I’ve been fascinated by Loggerhead Shrikes since I first saw one. Their Butcher Bird nickname, earned by impaling their prey on barbed wire and other sharp objects, certainly contributes to the fascination.
They quite literally fight above their weight using interesting behaviors & a little mechanical engineering. They use their Tomial “tooth”, a beak feature they share with the big guys & gals, to penetrate to and sever the spinal cord. They impale larger prey to immobilize them because they don’t have strong feet and talons like regular-sized raptors. They will also impale or wedge in a tight space even larger prey – e.g., small birds – as a food cache. Even leaving insects and amphibians that are toxic to degrade to eatable. During breeding season they may even hang their kills in conspicuous places to show off for possible mates.
This go-mechanical approach to solving challenges is cool to a GA Tech grad.
Up to this point in the post I’m comfortable describing Loggerhead Shrikes as (mini) raptors. I’ve been using the same ‘traditional method’ of differentiating species as raptors used for years. It is primarily morphological and ecological. That is, species that share a lot of the same anatomical features and behaviors. For example, sharp eyesight and hunt and eat live prey. The problem with this approach is for many folks it implies a familial relationship. Which when observation is the principle scientific tool makes sense. However, there are often inconsistencies when comparing just a subset of a species morphology and ecology that often doesn’t make sense.
Science, as we know, advances and in this case DNA studies increasingly document that species that we thought to be related aren’t. Irrespective of morphology or ecology. For example, we now know know that falcons are more closely related to parrots than hawks. But, Old World Vultures are related to hawks (and eagles). Even though they have many physical traits and behaviors in common with hawks, eagles, owls, and other common birds of prey, shrikes are in the songbird Order Passeriformes because of clear ancestry. Their raptor-like morphology and ecology being a result of convergent evolution rather than being inherited from a common raptorial landbird.
So in December 2019, Christopher J.W. McClure and seven colleagues proposed in an article in The Journal of Raptor Research that raptors be defined as “all species within orders that evolved from a raptorial landbird lineage and in which most species maintained their raptorial lifestyle as derived from their common ancestor.” These orders are: Accipitriformes (hawks, eagles, etc.), Strigiformes (owls), Cathartiformes (New World vultures), Falconiformes (falcons and caracaras), and Cariamiformes (seriemas). (Ken Kaufman) This definition and its use in reconciling the various bird lists in use is still be discussed by the birding powers to be.
No Passeriformes so no shrikes as raptors, at least officially.
That doesn’t diminish my interest in Loggerhead Shrikes as raptors. The new classification makes sense because it brings taxonomy clarity. It doesn’t, however, stop NGOs and individual researchers from using the classic methodology of grouping shrikes with raptors based on morphology and ecology for conservation study and policy making purposes.
This is important to me because even if they don’t share a common ancestor, they do share common threats with the more celebrated, and often more conservation funded, Raptors.
As tough as they are, shrikes are not faring well. Loggerhead Shrike population numbers are down 76% since 1966. They have been listed as endangered, threatened, or of special concern in several states and Canada.
They can ‘fight way above their weight’, but habitat loss and pesticides killing their food sources is a larger than life (pun intended) foe. Even for this mini-raptor.