Field Journal #3- Social Behavior and Phenology

Time: 12:00-1:30
Date: March 25, 2019
Location: Centennial Woods
Weather: Sunny, clear skies, 40 degrees
Habitat: Deciduous forest, trail running through, river and swampy areas create break in dense vegetation

note: my phone suddenly stopped working about halfway through the bird walk, so I recorded species by hand and tried to describe their relative location in the woods

Because my phone stopped working pretty prematurely on this bird walk, I was not able to record the exact location of every single individual I saw. However, I used that malfunction as an excuse to really slow down and spend more time observing how the various species of birds interact (rather than trying to record as many as possible on the app). When I took the time analyze the different sounds and behaviors of different birds, I was able to recognize some communication patterns across certain species.

Black-capped Chickadees were by far the most abundant species that I observed during my walk, and I was constantly hearing both their songs and calls as I traversed the forest. I noticed that when I heard a Black-capped Chickadee call (i.e. the “chicka-dee-dee-dee”) in one location, it was often followed by a different individual making the same call. I figured that this occurred due to the fact that a call signals some sort of danger or alarm, therefore it makes sense for other nearby individuals to respond and vocalize their recognition of said stimulus. The sing-songy “here petey” sound, on the other hand, seemed to be more randomly dispersed and less frequent. This is perhaps due to the fact that males are often the ones to sing for purposes of attracting mates, therefore it may not be as much as a call-and-response type of vocalization. In terms of visual behavior, the clusters of Black-capped Chickadees that I observed would often jump around the branches of a specific tree (perhaps foraging for food) and would often jump towards each other before spreading apart again. This type of behavioral interaction could perhaps indicate some sort of communication regarding the presence of a food source, or could be some sort of communication between a breeding pair (male and female).

Another species that I observed to be (potentially) communicating during my walk was the White-breasted Nuthatch. Much like the chickadees, I heard several nuthatch calls that came from individuals in different locations. The most common nuthatch sounds I heard were the “wha wha wha wha” songs as well as the raspy and more abrupt “yank” calls. I heard the song less frequently throughout the my walk, however I did hear it on multiple occasions in which it was carried out for an extended period of time. From what I know about White-breasted Nuthatches, their songs are used to find suitable mates for the upcoming breeding season (beginning in April, usually), therefore hearing this infrequent song makes sense. The “yank” calls were somewhat more frequent, and I presumed to have more of a two-way communicative purpose. During this time of year, monogamous pairs of White-breasted Nuthatches are most likely building their nests as well as foraging for food, therefore the “yank” or “yink” sounds that I heard were most likely signaling to each other a certain source of food or perhaps protecting the nest.

I saw a couple of American Robins during my walk, and heard several “cuck” calls as well as songs (“cheerio-cheeri-ie”). When I observed the robins, I heard these different sounds given in the same time period by the same individual(s). For this reason, I assume that both the song and call may work together to form similar purposes. For example, both the song and the call could be used as a signal of defending territory from potential trespassers, therefore it makes sense to hear them both in the same vocalization.

There were several species that I could not observe interactions for due to their more independent presence and lack of interaction with other birds of their kind. These birds include Pileated Woodpecker, American Crow, and Mourning Dove. I heard and observed all three of these species, however I only saw one individual of each throughout my walk. The American Crow was flying overhead above the forest, and gave out a few “caws”- which I assume was made to communicate with nearby crows that I did not see (because the call is fairly loud). The Mourning Dove that I observed was singing its beautiful “ooo-OOOH,- ooh-ooh-ooh” song from atop a very high perch. I presume this was a lonesome male that was singing this song for the purpose of finding a mate. The pileated woodpecker did not make any audible calls, however was drumming on a tree for an extended period of time- therefore I could not make out any specific type of communication/interaction.

During my walk, I spent time looking at the plumages of the Black-capped Chickadee and the Pileated Woodpecker, as I was able to get a pretty constant view of both of them. They are similar in that the main bodies of both of these birds have black and white feathered areas that are very contrasted and take on quite distinguishable patterns. They both have stark black and white stripes that begin on their head and may extend downward onto their body. One of the main differences between these birds’ feathers is obviously the bright red crest that exists atop the head of the Pileated Woodpecker. While this crest does not seem very practical for the purpose of blending into surroundings or keeping a low profile, it is heavily used in courtship displayed and as mechanisms of attracting mates. Evolutionary, it makes sense that more successful woodpeckers are those with brighter and larger crests that are more effective at attracting a breeding partner. Because the Black-capped Chickadee does not have any sort of vibrant distinguishing feature (nor any huge visual differences between males and females) it makes sense that these birds rely on other behaviors for courtship (i.e. buffing feathers or singing their song).

In terms of behavior of the birds which I observed, I found the Black-capped Chickadee and the American Robin to have interesting behaviors (which were fairly distinct from each other). Every time I saw a Black-capped Chickadee it was moving about- usually hopping on branches or taking quite flights around a tree. The birds were usually faced inward to the tree, suggesting that they were moving about in order to forage for food from the surface of the various branches or trunk. The dynamic nature of the chickadees suggests that their circadian rhythm is one that heavily surrounds foraging and eating throughout time spent awake.

The American Robin(s) that I observed, on the other hand, which much more composed and stationary than the chickadees. They were found on a tree towards the edge of a dense patch of vegetation, in a spot in which sunlight was directly hitting them. While they would give out a call/song, they did not seem to move too much. This could be because their circadian rhythm does not require them to be foraging/eating for a large part of their day, but rather it is more energy-efficient and preferred for them to be resting upon a perch and sunbathing.

“Pishing” Activity

There are many reasons why “pishing” can be used to attract or signal small birds. Although the “pshh” sound does not necessarily mimic the song of small perching birds, the raspy and abrupt nature of this sound can be very similar to some of their calls. Many small birds, such as the Black-capped Chickadee and the Tufted Titmouse, give shorter raspier calls that are used to signal alarm or distress, usually in the presence of some sort of predator. When hearing this call, small birds often will flock together to either chase away or find safety from a predator. Thus, if a similar call is made by a human, small birds may be enticed to flock towards this sound. Another reason why small birds may be attracted to this sound is perhaps the soft and raspy “pshh” sound is similar to the sounds and pitches created by potential prey, specifically smaller insects. Of course, there is also the possibility that the specific “pish” sound that is created by humans does not quite mimic any sound that the small birds are accustomed to hearing. In this case, it seems quite possible that the sound could attract birds out of their mere curiosity of this foreign sound.

Publicado el marzo 26, 2019 12:11 MAÑANA por haleyferrer