4/25/21 RedStone Campus Walk with TA's

Temp: 50F
No wind
100% cloud cover
Habitat: Urban, clustered mixed tree coverage, Pond behind Redstone lofts with cattail underbrush and sparse Mixed tree coverage - mostly deciduous types.

During this trip we heard a lot of bird song and calls. Seeing as it is still early in the nesting season I believe these are the early precursors to nesting, males are setting up territories and calling to defend them as well as to attract mates. Visually we saw saw the Canadian Geese pairing up and possibly also setting up a nesting site in the cattails around the pond on redstone. This species are ground nesting, the cattails provided good nesting material as well as dense cover. Red-wing Blackbirds were also prominent in this area. We saw two males (heard a few others) and one female. The female came into one male's territory and the male chased her around the cattails, possibly as courting behavior. During this time the other male tried to swoop in but the original male diverted to chase his competitor away. For the Red-winged Blackbirds I would call this habitat unideal. There doesn't appear to be a lot of food availability and high competition with con-specifics and other species. However, there is good cover within the cattails and further an abundant amount of potential nesting material from small twigs to dead undergrowth for the parents to use to construct a nest when it is time. The male doing the chasing is the same one that successfully called in the female, therefore I'd say this male is more fit, or possibly more experienced with age, than the male that tried to fly into his territory. This may also suggest that the area he was defending (much thicker in cattails, with more cover over all) has a slightly better territory habitat than the competing male (who was calling from a lone tree). For the Geese I would say this habitat is more ideal, although still very shallow water with limited food resources, but potentially more for the geese than there is for the Blackbirds as they can feed from the lake as well as the surroundings. Most importantly for the geese this is a very well protected area, with a fence and thick cattails, this would be a reasonable place to raise a clutch, at least for a while. One major downfall of this area is the litter. There were a lot of discarded cans and variable plastics, which may provide nesting material but if ingested by the geese's precocial young, while they're learning to feed, could be deadly or even risk contaminating the shallow waters.
The Chipping Sparrows were all heard in various pine type trees. This suggests this kind of cover is more idea for this species, and that their territories are confined to individual trees, as it seemed only one male was present per pine tree. They defend their trees by constantly calling, they had a jack hammer type call and repeated it every few seconds to reaffirm their territory. These Sparrows create very small and uniform nests using mud to stick twigs together. Similar, I believe to how American Robins form their nests. This method helps make the nests sturdy to hold all the young. Using mud to cement the nest together provides more stability than twigs alone. Twigs aren't the only nest building material, leaves, grasses and even plastic have been utilized for nest construction. This area has an abundance of all of these from the mixed tree species available. Mud can be gathered from the pond that's not too far away, although this may lead to territory disputes the closer to the pond these birds get, as competition for this resource grows. Whereas the Robin uses more branches and hard woods, I believe the Chipping Sparrow uses more pine needles, which would make sense as they were regularly seen among pine trees, which would provide an abundance of nesting materials. Further, Birds may return to the same nests year after year and simply add to them. We noted a rather large nest right outside Jeffords, possibly a Robin's nest, that was huge. It appeared to be continually added to and suspected to be at least a year old. Adding to nests, versus total reconstruction, requires less efforts and provides an overall larger and sturdier nest. This nest was more oval shaped, between larger trunk/base branches, and made mostly out of branches and leaves.
My favorite bird seen on this outing was the Yellow-rumped Warbler. There was roughly 2-3 individuals noted along the fence line leading towards the redstone pine grove. This area has the most mixed tree cover, and near the pine trees would offer a good resource for nest supplies and food supplies, although a highly competitive area with other species. The Yellow-rumped Warblers defended their territories with calls, although no clear territories seemed defended and they frequently invaded each other's space/trees, this could be the early conflicts of territory defense, clear boarders are yet to be defined. This species it seemed they were behind when compared to the Chipping Sparrow or Blackbirds because they haven't solidified their territories just yet. This is most likely due to them just arriving in VT from their migrations. They may also not settle in this area and continue more north before they actually settle down and nest.

Julkaistu huhtikuu 26, 2021 02:49 IP. käyttäjältä jamiek347