Re: [cobirds] Loon molt
Nick et al.: While wing molt may not be the cause of the McIntosh PALO not diving, there are any number of other possibilities, such as illness. However, it might behoove us to know what it's eating, if anything. If nothing, that could provide more suggestion in the vein of illness or other infirmity. However, loons eat things other than fish, though usually considered obligate piscivores. From the Common Loon BNA account (I couldn't get to the PALO account) -- bna.birds.cornell.edu/bna/: Crustaceans—e.g., crayfish (Decapoda) constitute major part of diet when fish are scarce or water is murky (1.0 m visibility), up to about a third of diet for males and more for females (Barr 1973). On some Wisconsin lakes, observed adults and chicks regularly observed foraging on snails (W. Piper, pers. com.). Leeches (Hirudinea) are occasionally an important food, and individuals that are stressed or ill sometimes eat vegetation (Barr 1973). Having no chance to go see the loon in question, others will have to provide the data on the bird's foraging, or lack thereof. Tony Leukering Villas, NJ -Original Message- From: Nick Komar quetza...@comcast.net To: coloradodip...@aol.com; cobirds@googlegroups.com Sent: Thu, Aug 26, 2010 11:47 pm Subject: Re: [cobirds] Loon molt Many thanks to Tony Leukering for setting the record straight on underwater wing-powered locomotion (or rather, lack thereof) among loons, and also for sharing his vast wealth of ornithological knowledge with our Colorado birding community, making us all wealthier (in knowledge, anyway). I should have done some basic research before sticking my foot in my mouth in a public forum like Cobirds. I have now done the appropriate homework to learn more about underwater locomotion among diving birds. A number of bird taxa including alcids, diving petrels, some shearwaters, and our Rocky Mountain dippers use their wings to power underwater diving as well as aerial flight, but not loons. Interestingly, I learned that some of these species undergo very heavy wing molt and yet still dive during these periods of wing molt. So, it begs the question (maybe Tony can answer this as well), why is the Boulder Pacific Loon not diving as would be typical foraging behavior for this species. Thanks again, Tony! Nick Komar Fort Collins CO -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
Re: [cobirds] Loon molt
Hi Folks, I just returned from watching the Big Mac Pac Loon and it was diving frequently. Many of the dives were very short, 1 - 4 seconds. A few were closer to 10 seconds and one time when I got to 20 seconds I looked around and realized it had swum out of view while under. It was also spending a lot of time simply holding its head under. The clartity of the water was rather poor. You cannot see the bottom three feet from shore. There was just a slight breeeze and it was only making a ripple on the surface. I wonder if its behavior could be due to the water conditions rather than illness of injury? I also found a City of Longmont doc which states that fishermen could expect to catch carp, walleye, and crappie. And the shoreline has always been popular with large waders like Great Egret and Great-blue Heron. Bob Zilly, Longmont On Fri, Aug 27, 2010 at 3:27 PM, coloradodip...@aol.com wrote: Nick et al.: While wing molt may not be the cause of the McIntosh PALO not diving, there are any number of other possibilities, such as illness. However, it might behoove us to know what it's eating, if anything. If nothing, that could provide more suggestion in the vein of illness or other infirmity. However, loons eat things other than fish, though usually considered obligate piscivores. From the Common Loon BNA account (I couldn't get to the PALO account) -- bna.birds.cornell.edu/bna/: Crustaceans—e.g., crayfish (Decapoda) constitute major part of diet when fish are scarce or water is murky (1.0 m visibility), up to about a third of diet for males and more for females (Barr 1973http://species/313/biblio/bib015). On some Wisconsin lakes, observed adults and chicks regularly observed foraging on snails (W. Piper, pers. com.). Leeches (Hirudinea) are occasionally an important food, and individuals that are stressed or ill sometimes eat vegetation (Barr 1973 http://species/313/biblio/bib015). Having no chance to go see the loon in question, others will have to provide the data on the bird's foraging, or lack thereof. Tony Leukering Villas, NJ -Original Message- From: Nick Komar quetza...@comcast.net To: coloradodip...@aol.com; cobirds@googlegroups.com Sent: Thu, Aug 26, 2010 11:47 pm Subject: Re: [cobirds] Loon molt Many thanks to Tony Leukering for setting the record straight on underwater wing-powered locomotion (or rather, lack thereof) among loons, and also for sharing his vast wealth of ornithological knowledge with our Colorado birding community, making us all wealthier (in knowledge, anyway). I should have done some basic research before sticking my foot in my mouth in a public forum like Cobirds. I have now done the appropriate homework to learn more about underwater locomotion among diving birds. A number of bird taxa including alcids, diving petrels, some shearwaters, and our Rocky Mountain dippers use their wings to power underwater diving as well as aerial flight, but not loons. Interestingly, I learned that some of these species undergo very heavy wing molt and yet still dive during these periods of wing molt. So, it begs the question (maybe Tony can answer this as well), why is the Boulder Pacific Loon not diving as would be typical foraging behavior for this species. Thanks again, Tony! Nick Komar Fort Collins CO -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.comcobirds%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/cobirds?hl=en. -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
Re: [cobirds] Loon molt
When Joel and I observed the loon on July 26th, it dove frequently and readily enough (every couple of minutes). It would stay under for 30 seconds at most and seemed to have its head underwater for most of the time otherwise. It had a fairly good success rate, as it came up with what I believe were shad (a non-game fish which I know to be in the lake) every dozen or so dives. Marcel Such NW of Lyons, CO mps...@gmail.com suchboys.blogspot.com On Fri, Aug 27, 2010 at 5:25 PM, Robert Zilly bzbir...@gmail.com wrote: Hi Folks, I just returned from watching the Big Mac Pac Loon and it was diving frequently. Many of the dives were very short, 1 - 4 seconds. A few were closer to 10 seconds and one time when I got to 20 seconds I looked around and realized it had swum out of view while under. It was also spending a lot of time simply holding its head under. The clartity of the water was rather poor. You cannot see the bottom three feet from shore. There was just a slight breeeze and it was only making a ripple on the surface. I wonder if its behavior could be due to the water conditions rather than illness of injury? I also found a City of Longmont doc which states that fishermen could expect to catch carp, walleye, and crappie. And the shoreline has always been popular with large waders like Great Egret and Great-blue Heron. Bob Zilly, Longmont On Fri, Aug 27, 2010 at 3:27 PM, coloradodip...@aol.com wrote: Nick et al.: While wing molt may not be the cause of the McIntosh PALO not diving, there are any number of other possibilities, such as illness. However, it might behoove us to know what it's eating, if anything. If nothing, that could provide more suggestion in the vein of illness or other infirmity. However, loons eat things other than fish, though usually considered obligate piscivores. From the Common Loon BNA account (I couldn't get to the PALO account) -- bna.birds.cornell.edu/bna/: Crustaceans—e.g., crayfish (Decapoda) constitute major part of diet when fish are scarce or water is murky (1.0 m visibility), up to about a third of diet for males and more for females (Barr 1973http://species/313/biblio/bib015). On some Wisconsin lakes, observed adults and chicks regularly observed foraging on snails (W. Piper, pers. com.). Leeches (Hirudinea) are occasionally an important food, and individuals that are stressed or ill sometimes eat vegetation (Barr 1973 http://species/313/biblio/bib015). Having no chance to go see the loon in question, others will have to provide the data on the bird's foraging, or lack thereof. Tony Leukering Villas, NJ -Original Message- From: Nick Komar quetza...@comcast.net To: coloradodip...@aol.com; cobirds@googlegroups.com Sent: Thu, Aug 26, 2010 11:47 pm Subject: Re: [cobirds] Loon molt Many thanks to Tony Leukering for setting the record straight on underwater wing-powered locomotion (or rather, lack thereof) among loons, and also for sharing his vast wealth of ornithological knowledge with our Colorado birding community, making us all wealthier (in knowledge, anyway). I should have done some basic research before sticking my foot in my mouth in a public forum like Cobirds. I have now done the appropriate homework to learn more about underwater locomotion among diving birds. A number of bird taxa including alcids, diving petrels, some shearwaters, and our Rocky Mountain dippers use their wings to power underwater diving as well as aerial flight, but not loons. Interestingly, I learned that some of these species undergo very heavy wing molt and yet still dive during these periods of wing molt. So, it begs the question (maybe Tony can answer this as well), why is the Boulder Pacific Loon not diving as would be typical foraging behavior for this species. Thanks again, Tony! Nick Komar Fort Collins CO -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.comcobirds%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/cobirds?hl=en. -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.comcobirds%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/cobirds?hl=en. -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
[cobirds] Loon molt and Uppies over Boulder (longish)
Hi all: I've recently read most of the posts about the McIntosh loon and nocturnal flights of migrants and had a few things to write in response. First off, the pattern that I see in Ted's Upland Sandpipers-over-Boulder data, is that insomniacs detect more nocturnally-migrating Uppies than do most other birders. I mean, I'm almost always up around 11:30 pm, but only rarely so after 2 am. Thus, I hear very few Uppies going over, Boulder or elsewhere. Mostly, though, I wanted to comment on the debate about the McIntosh Res. Pacific Loon and loon flight-feather molt. What and why? All loon species (and presumably individuals) conduct a complete flight-feather molt each year, with the timing of such varying between ages and species. Like waterfowl, loons drop all of their flight feathers at once (or very nearly so), becoming flightless for a fairly substantial period (1-2 months). It is believed that this benefits these species more than a more-typical-for-birds slower and staggered flight-feather molt, as it reduces the time during which flight is impaired by missing feathers. Yes, their flight gets supremely impaired with no flight feathers, but it works. There just aren't a lot of predators out on the open water that can tackle a bird the size of a loon. It should also be noted that it would behoove a species that finds it necessary to use its wings in foraging to NOT drop all of its flight feathers for such a long period of time. Loons do not use their wings under water, rather using their somewhat outsized feet to propel them. Where and when? On the East Coast, Common and Red-throated loons are both common and widespread migrants and winterers, but they have very different strategies to dealing with timing their flight-feather molt. Adult Common Loons migrate away from breeding grounds in alternate plumage, arrive on winter grounds, and commence their pre-basic molt, which includes flight feathers. On the other hand, Red-throated Loons conduct their pre-basic molt on or near the breeding grounds, arriving on wintering areas in basic plumage and with their flight-feather molt already completed. Thus, if one goes out on the ocean in winter, all of the Red-throated Loons fly away, and most of the Commons dive or patter off with their useless wings rowing them along. Note that, above, I wrote that most of the Commons. This is the smooth segue to the variance among ages of timing and/or location of the flight-feather molt. First-year Common Loons primarily stay on the winter grounds during their first summer, conducting their pre-basic molt, which includes their flight feathers. Most young Red-throated Loons depart NJ latitudes for points north or elsewhere and, presumably, conduct their pre-basic molt (including flight feathers) nearer the breeding grounds. My lifer Pacific Loon was a summering bird in New Jersey, lo these many years ago, that was conducting its flight-feather molt, was ragged, and very much (in some regards) disappointing to one hoping to see a stunning bird. The McIntosh Res. Pacific Loon is simply going through the normal processes of almost all other Pacific Loons: conducting its pre-basic molt on the safety of a larg(ish) body of water while killing time waiting to go to the breeding grounds next summer. Whether all or most young Pacifics follow the Common strategy or not, the Boulder Co. bird is in no way in more danger than is any of its conspecifics of that age. Having none of my references at hand here in Alabama, I cannot send you to particular passages or pages in certain references, but I would suggest checking out the various behavior and ecology bird books (Sibley's, Kaufman's, and the yellow-covered one whose authors' names I cannot recall right now) or even the old Audubon Encyclopedia of North American Birds (edited by John Terres). I would bet that it's all in there. Sincerely, Tony Leukering Villas, NJ P.S. Now is a great time to go out and find migrant Mourning Warblers!! -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
Re: [cobirds] Loon molt
Many thanks to Tony Leukering for setting the record straight on underwater wing-powered locomotion (or rather, lack thereof) among loons, and also for sharing his vast wealth of ornithological knowledge with our Colorado birding community, making us all wealthier (in knowledge, anyway). I should have done some basic research before sticking my foot in my mouth in a public forum like Cobirds. I have now done the appropriate homework to learn more about underwater locomotion among diving birds. A number of bird taxa including alcids, diving petrels, some shearwaters, and our Rocky Mountain dippers use their wings to power underwater diving as well as aerial flight, but not loons. Interestingly, I learned that some of these species undergo very heavy wing molt and yet still dive during these periods of wing molt. So, it begs the question (maybe Tony can answer this as well), why is the Boulder Pacific Loon not diving as would be typical foraging behavior for this species. Thanks again, Tony! Nick Komar Fort Collins CO -- You received this message because you are subscribed to the Google Groups Colorado Birds group. To post to this group, send email to cobi...@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
