Martins pair for season... or life?

[tboydshirt]

I've been taught that as a rule, if a species exhibits sexual dimorphism (males looking different from females) they will mate for a season at most. but species with males and females looking the same (Canada geese, angelfish, etc.) tend to mate for life.

So, is there evidence like banding which shows whether martins are mated for life, or battling for mates yearly? The fact that "scouts" arrive earlier and are mostly male leads me to suspect that there might be an annual battle for mates.

[Spiderman]

I think the evidence will show that Martins only mate for a season.

[mwren]

The martins select a new mate each season. DNA testing has also shown that all eggs, and babies in a clutch need not be from the same pairing.
Both males and females are known to take advantage of breeding opportunities presented in "colony life'.

[Dave Duit]

I'm paired for life. lol.

[James Strickland FL]

I can not confirm it, I have had several pairs that have shown up year after year and the male would go right in the same gourd or house and a female would come to the same place. Now that seems unusual that these birds did not know each other. As my parents would say to much of a coincidence to be a coincidence.

[Chris B]

I think the barnies on my front porch are a returning pair, and the few TS which are back around seem to be paired up also.

No PMs yet but I think it will be any day now, hopefully after the Sat night storms they are calling for. Bring up some bugs please Mr. storm.

[TheSmiths]

I've been taught that as a rule, if a species exhibits sexual dimorphism (males looking different from females) they will mate for a season at most. but species with males and females looking the same (Canada geese, angelfish, etc.) tend to mate for life.

I've not heard that rule before. Off the top of my head I can think of two sexually dimorphic birds that tend to mate for life, the eastern bluebird and the northern cardinal. You can read about the eastern bluebird here.

Info about purple martin breeding behavior can be found here. Banding has provided evidence that most purple martins change mates each season.

[TheSmiths]

Accidental post...

[GFB]

Interesting read on pair bonding. I always wondered if it was the same female that came back with the ASY male.

[Doug Martin - PA]

I always found it interesting when birds first arrive. It seems the male is quicker to find a new mate as females arrive a bit later. There seems to be strong loyalty to the gourd they nested in the previous year by both sexes. So I believe some pairs may possibly stick for several years. But inevitably because they seem to separate during the non breeding season they lose their pair bond. Seems some of the fighting between females is when the prior season mate returns to find a new girl in her gourd. Without banding it would seem difficult to support my observations. But I believe some pairs especially in smaller colonies may renest together in successive years.

[tboydshirt]

Thanks for the replies, and my question probably is best addressed by actual banding studies. I got the dimorphism angle from a professor while working on my masters degree long ago. it seems to hold here with our geese who arrive each February with their last year brood tagging along. the pair first drives off their offspring, then together drive off any other geese which try to land on their pond.
I'm surprised to hear that cardinals mate for life because we feed them through the winter, and multiple males tolerate each other in winter at the feeder, but starting about now only the males start defending territories ferociously with song, and sometimes knock down drag out battles.

[TheSmiths]

Thanks for the replies, and my question probably is best addressed by actual banding studies. I got the dimorphism angle from a professor while working on my masters degree long ago. it seems to hold here with our geese who arrive each February with their last year brood tagging along. the pair first drives off their offspring, then together drive off any other geese which try to land on their pond.
I'm surprised to hear that cardinals mate for life because we feed them through the winter, and multiple males tolerate each other in winter at the feeder, but starting about now only the males start defending territories ferociously with song, and sometimes knock down drag out battles.

How about a study using light-sensor geolocators? https://www.purplemartin.org/uploads/me ... tr-794.pdf
"Only 1 of 12 pairs that were tracked remated after migration". I know I've read an older study (that likely used bands) but I can't find a link at the moment. If interested, you can find additional published research under the "Research" tab in the forum menu bar.

I'm not well versed in waterfowl. There have been a number of studies conducted on the northern cardinal some of which can be found online. This one centers on testosterone but it addresses the behavior you've observed. I don't know how much interest you have in the northern cardinal but there was a gynandromorph found last year that is female on the left and male on the right (photo courtesy Shirley Caldwell). I've been wondering if this has been documented in purple martins and, if so, on which side the female portion developed.

[tboydshirt]

Thanks for the info. I read/skimmed that lengthy article, and think now that both sexes will have strong imprints to the site of their previous nesting but not to their previous mate. Apparently the second year birds are not so strongly imprinted too the exact location. I'm still trying to get martins here and putting my main hopes on those second year birds. I have made about as many changes as I can here including opening an entire tree row of tall pines which were between my pond and the houses. wish me luck

[Ransom Graham]

No, and I dont know any other way to put it; but
especially in large colonies during the nest building phase multiple males will often gang rape a female who has landed on the ground.

[John Barrow]

I don't know how much interest you have in the northern cardinal but there was a gynandromorph found last year that is female on the left and male on the right (photo courtesy Shirley Caldwell). I've been wondering if this has been documented in purple martins and, if so, on which side the female portion developed.

The Smiths,
Louise and I hosted a PM at our site in Port O'Connor for two consecutive years, after which we sold the property and gifted out our systems to landlords in the area. We called the bird Two-Tone. We had some difficulty in sexing the bird due to the fact that it appeared to be a male on one side and female on the other. Expert PM biologist, Gene Morton, saw pictures of the bird and thought it might be half male and half female, but the only way to determine that would entail killing the bird. Folks could likely call it a heavily plumage subadult male, but its arrival preceded subadult timing. It never gave any vocalization associated with males. Louise and I disagreed on its sex after our individual observations. During the course of both seasons, Two-Tone mated with an ASY male, laid eggs and successfully fledged young. Attaching a photo of Two Tone.

[Louise Chambers]

She returned and nested the following year, too - and then we moved, so had not further knowledge of how she was doing. We also looked into melanistic plumaged birds, meaning birds that were kind of the opposite of leucistic, and appear all dark, but with no color/purple.

[TerryW]

I don't know how much interest you have in the northern cardinal but there was a gynandromorph found last year that is female on the left and male on the right (photo courtesy Shirley Caldwell). I've been wondering if this has been documented in purple martins and, if so, on which side the female portion developed.

The Smiths,
Louise and I hosted a PM at our site in Port O'Connor for two consecutive years, after which we sold the property and gifted out our systems to landlords in the area. We called the bird Two-Tone. We had some difficulty in sexing the bird due to the fact that it appeared to be a male on one side and female on the other. Expert PM biologist, Gene Morton, saw pictures of the bird and thought it might be half male and half female, but the only way to determine that would entail killing the bird. Folks could likely call it a heavily plumage subadult male, but its arrival preceded subadult timing. It never gave any vocalization associated with males. Louise and I disagreed on its sex after our individual observations. During the course of both seasons, Two-Tone mated with an ASY male, laid eggs and successfully fledged young. Attaching a photo of Two Tone.

Hi John and Louise, long time no see! I don't recognize many names in the little bit of browsing of posts. Is Jamie and Chuck still around? I can think of other faces but not the names that go with them...hope this doesn't post twice...

[Louise Chambers]

Terry! how nice to see you here again! I have not seen either of them post here in years, but they are both on facebook, and PMCA has a martin group there, too. Some other 'old timers' are here, though - Emil of course, to name one. Do you have any martins these days?