The weekly HawkWatch updates from Jenna Dodge:
The past couple of northerly wind days have helped push over 400 migrating raptors right over our heads on top of Cadillac Mountain providing HawkWatch participants with great views and memories of these passing birds of prey. The most common migrant we have seen is the sharp-shinned hawk; to date we have counted 347 different individuals of this particular species. The sharp-shinned hawk belongs to the accipiter group along with two other species, Cooper’s hawk and northern goshawk, that we expect to see fly south.
Species deemed accipiters, or true hawks, are found to dwell in dense woodland habitats wherein their short, rounded wings and long tails help them dart in and around trees whilst they are in pursuit of food. Due to a general lack of awareness and use of an infamous pesticide, DDT, accipiter populations became very threatened in the 1960s and 1970s. Thankfully, the times have changed and their numbers appear to be healthy again. This has been partly surmised from the annual migration count and is a motivating factor for HawkWatch, to determine population trends of these very important birds and to ensure that they continue to thrive.
Sharp-shinned hawks (Accipiter striatus) are the smallest of the accipiters with an average wingspan of 20-27 inches and ranges throughout North and Central America. Their diet comprises mainly of other birds (such as songbirds) but can take lizards, insects and small mammals as well. In flight, the classic sharp-shinned wing beat is very quick and described as a ‘flappity-flappity-glide’. Once they depart from their northern breeding grounds, this blue jay sized raptor will journey over hundreds of miles down to the southeastern United States where the will stay for the winter. This is a very common species and we tend to see about 1,000 migrating through annually.
Cooper’s hawks (Accipiter cooperii), or chicken hawks, are very similar in appearance to the sharp-shinned hawk and vary only slightly in size and in flight; it has a wingspan of 24-36 inches and a more pronounced head while in flight. While in flight, Cooper’s hawks tend to glide more and have a slower wing beat than the quicker sharp-shinned. They like to hunt other birds, often game fowl, as well with the occurrence of taking other prey items such as mammals, lizards and amphibians. Their preference for hunting poultry ironically made them very popular to be hunted; farmers persecuted these birds with bullets that contributed to their population downfall. Thus far we have seen just nine individuals migrating over Cadillac Mountain and can travel to parts of the southeastern U.S. as well as Caribbean Islands and parts of Central America. Acadia sits at towards the northern end of their range so we only average about 33 birds per season.
Northern goshawks (Accipiter gentilis) are the largest accipiter with an average wingspan of 36 to 48 inches and can weigh between 1 and 3 pounds. Its range is limited to thick forests of the northern hemisphere wherein conifer dominated habitats are much more preferred. They are formidable predators that can hunt more challenging prey: small and medium sized mammals like a quick snowshoe hare, as well as other birds. To date we have seen no northern goshawks begin their migration south, which is normal since they tend to migrate a little later in the season when the amount of prey forces them south. This is a fairly rare species for us to encounter migrating through since we only average 7 per season.
To spot the more common sharp-shinned hawk, catch a glimpse of the infrequent Cooper’s hawk or awe at the rarity of a northern goshawk please join us from 9 a.m. to 2 p.m. (weather permitting) 200 yards down the Cadillac North Ridge Trail. Bring your binoculars (the park may provide some if you do not) and an eager curiosity for raptors and their splendor.
Leave a comment