Three puzzles

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malachy cleary
Posts: 70
Joined: Wed Feb 25, 2004 8:01 pm
Location: cold spring n.y.
Martin Colony History: First breeding pair in 2011. Site moved up hill 350 feet at beginning of nesting season
2019 to accommodate road construction.
Colony seems to have weathered the upheaval

I have a Colony with about 55 breeding pairs spread between a T-14 with 12 Gourds attached, an eight compartment Aluminum Waters Edge house, a Gourd Rack and an old Redwood House with Gourds.
While doing a weekly nest check I expected to find
Six eggs in a T-14 compartment that had
A pair whose first began the clutch on 5/29. When I last checked
This particular nest there were still six eggs on 7/10.
Imagine my surprise to find two young at three days old
And three eggs.
The first mystery is why some nests are abandoned. The second is why some nestlings seem to have a high mortality rate
and appear neglected and underfed. The third is what I first mentioned. How do eggs hatch that have been sitting around
For well over a month.
Hanover Bill
Posts: 633
Joined: Thu May 14, 2009 3:10 pm
Location: Pennsylvania/Hanover Township
Martin Colony History: 2009 & 10 - 0
2011 & 12 - Visitors
2013 - 2 pr. fledged 9
2014 - 3 pr. fledged 13
2015 - 7 pr. fledged 27
2016 - 15 pr. fledged 72

I have had some strange happenings at my site this year also. I have a gourd which I had scheduled to fledge 5 Martins on Jul. 6th. I assumed all had fledged successfully. While walking under the housing yesterday I noticed a female carrying a bug go into this gourd. I lowered the housing and much to my surprise found two tiny babies, no more than a couple of days old, and two unhatched eggs. I am scratching my head over this one.

There's no way another pair could have moved in, laid eggs, and had them hatch since the others fledged, even if they fledged exactly on Jul. 6th. I am totally puzzled by this one. I thought maybe I made a mistake on my record keeping but I don't think so.

Hanover Bill.
2009 & 10 - 0
2011 & 12 - Visitors
2013 - 2 pr. fledged 9
2014 - 3 pr. fledged 13
2015 - 7 pr. fledged 27
2016 - 15 pr. fledged 72
randyM
Posts: 129
Joined: Thu Jun 18, 2015 2:30 pm
Location: Long Lake SD
Martin Colony History: * 2006 - SY pair, unsuccessful nest attempt, 3 houses = 52 cavities
* 2010 - ASYM + SYF pair - male disappeared after storm, female fledged all 4 young.
* 2015 - Lone SYM stayed month of June...added 8 gourds = 60 cavities
* 2016 - 1 nesting pair (ASYM + SYF) 2/3 eggs hatched 2 young fledged.
* 2017 - 4 nesting pairs, 16/17 eggs hatched, 16 fledged, 16 banded - 2 banded SY returned in 2018 (12.5%), added housing: 11 houses w/gourds, 4 gourd poles = 376 cavities
* 2018 - 10 nesting pairs, 46/52 eggs hatched, 45 fledged, 29 banded - 3 banded SY returned in 2019 (10.3%)
*2019 - 32 nesting pairs, 145/160 eggs hatched, 139 fledged - 87 banded - 12 banded SY returned in 2020 (13.8%).
* 2020 - 35 nesting pairs, 180/199 eggs hatched, 178 fledged - 150 banded - 33 banded SY returned in 2021 (22.0%).
* 2021 - 89 nesting pairs....150 banded.

malachy cleary - Nests are abandoned for many reasons (death of 1 or more adults, infertile eggs, some type of major disturbance, eviction from cavity due to another bird, etc). Some nestlings may hatch with internal abnormalities and may not beg for food as intensively as nest mates, and parents will continue to feed the stronger chicks and the weaker chick will perish. Not all chicks hatch on the same day in some nests so some nestlings may be a bit bigger than others and if insect numbers are low in a given year or weather is bad for a period of time, parents will use the limited insect resources to feed the stronger/older chicks and the weaker/younger chicks will perish. Also, if one parent dies, a single parent can't usually feed a full brood, and again, the smaller/weaker of the brood with perish. As for the third situation, difficult to know for sure what happened here...do you know if the pair that began laying eggs on 5/29 was an ASY pair? Is the current pair SY birds? Maybe something happened to the first pair of birds and another pair moved in and removed most of the eggs from the 1st clutch and laid their own. If you check nests every 7 days that is enough time for a new pair to lay 5-6 new eggs after they remove the other eggs?? However, it could still be the same initial pair....I used to raise chickens and I've hatched chicken eggs in an incubator that were 3-4 weeks old...hatching rate does decline after about 3 weeks, but eggs can remain viable for up to a month. Some pheasants will lay 15+ eggs in a nest(and typically miss a few days of egg laying while adding to their clutch) and will hatch them all even though the first egg laid may be 2.5-3 weeks old when incubation begins. If your initial pair of martins delayed beginning incubation for a week or more, it's quite possible a few of their eggs were still viable when incubation began.

Hanover Bill - When did you complete your last nest check of the gourd? How many days old were the chicks then (do you have the PMCA chick age reference picture guide for increased accuracy of aging chicks)? How confident were you on the anticipated fledge date? If the young fledged sooner than your anticipated fledge date or If the young in that nest were taken by a predator shortly after your last nest check, a new pair of martins could have laid eggs in the nest within the next day or two. If the new nest had 4 total eggs with 2 that hatched in the last two days, the new nest was initiated 21 days ago = (3 days for egg laying [incubation starts the day before the last egg of clutch is laid] + 16 days for incubation + 2 days for current age of hatched chicks). If your last nest check was more than 21 days ago (June 28), it's possible for a pair to lay 4 eggs, incubate and hatch them. If your last nest check of that gourd was less than 21 days ago and there were live young in the nest at the time, I'm don't have any reasonable explanation as to what is going on there.

I hope this info is helpful to you.
Hanover Bill
Posts: 633
Joined: Thu May 14, 2009 3:10 pm
Location: Pennsylvania/Hanover Township
Martin Colony History: 2009 & 10 - 0
2011 & 12 - Visitors
2013 - 2 pr. fledged 9
2014 - 3 pr. fledged 13
2015 - 7 pr. fledged 27
2016 - 15 pr. fledged 72

Thanks for the responses, I think I'll have to go back over my records and see if I missed something. Maybe I had a senior moment when recording the information, it's been known to happen before. LOL.

Hanover Bill.
2009 & 10 - 0
2011 & 12 - Visitors
2013 - 2 pr. fledged 9
2014 - 3 pr. fledged 13
2015 - 7 pr. fledged 27
2016 - 15 pr. fledged 72
Spiderman
Posts: 825
Joined: Thu Jan 31, 2008 9:19 am
Location: Gladewater, Texas

I had a nest of 5 eggs that hatched after being in the nest for over 30 days. Don't know what to tell you there.

When a nest with eggs is abandoned I think of Hawks or owls taking the adult female. If the male disappears the female will hatch the young and feed as many as she can if the bugs are available. Sometimes the young will be underfed and take a long time to mature and fledge.
2008 - 33 PAIR - FLEDGED 96 YOUNG
2009 - 51 PAIR - FLEDGED 166 YOUNG
2010 - 45 PAIR - FLEDGED 146 YOUNG
2011 - 33 PAIR - 128 HATCHED, 97 FLEDGED
2012 - 37 PAIR - 119 HATCHED, 101 FLEDGED
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