Archivos de diario de abril 2020

08 de abril de 2020

Field Journal 5 Migration

On April 7th I went birding from 1:10 to 2:45 in the forest and riparian habitats near the Malone central high school. The weather was excellent with a crystal clear sky and a west wind of about 10 miles per hour. The temperature was quite warm for early march at 54 degrees Fahrenheit.

We are fully into spring in northern New York with the last traces of winter disappearing as the last bits of snow and ice have melted. The birds which overwinter in the region have become very active but the spring migrants are just starting to arrive. Several species that I observed that stay year round include the American Crow, American Robin, Canada Goose and Black-capped Chickadee. All of these birds have to be capable of finding food during the winter when many sources of food are cut off or limited. They also have to be able to withstand the cold temperatures. The American Robin in particular undergoes behavioral changes to be able to survive the winter. During the spring and summer seasons robins forage on worms in the unfrozen soil alone. During the winter the robins will congregate around shared food resources such as fruit trees which they use to survive the winter. The black-capped Chickadee makes use of snags for shelter during the winter. In addition the birds which overwinter rather than migrating south are able to increase their fat reserves and insulation in anticipation of winter. Migration is a very costly process to undertake. It is energetically expensive and the mortality rate is often high due to poor weather. The species that overwinter have adapted to overcome the challenges of winter rather than undertaking a costly migration.

Facultative migrants which may migrate based on weather conditions such as moving a little farther south if winter conditions are very harsh or moving north if they are more mellow. In northern New York both Canada Geese and Song Sparrows could be considered faculative migrants. Individuals that live farther north will migrate south for the winter but in northern NY we are on the northern edge of the region in which they can overwinter. Canada Geese in particular rely on open water during the winter. With winter breaking quite early the Canada Geese who had traveled slightly south are now able to return north. In the case of Song Sparrows and other facultative migrants when food resources are unavailable during the harshest parts of winter they can be forced south. With warmer temperatures and reduced snowfall they can return. In particular the winters in northern New York are changing due to climate change. Periods of intense cold and winter conditions are more often broken up by extended thaws or warm periods during the winter. Facultative migrants are able to take advantage of these thaws moving south when the conditions worsen and returning north during the thaws and warm periods to take advantage of the available resources.

I unfortunately did not come across any obligate migrants. While it appears that winter is done past years are evidence that we could still receive a significant snowstorm. Obligate migrants who arrive here in early April are taking a gamble. If winter is done than they will have first dibs on resources and nesting sites. But in the event that we experience a sudden snowstorm or several days of cold temperatures the obligate migrants weakened by their migration will be very vulnerable.

I tallied up the distance some of the faculative migrants could potentially migrate during the winter. I came up with the rough numbers of 300 miles for Canada Geese, 210 miles for the Brown Creeper, 150 miles for the Mallards and 100 miles for the Dark-eyed Junco. These were pretty rough calculations but I would call them an educated guess. Mallards only overwinter in a small strip running NE up from Lake Ontario following the Saint Lawrence river north. Farther north into Canada above Malone and south into the Adirondacks the mallards migrate. But Malone appears to fall into a small band where they can overwinter.

Publicado el 08 de abril de 2020 por tsshafer tsshafer | 14 observaciones | 0 comentarios | Deja un comentario

15 de abril de 2020

Field Journal 6 ID

I went birding from 10:45 until 12:15 on April 15th. The weather was quite variable. The temperature was 37 degrees Celsius and the outing started with mostly clear skies with a west wind around 10 miles per hour. By the end of the walk the sky had become almost fully overcast and the wind had increased to about 16 miles per hour. I worked my way down two residential streets then cut across the high school property to the salmon river. The residential neighborhood is mostly made up of small homes but includes a fair number of trees. The school property is a mixture of buildings and fields. I then went to the top of the first of three dams that the Salmon river runs through. There was a large group of Canada Geese and several Herring Gulls. The river pools up and several sand bars and small islands are present above the dam. One the side of the river I came from there is a decent amount of cover in the form of trees and vegetation growing up alongside the edge of the river. On the far side however it is a bit more developed. From this point on the wind picked up steadily and I saw a smaller number of birds. I worked my way out and back through a wooded forest made up predominately red pine trees. I unfortunately did not come across anything besides some Black-capped Chickadees and a few American Crows. As I worked back down into the residential neighborhood I did spy a Red-tailed Hawk circling near the local ice arena which is adjacent to several youth athletic fields. As I finished up the outing a few snow flakes were coming down.

Publicado el 15 de abril de 2020 por tsshafer tsshafer | 14 observaciones | 0 comentarios | Deja un comentario

22 de abril de 2020

Field Journal 7 Reproductive Ecology and Observation

I went birding on April 20th from 5:30 pm until 7:00 pm. I started out behind the North Country Community College campus in Malone NY. The campus is situated next to the first dam that the Salmon River flows through as it passes through the village of Malone. The weather was excellent with bright sun, a mild breeze out of the west and the temperature was about 45 degrees Fahrenheit. I started out on the edge of the salmon in a small deciduous forest. As I worked my way down the river the ground on the riverbank extending deeper into the small forest became much more moist and became a marsh eventually. I then crossed the Salmon River and came out on the football field at Franklin Academy. I worked my way down the field and ascended a hill to the edge of the forest that comes to the edge of the school property.

On the edge of the college campus I came across a decent number of Black-capped Chickadees and European starlings. Both species were quite active vocally. The Chickadees were singing more than any other time I have heard this spring. In this stand of deciduous trees there was a decent number of snags which would make excellent nesting habitat for the Chickadees. Not to far off on the Salmon river there was approximately 50 or so Canada Geese. The river pools a bit above the dam and there are several decent sized islands in the river with a good amount of vegetation. The islands would make very good nesting habitat for the Canada Geese as they would add an extra level of protection from predators. Also the Geese would have easy access to grass and other vegetation with which to construct their nests.

A bit farther down the river where the riparian zone turned into more of a marsh I came across a male Red-winged Blackbird. the red on his wings was just starting to come in. He was very vocal the entire time I observed him. He was situated in an excellent territory he had the river close by and by and the area underneath the tree he was in was a marsh. This would provide an excellent nesting site. The male was very vocal indicating that he had good fitness overall. He might have been trying to attract a female to his territory or he might have been trying to keep other males at bay. Either way his vocal display demonstrated a commitment to his territory and his health. There would also be easy access to marsh type vegetation such as cattails and reeds with which to construct the nest. In one of the drier spots along the river I saw a pair of Song Sparrows. The Sparrows were near a pretty good nesting location. The Song Sparrows would be able to accumulate grass and other weeds especially during the spring before the thicker riparian vegetation is in full growth. The birds would not have had to go far as there was some grass growing in between the forest and the river. Also the Song Sparrows could have ventured in the other direction into a more urban area with a large number of small yards to search for nest building materials.

I did the listening activity early on during the walk not long after I had entered the small forest. The link to the map is here

https://docs.google.com/document/d/1jbqlUuh1DgxE4WhCZTskm05Voqq04bmMk8-Yy_XGpqE/edit?usp=sharing

In terms of what I was hearing I was able to identify a few species by call first and was then able to spot some but not all of them from where I was sitting.

Publicado el 22 de abril de 2020 por tsshafer tsshafer | 17 observaciones | 0 comentarios | Deja un comentario

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Vida Silvestre es una entidad asociada a la Organización Mundial de Conservación