Are we producing too many tree swallows?

[Ed Svetich-WI]

I have referenced the following article in the past postings. My goal in referencing it again was influenced by many posts here on the Forum regarding tree swallows as well as personal contact with a number of bird lovers who have "gone overboard" by providing multiple bird houses for blue birds and tree swallows, some to relieve pressure on martin housing and some simply because they like blue birds or tree swallows. One local property owner has a blue bird house on every fencepost along his pasture. A recent survey showed 11 tree swallow nests, 3 house sparrows,1 wren and 2 bluebird nests, hardly the ideal outcome.

The Drew TS Protocol to provide alternate housing for both tree swallows and blue birds when attempting to establish a new purple martin colony has been very successful in helping potential landlords establish new colonies. I used the same protocol when establishing my current colony. I found tree swallows to be the most aggressive native birds that deterred martins at my potential site for a number of years. At times, groups of tree swallows mobbed investigating martins and drove them away.I had two blue houses widely separated on my property and had resident blue birds in both (one luckily near the martin pole). I added three more nest boxes to attract the tree swallows and hopefully deter tree swallow aggression directed at martins investigating the martin housing. I ended up with one pair of blue birds and four pair of tree swallows for a net loss of one pair of blue birds.

Historically, housing placement to assist the bluebird recovery emphasized placing blue bird houses at least 100 yards apart! This was because of the territoriality of the blue birds. Housing placed too close rarely attracted other blue birds and often attracted tree swallows and other cavity nesting birds. Unfortunately, if one house was good then many more had to be better. This article discusses house design and placement.

The question that I am asking for consideration is whether we are producing too many tree swallows, fewer blue birds and ultimately adding to the challenge of establishing new martin colonies?

In my own case, I reduced the number of blue bird/ tree swallow houses at home and at two blue bird trails that I manage with the result that I now produce more blue birds and fewer tree swallows.I do not dislike tree swallows, but I prefer blue birds. The blue birds still need our assistance while the tree swallows have more nesting options due to their ability to utilize more environments unattractive to blue birds.

Ed

http://dnr.wi.gov/wnrmag/html/stories/2 ... uebird.htm

[DAVE]

I agree with you. I have 2 boxes for 1 set of tree's and 1 set of Blue Birds. They are 12 feet apart 25 feet from Martin Racks. I leave the Blue Bird box closed until I see them. I only open 2 Gourds until the Martins come. Seems to work OK!
Dave

[Hanover Bill]

Hi Ed;

I am certainly no expert, but I am overrun with Tree Swallows this year. I have never seen so many. They have been harrassing the few visiting Martins I have had even though I have provided nesting options for them.
Thankfully the Martins are holding their own against them.

They are great little birds, but I could do with a few less of them.

Hanover Bill.

[lcline85]

I am still attempting to attract martins and am in no way an expert, but my opinion is that the Tree Swallows need all the help they can get as well. Sure they may not be entirely dependent on humans like Martins are, but their natural cavities are quickly over taken by starlings and sparrows. We just don't see it happening because it is off in the woods and trees and other cavities we don't monitor.

I think that properly placed and timed TRES can be a help to your martin colony by helping protect the housing from HOSP and other investigating TRES.

I have one pair of nesting TRES, and luckily they are pretty docile. I have had a few martins investigate my housing and the TRES have sat on the line simply observing. I had a martin sit right next to my TRES and have had no reaction. But I have heard quite the opposite experiences from quite a few people.

Having boxes available for TRES really helps out their species too and they are beautiful and entertaining backyard birds to have around. And also eat flying insects and pests.

There is a fairly large colony here that I visit. They have 4 large houses. And since they have a fairly large property they have about 10 TRES boxes spread throughout their property as well. The biggest problem might be when it starts to get crowded. Proper spacing of TRES boxes might clear up alot of problems.

[Ed Svetich-WI]

As the article on the link says, more blue bird type houses do not equate with more blue birds. To the contrary, just the opposite is true. I found the article very informative 10 years ago and found that the field research made sense. I took the information and the suggestions to heart and found that I produced more blue birds with fewer houses. I have four bluebird type houses on 1.5 acres. The two tree swallow nests are 200 feet apart on the lake shore and the two blue bird nests are at the opposite ends of the property about 250 feet apart. The extra houses were used to start an additional blue bird trail.

You may be correct and tree swallows need help, but if you are trying to establish a new martin colony, the last thing you want is to have a neighbor increasing the tree swallow population by placing too many houses. A few well spaced houses for tree swallows may be fine, the issue is overdoing it and not following the Drew protocol to the letter. The end result could be as Bill says and you too could be overrun by tree swallows.

I just spoke with a friend who is trying to establish a new colony a few miles from me. He watched as a number of tree swallows harassed a lone SY martin tonight. I'll wager that he is regretting the two occupies tree swallow houses near his future colony.

I hope everyone is successful in establishing martin colonies.

Ed

[lcline85]

Thanks, I agree some get too over enthusiastic about adding boxes to a property to accommodate these birds, while really they are creating more of a problem.

[tonyg]

I agree Ed..I have 15 acres and have 7 boxes on 8ft landscape timbers and 2 on telephone poles, all spaced 75/100 yds. 7 have TS and 2 BB. When I first put them all up, I had 6 pair of BB. That lasted about 3 years till the TS found them....don't get me wrong, I like the TS, but miss the BB more.. Some people may not like this, but I don't let the TS raise a full clutch of eggs. I limit 2/3 per nest, most lay 5/6..don't knowif i'm accomplishing anything, but may limit TS showing up the following year...who knows..

[KathyF]

Ed,
That was an interesting article. I have 12 bluebird / tree swallow nest boxes on my property. None of mine are "paired" and 4 of them have the round holes to allow bluebirds in and are the required 100 yds apart and away from my 'grid' of TRES housing. The other 8 are closer together (100 ft) and those host tree swallows.

Even with the required spacing of 100 yds, and before the TRES arrive, I can't seem to get more than one nesting pair of bluebirds. I have seen a second pair arrive, but eventually, the second pair will disappear and all year I'll only have the one pair. I even had 2 empty nestboxes available last year and no BB or TRES took them - this year the TRES moved into them. My nesting pair of BB's even raised a family in one box this year while a pair of TRES were sitting on top of their box. The TRES moved into their nestbox the evening of the day the BBs fledged.

I would love to have more BBs, but I don't know where to put the housing to get them. All of my boxes have the floors at about 5 or 6" from the entrance hole, so I don't think my nestboxes are a problem. In fact, the plans for it were from the BB assoc. At this point, TRES would probably take them over.

[Ed Svetich-WI]

Kathy,

I don't know how large your property is. Is it possible that you have too many blue bird type houses available? I also have a 10 acre parcel with about 5 acres of pasture. In that 5 acres I have 4 blue bird houses. Two have blue birds, one has a Tree swallow and one has a chickadee nest. I have the same number of blue birds nesting that I did when I had twice as many nest boxes. Since the blue birds have two clutches around here, they( hopefully) produce twice as many young/nest box as the tree swallows, which only have one clutch a year and the population of blue birds should increase at a greater rate to my way of thinking.

I will close empty houses here at home when I observe tree swallows investigating them early in the season to drive them somewhere else. I would rather have the house empty than have tree swallows. They usually take the houses on the lake shore that the blue birds are not interested in and there are only two of those. I don't let them nest on the land so to speak. Usually, the blue birds nest in late March or early April here in central Wisconsin. The first blue birds have fledged here about a week ago while the tree swallows have been laying eggs for about a week. The blue birds are now back at the nest box getting ready for the second clutch of eggs.

I just think that it is a mistake to encourage tree swallows even if only as a consolation when the martins have not colonized. There will be trouble later when the SY martins come, if not this year than next. I am singularly focused on martins both here and at the sites of those I mentor.

Ed

[KathyF]

Ed, I have 23 acres. I wanted a BB trail, but it's turned into a "tree swallow" trail. I'm ok with that, but I'd like to get more nesting bluebirds.

I have a large martin colony, so that's not a concern. I guess I could close up nestboxes, but as I have 4 BB houses and only one pair take up residence in the spring, it seems like a waste to close up the rest.

I also had a nesting chickadee and tufted titmouse nest here also, eventually.

I'll probably have to experiment with housing placement and see what happens next year.

[Glen Webb Jr]

I'll never stop enjoying tree swallows. I know they can be troublesome with establishing martin colonies (as I've had experience in that situation years ago). But I don't care how many tree swallows have monopolized my bluebird boxes, I'm still able to get 2-3 pairs of bluebirds in the boxes my dad and I provide. This year was the year for the tree swallows in our area. We've always had good numbers, but word must have gotten out about nice homes for lease because they arrived earlier than ever and 8 out of 10 boxes have tree swallows in them.

In the past when my martin colony was establishing, tree swallows were VERY persistent in trying to nest in the gourds and later the one Trio house I offered. Martins were there, but the swallows were dead set on nesting among all that chattering. I was finally able to get them to nest in a wooden box and I have never had a problem in the 10+years since establishing my recent colony.

What I actually have a problem with is the one pair of bluebirds that continue to nest in the densest tree swallow area and fuss and boss the swallows around. Now that baby swallows are in the boxes, the bluebirds are put in their place.

[Ed Svetich-WI]

Kathy,

Maybe the blue bird question is best answered by the local Bluebird Restoration organization. The article was written the the Wisconsin chapter. Missouri probably has one also. They may have some suggestions. I am going to check with local group in Wisconsin and see what they advise regarding tree swallows taking over blue bird trails. As we both have established colonies, the issue is not a pressing one but the answers may apply to those trying to establish new martin colonies.

Good conversation at any rate. I will share whatever info I receive.

Ed

[Madame WingNut]

I do a lot of Eastern Bluebird (EABL) trail and Purple Martin (PUMA) conservation work in central and northern Ohio. I also raise a lot of Tree Swallows in TRES grids and pond perimeter trails. I love working with all these species. All the PUMA rigs I monitor have at least one nestbox sited near the PUMA rig (I usually place box about 10 feet from it to maximize territoriality of TRES) to entice TRES to nest in box and keep other TRES out of the PUMA rig.

EABL and TRES have very different territory requirements. They also have different preferred habitat. As a rule, EABL will only nest over 100 to 150 yards from another of their species. TRES will comfortably nest 22 -25 yards from another TRES. There is definitely harrassment and competition by both species when they are choosing a nesting site, but we consider these birds "good neighbors" as I have never experienced either one harming the other inside the nest box - i.e. they don't destroy each others' eggs or young as we see with House Wrens and House Sparrows.

I work with isolated, paired box stations, and TRES grid set-ups. If you do not have House Sparrows (HOSP) or TRES on your trail AND you have good EABL habitat (expanse of short mowed grass adjacent to box), isolated boxes spaced every 100 - 150 yards will work great for EABL conservation.

If you have the other species on your trail, I much prefer paired stations with two nest boxes spaced 12 to 15 feet apart. This seems to be the ideal spacing as it allows EABL to take one box and TRES to take the other. Putting them this close uses the territoriality of the TRES to keep other TRES from using the adjacent box, essentially reserving it for EABL if they are looking for a nesting site. In central Ohio, EABL outcompete TRES in paired box stations. They begin nesting before TRES migrate back. They throw their weight around and very often will not allow a TRES to use the box adjacent to theirs. EABL will often build nests in both boxes, using one and reserving the second one for future brood or to dissuade other birds from using the box. Now, if you have HOSP in your area, this second box can act as a trap box when/if HOSP show up looking for a nest site. As a general rule, HOSP are more likely to "try" to use the box that is not as heavily guarded by the EABL. The key is to trap them ASAP when they have "claimed" the box. I often get them before they put any nest material in a box.

In TRES grids or TRES pond perimeter trails (boxes spaced 25 yards apart), we still almost always get one EABL nesting in the grid and this occurs with intense competition from a lot of TRES. We would not expect to have more than one EABL nesting in a grid due to their territory requirements (100 to 150 yards).

TRES grids can be placed in unmowed tall grass or marshy areas. If you do install boxes in this habitat, without short mowed grass nearby, you cannot expect to have EABL nest with you at all because they require short mowed grass near their nest site to hunt for ground insects. TRES, of course, only eat insects on the fly so tall grass near water is ideal habitat for them. They like short mowed grass fine too, but seem to need a source of water nearby to help provide the flying insects they feed on.

When you work with TRES grids, there is also a dynamic of competition between other TRES too. All my PUMA rigs are stationed inside TRES grids and I find that the TRES are so intent keeping their box safe from other TRES that show up to nest, that they leave the PUMA rig alone. Of course, if you do not space a box close to the PUMA rig, they will simple consider it another nest site opportunity. The protocol referred to recommends putting a box 25 feet from rig, but in intense TRES breeding grounds such as my rigs on Lake Erie, I put the box about 10 feet away, maximizing that territoriality as they get more defensive of the space nearer their box. Has worked extremely well for me.

Paula Z
Delaware County Area Contact
Ohio Bluebird Society

[KathyF]

Paula,
This is excellent information!

I have a TRES grid setup as you describe and BB housing spaced as required. But my BBs still seem very dominate in the spring. One thing I've noticed is that in the spring, all the investigating BBs tend to congregate at center of my PUMA colony on all the perches where a male & female will fight with another pair, usually successfully running them off. They will torment them and follow them all around the property until they leave.

One thing you mention is the "mowed areas" and that has cued me in to the potential problem. Since we keep only the areas around my house & PUMA colony mowed, this is the only area where they come to hunt (creating a hunting territory issue, perhaps?). Maybe by keeping the areas around the BB houses that are much further out would reduce that conflict, as they all wouldn't have to come up here to hunt. Hmmmmmm......

I do love my TRES grid and love hosting them, but we really want to host more BBs too. I have a feeling when I tell hubby of my new plan, he's going to teach me how to run the bush hog.

HOSP don't make it very long here either. As you do, I have every box setup for the VanErt traps (5 of them ), so they're dealt with very, very quickly.

[MB12RING]

There are pleanty here in MI

I have tried to start 2 different satelite colonies this year in really prime spots, both on lakes.

Both set-ups were installed 10/14 days ago to coincide with SY returns and both have TRES defending the whole set-up from any other birds. One is a T-14 with 4 gourds and the other is a multi purpose pole with 2 trio castles and 4 gourds. In both cases the TRES took up residence in 1 of the gourds and now defend the entire set-up.

It is really frustrating trying to do all the right things and getting these results. I would have assumed that the TRES would have already had nests somewhere this late in the year, that is why I waited this long to install the housing. In many ways they are more frustrating than HOSP because you legally can't eliminate them and they are more agressive towards the Martins than HOSP are.

[Ron Shaffer]

Anyone tried using more Gilbertson PVC housing? I just bought 2 additional to add to the one I've had for 3 years....I have plenty of other housing, but in my limited experience, bluebirds are the only ones who have attempted to nest in my lone Gilbertson box?????

[DAVE]

My previous post didn't work out to well. The tree's took over the Blue Bird box after their nest was built So in order to keep from having 3 sets of tree's I moved the Blue Bird Box at 10 feet from another Tree's box and the new Tree's moved on and 2 days later the Blue Birds moved back in. I don't know if this will work elseware but put up 2 Boxes with in 10 feet of one another and a hundred yard apart you just might have the best of two worlds. Next year I'm going to try this. Good luck everyone.
Dave