Archive for July, 2009

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.

The Numbers Are In!

Wednesday, July 29th, 2009

Final 2009 Purple Martin Season Tally

With a whole lot of drama and excitement, the 2009 Purple Martin season is officially over in South Florida. Even the roosts have faded away to a distant memory and the gourd racks and houses all sit quiet and empty with only curious paper wasps showing interests in nest building. Our goal here was to make it to the 100 fledge mark and that goal WAS reached. So with pride in my efforts and much thanks to God, here are the totals.

Total Pairs: 33

Total Eggs Laid: 163

Total Eggs Hatched: 140

Total Young Fledged: 130

Egg to Hatch percentage: 86%

Egg to Fledge percentage: 80%


Most of my colony is comprised of Troyer Horizontal Gourds with an occupancy rate of 96%. I only had 1 natural gourd with a round opening. All other entrances were SREH. The SREH (starling resistant entrance holes) were mostly Clubhouse entrances (Conley 2) with some Modified Excluders thrown in for good measure.
My other housing option is a Sunset Inn Aluminum Purple Martin Houses (also with SREH) which was only about 50% occupied.
1 case of wing entrapment (no casualties)
1 entire nest lost due to a case of snake predation

I left a couple of messages trying to get a status on the 2 purple martins that were “abandoned” and I did not get a call back. I will keep you updated as soon as I here what the plan is for these 2 poor guys.

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.

BIRDING COMES TO THE SMALL SCREEN

Tuesday, July 21st, 2009

Finally Adventure Birding comes to the small screen…After a successful season premiere on 2 well-known local networks, Birding Adventures TV will now be available in most TV households across the US!

Hosted by professional wildlife and birding guide, James Currie, BATV is a unique blend of adventure and information, making birdwatching refreshing, contemporary, interesting and exciting. The show has a strong conservation emphasis and highlights the importance and urgency of preserving the planet’s incredible birdlife. Featuring the quest for a rare Golden Bird each week, James is joined by birding and conservation experts from around the globe.

The first show on July 18th 2009 features the ocean wildlife of the Californian coast and the most range-restricted North American endemic bird, The Island Scrub-jay. Show 2 on the 25th July features the search for the critically endangered Sun Parakeet in Guyana. BATV will be carried every Saturday morning Prime-time from 7.30-8.00 am local time by the following Fox Sports Networks:

FS Arizona (Dish 415; Direct TV HD686)

FS Detroit (Dish 430, 5430; Direct TV 636, HD663)

FS Florida (Dish 423, 5423; Direct TV HD654)

FS Midwest (Dish 418, 5418; Direct TV HD671)

FS North (Dish 436; Direct TV HD668)

FS Ohio (Dish 425; Direct TV HD660)

FS South (Dish 420; Direct TV HD646)

FS Southwest (Dish 416, 5416; Direct TV HD676)

FS West (Dish 417; Direct TV HD692)

FS Wisconsin (Dish 436; Direct TV 669)

Other Fox Networks and affiliates have also picked up the show go to

www.locatetv.com or http://areyouwatchingthis.com/tv/programs/SH011093200000-Birding-Adventures/18015786 to find BATV in your area. Check your local cable provider channels for cable listings.

www.untamedsportstv.com) at the following days and times:

www.BirdingAdventures.com or email info@birdingadventures.com

It’s Not About Your Cat, It’s About MY Birds!

Saturday, July 18th, 2009

Did you hear that? It is the sound of my soap box being pulled out of the closet and dusted off. I have been wanting to write about a very big pet peeve of mine for some time…so now that my birds are gone, here goes.

As a birder, it goes without saying that I am a conservationist. As a purple martin landlord, that just adds fuel to the fire and makes me even more pig headed when it comes to the house cat being outdoors. First off a few facts MUST be cleared up.

Fact #1 Cats are domesticated animals-not wild. Many people consider letting their cat room outside as an extension of the cats native environment. They consider it cruel to keep cats indoors. When actually the opposite is true. Cats were domesticated some 4,000 (four THOUSAND) years ago. They do not occur naturally anywhere. They have only been in North America since European Settlers arrived.

Fact#2 Cats hunt and kill whether or not they are hungry. Studies show that well fed cats actually kill MORE than feral cats. In other words they hunt for pleasure. The portion of the cats brain that is used to hunt is not the same part of the brain that registers hunger. Thus a cat will hunt even if it just ate a huge bowl of food. They hunt to kill, not necessarily to eat. Also neutering and spaying have no impact on a cats desire to hunt.

Fact#3 Studies have shown that Bells do not keep cats from killing. On the contrary bells may actually make cats more successful at hunting. Besides the fact that a bird does not necessarily associate the sound of a bell with danger, bells teach a cat how to hunt even more efficiently. The cat will learn how to move silently. And bells are of no help when a nest full of helpless nestlings is being stalked. Consider this product called the CatBib. Their website has a study that was conducted that shows an 81% decrease in the amount of BIRD KILLS! That is impressive. Unquestionably more effective than a bell this device allows the cat free movement, is soft, flexible and lightweight yet restricts a cats ability to stalk prey.

Fact#4 Cats kill HUNDREDS of MILLIONS of birds nationwide per year. That is no trivial number even though it is a low ball number. According to a post on Windstar.org that estimates over a BILLION birds are killed each year in the US alone. And looking at the math, that number may be conservative as well.

Follows is a sobering quote from www.Windstar.org :
The American Veterinary Medical Association estimate in 2007 there were 81,721,000 pet cats in the U.S.
According to Cat Fanciers, 43% of cat owners allow their pets to roam outside, that gives us: 35.1 million outdoor pet cats in the U.S. Add the number of feral and stray cats. numbers published by feral cat advocacy groups say there are between 60 to 100 million cats. Lets just take half that number say 81 million.

So that’s 81.7 million + 35.1 million = 116.8 million outdoor cats. More realistic might be a range of 95.1 to 135.1 million (based on possible feral range). But for arguments sake, lets just stick with 116.8 million cats for now.

How many birds killed by cats? According to a study in Michigan by Lepczyk et al, outdoor pet cats across an urban to rural gradient killed an average of .683 birds each week during the breeding season. If you can extrapolate that across the full year, that would be an average of 35.5 birds killed by each cat/each year. If you can use that figure for all outdoor cats, you get a calculation of 4.1 billion birds killed each year.

But maybe cats don’t kill birds at the same rate all year long, or at the same rate everywhere that they do in Michigan. But lets presume that the only kill birds during the breeding season (22 weeks in MI), that would still be 1.76 billion birds killed per year.

Another study in San Diego found each cat to kill an average of 15 birds per year (and 41 other small animals). If you multiply this number by the number of outdoor cats you get 1.75 billion birds killed per year. And that’s just in the U.S. and doesn’t take into account our migratory birds killed by cats in Canada or Latin America.”

Fact#5 Cats are responsible for the EXTINCTION of 33 bird species since the 1600′s. That is more bird species than any other cause, except habitat destruction. Currently there are dozens of seriously threatened birds that are still experiencing high levels of predation due to cats. Ground nesting birds, such as the Piping Plover, Least Tern and California Tern are even more at risk and several monitored nesting sites have been abandoned by these birds due to cats.


So you know all this data and you still feel it necessary to let your cat out. If that is the case, you are placing more value on your cats experiences outside than the animals that it will kill in its time outdoors.

If you think your cats rodent killing is a positive, think about this. Each mouse that a cat kills is decreasing the available food supply for native hawks, owls, snakes and other predator species.

If you believe TNR (Trap Neuter Release) programs work to decreasing the problems caused by feral cats, I urge you to visit TNR Reality Check. This site offers an eye opening reason why TNR programs are a huge dis-service to the community, environment and our birds. Most importantly it show why these TNR programs do NOT work.

So if bells don’t work, what can be done. The American Bird Conservancy runs a program called “Cats Indoors!” which I am a big supporter of. (I am available to give PowerPoint presentations of the “Cats Indoors!” programs to groups, BTW)

Don’t have a cat and want to make a difference? Re-Tweet this post and help inform birders and cat lovers alike.


Sources:

Coleman, Temple and Craven  (1997). Facts on cats and wildlife: a conservation dilemma., USDA cooperative extension, University of Wisconsin. http://www.cnr.vt.edu/extension/fiw/wildlife/damage/Cats.pdf

TNR Reality Check

Winter, Linda and Wallace, George (2006) Impacts of Feral and Free-Ranging Cats on Bird Species of Conservation Concern

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.

I Can See Clearly Now!

Tuesday, July 14th, 2009

The nestlings are holding on tight. They should be about 25 days old so fledge day is fast approaching. I am watching them closely and continue to pray for them. I am working on several posts for this blog at once. One is on Bot Fly and Blow Fly infestations and another on cats. Keep an eye out for those.

I have been watching the nest with a pair of Nikon Ecobins 10×25 Binocular and they are perfect to use around the house especially with 2 young boys running around. Remind me to tell you the story of what happened to my expensive binoculars when my then 2 year old found them.

At just under $200.00 Nikon has entered into the “green era”. Recently introducing a new binocular, the Nikon Ecobins 10×25 Green Binocular are going to be my new favorite binocs.  These optics are perfect when you don’t feel like toting around a pair of really expensive binoculars. They can be cumbersome and who wants to loose a pair of binoculars that can cost several thousand dollars. But now I can take the Nikon Ecobins with me on the most spontaneous of adventures and always have a great looking high quality pair of optics that brings me closer to nature. They are great viewing at a great price, Earth friendly and EASY to carry around..these binoculars are perfect!

For more info on the new Nikon Ecobins go to http://www.nikonecobins.com.

Last Nest and their Diminished Care

Monday, July 13th, 2009

The last nest is in the zone where nest checks are not advised. Fearing that I can flush out the 2 stronger birds and decrease their chances of survival, I have stopped supplemental feeding of the runt. I have seen the mother flying overhead and calling out but not actively feeding. Within the last week I have noticed a decrease from over a hundred birds flying about in the morning to none. Only about a dozen or so will stop by for several minutes at different parts of the morning. The season is ending quickly and the SY female is in a hurry to leave. Whether or not her instinct to stay and care for her young wins out over the instinct to join the flock and migrate, I am not sure. I hope the 2 larger and more robust nestlings make it but I doubt the runt can catch up now. This situation is a textbook example of something described as diminished parental care in some late nesting purple martins by a fellow PMCA forumite and purple martin landlord Mr. Steve Kroenke. You may have read this article on the forum but for my non-PMCA readers this is an issue that is fascinating if not tragic. With Mr. Kroenke’s permission I am posting his article here.


Diminishing Parental Care In Some Late Nesting Martins

Purple martins are a highly colonial and migratory species. They spend a good portion of their lives on the go, as they travel with other martins between their wintering grounds in South America and their nesting sites throughout the United States and Canada. So, the instinctive drive to migrate with the flock is deeply engrained in a martin’s genes and behavior. This drive is highly prevalent toward the end of the nesting season when nearly all martins have finished breeding and are forming pre-migratory flocks in preparation for the flight south. The urge to assemble and migrate south seems to dominate the purple martin species after the young have fledged and are independent. Martins have a long journey ahead of them and they must also finish molting all their feathers while on their wintering grounds. Migration instinct is extraordinarily strong in purple martins.

Competition Between Instinctive Drives In Late Nesting Purple Martins
This highly developed migratory drive will sometimes compete with a martin’s instinct to stay with its young, particularly when nearly all martins in the area have finished breeding and are heading south. Late nesting martins may be torn between the urge to migrate with the flock and the urge to continue staying behind and feeding their babies. When there is only one pair of nesting martins left at a colony, the conflict between the drives may be particularly strong. These are often, but not always, sub adult martins (SY) that have colonized a new site or are nesting at an older, established colony. When martins initiate such late nesting behavior, any young produced may be nest bound until late July into September depending on the geographical location of the colony. By this time, many martins are forming pre-migratory roosts or heading south. This may exert migratory pressures on these late nesting parent martins as they try to feed their young while suppressing their desire to fly with the flock and head south.
Late Nesting Martin Feeding Behavior/Parental Care
Most martins that are nesting during the “normal” breeding period for their area begin feeding their young at dawn, often while there are dim lighting conditions. They continue to feed their babies throughout the day, with occasional “slow down periods”, and persist until the evening. I have observed martins start feeding their babies just after 6:00 am and stop between 8:30 and 9:00 pm.
For very late nesting pairs, particularly those where all the other martins have finished breeding in the colony, you may observe significant variations from the “norm” relative to feeding young. Late nesting martins may vary considerably in their frequency and daily time frames of feedings to their young. If these late nesters are not roosting with their young, then the parents may arrive later in the mornings to begin feedings. I have observed some of these parents arrive at 8:00 am or later to begin feeding their young though most returned earlier. During the day, their feedings may be sporadic at times with the parents leaving the area during the late afternoon. Sometimes both parents will be gone when there are still several hours of daylight left to feed the young. I have observed some of these late nesting adults leave the area by 6:00 pm or even earlier. Both the beginning and ending feeding times for late nesting martins are greatly impacted by the age of the young and roosting behavior of the parents. If one or both of the parents are roosting with their babies, then you may see a more “normal” feeding schedule, starting early and ending before dark. However, even these roosting parents may start feeding their young later than normal.
When parent martins arrive late at the nest in the mornings and leave early in the afternoons, this behavior may relate to the distance they must fly to reach the closest pre-migratory roost site. If neither of the parents is roosting with the young, the adults are probably spending the night at the nearest pre-migratory roost. If it is late in the season and most martins are gone from the area, then there may be no nearby roosts, so the parent martins may be flying many miles to reach the closest one. This could result in several hours of flight time for the parent martins in the mornings to arrive at the nest and in the afternoons to reach the communal roost.

Also, late nesting martins must face much higher daytime temperatures and this factor can impact the number of feedings to the young. During extremely high temperatures in the upper 90s for example, insects, such as dragonflies, may not be flying in large numbers, thereby reducing the prey base for the parent martins. The young martins may become heat stressed and not be as responsive to the food stimulus.

And, just prior to fledging their young, parent martins will start reducing the daily feedings to prepare their babies’ transition from nestlings to fledglings. Hungry young are more prone to fledging than well fed ones, particularly when the parents tempt them with a dragonfly. So, it is normal to see fewer feedings during the last week prior to the young making their maiden flight.

There May Be Significant Differences In Feeding Behavior Between Male and Female Martins

From my observations of these very late nesting pairs, you may see significant gender differences between male and female martins in feeding their young. The female martin is clearly more attentive to the young and spends more time with her babies than her mate. This is largely a function of the specific gender roles in purple martin family life. The mother martin broods her young during their early lives and she usually roosts at night with the babies for much longer than the male. Some males may quit roosting with their families after the young are older and nearing fledging. For late nesting pairs, the males may quit roosting with their families soon after the young have hatched.

Late nesting male martins may show reduced parental care to their young by feeding them fewer times than normal and then leaving earlier in the day. This may become more pronounced after the young are about two weeks old and it is later in the breeding season. These males may arrive at the nest site later in the mornings and feed the young a few times. Then they may disappear for long periods and show up again later with an occasional food item. Generally, their feedings to the young may be lower than the females. Other males may function mainly as guardians to the nest and chase away other males, particularly SYs that try to enter the cavity. These males may stay around the nest site in the mornings and bring in an occasional dragonfly. Then they gradually disappear in the afternoons and will not return until the next day. Some males may eventually abandon their families after the young are older or just after fledging. I had several cases where the males finally just quit coming around and the female went solo to finish raising the young.

Female martins are extremely attentive to their young and closely bonded to them. Nurturing the young is a key gender role of the female martin. Females usually feed late hatching young reliably and provide good parental care. I never had a case where a female abandoned her late hatching young though some of these females may not feed their young as often as normally. Also, these females roosted with their babies almost up until fledging and some through that time. However, I did observe several situations where non-roosting females with older young would arrive late in the morning to start feeding their babies and then departed relatively early in the afternoon. In these cases, the females may have been flying many miles to reach a communal pre-migratory roost. Again, the females are usually much more bonded to their young than the males and provide better parental care in late nesting situations.

Differences Between Late Nesting ASY Pairs And SYs

Generally speaking late nesting ASY pairs, both male and female, are more attentive to their young and provide more reliable parental care. These martins have most likely successfully raised young in the past and this experience no doubt helps them. Late nesting ASY males are probably more prone to feed their babies at higher rates than the SYs. The SYs, particularly the males, are raising young for the first time and embarking on this most important and potentially stressful adventure late in nesting season does create a challenging situation. However, I have seen both late nesting ASY and SY males significantly reduce their feedings to their nest bound young and even on occasion abandon their family prior to the babies fledging.

Late Nesting Fledglings

When late nesting youngsters fledge, I have observed cases where the parents or female parent brought their young back to roost in their natal nest for several nights and in other situations where they all disappeared. However, I did have several cases where the females brought their young back for longer than a week. It is possible that these youngsters may have greater difficulties in surviving to independence since the parents are under pressure to migrate with the flock. This may result in reduced parental care after fledging. However, martin youngsters grow up fast and learn to hunt flying insects quickly. So, that is a good behavioral adaptation to possibly help martins overcome problems with fledging later in the nesting season.

Summary

Purple martins are highly migratory birds and are nomadic for a good portion of their lives. This powerfully developed drive to “go with the flock” at the end of the nesting season may sometimes conflict with an equally strong drive to feed late hatching young. This “battle of the instincts” may result in some parent martins, particularly the males, reducing their feedings to nest bound young or in rare cases abandoning their families. Most females tend to be more closely bonded to their young and often maintain a good level of parental care in late nesting situations. These females continue to feed their babies reliably, roost with them until fledging, and may bring them back to sleep in the evenings for several nights or longer.

by Steve Kroenke