Inspired by an emailed photo from a friend Chris,inquiring as to its identification,Ive decided that over the next serveral cold winter weeks to highlight at least one species per week,using photos,slihouettes and information to help with identifications in the future. Chris' photo was of an adult male Northern Harrier,so I will start with the Northern Harrier.
Sizes for Northern Harriers varies greatly. Wingspan is as much as 105cm(42inches) Length is 42-60cm (17-24inches),with females being 1/3 larger then males,as is the case with most birds of prey. Females and juveniles look similar,with alot of rusty streaking on the chest. Juveniles have more. Their backs are brown. Males look completely different,appearing blue/grey on top. From below,they are very pale,appearing to be very white,with black wing tips. Many bird guides describe the wingtips as looking as though they've been dipped in ink. This is very diagnostic. All Northern Harriers have a prominent white bum patch. This is not soley a means of identification,but confirming evidence when other field marks are observed. In flight,all Harriers appear to have a long slim tail with long wings. To me on a down flap the wings look triangular and its very diagnostic. They appear to have a facial disk,owl like. When flying U will notice a strong dyhedral or v-shape.
At migration time Harriers often fly in heavy winds. Seeing males is a treat,as often migration sites see them at a rate of 8 females/juveniles to 1 adult male. Juveniles are often difficult to sex. The Perched birds are an adult female and a juvenile.
Sizes for Northern Harriers varies greatly. Wingspan is as much as 105cm(42inches) Length is 42-60cm (17-24inches),with females being 1/3 larger then males,as is the case with most birds of prey. Females and juveniles look similar,with alot of rusty streaking on the chest. Juveniles have more. Their backs are brown. Males look completely different,appearing blue/grey on top. From below,they are very pale,appearing to be very white,with black wing tips. Many bird guides describe the wingtips as looking as though they've been dipped in ink. This is very diagnostic. All Northern Harriers have a prominent white bum patch. This is not soley a means of identification,but confirming evidence when other field marks are observed. In flight,all Harriers appear to have a long slim tail with long wings. To me on a down flap the wings look triangular and its very diagnostic. They appear to have a facial disk,owl like. When flying U will notice a strong dyhedral or v-shape.
At migration time Harriers often fly in heavy winds. Seeing males is a treat,as often migration sites see them at a rate of 8 females/juveniles to 1 adult male. Juveniles are often difficult to sex. The Perched birds are an adult female and a juvenile.
No comments:
Post a Comment