The bright red breasts on these robins tell us that they are both males.
(Each also has a very sharp line between the dark gray face and nape
and the breast.) Also, male robins rarely fight with females.
Robins can fight with their beaks, wings, or feet. If a robin senses
a real threat of harm (an owl, for instance), it will attack with its
beak. (It's usually too dangerous for a robin to strike anything with
its wings. The bones are hollow and it could hurt itself.) But robins
often use their feet to fight with each other. It's the safest way to
send a strong message!
Robins Fight in Late Winter
robin fights take place as flocks are breaking up at the end of winter.
(Robins stay in flocks and share fruit resources in winter when their
hormones and urge to fight are low.)
days get longer, hormones and restlessness increase. Sometimes one bird
just NEEDS to sing or to chase off a nearby bird. The robins get uncomfortable
being so close together. Restlessness and fighting break up winter flocks.
Robins Fight to Defend Territories
Sometimes robins also fight like this when they arrive somewhere and
want to establish a territory. They
usually settle the boundaries quickly, and most territories are similar.
But if one area has a special resource like a birdbath, the birds will
fight more over that territory. Once the babies are hatched, the adult
robins may "declare" some kind of truce so they can all share
the water, but not the rest of the backyard. Then they can use their
energy to feed babies instead of fighting.
When male robins return to their territories, they usually sing from
various perches. Perhaps they're thinking, "I think this
is my territory, but if you fly over here and chase me off, then I'll
know it's YOUR territory." But
this can get tricky . . .
Early Birds Can Get Worn Out!
The first ones to return and set up territory boundaries are often the
robins who were in the same spot the summer before. Other robins that
migrate through get chased off by the male and female who have the territory.
If their territories have good resources (like a birdbath), the "home"
birds might have to spend a lot of energy and time chasing off the migrants. Sometimes, especially in a migration "magnet" area where thousands
of robins pass through, local birds use up so much energy that they
end up NOT nesting!
By Laura Erickson