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Hypothermia and BluebirdsFrom: "Dottie, Hickory Hollow, Brown County, Indiana"
yumyumkatts"at"voyager.net A friend in my area had four BB babies to die with hypothermia last spring. I was wondering if placing one of those battery operated hunter's socks inside the box under the nest would be a good idea. My husband said they don't get very warm. I thought I would find out what the experts think about doing that. So what do you think? Thanks!! Dottie, Hickory Hollow, Brown County, Indiana (50 miles south of Indianapolis) Date: Sun, 17 Feb 2002 17:23:40 -0800 There haven't been any responses posted to the List regarding Dottie's friend who had chicks die of hypothermia so here are a few comments: You didn't mention if the nest was wet, if so: 2) Try to place the box in a protected area (wind buffers) and turn the holes away from the wind. 3) Try to slant the face of the box slightly downward. I use hanging boxes and bend the wire so the box face tilts slightly downward--similar to the Peterson angle but not as drastic. 4) Front or side opening boxes will sometimes have too much gap at the opening seams. These gaps can be reduced with silicone caulk or trim pieces added to cover the edges. 5) New for my boxes this year: A strip of wood (wider than the thickness of the roof wood) screwed to the front edge of the roof so that an upper ridge forms at the top front roof edge to divert roof water off to the sides and the other side of the strip forms a lower ridge to prevent water from rolling backward under the box. 6) Most monitors recommend drain holes to keep boxes dry during winter and cool during the summer. In fact, some monitors say they can see light coming right up through completed nests from the hole corners and claim those floor holes create an air shaft which brings in cool air from the outside. If their statements are true, your friend doesn't want air shafts in the box during cold spring days . . . but most monitors say holes are necessary to drain away moisture that gets into the box during rainy weather and snowstorms. I, personally, no longer put holes in box floors because my boxes are tight and dry. But if your friend has a leaky box or gets snow blowing in, drains will be needed. Now, if your friend's box was tight and dry but the chicks died of hypothermia, perhaps food was scarce and the female was out hunting instead of sitting in the box keeping the chicks warm. In that instance, offering mealworms would help keep her in the box--a better alternative than sock warmers. As far as adding artificial heat to the box, please error on the side of safety. When I go out on the trail on cold days, I carry "ReHEATER" packs just in case chicks may need transporting. They work similar to ice packs except they get hot and can be reused. I have never used them in a nestbox but have thought of ways it could be done. My boxes are extra deep so I could put the activated heat pack on the box floor, lay a thickly folded cloth on top of the pack and put the nest on top of the cloth. A thickly insulated heat pack would probably provide several hours of low-level warmth. But the first step is to find out the cause of your friend's chicks dying of hypothermia and I wouldn't use anything with batteries under a wet nest or in damp box. Hope this helps. Linda Violett - Yorba Linda, Calif. Date: Sun, 17 Feb 2002 22:43:22 -0600 First of all, do you know they died of hypothermia? There are other causes for death in cold weather, including lack of food, since insects are not active in cold weather. As far as heating a box, this may be a survival of the fittest issue. Sometimes when we interfere, we cause more harm than good. Much as it distresses us, not all birds are meant to survive. That is how nature sorts out the fittest. Birds that are "smart" enough to wait until warmer weather, or who brood their offspring to keep them warm, will produce offspring who may also inherit these survival traits. And as Keith pointed out, these birds are tougher than you think. Kate Oschwald, Paris, TX, 100 mi NE of Dallas, 33.6853N 95.6293W From: "Dottie, Hickory Hollow, Brown County, Indiana"
yumyumkatts"at"voyager.net Thanks, Linda, Keith and Sandy, Kate and Gary, for your responses and suggestions. I took your suggestion last fall, Linda, and used a silicone waterproof spray on my boxes. Sprayed them real good on the outside. Then put duck tape on all the cracks. Holes were left open so the BB's could roost. I don't know if the nest of the BB babies that died was wet or not as my friend already had taken them in her house and put them in a shoe box by the time I got there. I didn't look at the nest. The lady Bluebirder in Maryland (Alice?) told us to blow on the babies as it sounded like they had hypothermia. They weren't moving at all. But when we blew on them, they started to move. We took them straight away to a Rehabber but they died within two days. Maybe they were too far gone. The Rehabber said also they had hypothermia. We had two cold and rainy days at that time. Thanks, Linda, for the tip about the ReHeater packs. I'm going to look for those. I assume a sporting goods store would have them. Thanks again, Keith and Sandy, for your information. I have it now in my file. I looked in my BB box Saturday to see what was happening in there. I was afraid I would see a nest being built but instead I saw that they had taken out all the straw that I had placed on top of the foil for the winter. The foil was still in there but crumpled so I took it out as well. Since I saw pop BB come out with what looked like a poop sack, I assume they are using the box for roosting this winter. I discovered last winter, on one snowy day, that they were using my boxes to roost when I opened one up, just to check, and four of them flew out at me and almost gave me a heart attack. I probably did the same to them also. Thanks again to all of you that replied with suggestions and help. It's much appreciated. Dottie, Hickory Hollow From: "Pat" lphunter"at"skyenet.net Kieth spoke that there is a good chance hypothermia will set in and chicks cannot beg for food when they are so cold as when temperatures are in the low 30's. The following story is testament to that! We had a nest of Bluebirds die of hypothermia in last weeks record low's. We also intervened in a box on 5-17 and I questioned my judgment in doing so at the time. We had a box on a Fish & Wildlife Area, that had 2 - two day old babies. My husband did the check and report they were dead. I decided to check and agreed with him. I couldn't bear to toss they out of the box and instead took them and held them for 10 minutes or so and as I did I began to see signs of life. A leg on a runt started to twitch and then I saw slight movement in the bigger baby. The longer I held them the more they came to life. After a half-hour to 45 minutes they were able to hold their heads up and beg for food. We watch the box in which they were born in for 20 minutes to a half-hour and never saw a parent return. It was then I made a desision to place them in a box with other babies of the same age. A week later we have the following to report. They are healthy and growing rapidly with the 5 others in the box we placed them in. Yes!!! this means that the parents are caring for 7 and not 5... but they are all doing great. I do think the warmth of the additional birds helped to keep the 2 nearly dead babies alive. We questioned our judgement (and still do) and if the parents could take care of 7 in the awful weather. We drove several miles each day for several day's to take mealworms out to the box. The parent's never did accept our help and it sure looks as if all seven will fledge in a week. Yesterday we again sat at the box the babies were born in and never saw a female bluebird... only the male. This box is located on a strip of land in a marsh and we are of the opinion that the female is indeed gone... either to predators or other means. To have left them I feel would have meant certain death. I am glad we saved the babies, but still wonder if what I did was right. Date: Fri, 24 May 2002 10:55:46 -0400 Hi Pat, I had a similar experience last weekend, though in my case I took the four 12-day-old chicks to a rehabber who is watching them grow by leaps and bounds. I was plagued by the same doubts as you have, but now believe my decision was right. Our lone male parent sang for a couple of days, attracting and mating with a female on the fourth day after his first mate disappeared, and female no. 2 is now industriously constructing her nest in the same box. So your male may also find another female and renest. One piece of advice the rehabber gave me when I called her last Sunday was to bring in the chicks (one was not responding, three were still able to open their beaks) and place them on a heating pad over which a towel was laid. After about 10 minutes or so, the nearly lifeless chick regained movement and took some food. The others were still able to eat, more or less. The rehabber says the tiniest nestling is still underweight (18 grams this morning), but gaining weight slowly. The others are doing fine. If I had had a couple of nests with babies of the same age, I would have foster-parented the nestlings as you did. But that was not an option in my case. Diane Seward From: Paula, PaulaZ"at"columbus.rr.com Judy Mellin wrote: "The only nests we have lost have been over Memorial Day weekend as our holidays tend to be quite miserable, weather-wise. However, what I have found when opening the boxes are tiny, partially feathered-out young that seem to be sleeping, with no signs of distress. And the nests they are in are perfectly clean." Judy's statement got me thinking and raised a couple questions regarding monitoring intervention. What she described in her post sounds probably like hypothermia in nestlings due to a wet nest? Here are some questions that I have. During periods of heavy rain, I have observed mother bluebirds sitting on the nest with their head partially out of entrance hole - appearing to be "taking it for the team" to keep the nest dry. Have others observed this? After a night of heavy rain, is it advisable to check boxes and replace wet nests with dry ones if possible? How long after getting wet could a young nestling succumb to hypothermia? How about an older nestling that can regulate their body temperature on their own? What is the temperature danger zone for hypothermia? - possible without wet nest? Finally, if the mother is in the process of laying her clutch (i.e. not setting on eggs yet) and evening temperatures dip below freezing, does the egg(s) become nonviable due to freezing temperature or do they have a chance once incubation begins? Yesterday, it was 68 and sunny here in central Ohio, but today it is 35 and snowing. There are 4 blues in the feeder and we are all feeling the chill... Paula Z Powell (Central) Ohio From: Haleya Priest, mablue"at"gis.net Could have been that the parents abandoned - rather than hypothermia if not enough food was avail. I've had that happen on too many occassions. :-) Haleya Priest Amherst MA From: judymellin"at"netzero.net Paula- Good questions but, as usual, difficult to answer with any certainty because of all the uncertainties! I have never found a wet nest so I can discount that as the cause of these losses on our trail in cold weather. And, in many years with the same temp and weather conditions, we have not lost any nests. Trying to put any range on temps would be hard because I would think it would depend on how much food is available, what the outside- and inside box- temps are, how far along in development the young are, how many young there are, how experienced the parents are, etc. I do know that the adults will abandon the young if they are unable to keep up with the demands of the young while keeping themselves alive. As far as eggs, I do believe they will stay viable to quite low temps (someone may know the range but I don't) as long as they have not been incubated. Our frost-free date here is mid-May so we would not have too much opportunity to have a combination of newly-laid eggs and temps below freezing for more that a night. I have had eggs sit as long as four or five weeks, seemingly abandoned, only to have the whole bunch hatch when the adults begin to tend the nest. Ah, the miracle of birth! Judy Mellin NE IL. From: Keith & Sandy Kridler, txbluebirder"at"sbcglobal.net Paula brought up the subject of wet nests and hypothermia. Paula: During periods of heavy rain, I have observed mother bluebirds sitting on the nest with their head partially out of entrance hole - appearing to be "taking it for the team" to keep the nest dry. Have others observed this? KK:Yes the females often sit in the entrance hole half in or half out on good days and bad. This way they watch what is going on around their nestbox. I doubt if this bird even thought about blocking the wind and rain entering the nestbox. If the rain is blowing into the nestbox through any ventilation slot or entrance hole then you could add a second roof over the first one and give the nestbox roof more overhang to prevent water entering your boxes. If she really wanted to help her young or eggs she would have been keeping them warmed to 99.6*F with her bare breast and keep the rain off of them with her water proofed feathers by sitting tight on the nest. Paula: After a night of heavy rain, is it advisable to check boxes and replace wet nests with dry ones if possible? KK:It is far easier to retrofit all of your boxes with larger, rain proof double roofs on a nice sunny day than to be out slopping in the mud after every storm trying to check on these birds. These cold rainy mornings are the time when it is critical for the adults to either be hunting for food or have the female brooding her young. Depending on the adults it can take up to an hour or more for some of them to settle down and go back to normal hunting and brooding after a simple nestbox visit by humans. IF you go and change the nest, at best you create confusion in a simple bird brain at worst you can crack fragile eggs or break bones or dislocate joints in these young birds you are trying to help. There are hundreds of open nesting species of birds that get cold and wet with every shower and bluebirds using a wet nest are just as capable of succeeding at raising their young as other birds. If the cold spell is prolonged and food supplies disappear then yes the young will perish even if you have heated their nestbox. Remember the House Sparrow young can have soft insect food go in their mouth and through their system in under 15 minutes! Paula:How long after getting wet could a young nestling succumb to hypothermia? How about an older nestling that can regulate their body temperature on their own? KK:1 day old to about 6 days old the young are cold blooded. The female should be able to brood and keep 5 or 6 young warm even in freezing temperatures. At about 6-8 days the young begin to produce heat on their own. With no real insulating feathers till about day 13 and needing maximum amounts of food now these babies are too large for the female to brood and keep all of them warm and hunt for food. When they get cold enough to stop gapping for food they will die in either a dry nest or a wet one. Paula:What is the temperature danger zone for hypothermia? - possible without wet nest? KK:Flying insects quit being active at about 45*F and this can be up to about 40% of the bluebirds food in spring. At near freezing, insects on the ground quit moving and bluebirds hunt by movement. On really cold days during heavy rain earthworms and other under the surface grubs and insects will move to the surface and are often found swimming or crawling along the bottoms of puddles that haven't frozen over yet. I have watched bluebirds and robin's wading in puddles up to their bellies and spearing food just like miniature heron's below the surface of the water when the temperatures were in the teens. Think about earthworms caught by bluebirds in puddles of water as the very last meals young bluebirds are going to be receiving. In 10 minutes the earthworm had been digested and the soil in the worm passes through the young bluebird. Every trip into the nestbox the adults are shaking off cold water onto their young. Survival of the young in any weather depends on the ability of their parents to provide them with the correct type and adequate amounts of food. Paula:Finally, if the mother is in the process of laying her clutch (i.e. not setting on eggs yet) and evening temperatures dip below freezing, does the egg(s) become nonviable due to freezing temperature or do they have a chance once incubation begins? KK: Eggs can take temperatures dipping down into the teens and still hatch. It depends on how many hours of actual freeze time. Even eggs that have been incubated often drop in temperature very quickly after the female leaves the nest on cold mornings to hunt or find water. Take five marbles and heat them to 99*F, now place them on a dry dish cloth in the refrigerator and see how long it takes them to reach the ambient temperature of the refrigerator. Repeat this experiment by sitting them on a wet dish cloth....You now can see just how quickly eggs will drop in temperature while a female is off the nest. There are over 5 million fifth graders in science classes across the country. How hard would it be for NABS or your state bluebird group or even each of us to contact one elementary school in our area and have them do some of these experiments along with their normal studies? Over 4.2 million people turned 18 in the US this year. Over 1.9 million new single family homes were started this last fiscal quarter. How many of these new home owners know what it takes for birds to hatch an egg and bring it safely to adulthood? Keith Kridler Mt. Pleasant, Texas From: charlene anchor [mailto:charleneanchor "at"msn.com] Sent: Monday, December 20, 2004 10:19 AM Subject: Hypothermia Before I officially started monitoring bluebirds, I saw a nestbox being used by a bluebird pair that wasn't being checked. I started looking at it occasionally. I unfortunately wasn't keeping any kind of exact records. But the time was in April and there were 5 small nestlings. We had a spell of very cold, rainy and windy weather. After about 2-3 days of this I checked the box only to find all five were dead. The inside of this old flimsy box was wet and so was the nest. I assumed the parents were unable to find enough food for themselves and the young, and couldn't keep the wet young either warm or fed. It was then that I decided to learn about monitoring and rehabbing boxes. Even if some young can survive a wet nest as a result of brooding by the female, I would think that a warmer dry box would make the job easier. In order for the female to stay warm enough to transfer heat to her young she needs to find enough food to keep her body temp up in the bad weather. It would seem that if the box were warmer and dryer that the young would require just a little less food and that that may make a difference in their survival. But I have no scientific proof of this. If a box is in a back yard where the adults have a food supply nearby (mealworms, etc.) they would have a better chance of surviving. On a trail where the adults would have to travel further for food and the young would be exposed longer, it seems their chances of survival would quickly diminish. As a result of that line of thought, I prefer to keep my boxes caulked and as tight as possible. I bought regular corks which fit the holes of my Peterson boxes. In the Spring I keep all holes corked and as the weather warms up I remove them slowly until the Summer time when they are all out. So far my boxes have stayed dry and as warm as I can provide for them. Charlene Anchor, Illinois From: Haleya Priest [mailto:mablue "at"gis.net] Haleya Priest Amherst MA From: Evelyn Cooper [mailto:emcooper "at"bayou.com] Sent: Monday, December 20, 2004 11:34 AMu Subject: RE: Hypothermia Haleya, this is why I think we need to supplement feed and encourage all Listers to do all they can to feed in WINTER. If birds know where a source of food is, they will come if they need it! If they can get the food, they can survive the cold if they are healthy. Abandonment of a nestbox because of food is quite a different story that one that is not dry and warm and they die because of damp, cold conditions. Evelyn Cooper From: jwick "at"tds.net [mailto:jwick "at"tds.net] Sent: Monday, December 20, 2004 7:29 PM Subject: Re: Hypothermia solutions REGARDING: (note from webmaster: post on Nestboxes (Insulation /Ventilation- Heat/Cold) "I bought regular corks which fit the holes of my Peterson boxes. In the Spring I keep all holes corked and as the weather warms up I remove them slowly until the Summer time when they are all out. Here's another possibility to consider: Foam weatherstripping (normally used to block cold air during the cold months on our window seams) works great as well. It's sticky on one side (sticks to itself/foam side out), can be cut into 2-3" Just letting everyone know what has worked for me.............. Ann Wick From: Dottie, Hickory Hollow, Brown County, Indiana [mailto:yumyumkatts "at"voyager.net] From: Dottie, Hickory Hollow, Brown County, Indiana [mailto:yumyumkatts"at"voyager.net] A few years ago, I had a friend who had five BB babies lying really still and not moving in her box on a cold and rainy day. She called me and I asked the List for help. From: mfpino"at"comcast.net [mailto:mfpino"at"comcast.net] This morning I found 5 dead nestlings in my bluebird box. They were approximately 6 days old. I live in southeastern Mazzzchusetts. We have been experiencing cool, rainy weather. Last night it poured. Does anyone have any idea why the female did not continue brooding the babies? She is still around. I saw her and the male starting to build a new nest in another box this morning. There were several pine needles at the bottom of the box. I supply mealworms and dehydrated caterpillars 365 days a year. I am at a loss as to why this has happened. Has anyone else experienced the same problem? Thoughts are welcome. Please ease my pain. From: JOHN & BARBARA SIBIO [mailto:jsibio"at"comcast.net] Sent: Sunday, May 01, 2005 7:03 PM Subject: Re: Fellow bluebirders I've had the same sad experience, and I'd be willing to wager most people on this list have also. I had a nest of five die after a cold rainy night the spring before last. Now I try to keep the nestbox water tight and warm I tape over the outside joints of the nestbox, with duct tape, and stuff the air vents near the top. I would imagine even that wouldn't help if it were bitter cold, but I live in California and we have mild weather compared to other parts of the country. It is very sad, no matter how often it happens, but the adult birds move on and start another nest. We can only do so much for them , and it sounds as though you are doing as much as possible. So sorry, Barbara in Cloverdale, CA From: mfpino"at"comcast.net [mailto:mfpino"at"comcast.net] Thanks for your kind thoughts and suggestions. I really have a terrible time dealing with my animal tragedies. I have had nest abandonments but never dead nestlings. From: Keith & Sandy Kridler [mailto:txbluebirder"at"sbcglobal.net] Sent: Monday, May 02, 2005 8:21 AM Subject: Why baby birds die in the nests & re: Dirty Food Keith Kridler Mt. Pleasant, Texas When young birds get cold the female "broods" or simply puts her small bare breast against the small bare bodies of the birds and these naked young absorb heat from their mother. This works fine the first two days because five young all fit under her feathers and they weigh about half as much as the female. They do not require as much food and male bluebirds are the most attentive up to about three days old with feeding their young or passing food to the female while she broods. (This varies tremendously with individual males.) Around day three they weigh as much as the female. By day five they weigh about 2>3 times as much as the female and only one at a time will actually fit under her brood patch. Picture a human mother wearing a short length jacket stranded overnight with one naked child in a blizzard or even a cold rainy night, with only one small jacket. She will open the jacket and place the child inside the jacket against her body and both will or should survive. Now picture the same situation and she is stranded with the entire Brownie Troop and she can only warm one naked child at a time during a long cold night. When you find a dead female bird at this time of year inspect her to see the size of a brood patch to realize how difficult it is for these birds to survive abnormally cold temperatures. As hypothermia set in with small birds they are not able to raise their heads for food. The food inside their stomach will not digest so they are not hungry anyway and adult birds have no way to force feed unresponsive young so the young birds die one by one, the adults begin a new nest and should raise the new young as the temperature should be warmer by the time the second nesting gets under way. Cold temperatures affect insects too so fewer insects are available and the female needs to be off the nest for longer periods thus the young get colder between trips. With temperature data loggers and a nestbox cam we could actually observe the critical low body temperature that these birds become unresponsive to the adults. Body warmth is probably more important than food on a cold day. IF you were to use a gunpowder scale to weigh the dead baby birds you probably would find that they weigh far more than the adult female making it impossible to transfer enough heat from her body to theirs without killing the female. In the past some people have run electricity to their back yard nestboxes rigged up a light bulb to heat the box and then proceeded to cook the baby birds or eggs with too much heat. Losing this early nesting will not prevent this pair from raising the normal two or three broods later this summer. From: Bet Zimmerman [mailto:ezdz"at"charter.net] Sent: Sunday, May 14, 2006 2:19 PM Subject: preventing fatal hypothermia in bluebird nestlings Some of us are having extended periods of cold wet weather. This is a huge problem for older There are a few things you can TRY to help out bluebirds in this situation. 1. Make sure the box is facing away from prevailing winds so water isn't blown in. (Best boxes have 2. If nest is soaked,do a nest change http://www.sialis.org/nestchange.htm 3. Monitor quickly (don't let babies get chilled or wet. Avoid monitoring during this weather, but 4. Offer mealworms. I think this can make the difference between life and death. I have not lost If babies are lost, don't beat yourself up. It's part of the harsh reality of nature. Many pairs Any other suggestions? Thanks! Bet from CT From: Keith & Sandy Kridler [mailto:txbluebirder"at"sbcglobal.net] Keith Kridler Mt. Pleasant, Texas OK are there not 600 or so other species of open nesting birds right now incubating eggs and feeding their young in the rain and cold in the New England states? Survival of the fittest ensures that the next generation of birds will inherit the skills of an attentive, brooding parent in cold weather. It will ensure that they choose a location where there is an abundance of food in all types of weather. Or that they are exceptional at finding enough food to survive when other parents are starving in the same location. We had a post about adult Purple Martin's starving a couple of days ago. One thing we have to remember that with bluebirds the MOST important thing for the adult pair with young is for them to eat enough food to maintain their health and vigor FIRST so that they can continue to out fly predators and have the strength to continue searching for food EVEN if this means that they will allow their young to starve to death or that they abandon a clutch of eggs. If they remain healthy they can simply re-nest later this summer when the cold front passes and food is more available again. Years ago I read that in cold rainy weather that bluebirds sometimes resorted to eating "pill bugs or rolly polly bugs" and feeding these to their young. When the young died they discovered that these young died due to intestinal parasites and not to hypothermia. It seems that pill bugs can be a carrier of certain forms of parasites. Same goes for some species of snails. Both of these are fed as desperation foods occasionally. During floods earth worms leave the ground in search of air and are often fed to baby bluebirds. At 90% water & dirt or so the baby bluebirds cannot form fecal sacks, the parents cannot clean the nests and you end up with a layer of undigested mud in the bluebird nests from the intestines of the earth worms. Bluebirds and Robins are closely related and baby robins can eat 45 feet of earthworms a day (as I recall). Baby robins back up to the nest edge and squirt their feces over the side of the nest as do Osprey and many other birds like Phoebes. Why would bluebirds die from eating earthworms when their first cousins rely on these for most of their food? If you look at a lot of bluebird nestboxes you will see that some bluebirds still retain the memory of open nesting birds as you will see that some young in some boxes still back up to the edge of the nest and they smear ALL of the inside walls of the nestboxes with feces. This will appear in some of the boxes after they fledged that they "white washed" the inside walls of their box. OK those who end up with a mass of feces in the nestbox and wet soggy nests how large is the floor area to number of baby bluebirds? IF you used a larger floor area would the boxes be filled with feces or would the young deposit this against the walls of larger nestboxes. Some bluebirds build nests out of pine needles that do not absorb moisture (very little) and allow any water in the nests to drain quickly to the bottom of the box. Others build nests out of freshly mowed grasses that when wet turn into rotten, moldy compost quickly! I wonder if bluebird banders check to see if the same banded birds build their nests out of the same material each time! The really neat thing about bluebirding for 40 years now is that I think up more questions and see and hear more strange stuff now than I ever did in the early years! The more you learn the more you question what you are actually seeing! KK From: Snoopy [mailto:snoopy"at"wmis.net] they are all ice cold....all 5 baby bluebirds. From: Mary Roen Joy and all, I too, had a nest of 5 5-6 day old nestlings that died. They were well nourished, so I don't know why. The parents were not around when I was there. There was no signs of trauma, maybe hypothermia, but I don't know why they weren't brooded. Maybe the parents were killed. Mary Roen, River Falls, WI From: Ruth Brinckman [mailto:r.r.brinc"at"comcast.net] I have an EABL nest. The first egg has hatched and it appears that the baby is dead. It has been cold and rainy here all week. Do the parents remove the dead nestling or do you suggest I do? From: lviolett [mailto:lviolett"at"earthlink.net] Parents are capable of removing small dead nestlings but not all will do that. If I see dead nestlings, I promptly remove them so that decaying flesh does not attract predators. Very cold babies sometimes appear to be dead. I place what appear to be newly-dead against my stomach for several minutes before declaring them dead with finality. From: Cher [mailto:bluelist"at"localnet.com] Sent: Saturday, May 20, 2006 8:05 PM Subject: Re: dead baby Ohh, that's so sad. Linda, have you ever had one revive that you thought Cher From: Max GITTER [mailto:mgitter"at"cgsh.com] I just lost 5 nestlings (about 12-15 days old) to unusually cold and wet weather in the spring of Columbia county NY. Isn't it possible to construct a box that has more insulation than the ordinary box to deal with cold weather-- or some kind of automatic heater that will kick in when such weather surfaces? Has anyone found a solution to this problem--particularly for someone like me who can only monitor boxes once a week at most (and sometimes only once every other week--and not necessarily during a short cold snap? (This loss was especially disconcerting because I have tried to get bluebirds for about twenty years, and this was the first year I found the right formula for attracting them in an environment where tree swallows compete for the boxes.) Thanks for your help. Max Gitter From: Robert Barron [mailto:rebarron"at"gmail.com] Hi Max, From: Bet Zimmerman [mailto:ezdz"at"charter.net] Sent: Thursday, May 25, 2006 7:37 PM Subject: RE: fecal glue photo and preventing fatal hypothermia I’m so sorry to hear that Max. It’s a huge disappointment, especially when they are so close to fledging. As Keith noted, even though they can thermo-regulate at that age, they may actually be more vulnerable because the mother can not cover them completely while brooding to keep them warm. I know some people see it as nature's way and survival of the fittest, and I respect that. But when there are as few bluebirds as we have here, I personally want to do as much as I can to increase the odds that they can survive. The only solutions I came up with were waterproofing the box as much as possible (large roof overhang with drip edge, caulking cracks, and facing it away from prevailing winds), doing a nest change if it gets wet, monitoring quickly to avoid drafts and water entry, and offering mealworms. David Shiels has been working on heat shields, but I don't know much about cold shields. I think some folks have experimented with double walls with Styrofoam for insulation. I have put Mortite (removable rope) caulk in ventilation holes also. I have one box that has wooden covers for the slots that Velcro on, and another clever box designed by Bill Freely that has a removable Plexiglass covers for the slots and a double roof, with the top made out of bowed fiberglass. I read of some desperate folks talking about using handwarmers (temporary solution and not recommended by Cornell), light bulbs, and heating pads set on low (which are also used by rehabbers). I'm guessing most people would be uncomfortable with those approaches. The only consolation is that once the box is cleaned out, the parents usually go on to have a successful brood when the weather is more favorable. Any other ideas from other folks? Bet From: KCBSP"at"aol.com [mailto:KCBSP"at"aol.com] Sent: Thursday, May 25, 2006 8:07 PM Subject: Re: fecal glue photo and preventing fatal hypothermia Bet and all, From: Kathleen Arnold [mailto:koscharn"at"cox.net] Sent: Thursday, May 25, 2006 7:18 PM Subject: RE: Cold snap in NY I’m sorry your first nesting ended this way. Nature is harsh sometimes. I hope the parents were able to feed themselves and will be ready to try nesting again, now that they have found your nestboxes. At that age, it is more likely that the birds starved due to lack of insects, which aren’t as active in cold weather. If young birds are well fed, they can handle cold snaps better than you think, especially after they develop feathers. Animals are capable of adapting to an amazing temperature range, and artificially heating a nestbox might actually interfere with their ability to do this, even if a practical and safe way could be found to heat it. I always marveled at my horses and the wild animals in northern Minnesota where there might be weeks of bitter cold (I experienced one day where the HIGH was -28 deg F) and at least one week of 90 deg days. When I moved a horse to Texas in May of 1985, his winter coat was half shed out, but looked like a full winter coat to the Texas horse people. He never had to grow a coat like that again. Kate Arnold From: Max GITTER [mailto:mgitter"at"cgsh.com] Sent: Thursday, May 25, 2006 7:30 PM Subject: RE: Cold snap in NY Thank you for your insight. I may try mealworms as a backup. But it looked to me in the days before the nestlings died that the parents were feeding them every five to ten minutes (even in the cold weather) so that insufficient food didn't seem the problem , and a neighbor who has several boxes told me he lost 10 nestlings and 5 eggs to the cold and wet. You are probably right that artificial heat is not the answer, but better insulation--which the natural habitat of tree cavities would seem to have--may be the better route for those maintaining bluebird boxes. I would like to hear from anyone who has devised a box with a bit more insulation than the basic box (which I bought from Audubon). Had the nestlings survived only two more days they would have found 75-80 degree temperatures in Columbia County, NY! Max Gitter From: lviolett [mailto:lviolett"at"earthlink.net] Sent: Friday, May 26, 2006 2:24 AM Subject: Re: Cold snap in NY Can you give us some more details? From: Keith & Sandy Kridler [mailto:txbluebirder"at"sbcglobal.net] Sent: Friday, May 26, 2006 9:07 AM Subject: Building insulated nestboxes Keith Kridler Mt. Pleasant, Texas For metal buildings there is a great insulation sheet that most builders are using instead of the 2" thick vinyl coated fiberglass normally used under the roof and wall sheets. It is a foil backed bubble wrap type insulation that has great R-value compared to old fiberglass. It comes in what they call a single bubble or a double bubble sheet. It can come double foil faced or foil one side and white on the other. One of the problems with fiberglass on steel buildings is that House Sparrow enter under a rib and pull out the glass in an area to build their nests. The new bubble wrap is more resistant to birds pecking through this but not completely and it is NOT rodent resistant. This could be used in new nestbox construction and you could wrap each piece with this insulation and if you use screws you would pull them down tight at the seams and pop the bubbles under the joints but leave the slick tough walls of plastic inside the nestbox. You can trim off the excess insulation outside the nestbox and build a little refrigerator box. The BIG problem with all of these insulated nestboxes is that there is NO outside heating or air-conditioning unit. With nestboxes you have to leave the door open for the birds to enter. You still end up with a nestbox inside that is only a degree or two off of the ambient air temperature. If you unplug your refrigerator and crack the doors on it in just a few hours, it is the same temperature inside as the room it is sitting in. There is very little thermal mass inside a nestbox. David Shiels thought that five large baby bluebirds only showed a 1*F temperature gain in a heat shielded nestbox. If the air temperature outside the nestbox is 29*F and inside the nestbox is 30*F then the baby birds are still going to have problems. IF sunlight can shine in the entrance hole of a nestbox with this foil interior it could actually heat the nestbox up and create a reflector oven so you would not want to face the nestbox to the western setting sun! I don't know how much reflected heat from baby birds this foil would save but they use foil space blankets for campers but I never used one in Texas. If the foil would make a difference in a cold nestbox on cold days then it makes sense that on really hot days it would make it hotter. Call around to metal building installation crews and ask them to save you this scrap insulation. Experiment with a few nestboxes and see if it makes a difference. It might be slick enough when new to limit wasps nests but I doubt it. KK |
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