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Posts tagged “predators

Barred Owl Diet

This is pure conjecture, but here goes. Barred Owls are known to consume small mammals, birds, reptiles, amphibians, fish and invertebrates. I have repeatedly encountered a Barred Owl lately near a pool of water in a brook that has all but dried up. Fish have become trapped in this pool due to the dryness of the summer, and are easy pickings for predators. Even though studies have shown that fish are a very small percentage of a Barred Owl’s diet (2.5% in owls from New Jersey, New York and Connecticut during the breeding season), I am betting that the owl that I flushed yesterday that was perched right next to the isolated pool in the brook was spending the day (and night?) at his favorite fishing hole. Three times it took off from its perch as I approached, but only flew a few feet away each time. Perhaps fish or frogs kept it from disappearing further into the woods.


Mating Season for Eastern Coyotes

If the increased yelping of eastern coyotes hasn’t caught your attention, you may not be aware that this is the peak of their breeding season. Female coyotes come into estrus once a year, for a period of about 10 days.  For the past two or three months, working up to this, male and female coyotes have been increasing their scent marking.  Occasionally you can find where a female has marked with urine, leaving behind a spot of blood (see photograph).  Eventually she attracts one or more sexually active males, and mating ensues. Something I’ve never witnessed, but would love to, is the howling duet of a pair of coyotes prior to mating.   

 


Red-tailed Hawk

Given the right lighting, it’s very easy to see how red-tailed hawks (Buteo jamaicensis) got their common name (although the tail of juvenile red-tailed hawks is brown for their first two years).  Central Vermont and New Hampshire is at the northern end of the red-tailed hawk’s year-round range – if they live much further north, they usually migrate south for the winter.  This common bird of prey typically inhabits open areas interspersed with trees.   It is usually observed soaring in wide circles over a field, or perched high in a tree, where it sits and waits, keeping an eye out for prey such as mice, voles, rabbits and hares.  Once it spots a small mammal, as the red-tail in this photograph just had, it quickly takes off and uses its talons to capture its next meal.

 


Larvae-seeking Downy Woodpeckers

12-3-11  Larvae-seeking Downy Woodpeckers

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When cooler days arrive and adult insects become relatively scarce, insect-eating birds are very clever at gleaning the twigs, trunks and buds of trees and shrubs for overwintering eggs, larvae and pupae.  Certain galls (abnormal plant growths that house and provide food for a variety of insects) are sought by specific birds.  Downy woodpeckers seek the larvae of the Goldenrod Gall Fly (Eurosta solidaginis), which overwinter inside Goldenrod Ball Galls (formed on Canada Goldenrod, Solidago canadensis) before emerging as adults in the spring.  A tiny1/4” to 3/8”-wide hole (and an empty gall) is evidence that a downy woodpecker had itself a meal!

   


Ladybeetles Mating

Many ladybug beetles (ladybeetles) mate in the spring, but some species do so in late summer and fall.  Each species of ladybeetle has its own pheromones for attracting a mate.  Mating can last up to two hours, with the male climbing up and holding onto the female’s outer wings, while intermittently vibrating rapidly (making photographing them somewhat challenging). Their eggs hatch in 4 to 10 days, and within two weeks the larvae have matured into adults.   Most of these aphid-eating predators will spend the winter hibernating, becoming active in the spring, when aphids are available once again.


Robber Fly

Robber flies have been covered in a previous posting, but their beak, or proboscis, deserves its own post, in my opinion.  These predators perch and scan the sky for prey. When they see it they  anticipate the prey’s direction and speed of flight and fly out and intercept it mid-air.  Their objective is to paralyze the prey and  liquify its insides so that the fly can drink it.  The tip of the robber fly’s beak is covered with microscopic stiff bristles, designed to secure it within the wound it creates. Once this is achieved, a dagger-like shaft hidden inside the beak is used to stab its victim in the head or thorax and inject the paralyzing  neurotoxic and digestive enzymes.  The resulting fluid is sucked up by the fly’s beak, or proboscis.