Have you had 100% occupancy?

Welcome to the internet's gathering place for Purple Martin enthusiasts
Post Reply
G Saner
Posts: 124
Joined: Wed Nov 13, 2013 3:37 pm
Location: TX/Kerrville
Martin Colony History: Fort Worth, TX (1967-1976), The Colony, TX (1981-1985), Carrollton, TX (1986-2013), Kerrville, TX (2015-present).

Two SuperGourd poles (12 gourds on each) at River Point Assisted Living Center.

Since 2000, I have had 24 SuperGourds as a small colony landlord. For the first time, this year all 24 gourds have martin nests in them. One other year, I had one pole full but not the other one. Of course the reason is a perfect site.

Prior to 2000, here are my best years in other martin housing. Trio Castle (17 of 24), Trio M12K (10 of 12), wooden house (7 of 14) and natural gourds (8 of 12).

How about you?
G Saner
Posts: 3010
Joined: Wed Mar 29, 2006 8:49 am
Location: Indiana/Henry Co.

I've never had 100%. One year I had 30 pair in 34 cavities and currently this year I have 47 of 54 cavities with nests in them.

The weird thing is you could keep 24 gourds for the next 5 years and you would probably average 18-22 pair. You could add 24 gourds and the next year you would probably have over 40 pair.
2020 Currently 42 nest, 110 babies, 64 eggs left to hatch(6-22-20) HOSP count-8
2019- 31 Pair over 100 fledged
2018- 15 pair last count 49 fledged
2017 3 SY pair nested, 12 eggs total, fledged 10. 4 additional SY's stayed all summer but never paired/nested.
2016 1 pair fledged 4
2015 Visitors
2014 Visitors
2013 Moved 6 miles away, 1 pair fledged 2.
2012 30 pair fledged 100.
2011 12 pair (11 that nested), 43 fledged.
2010 5 pair, 21 eggs, 16 hatched, 14 fledged.
Posts: 495
Joined: Wed Mar 16, 2016 9:17 pm
Location: Raymore, MO

Not here, I have been trying to grow, so trying to stay ahead of them. 33 nests this year and I'm where I want to be , time will tell.
Posts: 253
Joined: Sat Dec 30, 2017 3:40 pm
Location: Palm City, FL
Martin Colony History: 2018 will be my first try. 6 S&K B09s. 29 eggs - 8 fledged
2019 - 12 Troyer Horizontals with tunnels, 6 S&K B09s and 12 B011s all with tunnels. 43 eggs - 36 fledged
2020 - Rack 1 - 6 B011s, Rack 2 - 24 B011s, and Rack 3 - 24 Troyer Horizontals. All gourds have tunnels, porches and crescent/Conley 11 entrances; racks have predator guards. 161 eggs - 88 fledged

G Saner,
Am completing only my third season as a landlord but it seems to me that 100% occupancy is just a dream. Would love to see this happen one season but I just don't see it. I define "occupancy" as the nesting compartment (gourd, house) at least having eggs deposited therein. This season Rack 1 (6 B011s) is 5 of 6 or 84%, Rack 2 (24 B011s) is 19 or 24 or 79% and Rack 3 (24 Troyer Horizontals) is 9 of 24 or 38%.
In my three seasons of weekly nest checks, I have seen nests progress from scattered pine needles, to a bowl, to a bowl with leaves, to.....nothing. Occupancy, yes; production, zip. If I counted these gourds as occupied, my percentage would rise but not to 100%. But you have raised an interesting point and I'll review my first two years history and see where I stand counting non-productive nests into the total.
Somewhere in my forum perusals, I read a landlord's post where he/she basically said to "increase occupancy in what you've got before adding new compartments." That's my goal for the future. I want to get Rack 3 up to at least 80% before even thinking about expansion!
Happy Martining, Mike
Ed Svetich-WI
Posts: 798
Joined: Tue Jan 13, 2004 10:05 pm
Location: Brooks, Wi (McGinnis Lake)
Martin Colony History: 24 Super and Excluder Gourds on two gourd racks, all SREH. Full occupancy. My philosophy is to maximize fledge % with existing cavities rather than adding gourds to grow colony, thus providing opportunities for new colony expansion. Fledge over 100 nestlings yearly from 24 gourds. Band nestlings in cooperation with state university. 2019 Adendum: Reduced colony size to 12 gourds to focus on more intensive management regimen.

Interesting question. The answer may depend in part on geographical location. In the Great Lakes and across the upper tier of the martin range, historically lower martin numbers may make 100% occupancy challenging. I was always envious of those in the south who could have large colonies because of more martins available. That is why it may be wise to focus on whatever population you are able to attract.If you only have a handful initially, do everything you can to assure that those few nests produce as many fledglings as possible. In martin poor areas, you have to increase the numbers produced in your area to benefit all other potential landlords.

Some will disagree, but continually adding more cavities to active sites may prevent other potential now vacant martin colonies from attracting their first pair, especially where martin numbers are low or declining. I initially had over 30 cavities. I found it challenging with both Trio houses and gourds.I decreased cavities to 24 and focused all of my efforts on those relatively few pair. In a few years of better nestling survival, my 24 gourds were full with many extra martins showing up every spring. Where the overflow went to is anyone's guess, but there are now four relatively large martin colonies within 20 miles of here in the last 5 years. I kept a few blocked every year until the SY appeared.They were my bank of future ASY returns.

I now have only 12 gourds. Except for a very early SY male, all are ASY martins. If I added more gourds, I could probably fill more but I am happy to have the excess go somewhere else. 62 fledged here last year. Even with first year mortality being high, those that survived are somewhere near here at other colonies.

100% occupancy is possible, but it does not come easy.

Produce as many martins as possible.

G Saner
Posts: 124
Joined: Wed Nov 13, 2013 3:37 pm
Location: TX/Kerrville
Martin Colony History: Fort Worth, TX (1967-1976), The Colony, TX (1981-1985), Carrollton, TX (1986-2013), Kerrville, TX (2015-present).

Two SuperGourd poles (12 gourds on each) at River Point Assisted Living Center.

Thanks to all who responded. You raise interesting questions. I have no doubt that if I added more gourds that I would fill them up the first year.

Initially, I only had one pole at this Assisting Living Center and the second pole at another center. The other site was below average and did not attract martins. When I moved the second pole next to the first, it had 10 pair the first year and the first pole stayed at 11 pair. I have decided that 24 gourds is all I can handle.

Many people in this area are trying to start a colony. The local Wild Birds Unlimited sells dozens of units each year. For the last two years, only one pair of SY martins have managed to claim a gourd in my colony. That means the babies I raise (115 last year) are pushed somewhere else.

100% is not my goal. It just happened but took many years. It may not happen again.
G Saner
G Saner
Posts: 124
Joined: Wed Nov 13, 2013 3:37 pm
Location: TX/Kerrville
Martin Colony History: Fort Worth, TX (1967-1976), The Colony, TX (1981-1985), Carrollton, TX (1986-2013), Kerrville, TX (2015-present).

Two SuperGourd poles (12 gourds on each) at River Point Assisted Living Center.


I agree. The definition of occupancy is a nest with at least one egg laid.
G Saner
Brad Biddle
Posts: 523
Joined: Wed Feb 17, 2016 6:22 pm
Location: Marshall County AL

I have an all gourd colony. Yes I have had 100% occupancy many times. Once it gets to the point that my oldest nestlings get close to fledging age I don't lower the gourd racks again, but it's not hard to verify nestlings being fed in other gourds with binoculars. It's very common at my site to have two gourds being dominated by an ASY male, until that male starts feeding nestlings, then the 2nd gourd he was dominating gets claimed by a late SY pair. That just happened again this year, on an octagon shaped rack that I've had for a long time. It holds 24 gourds. I had 23/24 with eggs/nestlings as of last week. Saturday I noticed an SY pair on the porch of a formerly unclaimed gourd. It doesn't have eggs in it yet, but I'd bet that it will within another week.
Martin landlord since 2003. Currently offering 162 plastic gourds with tunnels, all with Conley II entrances with the Lewis modification. I have 24 Supergourds and the rest are Troyer Horizontals.
Sharon - Central TX
Posts: 648
Joined: Sun Feb 08, 2004 9:20 pm
Location: So. Central TX
Martin Colony History: All Troyer Horizontal Gourds with Conley Entrances
PMCA Member since 2004

Almost :grin:. We have all but one gourd with nests and young. The one has an SY staying in it. We have 26 Troyer Horizontal gourds. We’ve been checking every five days and at our last nest check we counted 122 young and 2-3 eggs (maybe more because they were buried so well) that had not yet hatched. We had two nests with seven eggs and they all hatched! Had to move a runt buried under the pile from one of them to another nest with fewer younger birds his size. Last check he was doing well with his adopted family.
So far we’ve only lost one Pinkie from a bad SY making trouble. It has been a good year. If we don’t have more new nests once some of these fledge I will be very happy. When that happens we end up in the triple digits and it’s hard on both birds and people. Especially when they don’t fledge until the end of July or first of August :-( . It’s so terribly hot in TX. It’s already in the upper 90’s, feels like 100.
Posts: 591
Joined: Tue Jul 15, 2008 2:28 pm
Location: Holly Springs, NC
Martin Colony History: 2009-2015-Helped to manage Raleigh site, 36 cavities
2016- 33 pairs at Raleigh site, 1 pair at home site.
2017- 34 pairs at Raleigh site, 3 pairs + extra SYs at home site
2018- 33 pairs at Raleigh site, 5 pairs + extra SYs at home site
2019 - 32 pairs at Raleigh site, 7 pairs at home site, 2 pairs at new Holly Springs park site

It varies. I manage 2 public sites and my personal one. At one of the public sites, it's an all-gourd colony, and in its second year, it is now 100% full, but it only has 8 gourds.
At the other public site, typically the 16 gourd rack pole is 100 percent full, and on the other pole with a house/gourd combo, all gourds are taken, and about 2/3 of the house. This year, numbers are down some, so it's not full.
My personal site is all gourds and has slowly grown over the years but it is not full, either.
Gourds are definitely more popular with the martins in my area.
NC Purple Martin Society (PMCA affiliate)
Posts: 241
Joined: Wed Feb 25, 2009 4:35 pm
Location: Marlboro County, SC
Martin Colony History: Capacity: 72 Troyers on 3 X Super-24 racks

One gourd left out of 72 this year. Never had 100%.
Location: Marlboro County, SC

2021: Capacity: 72 - First Scouts: 2/22
2020: Capacity: 72 - First Scouts: 2/11 - 71 pair - 298 fledged
2019: Capacity: 72 - First Scouts: 2/22 - 70 pair - 315 fledged
2018: Capacity: 70 - First Scouts: 2/18 - 60 pair - 270 fledged
2017: Capacity: 42 - First Scouts: 2/25 - 39 pair
2016: Capacity: 42 - First Scouts: 3/10 - 32 pair
2015: Capacity: 24 - First Scouts: 3/23 - 4 pair

Purple Martins Of South Carolina
G Saner
Posts: 124
Joined: Wed Nov 13, 2013 3:37 pm
Location: TX/Kerrville
Martin Colony History: Fort Worth, TX (1967-1976), The Colony, TX (1981-1985), Carrollton, TX (1986-2013), Kerrville, TX (2015-present).

Two SuperGourd poles (12 gourds on each) at River Point Assisted Living Center.


I think 71 of 72 would be much harder to get than 24 of 24. I notice that most replies mention gourds. Nothing from Trio owners. My experience is higher occupancy with gourds.
G Saner
Posts: 46
Joined: Mon Jun 13, 2016 12:06 pm
Location: fredericksburg, va
Martin Colony History: 2016 bought 6 gourds. Pole put up late in June due to HOA approval. Had visitor birds but no pairs that stayed.
2017 12 gourds- Pole up 3/1 and had male and females visit but didn’t pair up.
2018 upgraded to 2 inch sq pole/winch and will have 24 gourds. Many solo visitors but seem to be passing by. Will trim trees and check fly ways.
2019 saw only one or two martins all summer. Brothers Martins didn’t show up at all.
2020 3 pairs, 1st- 5 eggs/ 2nd hatched 2 fledged, 2 - 5 eggs/ 2-5 hatched fledging 7/20-8/1, 3rd formed late July and no nest built.

I assume that having a full rack is harder since males tend to try to control more than one gourd. So, having 20 out of 24 is a great percentage. Putting up another pole with more gourds would seem to be the best way to give more housing and control the percentages. I think it is nice to have a few empty gourds for fledglings that I heard can stay around the pole for a few days. Just keep the bad guys out. Gourd and rack spacing might play a role as well. I know male aggression is reduced if the entrances of the gourds can't see each other well and I have seen little walls placed up for some types of houses to block the aggression so more males can nest closer. I would think if the same gourd or house entrance is empty a lot or last to be taken I might change the direction or location it faces if possible.

Posts: 189
Joined: Sat Apr 29, 2006 8:45 am
Location: Indiana/Scottsburg

I'm at 100% with 32 out 32 gourds with eggs. In over 20 years this is a first. Typically there are 2 to 3 scant nests built and never completed or become active with egg laying.
Landlording since 1996 in beautiful southern Indiana.
Andrew Smith
Posts: 28
Joined: Thu Jun 20, 2019 6:11 am
Location: Burford, Ontario, Canada
Martin Colony History: 2019 - Hundreds of fly-bys August and September
2020- Visitors in April and June

I tend to agree with Ed "Some will disagree, but continually adding more cavities to active sites may prevent other potential now vacant martin colonies from attracting their first pair, especially where martin numbers are low or declining." I am trying to start a colony myself so may be a bit biased. My thoughts are that with climate change bringing on so many severe weather events having too many martins in one location can be risky. For example here in southern Ontario, Canada the weather can be severely varied due to the great lake affects. Also spill over may be good for the next generation of landlords. Some of the younger generation may not have the patience to wait many years to start a colony. One thing that we can all agree on is that getting young people to carry the tourch is a must... the very survival of the Purple Martin depends on it!
2019 - Set up T14 Multiple flyovers during migration in August
2020 - ASY male visit in April , SY male visits in June
Curtis Reil
Posts: 119
Joined: Mon Apr 29, 2013 7:51 pm
Location: Alberta/Tofield
Martin Colony History: I inherited this colony when I purchased the property from my Great Uncle. To the best of my knowledge, he had hosted Martins since 1977. Housing consisted of three twelve compartment units that he had built. Small compartments, round holes and no way to lower for managing. There were maybe 6-8 pairs here when we moved in. Through reading up on information provided by the PMCA and that provided to me by Bob Buskas, the decision was made to upgrade the housing. We are now fully switched over to North Star houses and hosted 58 pairs this season(2017). 60 compartments open for business and being so close to 100% occupancy, I believe we may expand housing offered next season. Expansion will continue contingent to high occupancy, being able to keep up on management and or until it starts to feel like work.

Without pulling out “The Binder” with all my records, I know I’ve been at 100% four seasons out of the last 14 or 15. At 36, 48 and twice at 60 pair(60 is what I offer). It’s much more common for me to see the 54-58 type count but 100% is not impossible. I’ll be close to, if not full again this year. Great ASY return and lots of SY birds to fill the gaps.

When I first started expanding/changing to modern housing, I had it in my head that I wanted around 100 pair. I still might at some point but to echo Ed to a degree, I can do a really good job caring properly for what I have. I never want this hobby to feel like work. A pile of healthy chicks are fledged here annually. Two of my neighbours have started colonies and they have exploded. My cousin erected a house this spring and has Martins already. I’m not saying it’s because of me because it isn’t, but it sure can’t hurt and I believe that at least a portion of the shared success is because of spill over from all the colonies in the area.

Similar to Ed, I did a bit of a test on leaving 20% of my compartments closed until SY birds started arriving over the last couple years. I have no way of proving anything other than occupancy but it did seem to help a bit in the reduction of fighting and such. Still had a couple single, troublemakers but that’s to be expected. Seems to be a pretty sound method to keep a colony “fresh”. That being said, I did not do it this year so I’m interested to see if there is any change in occupancy. Not to mention, an ASY male who may have been forced to look elsewhere is the greatest attraction tool a new colony could ask for upon start up.
Posts: 390
Joined: Thu Jun 28, 2007 7:07 am
Location: Iowa, New Sharon

Since approximately only 10 percent of subadult come back to their natal colony that would still leave 90 percent to go elsewhere.
2007 2 pair 8 fledged
2008 4 pair 18 fledged
2009 21 pair 87 fledged
2010 44 pair 174 fledged
2011 68 pair 244 fledged
2012 82 pair 364 fledged
2013 82 pair 359 fledged
2014 86 pair 415 fledged
2015 101 pair 427 fledged
Post Reply