How Far Along In The Migration?

[T Seber]

In another post a question was asked about the stage we were in in the migration. No one seems to really know. Of course the answer will vary from south to north as the birds come back.

Let me suggest a good project for all who read this that will advance our understanding of the migration. Why not write down our numbers about once a week as best we can count or guess. Then at peak we can look back and get an idea or at least and educated guess of the rate of migration and have a good idea when we were half way to peak in our area of the country. I believe I get half way to peak around the last week of April to the first week of May Here in Middle Tennessee.
Where do each of you hit half way peak from your best guess from other years? Why not keep written records for better understanding

The asy and sy return overlap here in my area. There are still many asy birds returning when I start to see the first sy birds show up around the middle of April


This would shed light on the question

[Louise Chambers]

Thurman,

This is a good idea, it would complement the scout arrival report, which is meant to track first adult and subadult arrivals only, not to track general numbers or later migration. People who think the scout arrival predicts other migration data often get frustrated that their own colonies are still waiting for birds. We hate for anyone to become discouraged and give up, just when the floodgates are about to open.

[T Seber]

Louise; While nest checks and counts are very accurate head counts and estimates of numbers are not very accurate at all, but it still would give us some idea of where we are in the migration process.

You are very correct again. Many people read first scout arrival reports and think they are missing the migration. Truth is, as you well know, the first arrivals in a particular area of the country are just the very start of the migration itself. Most of the really anxious people are not going to see early arrivals anyway. Even an established colony of small to medium size is very unlikely to have the first birds back. the older and larger colonies almost always get the first birds back. Then other landlords get anxious and those just trying to start get discouraged. I have twenty or thirty birds back here in Middle Tennessee, but that means nothing when someone 10 miles away sees mine and thinks he may not be going to get his birds back from last year. They will be along soon. they probably didn't die in Brazil or perish in a hurricane. They will be along in good time...smile

[cchild03]

This is a great idea! I can speak from my experience last year when I became very discouraged and was sure that something happened to my colony during migration. I kept seeing scout reports all around me--even in my town--but I continued to wait and wait and wait. My birds were a good month behind when everyone else around here was seeing them. And it seem like this trend is continuing this year. But now I'm not nearly as anxious about it. I know they'll get here.

[CraigMo.]

Thurman I have done this since I started martineering. I also have kept records when I see my 1rst killdeer and hummingbirds. This info has not helped me with figuring out anything though. Every year is different. I think weather is the only factor and thats weather in the martins head not ours. Here or in South America or where ever. Not trying to be a butt head but just letting you know that I can't figure it out and its different every year. I thought maybe killdeer was a sign martins are coming. Well I think Killdeer just show up first probably cause their food is available first.

[birdy girl]

We have 30 to 40 martins now this year and no killdeer. Usually we have killdeer first. Usually when I see the killdeer I know martins will be here shortly. Things are really strange this year. Off subject of the post but our blue birds are not even building nests yet. Last year several nests were already built by now.

[Allan Day]

I'm trying to stay patient, but I'm getting a little concerned. This is my fourth year and right now I have no birds spending the night. Martins are everywhere around me, and after hosting 40 pair last year, I thought I'd have some early birds.

I awoke Sunday the 21st to five adult birds. 3 male and 2 female. They took the traditional waterfront gourds first and I thought I was on my way. They left to go hunting in the afternoon and never returned.
I've had some lookers, but no overnight stays. This is starting to freak me out a little. The last two years, all my birds have stayed as they've trickled in. Not this year.

The only thing I changed was expanding my Super 36 to 48 gourds.
I had a small snake get through the guard last year and kill 2 fledglings and two broods died from heat, but other than that, a very successful year with 162 fledged. You'd think they'd be back with as many as I've had.
Do you think I spooked them some how?

By the way, They height of my #'s the last two years has been the around the 10th to 15th of May.
Halfway around the middle of April.
I'll keep detailed notes this year.

[CraigMo.]

Allan I am no expert, but I bet your birds are just taking there time getting home. Try not to worry and before you know it you will be buzzing with pms. Last year they were in Iowa before I got mine and I live in Missouri.(That was getting on my nerve) So I think its just when they decide to come home. Good luck.

Thurman also by April 1rst my site is usually booming with pm's. no matter if pms are early or late. I got my 1rst pm on the 18th of March and a week later I have 9 for sure, but I think probably more like 11 to 13.

[Steve Kroenke]

So far we have fewer martins in our colonies than we did at this same time in 2009. I have gourd racks that were 100% occupied with ASY pairs by the first of April last season that have less than a 50% occupancy level right now. I doubt these racks could become fully occupied over the next week considering how few martins have been arriving lately.

We did get some good numbers in mid-March and March is our big month for ASY martin arrivals in northwest Louisiana. But I have seen very few more arrivals in the last week. This evening, March 25, I only saw two "sleeper" type martins in our colonies; these are usually migrant martins that are stopping over to roost for the night. I have been amazed at the low martin activity level we have been experiencing lately during the evening roosting period.

I probably have around 100 pairs of ASY martins and some single males in residence and last year I had a lot more at this time. We still have the remainder of March, all of April and a good part of May for more martins to arrive. The SY martins mainly come during April and continue through May.

So our current martin numbers are down from what we had in 2009 at this same time. This has been a strange martin year with the late arrivals and terrible weather. However, this could all change over the next few weeks if we get a large influx of late arriving ASYs and the normal SY returns. Only time will tell.

Steve

[Guest]

Thurman,
This is a good post and a good idea. The only way I've tracked the build-up in numbers is by what I would post as a colony report previous years. As some have said, you follow a trend for a while and then you'll have a year that follows no pattern at all. Usually at my place, the barnies arrive first, then martins. Not so this year.

Although my birds this year were 2 weeks later than 2009 and 2008, the numbers at my colony have caught up quickly and I would say that I am now at where I was last year at this time. I would say I am at the halfway lull and this weekend we will begin to see what I consider the big wave of adults and soon the first trickle of SYs. Like you said there is an overlap in migration, especially the last few years.

It is hard for me to gauge the "normalcy" of numbers at this point because I have been growing my colony each year. I've gone from 16 gourds to 40 to 64 and now to 80 this year. A more stable large colony could give much better readings on progress than me.

[dcartwright]

Thurman,

I have also done this very thing since 2004. The first few years I could see big changes in the dates the first PMs arrived and the total number on certain dates. In the last three years these numbers are matching more closely with some differences, as some have stated, due to weather. Today I have exactly the same number of PMs (6) 4 males & two females as I did on this date last year, topping out at 50 last year. Tree Swallows in the early years beat my PMs here by two weeks. Now the PMs & TSs are within days of each other over the last three years. BSs are expected next week. My peak is right around May 1st with ASY & SY overlapping as well but have new comers for a period of two in a half months.

Too early here to tell if numbers are going to lower or higher this year. Great post to share data though.

Don in central Kentucky

[T Seber]

Don that makes sense to me that the older and more stable a colony is the more closely the numbers will match from year to year. A growing colony will be harder to gauge because allowance would need to be made for the growth. There are always going to be some variations, especially early in the season. Weather and wind direction will have quite an impact on the arrivals during the first couple of months of the migration but should have less effect toward the middle to the last of the migration as the weather becomes more stable.


My colony has been at just over 200 pairs for a few years now. I don't know for absolutely sure, but I doubt the day when it reaches 100 pairs would vary more than a week or so from season to season. I believe the same would be true of the day when it becomes full for the year. I am thinking it gets full up very near the same time each year with perhaps a week variation.

By the way, I have taken down over half my housing this year so this years numbers are sure to be very different.....smile

[John Barrow]

Hi Friends,

This is an interesting thread and some very valid observations have been made. Living along the Gulf coast, and with numerous contacts along the coast, I am blessed with a pretty amazing vantage point of migration--both in and out of the USA. The next Update will run a story detailing some of my observations about migration, and I would like to share a few comments in this thread.

Observing migration and posting reports for a number of years has familiarized me with a pattern of arrivals, and that pattern has been pretty consistent every year, until this one. I agree that migration is running a little later this year. In another post, Spiderman, a central Texas landlord, attributes the delay to an increased pattern of northerners blowing through the country this year. I agree with his assessment. I do not believe a significant number of martins perished because of harsh weather in early February. I think migration has primarily been delayed, by significantly more frequent arrivals of low pressure systems moving south through the continent. Martins taking the long flight across the Gulf rely on strong southerly high pressure wind currents that are sucked in by the emerging low pressure troughs to assist their flight across into the country. As the pressure systems merge, martins encounter strong head winds that basically shuts down migration.

Where we would normally have a northerner capable of shutting down migration to arrive every 10 days or so in most years, this year we are often seeing two a week. As this pattern changes, migration will pick up. It is the strong southerly winds preceding the arrival of the north winds that encourages increase in migration numbers. The increase this year in number of northerners has reduced the optimal period of migration for martins.

It has been observed, correctly so, in this post, that the scout reports are meant to discern the first arrival to different colonies in different parts of the country. It is not a timeline showing when landlords in a particular area should expect martins to arrive at their colony, or for that matter, to even see a martin. As Thurman notes, it is a date marking the beginning of the migration process at a particular location. Sadly, some folks are unable to recognize this, and every year some lose hope about getting martins, when the floodgates of migration have yet to open. In my migration reports I have preached this fact. I even stopped making migration reports one spring because I felt they caused some folks to lose interest in becoming landlords.

Where are we with respect to 2010 migration?
To date, I have posted two migration reports on this forum, of what I believe were general arrivals into the country--arrivals of the magnitude that would effect numerous colonies in North America. In prior years I would probably have posted three reports by this time.

My first report was around February 20. Comparing that arrival with prior years would closely approximate an early general arrival in the first half of February. Noticeable, but primarily at larger established colonies. My second report on March 15 noted steady arrivals throughout early March and predicted a quick turn around of migration we hoped for. On March 16, Adrian Hans posted incredible pictures and a report of approx. 300 migrants arriving at her Port O'Connor housing. Two other landlords who don't post on the forum advised me of arrivals of approx. 200 martins each at their colony locations, also in Port O'Connor. These arrivals were not limited to that small town. Similar arrivals likely occurred thoughout the Gulf Coast, moving north and eastward, as the advancing low pressure system moved in that direction also--continuously sucking in southerly high pressure winds in its advance. That was a huge general arrival and its movement can be followed on the scout report pages advancing northward and eastward several hundred miles each day. Those reports don't account for the massive number of birds that stopped at already occupied colonies, increasing their numbers.

That arrival, in my opinion, is comparable to arrivals we would witness in other years occurring in mid to late Feb., with a noticeable size increase as migration catches up to where it typically would be. That arrival, although it had some 2 year old martins observed from band readings, was not of the massive size that large general arrival(s) of 2 year olds would generate. That arrival(s) traditionally would occur around mid-to late March. To date it has not occurred.

It is important to note that the majority of the martin population consists of birds of its two youngest age classes--yearlings (SYs) and 2 year olds. Even with harsh nesting conditions last year in much of the country, it is still most likely SY numbers will outnumber all age classes. Those arrivals normally begin peaking along the coast after the first week in April.

At this point in time, my colony has reached a half full status. Normally it is functionally full by April 1. While that is unlikely to occur this year, it will most certainly occur with one or two general arrivals of 2 year old martins. That is the point in migration we are at now. Awaiting the first general arrivals--not first scout reports--of two year old martins. Because the age class is so large, these arrivals can quickly fill out an established colony, and will bring martins to many new landlords throughout the continent, as arrivals along the coast spread north and eastward at 100 miles or more per day. No one knows when such arrivals will begin, but in my opinion, that is where we are at today with respect to migration. At the point awaiting arrivals of the large 2yoa class, followed by even larger arrivals of the SYs. While weather patterns will largely dictate the timing and size of these arrivals, they will occur.

Keep your hopes high. We have at least six more weeks of peak arrivals ahead--at the most southern part of the continent.

I am bumping up my migration post 2 and Adrian's spectacular post.

Good luck, and best wishes to all.

[trisha]

Thank you John for this uplifting post. I always look forward to your updates/reports. Thanks for all you and Louise do to take care of our martins..

[tor]

Wow. Tons of valuable information, John. Thanks a lot.