No Pro Baseball, but orioles nesting in the park
While former Baltimore Orioles baseball player Adam Jones swings his bat for the Buffaloes in Japan, our own Oriole Park at Camden Yards is closed until further notice or until Jim Palmer has his way. All the while we’re still asking ourselves: When will our Orioles get back to business? Well, wait no longer. It’s not quite professional baseball, but instead real-live oriole action happening in Oriole Park at Druid Hill. Yes, that’s right; several families of Maryland’s official state bird, the Baltimore Oriole, Icterus galbula, are nesting in our nation’s third oldest established park (September 27, 1860)!
Leave your glove at home, and bring a blanket or reclining beach chair if you want to avoid craning your neck upwards in amazement. You will likely hear them before you see them. Visit this Cornell Lab of Ornithology link to hear oriole songs and calls. If you think you hear its song, find a mulberry tree and set up your spot. You might even spot them foraging for the darkest ripe mulberries. Come alone or bring a friend, but don’t stay too long in any one spot. The other birds are watching you too. And you might tip off a predator with the nest location.
These seasonal visitors spend most of their year in the warmer climes of central America, and they have serious business once they’re in town. The best time to observe the action is when they first arrive in May. The males make quite a show, as they whistle their songs and defend their territories, sometimes offering nest materials of dried grass to the female. The female, whose plumage eventually turns almost as bright-orange as their male counterparts, weaves her nest in a uniquely dangling fashion. The hanging pouch-like nest conceals herself and an average of four eggs during incubation. Her eggs require two weeks of incubation before they hatch. Both parents feed the nestlings for another two weeks before they fledge. A nest is delicately woven and thickly insulated from outside-in to trap heat for incubation. Female birds develop something called a brood patch on their breast during pregnancy. Feathers there will shed off, adding more insulation to the base of the nest. The exposed brood patch is highly concentrated with blood vessels. Design here allows for efficient heat transfer to the eggs during incubation.
The location of an oriole nest is very particular: near the end of a drooping branch high above the ground and far away from the central tree trunk. The positioning of the nest is an important strategy in successfully raising young. One can only imagine the difficulty a squirrel or other nest robber might have in accessing the nest in such a precarious site. While a closed-canopy forest such as the “back hills” of Druid might at first seem to offer a good hiding place for such a nest, the disadvantage here is a squirrel’s ability to jump from the branch of one tree to the next. The human-designed, formal landscape of Druid Hill Park, with its widely-spaced specimen oak trees whose branches arch upwards, outwards, and downwards, offers the most secure nesting habitat of all: a perfect little lofty dangle in which raise one’s young.
Early morning visits will provide the best opportunity for nesting action. Once hatched, these babies know only one thing. And that is to call, and call loudly, for food. The noisy nest cry may attract predators. The parents, and even birds of other species, spend energy fending off or distracting any potential nest robbers. The nestlings have underdeveloped wings, so they usually emerge from the nest on foot, awkwardly climbing the twig branches of the nest tree.
Many bird watchers observed orioles nesting far out on those famously arching elm boughs until the great elm began to meet its fate. Spread by humans and elm bark beetles, the dutch elm disease was first discovered in North America in 1928 and eventually decimated over three quarters of all elms between the 1930 and 19901. Unfortunately, those ideal nesting locations disappeared when the elms came down. Today, many elmless streets in cities nationwide still bear the name Elm Street or Elm Avenue. Thankfully, horticulturists have developed some resistant varieties, but these new ‘cultivars’ require extra careful pruning during the early establishment years. Perhaps some bird watchers are still out there observing orioles in the survivor elms or other trees in open parks.
The Baltimore oriole received its name from the similar colors found on the family crest of first Lord Baltimore, Calvert. Just look for the black and gold (yellow) portions of the Flag of Baltimore. The word oriole is of Latin origin: aureoles meaning “golden.” At one point, ornithologists decided that the Baltimore and Bullock’s Orioles should be combined as one species. Despite distinctly different plumages and songs, some evidence showed that their populations interbred where their ranges overlapped in the midwest. So they lumped them both together as the Northern Oriole. In March 1995 it was decided with the help of genetic studies that these two species of birds did not freely interbreed enough to call them the same species. So Baltimore got its oriole bird back.
We are so very fortunate to have orioles finding sanctuary in our park in 2020. According to Bowditch and Draddy in their historical account “Druid Hill Park: The Heart of Historic Baltimore”, about 175 species of birds can be found within the park. A 1993 study in the park lists 29 species of birds found to be breeding in the park. Eight of these are considered uncommon to Baltimore. As some of our sentinel oaks decline, maturing yet massive oaks fill in their place. If it were not for the continuous care given towards growing young trees as reserves, we may not be able to celebrate this treasure. It won’t be much longer into summer before the orioles say goodbye to Baltimore and make their way southward stronger in numbers. Be it baseball or birds, we’re already looking forward to their return.