Archive for the ‘Fledgelings’ Category

Purple Martin Season Is Over for 2010

Thursday, June 17th, 2010

SY maleIt’s official, the last of the nests have fledged and all the babies have taken to the air. A hawk was making daily visits and though I am sure (s)he got at least 2 fledglings, I am sure more fell victim. I was unable to get a good look so I am hoping it was the resident Red Shouldered Hawk, a slower and larger hawk that poses a formidable threat but less so than the smaller faster Coopers Hawk that are common in South Florida also.

The Red Shouldered hawks nest close by and protect this as their territory from other hawks. If that can be counted as protection…I am not too sure.

Night time is quiet and I am not sure if many martins are returning to the nests to roost at night. They may have moved on to a local assembly area or pre-migratory roost. The fact that I am talking about the roosts already almost sounds crazy! Can time have flown by so fast? I guess I will start planning another trip to the roost in Davie this year.  It has almost been exactly a year since I went to see it and video taped it. You can see it at my blog post titled Purple Martin Pre-Migratory Roost Spectacular. It is a great YouTube clip taken at the roost with swarms of purple martins.

The webcam will not be up again for the remainder of this year as the computer I had it running on is dead. I plan on replacing it as soon as I can and it will be up again next January. I promise.

©2010 PurpleMartinArt.com / S.Halpin

Fledglings Take To The Air

Wednesday, May 19th, 2010

Over the last 3 days purple martins have been fledging left and right, taking to the air robustly without a hitch. I have witnessed several nests from both racks fledge and all the parents seemed to be ecstatic. The energy level of the colony is through the roof as the morning social doesn’t let up until well after noon. Birds are flying about in large swooping circles about the colony site. In groups of one youngster to several adults who seem to be guiding the birds into the sky. Several spots on the electrical wires seem to be gathering spots for the youngsters and the rainy afternoons are enjoyed by all. Just enough rain to cool things off but not enough to drive food out of the skies for long.

Sub-Adult Purple Martin Mayhem

Thursday, May 6th, 2010

Last year I wrote a blog post called SY Males-The Enemy Within. It dealt with some of the facts and dangers that Purple Martins face from their own kind. SY or subadult male purple martins, arrive later than the ASY martins. They return home having survived the migration only to find all nest compartments full or guarded by protective ASY males. Eggs and nestlings run the risk of being destroyed or killed by the younger SY males. These males are so eager to breed that they will kill their own kind to force the females to start a new family.

Today I found the first casualty and my nest check results show that several nests have been affected by these SY males. The first tip off is a compartment previously claimed by a ASY pair is now protected by a SY male. Eggs or nestlings on the ground are dead give aways of course and the bickering and fighting can get intense. Though unless witnessed, you may never really know what was the cause of eggs or nestlings that mysteriously disappear, in the absence of sparrows and starlings, one can assume that SY’s play a part.

Can something be done about this? Well, many people wait until the SY males arrival to open up some of their housing. Others put up temporary type housing to alleviate some of the nest site competition like the Trendsetter Create-A-Rack Arms that  can be added on to your telescopic pole to make an affordable and easy spot to hang a few extra gourds in a pinch. Still others may yell and shoo those pesky SY males away.

In the grand scheme I suppose I tolerate this behavior in my colony as the ugly harsh reality of survival. If a ASY male is off guard and not protecting his mate and nest, his gene pool suffers. Those males that are dutiful in their jobs as protectors can drive away would be dangers and their off spring survives. It is a hard thing to witness and if I witness the tossing of a nestling I will intervene and return it to its nest. Is that what National Geographic would do if they were filming a documentary? No, they would probably film it happening and talk about the harsh reality of nature and watch death come slowly. Is that interfering with nature? Or is it our nature to interfere?

Nest Check Results:

Total Eggs: 34

Total Young: 124

Found Dead: 1

Pairs: 36

©S.Halpin/PurpleMartinArt.com 2010

Purple Martin Released

Wednesday, September 2nd, 2009

I was torn between relief and despair when I found out on Aug 26 that the last remaining purple martin at the Busch Wildlife Center was released at some point.

I had forwarded some information to the folks at Busch Wildlife Center regarding some of the latest, cutting edge information on the releasing of rehabilitated fledgelings. It was on the post Update On Late Nest Martins at Rehabber. In short, the preliminary data highlighted the dismal survival rate of purple martins released without benefit of the post fledging instruction period given by the parent purple martins. The same info also pointed out a potential revolutionary approach to their release. Last year 3 martins were released AFTER being taught (in a flight cage) how to catch flying insects and 1 of the 3 returned to the natal colony this year. This information is groundbreaking and could give new hope to fledgling purple martins released after rehabilitation.
I am unsure if this martin that was released had the benefit of being “taught” the basic survival skill of feeding or even if it was released with other martins which is what is recommended by the PMCA.

I do know that if the bird was released without any other purple martins around that it is dead. Purple Martins, unlike some birds, seem to require a period of post fledgeing instruction

As of this time, I have not received any reply to my email to Busch Wildlife .

On another birding note, a large group of about 15+ nighthawks was moving south bound through the area. Tons of barn swallows feeding in the orange groves nearby also. Fall migration is in full swing.

Blow Fly Infestations- What a BOT it?

Tuesday, August 11th, 2009

I thought being in the South that I was safe from Blow Flies (Protocalliphora sialia) but alas after talking to a few folks and doing some research I am sure I have experienced a more sinister type of Blow Fly here at my colony.

A few weeks ago I posted about a nestling that had some sort of “lump” or cyst on its abdomen. The nestling died soon thereafter. Since then I have been doing a little digging into what it actually was. When I found the dead nestling it was quite apparent that the mass had opened and since I saw no other injuries or obvious issues with the nestling, that very well may be what killed the bird.

This led me on a quest to find out what may have been the cause.  At first I thought they were Bot Flies. What is a Bot fly? Well, in short it is an insect that’s larvae lives as a parasite within the tissues of a living organism. Horses commonly get them as do other mammals. I have since come to learn that there is a type of subcutaneous BlowFly (Trypocalliphora braueri) or a type of Housefly (Philornis sp) that may be to blame.

I realized it wasn’t just me when I was reading my latest issue of “Feathers and Friends” (a magazine published by “The American Bird Conservation Association”) I read about several landlords reporting birds with “bubbles” that are “caused by an insect that laid eggs there and the eggs hatch into little worms” When I read this, It sure sounded like a BotFly.

I spoke with Mr.Terry Whitworth, PhD, who is the Adjunct Professor of Entomology for Washington State University. A portion of his email to me was as follows, ” There are two possible culprits in Florida, one is Trypocalliphora braueri, a subcutaneous blow fly. The other is Philornis, a Muscidae (a type of house fly) that occurs in Florida. By the time the larva comes to the surface where the bump can be seen the damage is done. Removing it or killing it at that point will not change things much for the nestlings. Neither pest is always lethal, it depends on the number of larvae that develop and where they burrow. I once took 25 mature Trypocalliphora larvae off a nestling junco and it survived long enough to fledge.”

Whether they be Blowflies, Houseflies or Botflies, whatever you call them, these nasty bugs can kill! Though not the same bug they are somewhat related. Some infest by way of laying their eggs or larvae into living tissue. Others crawl up through the nests and suck blood only to drop into the nest to grow then repeat the process. Getting larger and needing more blood each time. Usually a “Northern” plight, Blow flies can be controlled via nest changes as Sevin has NO affect on the larvae. A pair of forceps or tweezers can be used to pull these nasty things off of the nestlings. Once the Blowfly larvae are done feeding and growing in larval stages they form a pupal case in which they remain, dormant, until they are ready to emerge as an adult. Something like a caterpillar forming a cocoon before it emerges as a butterfly.

The typical BlowFly, can exsanguinate a nestling when present in large enough numbers but if caught early are controllable. These other guys (Philornis, Trypocalliphora and Botflies) however spell bigger trouble.

You think I am dreaming this all up? Read this article by The University of Northern British Columbia. (Be warned, if you don’t like bug pictures…don’t click) Basically it explains how death can result several ways. The Bot larvae move around and migrate in the soft tissue and can kill the bird, the wound itself can become infected and kill the bird, the Bot larvae will feed on the tissue and weaken the bird to the point of death, the Bot can damage the wings and thus, “produce an obvious awkwardness in locomotion, which may render them more susceptible to predation.” (that is a direct quote) In short the damage is severe and serious.

And talk about BiZzArRe? There is even a species of Bot Fly that lays its eggs on mosquitoes.When the mosquito bites the eggs are transferred. What does that mean? That means look out! Humans can get it too! Still don’t believe me? Just Google it. But that is another story.

What can be done about these subcutaneous (under the skin) Flies? Unfortunately, nest changes may not be helpful as once the adult Fly lays the eggs/larvae they crawl onto the bird and burrow into the skin. Another options is pretty gruesome and may not be legal. Also, it may cause more problems than it solves. Now, I could explain how the skin is cleaned with an antiseptic such as betadine prior to making a small incision from which the Bot Larvae is removed with a pair of forceps or tweezers but I wouldn’t want anyone with paranoia cutting holes in a purple martin with a wart. And legally, I think I could get in trouble for telling people to perform surgery on a federally protected bird without some sort of Veterinary license. All of this may be a mute point as once the larvae are large enough to cause the visible lump, the damage to the birds soft tissue is done. As www.kingsnake.com puts it, “They develop under the skin of some birds.The bird has died after…maggots have consumed much of its muscle tissues. Once their host is dead, the larvae leave it to pupate…”

In humans, the true Bot Fly wound (which is open so the larvae can breathe) could be covered with petroleum jelly or some other occlusive salve so that the larvae will emerge on its own, seeking air to breathe, after a day or so. I think that on a bird this course of treatment would not be successful. How could you place a dressing on a bird? We have the issue of a pretty dirty living environment (a nest) talk about infection!  So, basically the wisest course of action would be to take the bird to a wildlife rehabber.

Of course we also have the problem of not really being sure which one of these 3 flies is the true culprit. Perhaps it is a combination of the 3, maybe some other. In order to find the true source of this problem I urge all that may witness this to photograph any lumps you may see on your nestlings and monitor them. Of course you can email them to me at the “Contact Us” section.

It is important to stress that with the classic and somewhat common Blow Fly infestations, that nest changes are by far the easiest and best treatment. Elevated subfloors help and nest trays make cleaning your purple martin bird houses super easy. Pulling off any Blow Fly larvae that are latched on to the nestlings with tweezers. For those of you that have questions regarding nest changes, this short video may help you overcome any trepidations that you may have.

Sources:

If you want to learn more about Blow Flies or help with blowfly research go to www.birdblowfly.com for some interesting facts.

The American Bird Conservation Association / Feathers and Friends can be contacted via phone at (260) 768-8095 x:5 Subscription rates are  $18 for 1 year. Tell them Susan from PurpleMartins-R-Us sent you!

http://www.kingsnake.com/westindian/metazoa7.html

©2009 S.Halpin / PurpleMartinArt.com

One Martin at Rehab Passes On

Thursday, July 30th, 2009

Sad news to report as one of the two purple martins from the late nest that was abandoned has died. For those of you that did not read in past posts, there was a very late nest of 5 nestlings were pretty malnourished having become victims of  Diminished Parental Care.  You can read the blog entry HERE.

But in short, 3 of the 5 were taken to the rehabbers for emergency hydration. I left the two stronger, larger nestlings in the nest so that the parents would stay bonded to the site. I would lower the housing and offer food and fluids to the weaker and thinner of the 5 at several points during the days. When the first 4 fledged and only the smallest runt remained, still not being fed by the parents, I made the decision to take him to the rehabber. That same morning I was packing up to drive to Busch Wildlife Sanctuary, I found another of the smaller and weaker which had technically fledged, on the ground next to my pool, too weak to fly.

As of today, from what I am told, the stronger of the two which survived is in an outdoor songbird flight enclosure. This fledgling was eager to eat in the time that I cared for them, unlike the nestling that ultimately died. I am not sure yet, if this purple martin is feeding off a platform or still needs to be fed. I hope to visit Busch Wildlife Sanctuary this weekend to see how he (she?) is doing.

Update On Late Nest Martins at Rehabber

Wednesday, July 22nd, 2009

I believe the critical period is over and the 2 purple martins from the last late nest will survive. As of yesterday, Busch Wildlife Sanctuary reports that they are eating and gaining weight. It appears as though my efforts to keep them hydrated has paid off. My hopes that they get released back with the colony are dashed however as the day that I removed the most critically thin and dehydrated nestling was the last day that the martins were here in any significant numbers.

It is quite apparent that they were all returning because of the nestlings in the one nest, almost as if to keep them company. Though the parents of the other successful nests did not contribute with feeding the nestlings, they did return as if tied to the colony site while it was still active. Once the nests were empty, they were obviously released from whatever ties they had to the location and have most definitely moved on. Yesterday I counted 6 martins on the wires for less than 5 minutes. They did not land on the housing at all which leads me to believe that they were not my birds, only passers-by. Today there were none. And so the days have passed since the nestlings were taken to the rehabilitation facility.

Unfortunately this does not bode well for the nestlings/fledglings, as far as their survivability post rehabilitation. Without parents to instruct them on feeding, their chances are poor. But there may be a new hope for some rehabbed nestling martins that miss the opportunity for the post fledging instruction period that they usually receive from their parents. In a post on the PMCA forum, a purple martin conservationist in California has had positive, albeit early results from a radically new and controversial theory in the rehabilitation of nestling purple martins. Check out the thread HERE.

In short, it describes how in past years in banding and releasing into colonies, nestlings that required rehabilitation, that none had been recovered. But last year, 3 nestlings that were rehabbed were “taught” to catch flying insects in a large flight cage. These 3 purple martins were them banded and released. This year one of the 3 birds was sighted in the area having obviously survived and returned from migration. This just may be a huge turn in the current thinking in rehabilitating purple martins. If this hypothesis is correct purple martins may very well have new hope when it comes to purple martins that miss that critical post fledging instructions. Rehabilitation that may have been in years past-delaying of the inevitable, may very well be  a new beginning for these birds.

Many thanks to Daniel Airola, from Sacremento, California for this important information.

Martin Fledgling Found on Ground-Back to Busch

Friday, July 17th, 2009

I was out several times in the morning giving Pedialyte to the nestling that I took out yesterday. He is visibly afraid at what I am doing but doesn’t give up a fight. His beak has more strength today and required some patience and gentle effort to open for some crickets today. As I was feeding him around 11AM or so, I saw the few Swallow-Tailed Kites flying overhead and low. I kept hearing a purple martin like chirp and found myself looking around. Hmmmm, I didn’t know Kites sound like martins? I kept hearing the chirp. No martins were around, they had visited this morning and were not around now. Then low and close I saw another one of the fledglings an the pool deck on the inside portion of the baby gate surrounding our pool. I went and picked him up and he chirped to me as if I was familiar.

Placing him in the bucket, with what I am sure is his sibling, I placed a drop of Pedialyte on my finger and as I approached him with my finger he practically bit my finger off. Not in fear or hostility but out of hunger. I picked up a cricket and approached his beak with it and between chirps he gobbled it down, looking for more. A friendly sort this little fledgling must have sat up in the trees all night. Finally when the other martins returned he tried to fly with them, only to be without strength to join them. He must have quickly lost altitude and thankfully landed where God would let me see him. Instantly, this little bird has especially touched my heart.

I placed a call to Busch Wildlife Sanctuary and drove them up to Jupiter. Beyond my help these 2 little birds need aggressive intervention. Even with that they seem so weak and malnourished that they may never be able to catch up to the HY’s flying about like experts now.

Calling for an update from David Hitzig (the Director at Busch Wildlife Sanctuary) I can report that both are being hydrated,  the outgoing fledgling is eating enthusiastically but the more timid nestling is not fairing as well. I am hoping that by watching his sibling accepting food, that he will follow suit, but as David related, it may be that he is beginning to shut down and death is imminent for him.

I will keep you updated.

Three More Fly the Coop

Thursday, July 16th, 2009

Three more nestlings became fledglings. It was the most painful thing to watch. Once again no parent in sight. I ran outside this morning and one of the larger nestlings had made it to the top of the gourd. It begged pathetically at every bird that flew by. I knew that if a Hawk, or one of the many Swallow-Tailed Kites saw him, he would be picked off. Luckily for me, I did not witness that. What I did witness was the begging that went on for about an hour. Sitting in the sun as the flock of purple martins would spook and fly up in a panic at the slightest disturbance and then settle back on the racks looking in and out of all the compartments. The showed great interest in the nestlings but no adult took pity and brought a morsel.

The Nestling that was sitting outside was visibly thinner than it should be. But the thinnest stayed in the gourd. Finally with a sudden burst the nestling took to the air and made a wide circle and easily gained altitude. It made an ungraceful landing in the Slash Pine and all the martins followed enthusiastically. Many of them also perched in the tree chirping and calling to the new fledgling. It was trying to keep a hold of the pine needles it was holding on to and at this point I went inside. I checked the nestcam and there still was the runt, chirping away.

I know that in theory that this fledgling had successfully fledged. My numbers get the benefit of another “plus” but in my heart, I don’t feel this nest will do well. Behind the eight ball there is a lot of catching up that needs to be done and I wonder if they will have the time to do it. Learning to fly is the easy part. Being in condition to fly to South America is another. I estimate that the number of visitors that I have seen will again drop withing the week. I would be surprised to see more than the occasional purple martin come by August.

I went ahead and went out with my boys and we did not return until the afternoon. Looking out I saw nothing. I looked with my binoculars, I saw nothing. I checked the nestcam and there was the runt. All alone. I still had some of the crickets and knowing how he was yesterday when I checked them I went ahead and lowered the rack. I again carefully slipped a mesh bag over the entrance so that he would not flush out. I took him out and my hopes for him fledging are nearly zero. Even skinnier than before his keel bone is protruding more than ever. I feel at this point that he is so malnourished that he wouldn’t have the muscle tone to even be able to fly. I gave him some Gatorade and am keeping him outside in a 5 gallon bucket hanging up an a peg. No snake or coon will reach him and if he wishes to fly out he can. But as I suspected, he has not attempted to do so yet. So Gatorade was given till dark and I will start again early in the AM.

My prayers are for his peace and mine.

One Missing of Last Nest of Five

Wednesday, July 15th, 2009

My husband was outside hollering at me as I lowered the gourd rack. Thunder was cracking and the sky was way to volatile to be messing with the purple martins. But I had just gotten home with a few dozen crickets and the Nestcam was not very reassuring. It seemed like something was not quite right.

For those of you unaware of the current drama. The last nest of the season and the 5 nestlings within (now at 26 days old) have been suffering from diminished parental care. The ASY male curiously has been around on and off during the day but with no meal to offer the nestlings. The SY female also has been circling and feeding high above watchful but also not feeding the young. Last Saturday I took the skinniest of the lot (including a runt) to the Busch Wildlife Sanctuary. A few feedings and bolus of fluids given later, they were perky and I put them back in the nest. Today I could not watch anymore. So down the rack came.

I had left the rack only halfway down and placed a net bag over the opening so that no birds could fly out while I lowered. When I opened the Troyer gourd only 4 nestlings were inside. In a mad rush I fed the 2 skinniest but am unsure if the runt had caught up or if one of the older more vigorous siblings fledged at some point today.

Back to my husband hollering at me, “Do you want to get struck by lightening?” Came in between thunder  claps. My hair wet as a slow drizzle had begun to fall. In a rush I raised the rack back up and after putting everything away I pulled the sock on a string that held the nestlings within. They stayed put and mom and dad circled.

The thin keel bone of the skinniest nestling is disturbing to me and I should have kept him out and fed him over the course of the remainder of the day and tomorrow.