it, I changed nest material and plugged the leaks the best I could. At that time I had lost 7. They continued dying even with the dry nesting material so it was theorized that they continued to die due to the mold that had entered there airways. These gourds were not vented at that time so there was no fresh air entering. I only lost babies in the gourds with the black mold, no other babies were lost in any other gourds. In 2007, we had a period of daily thunderstorms, extreme heat and humidity. It was like a sauna in those gourds. In these conditions it is very important to have a dry vented gourd and why I have went to extremes to stop these problems before they start.

[Scully]

Well that sounds pretty definitive.

On the topic of vents we haven't been able to show that they make much difference temperature-wise (which aint the same thing as circulation I know) in commercial gourd designs.

Except this year we decided to add a little power to our vents.... solar power...



Here's a rear view of our somewhat rough prototype, styrofoam covered with white duct tape. The small top hole front and back is where the hanging rod went through. The larger hole in back contains a 4" dia. 12V fan.



I am amazed at the power output of that modest solar panel, you could practically use that fan setup to dry your hair. Noontime, it evacuated a volume of air equivalent to nearly four times the internal volume of that styrofoam compartment every second.

(Fortunately we never tried it with martins in it, else them little nestlings might have suffered the "woodchipper" effect )

Replacing the air this way, we got as much as a ten degree temperature difference at midday between the one with the fan and the one without.

Mike Scully