Journal 3 Phenology

My bird walk in Warren NJ, (suburban neighborhood) started at 12:30 in the afternoon on March 22, and it was 55 degrees F and very sunny. When I walked outside there were about 20 American Robins eating on my open lawn and neighbor's open grass lawn. Because it was later in the day and sunny and warm these birds were very active in feeding which has to do with their circadian rhythm. Another thing that is specific to this time of year and synced with their circannual rhythm is what they are feeding on. Because it is warmer out now in the spring and the ground has thawed out the Robins are able to eat worms from the ground - a food source that wasn't available in the winter.
As breeding season gets closer all the birds are much more vocal, in defending territory, warning calls, attracting mates, and defending mates. On the walk I could hear many birds and also saw birds in pairs. I saw a couple of pairs of robins and one pair of blue jays. Comparing the plumage of Blue Jays and Robins both are similar in the fact that they are near identical in the different sexes. Male Blue Jays are slightly bigger and male Robins are a little more darker but overall i is hard to tell the two sexes apart in both species, especially if they are not standing right next to one another. Robins have more of a darker earth tone to their plumage which is helpful for them when they are feeding on the open ground for worms. Blue Jays are a little bigger and feed primarily on seeds and are often higher up in trees that provide good cover which allows them to have a brighter, blue plumage that would otherwise give them away. Robins and blue Jays plumage are affected by their behaviors that revolve around their diet.
The mini activity of "Spishing" near trees in the side of the road attracted some house finches to come a little closer in the trees above for a little bit and then fly away. Spishing attracts birds sometimes because smaller birds will often flock together to chase away a predator. The reason the may leave after or before might be to scatter. If they scatter in different directions then it is harder for a predator to follow them each individually. I think this activity mostly works on smaller birds or some passerines because they are smaller and need support to chase of a predator bigger than them.
On the trip I saw 30 American Robins, 5 Blue Jays, 4 House Wrens, 3 Dark-eyed Juncos, 1 Mourning Dove, 1 White-breasted Nuthatch, and 2 House Finches. I also heard many other birds (some I could not identify by sound) that I could not see because they were hidden in the trees.

Publicado el marzo 23, 2020 12:14 MAÑANA por