A river of crows flowed across Menaul Blvd. in the north valley as I drove east in the late afternoon. They were headed to their night roost in the bosque along the river. I knew that when I traveled a couple of miles further east, crows would be starting to funnel into staging spots near Coronado Mall.
There are two groups: crows that congregate in the natural habitat along the Rio Grande, choosing the tall barren cottonwood trees, and those that prefer the bright lights of a shopping center. Hmm…
I don’t walk along the river after dark so haven’t had the opportunity to observe the roosting behavior of the ‘valley’ crows. However, I am fascinated by the ‘heights’ crows and often make detours by the mall in the late afternoon and evening to observe them.
The crows begin to funnel into staging areas in the vicinity of Menaul and Louisiana, picking different areas to gather each night. One afternoon they might forage in a vacant lot near a restaurant in the vicinity of Pennsylvania and Menaul, on another evening they might be found in a Winrock parking area, along Uptown Blvd west of Louisiana, or on the rooftops near Staples on San Pedro. One evening I saw them gathering in the trees in the median along Menaul between San Pedro and Louisiana.
Before dark settles in, they start leaving the staging area and begin settling into trees at Coronado Mall – in what might be called mega murders of crows (a group of crows is called a murder). This year they seem to prefer the area near Sears. While they don’t always occupy the same trees, there is evidence of areas that are frequently occupied.
One evening I parked near the roosting spot and lowered my window to listen to the gathering corvids. The earliest arrivals secured the prime to branches and their calls seem to dare others to displace them. Late arrives complain as they jockey into place lower in the tree. The photo above clearly demonstrates the benefits of an upper perch.
Communal roosts provide a number of benefits during the cold winter season. Crowding hundreds of birds into one tree provides more warmth than perching independently. Since crows do not have good night vision, there is more protection from nocturnal predators – yes Great Horned Owls are found in the city. Some have also speculated that the cawing chatter as they arrive is also exchange of information about food sources and the opportunity to find a mate for the upcoming nesting season.
By March the nocturnal roosts will have dispersed. There are already signs of crow testosterone kicking in, e.g. harassing hawks and eagles.
If you haven’t already done so this winter, there is still time to head to mall to observe the mega murder of crows.