Scavenging of Roadkill by Mississippi Kites (Ictinia mississippiensis)

Abstract

Mississippi Kites (Ictinia mississippiensis) prey primarily on large-bodied aerial insects such as cicadas (Hemiptera), locusts (Orthoptera), dragon flies (Odonata), and beetles (Coleoptera) but will, occasionally, take small aerial and terrestrial vertebrate prey (Glinski and Ohmart 1983, Shaw 1985, Bader and Bednarz 2011, Chiavacci et al. 2014, Welch and Boal 2015). Mississippi Kites are aerial hunters, capturing their prey while in flight, but also glean prey from branches of trees and capture nestling birds from nests (Welch and Boal 2015, Parker 2020). Several species of Accipitriformes (e.g., Golden Eagles [Aquila chrysaetos], Ferruginous Hawks [Buteo regalis]) and Falconiformes (e.g., Merlins [Falco columbarius], Peregrine Falcons [F. peregrinus]) are known to engage in facultative scavenging (Knopper et al. 2006, McIntyre et al. 2009, Lonsdorf et al. 2018, Varland et al. 2018, Skalos et al. 2022). However, scavenging by Mississippi Kites has not been described; the only published reference to the behavior that I have found is the statement that they ‘‘Will scavenge diverse roadkills (JWP)’’ (Parker 2020). Here I reported two observations of scavenging by Mississippi Kites in the urban setting of Lubbock, TX, USA. On 7 July 2022 at 0940 H, I was in a vehicle on a residential two-lane street waiting to enter the flow of traffic on a north-south running six-lane (three lanes in each direction with a turn lane in the center) thoroughfare. I observed an adult Mississippi Kite flying up from the road as traffic came by. It circled and went back down low between lanes of south-bound traffic, flared up, circled again and went back down and landed on an apparently road-killed White-winged Dove (Zenaida asiatica). It appeared to try to peck at the dove before quickly taking flight again as a new wave of vehicles went by. I lost sight of the Mississippi Kite after that, but when I returned later in the day, the remains of the dove were still present. In a separate incident on 13 July 2022 at approximately 0830 H, I observed three adult Mississippi Kites making repeated swoops, one after the other, down to a road-killed bird while barely avoiding vehicle traffic on a busy residential street. The three birds landed only briefly on the dead bird and sometimes pecked at it. This continued for several minutes during which the kites swooped down then lifted up repeatedly, and sometimes circled around higher or perched on a tree in a yard before returning to swooping at the roadkill. They eventually gave up and drifted away from the area. I inspected the roadkill and found that it too was a White-winged Dove. White-winged Doves are not reported as prey of Mississippi Kites. However, the rich nutritional value and volume of an available White-winged Dove carcass, compared to the primarily invertebrate diet of kites, may be very attractive to a Mississippi Kite. The Mississippi Kites in these observations tried to feed on the carcasses where they lay rather than carrying them to a safer feeding location. This may be due to the mass of the doves exceeding what a kite can reasonably lift. Fully grown White-winged Doves weigh approximately 150 g or, depending on sex of the kite, 39– 70% of an adult kite’s mass (Parker 2020). This mass may prevent kites from removing road-killed doves to a safer location. Regardless, the kites I observed made repeated swoops and short landings at the roadkill and, thereby, subjected themselves to increased risk of a vehicle collision. Road-killed birds are not uncommon in urban settings and could provide abundant scavenging opportunities for Mississippi Kites. However, scavenging road-killed animals is a risky behavior that may result in death of the scavenging animal. For example, mortality of Golden Eagles from collision with vehicles while scavenging road-kills is a primary conservation concern (Lonsdorf et al. 2018, Slater et al. 2022), and Wildman et al. (1998) reported Red Kites (Milvus milvus) were killed by vehicle collisions while scavenging road-killed animals. Mississippi Kites typically forage at canopy heights and higher (Parker 2020) so vehicle collisions would not typically be an expected mortality risk for them. However, scavenging may be a 1 Email address: clint.boal@ttu.edu