? for PMCA

[Dale Hrncirik]

Why is the Feb 15th line like a roller coaster instead of showing the actual average arrivals for the past 10 years? I believe the line should be 'straightened out' just a bit. Take a look at the old arrivals and you will see that at least in the Dallas area, they are ALWAYS in the area by the 15th of Feb. Not trying to make a mountain out of a mowhill but it is possible that a new scout arrival map could be drawn up to show what is actually happening in north Texas and northern MS/AL? I've asked this same question several years ago and I thought the map was supposed to be updated. Thanks,

Dale

[John Barrow]

Hi Dale. I'm not the PMCA but would like to offer my thoughts. No doubt the old map could be updated, but at this time of the year it really doesn't matter what the map's prediction tells us. Arrivals during the first month are insignificant to nearly everyone. Mine arrive early but don't start nests for nearly two months

We get a few arrivals that fall within the parameter of the map, but too often many folks expect to see arrivals at that time and don't see them. For first arrivals for many folks the current map is only off by a week or so, but all of those early arrivals are hit and miss. I would much more prefer a map that shows general arrivals when many landlords can expect to see martins-such as will begin in the next week or so. I would also think it would be helpful if the scout directive would be to only post one's colony arrivals. Why? Because that would allow us to compare arrival dates with colony age and size and minimize flyover sightings that are often incorrect and sometimes duplicated as a few martins fly from town to town or about an area as they normally do .

But we go through this year after year. I would reiterate what I recently posted---when you get first arrivals doesn't matter. What really matters is whether you get martins at all; what you have achieved at the end of the season in a personal effort to produce martins; and what you have achieved at life's end to help martins.

Best of luck to you Dale. john

[Dale Hrncirik]

John,

I agree with your thoughts about posting scout data. I only post on the report page when a martin lands on my rack or usually goes into a gourd. I saw a martin back on the 5th but it was just a flyover so I didn't make an official report.

Somehow I have a problem with the way the Feb 15th line drops down to Houston and again on the gulf coast where the 2 lines meet. This makes little sense to me even though I understand these are approximate arrival times. I believe the date lines should be indicative of average arrivals of established colonies, however the yearly data clearly shows a discrepancy.

Sorry to bring it up again but I happen to be somewhat of a perfectionist...my bad!

John...have a great season my friend!

Dale

[Emil Pampell-Tx]

Dale, I don't think that you are a perfectionist for asking, I simply think that there is such a large difference to first arrivals in most places, compared to the first arrivals at a few places, that its hard to post anything that seems right.

These dates vary at my place by a couple weeks, and I have a large colony, so I could imagine that those dates would vary by as much as 3 or possibly 4 weeks at smaller colonies. I am not defending the PMCA in any manner, I am simply saying that I couldn't improve on what they post if I tried...I bet that as your colony gets older, that it will stabilize more to a 2 or 3 week period for first arrivals..I can't explain why the first arrivals have been later the last 2 years at my large colony (by 11 days later than 2 years ago)...just my thoughts....

[klcretired]

Good Point dale, I was wondering that same thing myself???

[Pat Kramer]

I bet that as your colony gets older, that it will stabilize more to a 2 or 3 week period for first arrivals..I can't explain why the first arrivals have been later the last 2 years at my large colony (by 11 days later than 2 years ago).

Emil, the older Purple Martins return to their colony sites first. It stands to reason that as your colony, overall, matures and grows you will acquire a few hardy, old martins that will risk their lives to secure the best cavities by arriving relatively early. It is an interesting phenomenon.

It's fun to think of what ecological trade-offs might drive that phenomenon. Perhaps older martins have much less to lose by dying than younger martins? They have after all already lived through several breeding seasons. Perhaps they have better survival skills (foraging and conserving their energy) or physical ability (more stored fat?) to survive through periods of low food availability. Perhaps, they need to get better cavities to offset a difficulty in acquiring mates (is there a preferred age of mates?). Scientific study is needed to answer that question.
If I had to guess, it is a combination of things; the risk of death is probably offset by the acquisition of higher quality cavities and mates.

I will say that SY Purple Martins do arrive significantly later than older martins. It is thought that since martins are less likely to mate as SY, they don't risk their lives by coming early. I refer you to Gene Morton's article.

As for the map, James R. Hill, III generated that map several years ago. I do not have the date exactly, but we do have much, much more scout data now. Mr. Hill, when he returns from his work with the Ivory-bill Search Team in AR, plans to do some work with the scout database. He may already intend to develop an new map. I will do some checking around to see if this possible to redo the map sooner.

The purpose of the map is to convey the estimated arrival times to a general geographic area to within a few weeks. Now it should be said that when you generalize any subject to that level, as was done in the timing map, there will be situations where it does not apply or is inaccurate. That does not mean it cannot be improved. Apparently, it can be improved in Texas.

Thank you for the suggestion, I will pursue an updated map. At this time, I cannot say how soon one will be available though.