Nests: Building, Structure, and Maintenance
Home, home building, and home improvement. Pogonomyrmex
ants and their nests
, at various locations in North America.
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***There may be multiple image pages; use page/image controls below to see them all!***
![<span class="captionImageInfo"> ● 9.3 km / 5.8 miles north of Madras [Jefferson Co], OR USA [el. 738 m / 2423 ft]</span> <a href="http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=100103460138962878270.000489156a1f0848cdadc&t=h&ll=44.699898,-121.047363&spn=2.733176,4.669189&z=7&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 7/21/09 7:15AM </span>
Built on a slope, this <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel</span></a> covered <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>P. salinus</em></span></a> nest in central Oregon measured about 60 cm / 2 feet wide, on its longest axis. There were several similar <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">dome/cone shaped nests</span></a> on this east-facing slope - optimally placed to receive direct sunlight in the morning.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-38LQTbJ/1/90a23dda/L/0729_09_40Df-L.jpg)
● 9.3 km / 5.8 miles north of Madras [Jefferson Co], OR USA [el. 738 m / 2423 ft] view location in Google Maps » ● 7/21/09 7:15AM Built on a slope, this gravel covered P. salinus nest in central Oregon measured about 60 cm / 2 feet wide, on its longest axis. There were several similar dome/cone shaped nests on this east-facing slope - optimally placed to receive direct sunlight in the morning.
![<span class="captionImageInfo"> ● Fernley [Lyon Co], NV USA [el. 1271 m / 4171 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.00048afd64f5e81bc4956&ll=39.614152,-119.262085&spn=1.481079,2.334595&z=8&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 6/23/10 6:36AM partly cloudy, air temp: 17°C / 62°F</span>
<div class="captionImageMain">While this looks like a fearsome defensive display, it is not. This <em>Pogonomyrmex californicus</em> worker has just dropped a load of coarse sand she had carried up from the subterranean depths of the nest. This kind of activity is ongoing, as the ants excavate new tunnels and galleries, and repair cave-ins. <span class ="footnoteTag">[scroll down for additional notes/references]</span></div>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-th98xg6/0/64e68340/Ti/4426_10_7Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Wanapum Rec. Area [Kittitas Co], WA USA [el. 190 m / 623 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470bd413e9e793ba1d&ll=46.905483,-119.9903&spn=0.164191,0.291824&z=11&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 5/16/10 9:00AM partly cloudy, air temp: 23°C / 73°F</span>
<div class="captionImageMain">[IMAGE 1 of 6] Winter rains had apparently washed away most of the external nest mound of this <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex salinus</em></span></a> colony, in central Washington state. In addition, large, jagged pebbles were either exposed by the erosion, or deposited around the nest entrance by the flowing water. In this series of images, dozens of <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">workers</span></a> can be seen attempting to remove the relatively huge rocks, by grasping them with their <a href="http://www.davidlouisquinn.com/pogolumina_mandiblesInfo.htm"><span class="glossLinkSm">mandibles</span></a> and dragging them away. Some of the objects appeared to be too large and heavy to be moved by a single ant, so in some instances, two or more workers would cooperatively carry them. It was also clear that the ants were completely unable to move some of the largest pebbles. Having a jumble of 'boulders' at the entrance to their nest would generally be unacceptable to these ants. The many nooks and crannies would make entering and exiting the nest very difficult (especially while carrying foraged seeds, etc), and spiders and other predators would be provided with many hiding places from which to prey upon colony members. In a situation like this, Pogos may sometimes choose to construct another nest entrance in a more suitable location.
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-K7vXcRq/2/13764274/Ti/3569_10_7Df-Ti.jpg)
![<span class="captionImageInfo"> ● Wanapum Rec. Area [Kittitas Co], WA USA [el. 190 m / 623 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470bd413e9e793ba1d&ll=46.905483,-119.9903&spn=0.164191,0.291824&z=11&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 5/16/10 9:02AM partly cloudy, air temp: 23°C / 73°F</span>
<div class="captionImageMain">[IMAGE 2 of 6] Winter rains had apparently washed away most of the external nest mound of this <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex salinus</em></span></a> colony, in central Washington state. In addition, large, jagged pebbles were either exposed by the erosion, or deposited around the nest entrance by the flowing water. In this series of images, dozens of <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">workers</span></a> can be seen attempting to remove the relatively huge rocks, by grasping them with their <a href="http://www.davidlouisquinn.com/pogolumina_mandiblesInfo.htm"><span class="glossLinkSm">mandibles</span></a> and dragging them away. Some of the objects appeared to be too large and heavy to be moved by a single ant, so in some instances, two or more workers would cooperatively carry them. It was also clear that the ants were completely unable to move some of the largest pebbles. Having a jumble of 'boulders' at the entrance to their nest would generally be unacceptable to these ants. The many nooks and crannies would make entering and exiting the nest very difficult (especially while carrying foraged seeds, etc), and spiders and other predators would be provided with many hiding places from which to prey upon colony members. In a situation like this, Pogos may sometimes choose to construct another nest entrance in a more suitable location.
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-9XLqQ3L/0/dc83bc2c/Ti/3573_10_7Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Wanapum Rec. Area [Kittitas Co], WA USA [el. 190 m / 623 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470bd413e9e793ba1d&ll=46.905483,-119.9903&spn=0.164191,0.291824&z=11&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 5/16/10 9:07AM partly cloudy, air temp: 23°C / 73°F</span>
<div class="captionImageMain">[IMAGE 3 of 6] Winter rains had apparently washed away most of the external nest mound of this <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex salinus</em></span></a> colony, in central Washington state. In addition, large, jagged pebbles were either exposed by the erosion, or deposited around the nest entrance by the flowing water. In this series of images, dozens of <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">workers</span></a> can be seen attempting to remove the relatively huge rocks, by grasping them with their <a href="http://www.davidlouisquinn.com/pogolumina_mandiblesInfo.htm"><span class="glossLinkSm">mandibles</span></a> and dragging them away. Some of the objects appeared to be too large and heavy to be moved by a single ant, so in some instances, two or more workers would cooperatively carry them. It was also clear that the ants were completely unable to move some of the largest pebbles. Having a jumble of 'boulders' at the entrance to their nest would generally be unacceptable to these ants. The many nooks and crannies would make entering and exiting the nest very difficult (especially while carrying foraged seeds, etc), and spiders and other predators would be provided with many hiding places from which to prey upon colony members. In a situation like this, Pogos may sometimes choose to construct another nest entrance in a more suitable location.
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-wxK4tvH/0/d410a68a/Ti/2080_10_40Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Wanapum Rec. Area [Kittitas Co], WA USA [el. 190 m / 623 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470bd413e9e793ba1d&ll=46.905483,-119.9903&spn=0.164191,0.291824&z=11&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 5/16/10 9:16AM partly cloudy, air temp: 23°C / 73°F</span>
<div class="captionImageMain">[IMAGE 4 of 6] Winter rains had apparently washed away most of the external nest mound of this <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex salinus</em></span></a> colony, in central Washington state. In addition, large, jagged pebbles were either exposed by the erosion, or deposited around the nest entrance by the flowing water. In this series of images, dozens of <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">workers</span></a> can be seen attempting to remove the relatively huge rocks, by grasping them with their <a href="http://www.davidlouisquinn.com/pogolumina_mandiblesInfo.htm"><span class="glossLinkSm">mandibles</span></a> and dragging them away. Some of the objects appeared to be too large and heavy to be moved by a single ant, so in some instances, two or more workers would cooperatively carry them. It was also clear that the ants were completely unable to move some of the largest pebbles. Having a jumble of 'boulders' at the entrance to their nest would generally be unacceptable to these ants. The many nooks and crannies would make entering and exiting the nest very difficult (especially while carrying foraged seeds, etc), and spiders and other predators would be provided with many hiding places from which to prey upon colony members. In a situation like this, Pogos may sometimes choose to construct another nest entrance in a more suitable location.
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-HkZ6RVB/0/56783e8b/Ti/3595_10_7Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Wanapum Rec. Area [Kittitas Co], WA USA [el. 190 m / 623 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470bd413e9e793ba1d&ll=46.905483,-119.9903&spn=0.164191,0.291824&z=11&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 5/16/10 9:20AM partly cloudy, air temp: 23°C / 73°F</span>
<div class="captionImageMain">[IMAGE 5 of 6] Winter rains had apparently washed away most of the external nest mound of this <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex salinus</em></span></a> colony, in central Washington state. In addition, large, jagged pebbles were either exposed by the erosion, or deposited around the nest entrance by the flowing water. In this series of images, dozens of <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">workers</span></a> can be seen attempting to remove the relatively huge rocks, by grasping them with their <a href="http://www.davidlouisquinn.com/pogolumina_mandiblesInfo.htm"><span class="glossLinkSm">mandibles</span></a> and dragging them away. Some of the objects appeared to be too large and heavy to be moved by a single ant, so in some instances, two or more workers would cooperatively carry them. It was also clear that the ants were completely unable to move some of the largest pebbles. Having a jumble of 'boulders' at the entrance to their nest would generally be unacceptable to these ants. The many nooks and crannies would make entering and exiting the nest very difficult (especially while carrying foraged seeds, etc), and spiders and other predators would be provided with many hiding places from which to prey upon colony members. In a situation like this, Pogos may sometimes choose to construct another nest entrance in a more suitable location.
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-LRvd9K4/0/3c287fab/Ti/3598_10_7Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Wanapum Rec. Area [Kittitas Co], WA USA [el. 190 m / 623 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470bd413e9e793ba1d&ll=46.905483,-119.9903&spn=0.164191,0.291824&z=11&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 5/16/10 11:11AM partly cloudy, air temp: 25°C / 77°F</span>
<div class="captionImageMain">[IMAGE 6 of 6] Winter rains had apparently washed away most of the external nest mound of this <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex salinus</em></span></a> colony, in central Washington state. In addition, large, jagged pebbles were either exposed by the erosion, or deposited around the nest entrance by the flowing water. In this series of images, dozens of <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">workers</span></a> can be seen attempting to remove the relatively huge rocks, by grasping them with their <a href="http://www.davidlouisquinn.com/pogolumina_mandiblesInfo.htm"><span class="glossLinkSm">mandibles</span></a> and dragging them away. Some of the objects appeared to be too large and heavy to be moved by a single ant, so in some instances, two or more workers would cooperatively carry them. It was also clear that the ants were completely unable to move some of the largest pebbles. Having a jumble of 'boulders' at the entrance to their nest would generally be unacceptable to these ants. The many nooks and crannies would make entering and exiting the nest very difficult (especially while carrying foraged seeds, etc), and spiders and other predators would be provided with many hiding places from which to prey upon colony members. In a situation like this, Pogos may sometimes choose to construct another nest entrance in a more suitable location.
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-6Zmmh5D/0/4fdf1f71/Ti/3649_10_7Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Castolon [Loc 41] Big Bend N.P., TX USA [el. 660 m / 2164 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.00048384c67ef9deb4b45&ll=29.13417,-103.513355&spn=0.05248,0.072956&z=13&source=embed"><span class="mapLink"> view location in Google Maps »<span></a>
<span class="captionImageInfo"> ● 3/04/10 11:46AM sunny, air temp: 24°C / 76°F</span>
<div class="captionImageMain">Before venturing to the surface, a <a href="http://www.davidlouisquinn.com/pogolumina_PdesertorumInfo.htm"><span class="glossLinkSm"><em>P. desertorum</em></span></a> worker peers out from the nest entrance. <span class ="footnoteTag">[scroll down for additional notes/references]</span>
</div>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>The integument (outer body covering) of these P. desertorum workers was quite translucent. When back-lit by the sun (as can be seen in some of these images), these ants glowed with the most beautiful orange-red color. In some cases, x-ray-like hints of their internal anatomy could be seen as well.</em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-WBSZDf3/0/a7ae283a/Ti/IMG_0796_10_7Dc-Ti.jpg)
![<span class="captionImageInfo"> ● Castolon [Loc 41] Big Bend N.P., TX USA [el. 660 m / 2164 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.00048384c67ef9deb4b45&ll=29.13417,-103.513355&spn=0.05248,0.072956&z=13&source=embed"><span class="mapLink"> view location in Google Maps »<span></a>
<span class="captionImageInfo"> ● 3/06/10 10:16AM sun/haze, air temp: 18°C / 64°F</span>
<div class="captionImageMain">A <em>Pogonomyrmex desertorum</em> worker emerging from her nest. <span class ="footnoteTag">[scroll down for additional notes/references]</span>
</div>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>The integument (outer body covering) of these P. desertorum workers was quite translucent. When back-lit by the sun (as can be seen in some of these images), these ants glowed with the most beautiful orange-red color. In some cases, x-ray-like hints of their internal anatomy could be seen as well.</em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-7h2ZCgt/0/f25b0e86/Ti/IMG_2139_10_7Df-Ti.jpg)
![<span class="captionImageInfo"> ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470f37e319b015bf28&ll=46.7596,-119.932433&spn=0.329276,0.583649&z=10&source=embed"><span class="mapLink"> view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 8/10/08 9:32AM air temp: 25°C / 77°F</span>
A tiny <a href="http://www.davidlouisquinn.com/pogolumina_incipientNestInfo.htm"><span class="glossLinkSm">incipient nest</span></a> of <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm">Pogonomyrmex salinus</span></a>, with <a href="http://www.davidlouisquinn.com/pogolumina_naniticInfo.htm"><span class="glossLinkSm">nanitic</span></a> workers. Width of raised sand crescent is approximately 6.3 cm / 2.5 inches. One worker can be glimpsed re-entering the nest entrance, at center of image.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-bpxQHc9/0/06684dc1/Ti/0495_08_Rf-Ti.jpg)
![<span class="captionImageInfo"> ● 9.3 km / 5.8 miles north of Madras [Jefferson Co], OR USA [el. 738 m / 2423 ft]</span> <a href="http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=100103460138962878270.000489156a1f0848cdadc&t=h&ll=44.699898,-121.047363&spn=2.733176,4.669189&z=7&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 7/21/09 7:15AM </span>
Built on a slope, this <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel</span></a> covered <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>P. salinus</em></span></a> nest in central Oregon measured about 60 cm / 2 feet wide, on its longest axis. There were several similar <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">dome/cone shaped nests</span></a> on this east-facing slope - optimally placed to receive direct sunlight in the morning.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-38LQTbJ/1/90a23dda/Ti/0729_09_40Df-Ti.jpg)
![<span class="captionImageInfo"> ● 9.3 km / 5.8 miles north of Madras [Jefferson Co], OR USA [el. 738 m / 2423 ft]</span> <a href="http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=100103460138962878270.000489156a1f0848cdadc&t=h&ll=44.699898,-121.047363&spn=2.733176,4.669189&z=7&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 7/21/09 7:19AM </span>
Another <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">low nest mound</span></a> of <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>P. salinus</em></span></a>, with long sloping face oriented to receive sunlight early in the day.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-m8FHBfs/0/f01337d8/Ti/0733_09_40Df-Ti.jpg)
![<span class="captionImageInfo"> ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470f37e319b015bf28&ll=46.7596,-119.932433&spn=0.329276,0.583649&z=10&source=embed"><span class="mapLink"> view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 9/4/08 8:53AM sunny, air temp: 23°C / 73°F</span>
A large, flat <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">disc shaped</span></a> nest of <em>Pogonomyrmex salinus</em>, in central Washington state.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-LLRRJRr/0/d47edf7a/Ti/0966_08_Rf-Ti.jpg)
![<span class="captionImageInfo"> ● SW of Pyramid Lake [Washoe Co], NV USA [el. 1323 m / 4341 ft]</span> <a href="http://maps.google.com/maps/ms?hl=en&ie=UTF8&t=h&msa=0&msid=100103460138962878270.00048ab74785d385f672e&ll=39.800096,-119.665833&spn=0.738551,1.167297&z=9&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 6/24/10 6:32AM mostly sunny, air temp: 12°C / 53°F</span>
The elongated <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">mound</span></a> of this large <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm"><em>P.occidentalis</em></span></a> nest was about 60cm / 2 ft wide, on its longest axis. The nest was oriented so that the side you see in this image faced east, receiving direct sunlight in the morning. The large cave-like main entrance can be seen in the center of the image (there was another smaller entrance just out of view on the northeast end). This mound sat in a 2.4m / 8 ft wide <a href="http://www.davidlouisquinn.com/pogolumina_nestClearingInfo.htm"><span class="glossLinkSm">clearing</span></a>, and was completely covered with <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel</span></a>. The shrub just behind the nest is saltbush (<em>Atriplex sp.</em>). <span class ="footnoteTag">[scroll down for additional notes/references]</span>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em></div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-RZzrbX3/0/303c3e4f/Ti/4223_10_Rc-Ti.jpg)
![<span class="captionImageInfo"> ● SW of Pyramid Lake [Washoe Co], NV USA [el. 1323 m / 4341 ft]</span> <a href="http://maps.google.com/maps/ms?hl=en&ie=UTF8&t=h&msa=0&msid=100103460138962878270.00048ab74785d385f672e&ll=39.800096,-119.665833&spn=0.738551,1.167297&z=9&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 6/24/10 8:28AM mostly sunny, air temp: 22°C / 72°F</span>
Another <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm"><em>P.occidentalis</em></span></a> nest, about 12 m / 40 ft from the previous one pictured. This <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">cone-topped mound</span></a> was approx. 30 cm/ 1 ft in height, and perfectly covered with <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel</span></a>. <a href="http://www.davidlouisquinn.com/pogolumina_workerInfo.htm"><span class="glossLinkSm">Workers</span></a> can be seen at the extreme right corner of the image, where the single entrance was located. <span class ="footnoteTag">[scroll down for additional notes/references]</span>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Many Pogo nests sport a prominent <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel-covered</span></a> mound, cone, or crater which contains a small network of galleries and tunnels. In some cases, this mound feature is not present, and the external nest structure consists simply of entrance holes in the ground, often surrounded by a gravel 'disc', and located within an area cleared of vegetation.
However, like the proverbial 'tip of the iceberg', the above-ground portion of a Pogo nest represents only a tiny fraction of the whole colony - in terms of ant population, and in the physical structure and extent of the nest itself.
The subterranean portions of Pogonomyrmex nests usually contain one or more large (approximately vertical) tunnels - and branching off from these, many 'side burrows' and chambers. These offshoots are more numerous (and larger) nearer the surface, and dwindle in frequency and size, as depth increases. These chambers function as granaries, nurseries, general quarters, and sometimes refuse dumps.
<a href="http://www.davidlouisquinn.com/pogolumina_PogonomyrmexInfo.htm"><span class="glossLinkSm">Pogonomyrmex</span></a> nests can reach considerable depths. Nests of <a href="http://www.davidlouisquinn.com/pogolumina_PrugosusInfo.htm"><span class="glossLinkSm">P. rugosus</span></a> (the rough harvester) have been shown to extend 4 m / 13 ft into the ground, and those of <a href="http://www.davidlouisquinn.com/pogolumina_PoccidentalisInfo.htm"><span class="glossLinkSm">P.occidentalis</span></a> have been recorded to reach depths of 3 m / 10 ft.
Along with distinct variations among different Pogo species, there are many variables that affect the proportions of a particular colony's nest. It's likely that most nests are somewhat shallower than the figures given above.
·MacKay, W.P. 1981. A Comparison of Nest Phenologies of Three Species of Pogonomyrmex Harvester Ants (Hymenoptera: Formicidae). Psyche, Vol. 88, No. 1-2, 1981
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press.
·Wheeler, W.M. 1910. Ants: Their Structure, Development and Behavior. New York, Columbia University Press
<em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-Nvwht9X/1/b656c19e/Ti/2224_10_40Dc-Ti.jpg)
![<span class="captionImageInfo"> ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470f37e319b015bf28&ll=46.7596,-119.932433&spn=0.329276,0.583649&z=10&source=embed"><span class="mapLink"> view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 9/4/08 7:52AM sunny, air temp: 21°C / 69°F</span>
This <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>P. salinus</em></span></a> nest is in the process of <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">transitioning from a crater, to a dome</span></a>. The wide crater opening can still be seen on the left (filled with workers), while the right side of the nest is expanding and rising into a dome-like structure. Much of the mound surface is covered with <a href="http://www.davidlouisquinn.com/pogolumina_chaffInfo.htm"><span class="glossLinkSm">chaff</span></a>, and chewed-down stalks of grass can be seen as well. An immature black widow spider's (<em>Latrodectus hesperus</em>) web is suspended above the left side of the nest - apparently the ants were not diligent enough in their <a href="http://www.davidlouisquinn.com/pogolumina_nestClearingInfo.htm"><span class="glossLinkSm">plant removal</span></a> operations...<span class ="footnoteTag">[scroll down for additional notes/references]</span>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>Based on our observations, juvenile western black widow spiders (Latrodectus hesperus) are frequent predators of <em>P.salinus</em> ants in central Washington state. We have not observed any adult L. hesperus preying on Pogonomyrmex salinus, nor have we seen any near the ants, or their nests. This is consistent with the findings of MacKay, in his study of L. hesperus and Pogonomyrmex rugosus, where it was observed that females apparently stop feeding on ants when they become adults (according to MacKay, it is possible that males continue to prey on the ants throughout their lives, though as noted above, we have not yet observed this).
Latrodectus hesperus spiders often position themselves in a web just outside the entrance to a Pogo nest. Pogos have been known to close a nest entrance, and open a new one a short distance away, to avoid these predators. Some species, like Pogonomyrmex rugosus, may stop foraging altogether (living on stored seeds), until a spider (or spiders) leave the vicinity of the nest (L. hesperus will move to an active nest nearby, if this occurs). We have seen evidence of these behaviors in Pogonomyrmex salinus (in central WA) as well, with web-covered entrances apparently blocked with debris by the ants, and no foraging activity occurring. Despite their powerful mandibles and formidable stings, Pogos do not appear to be able (or willing) to attack, kill, or repel these predators directly - relying instead on the more passive methods of avoidance mentioned above. We have also observed P. salinus workers attempting to remove webs (most likely webs of L. hesperus) from the vicinity of the nest entrance, however in these cases, no spiders were present.
In areas where we observe western black widows preying on P. salinus, it is usually evident that the spiders are not specializing on ants to the exclusion of all other arthropods, as we sopmetimes see the remains of beetles, and other insects in their webs.
·MacKay, W. 1982. The Effect of Predation of Western Widow Spiders (Aranea; Theridiidae) on Harvester Ants (Hymenoptera: Formicidae). Oecologia (Berl) (1982) 53:406-411
</em>
</div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-c9TmZHD/0/e9b9e468/Ti/0894_08_Rc-Ti.jpg)
![<span class="captionImageInfo"> ● Horse Ridge, SE of Bend [Deschutes Co], OR USA [el. 1310 m / 4297 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.00047a3daca81cf459487&ll=43.912533,-121.007083&spn=0.086565,0.145912&z=12&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 7/20/09 6:50AM sunny, air temp: 10°C / 50°F </span>
This massive <a href="http://www.davidlouisquinn.com/pogolumina_PsalinusInfo.htm"><span class="glossLinkSm"><em>P. salinus</em></span></a> nest is built around large rocks, and covered with a staggering amount of <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel</span></a>. The nest entrance (there was only one, last time we visited) is located under the edge of the large central boulder. The distance between the two yellow markers is approximately 1.9 m / 76 inches. <span class ="footnoteTag">[scroll down for additional notes/references]</span>
<div class="captionRefFootnote">ADDITIONAL NOTES/REFERENCES:
<em>On our first visit to this nest (7/15/08) the air temperature was 28°C / 82°F, and the ants were foraging along a trail in the shade of a large rock. Soon after I approached the entrance, many dozens of workers (defenders) poured out, and ran toward me. Most turned back after I backed away, but approximately 10 workers continued pursuing me more than 3.6 m / 12 ft from the entrance, often stopping to stand on small pebbles and twigs while waving their antennae wildly, and opening their mandibles.
At many other P. salinus nests nearby, workers were not aggressive, and ignored us - even when inches away from the entrances.
We think the physical size of the large nest (mentioned above), may have something to do with the very aggressive worker response to our presence. The gravel-covering of this nest was approx. 1.9 m / 76 in. wide, measured on its longest axis. This means that I had to walk over a large portion of the nest 'dome' in order to reach the entrance - undoubtedly collapsing many tunnels and galleries that lay just below the gravel covered surface. This would result in alarm pheromones being released in great quantities by the ants underfoot, alerting nestmates to the defense of their colony.</em></div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-pzFbT5R/0/c81daafe/Ti/0464_09_40D-Ti.jpg)
![<span class="captionImageInfo"> ● HWY 17, Sun Lakes S.P. [Grant Co], WA USA [el. 340 m / 1116 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.00047c0cb6a2b785aa136&ll=47.466324,-119.51498&spn=1.29976,2.334595&z=8&source=embed"><span class="mapLink">view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 9/21/08 11:58AM overcast, air temp: NA</span>
The <a href="http://www.davidlouisquinn.com/pogolumina_gravelInfo.htm"><span class="glossLinkSm">gravel covering</span></a> of this unique <em>P. salinus</em> nest, extended approximately 1 m / 39 inches on its longest axis. The mound takes the form of a <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">low dome</span></a> built around a large central rock. Mineral deposits abundant in this area of central Washington state are responsible for the sprinkling of white particles amongst the gravel, and for the white rock face.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-Brr8zhh/0/71f4e38c/Ti/1499_08_Rf-Ti.jpg)
![<span class="captionImageInfo"> ● NW of Mattawa [Grant Co], WA USA [el. 152 m / 500 ft]</span> <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&t=h&msa=0&msid=100103460138962878270.000470f37e319b015bf28&ll=46.7596,-119.932433&spn=0.329276,0.583649&z=10&source=embed"><span class="mapLink"> view location in Google Maps »</span></a>
<span class="captionImageInfo"> ● 9/21/08 9:28AM overcast, air temp: NA</span>
Here we see a gravel covered <a href="http://www.davidlouisquinn.com/pogolumina_externalNestInfo.htm"><span class="glossLinkSm">crater nest</span></a> of <em>P. salinus</em>, surrounded by <a href="http://www.davidlouisquinn.com/pogolumina_nestClearingInfo.htm"><span class="glossLinkSm">cut-down grass stems</span></a>, and a large amount of <a href="http://www.davidlouisquinn.com/pogolumina_chaffInfo.htm"><span class="glossLinkSm">chaff</span></a>.](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-GPfZ4Hb/0/a27fe4d9/Ti/1407_08_Rf-Ti.jpg)
![<span class="captionImageInfo"> ● Mission Espada, San Antonio [Bexar Co], TX USA </span>
<span class="captionImageInfo"> ● 3/01/10 3:14PM sun/clouds, air temp: 15°C / 60°F</span>
<div class="captionImageMain">[IMAGE 1 of 4] Late winter/early spring nest maintenance. These <a href="http://www.davidlouisquinn.com/pogolumina_PbarbatusInfo.htm"><span class="glossLinkSm"><em>Pogonomyrmex barbatus</em></span></a> workers were slowly bringing loads of sand/soil up from the depths of their nest. They appeared to be utilizing their <a href="http://www.davidlouisquinn.com/pogolumina_psammophoreInfo.htm"><span class="glossLinkSm">psammophores</span></a> in some cases, and their mandibles alone, in others - depending on the moisture content of the soil they were transporting. It had rained the day before these images were captured, and much of the soil was quite moist and clumped - allowing it to be easily picked up and carried in the mandibles of these workers (like a clump of sticky rice can be picked up with chopsticks). </div>](https://photos.smugmug.com/NorthAmericanPogosbyBehavior/Nests/i-N697dTR/0/9ff29f98/Ti/IMG_0549_10_7Dc-Ti.jpg)
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