I'm trying to pick out the best plants to attract birds to my yard, and have become very interested in serviceberry trees for this purpose. Should I avoid the hybrid varieties of this species (such as Amelanchier × grandiflora) in favor of versions like A. canadensis which birds and insects may be more familiar with? Or does that not matter, since both "parents" of the hybrid are also native species to my area? Does this apply more generally when selecting native plants to build a better wildlife habitat?
Amelanchier × grandiflora is an example of a "nativar," that is, a cultivated variety of a native plant.
While there's some range of opinions, reputable sources agree that it's best to plant the native species (eg, A. canadensis) if you can get them. If you can't get native species, nativars are at least better than non-native plants.
If you do have to plant a nativar, at least make sure it's not sterile. Beware of varieties that advertise "double flowers." Double flowers are usually sterile because they make extra petals instead of the pollen- and seed-producing parts. (Amelanchier × grandiflora does make non-sterile flowers, so it's better than some nativars.)
Native vs. "Nativar", by Ryan Pankau, Horticulture Extension Educator; University of Illinois at Urbana-Champaign.
Native, or Not So Much? Native plants transformed into flashy “nativars” may look pretty, but are they good for wildlife?, by Janet Marinelli, The National Wildlife Foundation.
Citizen Scientists Help Parse the Native/Nativar Debate by Jessamine (Jessa) Finch, Ecological Landscape Alliance.