Archivos de diario de abril 2020

04 de abril de 2020

Field Journal 4

Field Journal 4
3/12/20

Time: 8:15 am
Date: 4 April 2020
Location: Silvio Conte Wildlife Refuge, Hadley, MA
Temperature: 43℉
Cloud cover: 95% cloud cover
Wind: none

The morning was calm and still as my mom and I set off down a wooded trail in the Conte Wildlife Refuge. The woods consisted mainly of young birches and sumac and little wetlands, surrounded by large fields. Singing song sparrows greeted us, perched on low-growing plants near the forest edge. Although not obligate migrants, some song sparrows may have overwintered as Far south as Florida (1,300 miles from Massachusetts). Mourning doves and robins flew overhead, both congregating in flocks. In previous bird walks, I had not seen as many same-species flocks as I did on this one. Perhaps larger flocks are becoming more common as food resources are becoming more abundant and evenly distributed with warmer days. Spring is certainly here- I saw many trout lily leaves, red maple flowers, greenish-yellow willow buds, and heard a spring peeper.

I saw what I thought was a flock of robins perched in a birch, but after taking their picture and zooming in for a closer look, I was happy to discover that they were Cedar Waxwings. In contrast to the active and vocal robins, jays, doves and sparrows, the cedar waxwings were still and silent. If these birds recently flew up from their non-breeding range south of North Carolina, then they could have flown over 600 miles to reach western Massachusetts.

Once the trail became more heavily wooded, I spotted a Downy Woodpecker and many Eastern Phoebes. Downy Woodpeckers are year-round residents that are able to forage for food through the northern winters. They are well adapted to endure northern winters on a diet of insect larvae, berries, seeds, and acorns, and they are a common participant in mixed-species flocks, which offer better foraging-efficiency and protection to overwintering birds. Although winters are energetically costly and risky to year-round residents such as Downy Woodpeckers, they benefit from good access to nest sites early in the year and do not have to deal with the energy costs and high mortality rates of a long migration. Birds such as the Eastern Phoebes do not have the option to overwinter in Massachusetts due to a lack of flis to catch. The flycatchers I observed in Early April will have better access to nesting sites but less access to food than those arriving later in the spring. I noted a small swarm of bugs later on my walk, however, indicating that flycatchers indeed have a small food supply at this time of year. These Phoebes could have recently arrived from anywhere between Virginia and central Mexico. (From Massachusetts to Florida is 1,300 miles).

Reaching a river running through a tall pine stand, I observed a female mallard sitting on a downed tree in a river and a flock of jays flying loudly from a tall pine tree. We came upon an overlook to a large field, which was full of robins and a few red-winged blackbirds pecking at the ground. My mom noted that these robins looked smaller than the robins she had seen throughout the winter. Perhaps these particular robins were making their way back north and the strenuous flight had used the bulk of their fat reserves. Alternatively, they may have been the same birds she had seen earlier in the winter but had since lost their fat reserves. The wintering range of Robins extends as far south as Florida, although these birds probably would be coming from a closer state to minimize their flight distance. Robins that overwinter in the north benefit from early access to food and breeding resources in the spring at the cost of enduring harsh weather and food scarcity through the winter. Robins that migrate south for the winter do so to decrease their competition for food and exposure to unfavorable climates over the winter, but at the cost of a dangerous migratory flight and reduced access to breeding sites upon their return. Back in the woods, I came across a pond with three male mallards and a downy woodpecker hopping along the bank.

Leaving the woods, we walked down a road lined with willows and surrounded by large fields. Red-winged Blackbirds were everywhere, as well as a few tufted titmice. A small bird flew overhead, and its graceful movement was different from that of the blackbirds. A photo revealed it to be a female American Kestrel! A zoom lens had proved to be a useful ID tool for the second time during this walk. A camera was especially helpful on such a cloudy day, when most birds appeared as dark silhouettes against the grey clouds.

An interesting note about the location of my bird walk is that a barn on the refuge property houses one of the largest barn swallow colonies in Massachusetts. Sadly, the barn is in disrepair, and after much controversy between swallow advocates and the Fish and Wildlife service (who do not have the budget to maintain the decrepit barn), the barn and its colony are to be demolished this year. I did not see any swallows on my walk because they are obligate migrants, and the bugs that sustain them are not available in Massachusetts yet. However, more insects are starting to emerge earlier in the spring due to a warming climate, and the resulting phenological mismatch between insects and bird migration may contribute to recent flycatcher declines. Swallow populations have declined by 50% since the 1990’s.

The total migration miles traveled by the individuals I observed on my walk is about

= 15 robins (assuming only half migrated) * 700 miles
10 Red-winged Blackbirds (assuming half migrated) * 300 miles
6 Eastern Phoebes * 1000 miles
7 song sparrows (assuming half migrated) * 800 miles
10 cedar waxwings * 600 miles
= 31,100 miles total. That’s pretty far. Equivalent of going to California and back like 5 times.

Publicado el abril 4, 2020 07:55 TARDE por gmsaveson gmsaveson | 11 observaciones | 0 comentarios | Deja un comentario

13 de abril de 2020

Field Journal 5

Field Journal 4
4/12/20

Time: 10:15
Date: 12 April 2020
Location: Wendell State Forest, Wendell, MA
Temperature: 50℉
Cloud cover: 20% cloud cover
Wind: light breeze

Publicado el abril 13, 2020 01:28 MAÑANA por gmsaveson gmsaveson | 8 observaciones | 0 comentarios | Deja un comentario

20 de abril de 2020

Field Journal 6

Field Journal 6
04/19/2020

6:00 - 7:30am
04/19/2020
Spring Grove Cemetery, Florence, MA, 01062
28 degrees
Clouds: none

A white-throated sparrow woke me at 5:45am, and after briefly considering going back to sleep, I walked bleary-eyed into the dusky morning. A light frost coated the grass, and the sky was just starting to glow red in the east. Bird songs resonated from every tree as I made my way to the cemetery down the road. I saw a starling, chickadee, cardinal, chipping sparrow, and many robins on the short walk. The chipping sparrow seemed to be singing in response to another chipping sparrow further down the street. Perhaps they were singing to mark their neighboring territories.
The graveyard was an interesting habitat to observe birds. The few trees seemed to serve as prime singing platforms, while most birds pecked at the grass. Robins sang and squabbed in the trees, and some agonistic behavior was apparent between them. Often a bird would be driven out of a tree if the tree was already occupied, indicating that they were defending territories. Two robins were either fighting or copulating in short flights a few feet off the ground, and both actions demonstrate reproductive-related activities.
Lots of chipping sparrows were foraging in the grass, and some were singing on display in trees. A pair of song sparrows seemed to be checking each other out in one tree- one would hop away and the other would follow. Maybe it was a female testing a male’s interest, seeing how he responds to her movements? I moved to take a picture and scared one of them away.
I seated myself under a tree to make a sound map. There was a robin in literally every direction, both near and far. This makes me think that they were singing to attract females rather than defend a territory, because given their abundance, their territories would likely not have been large enough to be worth defending (also, there are not enough nesting sites in the graveyard to accommodate territories for all the singing birds that I saw). Also audible were two white-throated sparrows further away. In class, we talked about how white-throated sparrows have a lower-pitched song that carries well through dense vegetation, while the chipping sparrow has a high-pitched song that carries relatively well over open spaces. Indeed, the chipping sparrows were common in the open graveyard, while I only heard the white-throated sparrows from the far-off trees. A song sparrow was also singing nearby. A flicker was drumming and calling incessantly from a nearby tree. I presume that the drumming served communicative rather than foraging purposes, because it was accompanied by loud calls. There were three other flickers foraging in the grass- they did not seem to care whether the calling flicker was trying to drive them away or impress them. My map showed the birds to be spaced out as best they could be. It occurred to me that my map only accounts for male birds. In most birds, it falls on the male to defend a territory and attract a female through song, but I wonder about the female birds that do not show up on this map. Are females in some species territorial with each other? Singing to attract mates?
It is likely that the chipping sparrow I passed who was singing in my neighbor’s yard and the chipping sparrow singing from a tree in the graveyard had different qualities of habitat. Chipping sparrows feed mainly in grass, a resource found in greater abundance in the graveyard than the front yard, the latter being very shrubby. However, the mown lawn of a graveyard may not offer much food, given that it is a monoculture, while the yard may have a wider variety of plants and food sources. Also to consider is that sparrows like to build nests 3-10 feet from the ground in shrubs. The yard territory has far more low-lying shrubs than the graveyard in which to build nests. This may indicate that the chipping sparrow in the yard has a relatively better territory, and thus may have a fitness advantage over the sparrow in the graveyard.
I did not see any nest-building activities on my walk, likely because there are not good nesting materials or sites in the graveyard. Northern Flickers nest in tree cavities that they have either excavated or found/reused. Their cavities are not lined with anything but have a pile of woodchips at the bottom, meaning that Flickers do not need to forage for nest materials. The graveyard where I saw the Flickers did not strike me as a good nesting site, given that the trees are very exposed to weather, although the forest lining the edge of the graveyard may make a good nesting site.
White-throated sparrows build their nests on or very close to the ground. They line it with moss, grass, wood chips, twigs, and pine needles. Fine grasses, rootlets, and deer hair are also incorporated as in inner lining. These are all materials that would be found in the forest, so I imagine a white-throated sparrow would have a difficult time building a nest using materials sourced from the graveyard. There is also no cover at ground level, which would leave the nest in a vulnerable position.

Publicado el abril 20, 2020 08:20 TARDE por gmsaveson gmsaveson | 10 observaciones | 0 comentarios | Deja un comentario

26 de abril de 2020

Field Journal 6

Field Journal 6

Time: 12:00 - 3:00
Date: 4/25/20
Location: Arcadia Wildlife Sanctuary
Temperature: 60℉
Cloud cover: 10% clouds
Wind: none
Habitat: Swallows and mockingbirds seen on open farmland. Other observations taken in a deciduous forest bordering a water body

Publicado el abril 26, 2020 08:29 TARDE por gmsaveson gmsaveson | 17 observaciones | 0 comentarios | Deja un comentario

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