More Snow

We have gotten about a foot of heavy wet snow. There are branches down all over town since it hadn't gotten cold enough before the snow to drop the leaves and the snow really built up on the remaining vegetation. The power was out twice yesterday because of branches falling on the powerlines.
The Sharp-tailed Grouse were feeding in the Russian Olives along the road and Crean and I headed out to see what else we could find. We had a good morning wandering around in the snow until he followed Addie into the water and filled his boots. Then it was time to go home.



It warmed up later in the afternoon and most of the snow will probably be gone in a few days. This snow should really set us up well for the coming spring. The ground has not froze yet and all of this moisture should soak right in. Now we need more snow for the rest of the winter.


Prairie Falcon

Missouri River just above the mouth of the Milk River

Snow

This was the tree across the road early this morning. It is still snowing.

October Cold Front

We cleaned the garden out last night because we had heard this was on the way.



We had a good rain and lots of wind but it hasn't gotten cold yet. That will come tonight.
Our garden exceeded our first year expectations and we have been dining well on the produce we have produced but all things must come to an end. Next year we have plans for a bigger and better garden.

Excellent Weekend

An excellent weekend with some good new friends, some wonderful game filled meals, and a couple of mornings of fulfilling grouse hunting. Thanks for helping us make the connection Steve.

Gack

Recently Beverly asked me about bird vomit. In particular she wanted to know if the "material" ejected by the birds when it is used as a defensive mechanism was the same "material" used to feed the young.
I did a bit of digging and found out that prey derived stomach oils are used both as an energy source as well as a defensive/offensive tool, at least for petrels, the family of birds most often associated with defensive projectile vomiting. Oils are produced by both adults and chicks and it is indeed fed to chicks by the adults. The chicks also produce the oils as well.

Birds have 3 stomach-like organs as part of their digestive system - the crop (generally for quick food storage in seed eating birds), the glandular stomach, and the muscular stomach (for grinding food). The crop and gizzard are generally reduced in petrels and most of the digestion is done in the glandular stomach. All petrels except diving petrels (Pelecanoididae) are know to produce stomach oils and the ability to projectile vomit those oils and stomach contents is most developed in those species that nest in the open on the ground, such as the Southern Giant Petrel, which I have photos of here.

The oils are derived from the prey items of each petrel species and are thought to afford petrels a high energy, low volume energy source composed most often of wax esters and triglycerides. These oils may also retard digestion of food items and thus enable petrels to assimilate food over longer periods, which is advantageous for birds whose prey are distributed in widely spaced patches or whose young often endure long periods of fasting between meals. The oils may also provide water for fasting chicks through the internal combustion of the oils.



These oils are apparently quite effective in deterring predation and have been know to result in death of predators, particular bird predators whose feathers become matted and loose insulating value potentially resulting in death through exposure. Diving petrels are thought to have not developed these oils because they tend to forage close to breeding areas and nest in burrows.

Although it might seem like the loss of these oils while vomiting them at a predator may be maladaptive, the loss of life would most certainly be a greater impact to an individual that a loss of a meal. The evolution of this behavior may have also benefited petrels by giving chicks a way to independently defend themselves allowing both parents to forage when the chicks are younger therefor providing more food earlier in the chicks life, and nesting sites can be in more open areas, thus allowing expansion into habitats otherwise not available.



The petrel that I have worked most closely with is the Southern Giant Petrel, arguably the bird most adept in the art of projectile vomiting. They are large birds, nearly the size of a turkey and have a correspondingly large stomach. When disturbed they can project their oils about 2 meters. We called it "gack" and I can vouch for the fact that it is very oily, stinky, and persistent. Giant petrels are also well known scavengers, so the projectile often contains more than just prey derived oils! Their bills are well adapted to scavenging with the lower mandible shaped much like a curved wood chisel well suited to jabbing into a carcass; the upper mandible is sharply pointed and hooked to then grab and tear out chunks of flesh to wolf down.



Despite being known as the Antarctic vulture with photos often taken of individuals head deep in a recently deceased seal, these birds can be remarkably endearing. The birds I worked with had become accustomed to having researchers visit their nests rather often and although some individuals never did get used to us, others were quite accommodating. Often we were able to gently approach a nest and reach under an incubating bird to rotate the band on the bird's leg so we could read all the numbers on the band. One of my favorites was a pure white bird that often tried to move me under her with insistent downward nudges of her bill on my arm so she could incubate me as well as her egg.

References:

Armstrong E. 1951. Discharge of oily fluid by young fulmars. Ibis 93:245-51.

Warham J. 1977. The incidence, functions and ecological significance of petrel stomach oils. Proceedings of the New Zealand Ecological Society 24:84-93

Ducks in the North

Clare and any other Nunavummiut (I really just wanted to use that word!) should be on the lookout for a new species to add to their yard list - a rubber yellow duck.
NASA has apparently placed 90 yellow rubber ducks in the Jakobshavn Glacier near Ilulissat in western Greenland to help understand how glacial meltwater moves from the glacier (I know it's a long way from Arctic Bay but you never know!). There is a $100 US reward for the first duck found and smaller monetary amounts for subsequent duck discoveries. More here.

Wing Wraiths

Twice a year a movement of animals passes through my backyard. It is most likely the periphery of a great mass moving further east of here, but impressive never the less. It rivals what most would think of when asked to name an animal migration; wildebeest moving around the plains of East Africa , Mongolian gazelle moving through the steppes of Asia, or caribou moving through the barrens of the American arctic, but this one happens over the top of millions of people and most never know it occurred. It happens mostly at night and rather than large hoofed animals, the migrants are an assortment of small, feathered dynamos not any larger that the hooves of the animals I described earlier. For those of us who know what we are witnessing and know what is happening in the vernal and autumnal skies, the mass migration of millions of birds from the northern part of North America to more benign environs further south, is even more impressive, if not as obvious, as the more well known migrations of their bigger, terrestrial, counterparts.

Much like the migrations of large mammals with their deadly shepherds of lions, hyenas, and wolves, the movement of large flocks of birds have their attendant ghost riders as well. The shepherds I see most often are the shadow followers of warblers and sparrows. As Dad says, when the White-crowned and White-throated Sparrows start appearing in the rose thickets and dogwood, the accipters are not far behind. Most often it is the smaller Sharp-shinned Hawk we find, perched in the corner of the yard, noticed after the sparrows instantly melt into the rose thicket and the Downy Woodpecker merges with the suet feeder.




Last week it was the larger Coopers Hawk that resulted in a silence in my backyard. It was a young, brown cloaked bird that emerged from the neighbords cottonwood and slipped into the plum in my backyard. It waited and watched and I was able to find it through a gap in the fading leaves. It slipped away, there at one glance, gone the next.