[EBB Sightings] Skittish Burrowing owls

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It's unlikely that ground squirrels would drive away Burrowing Owls. In 
their far western range, Burrowing Owls depend on ground squirrels to 
excavate the burrows that they use, since the owls do not dig burrows. 
The squirrel's burrow systems is extensive and it is thought that the 
small section appropriated by an owl is not a problem for a squirrel. 
There has been evidence that Burrowing Owls have taken baby ground 
squirrels for food, but this is apparently a rare occurrence. Among 
their small mammal food selection, they are most likely to take voles. 
Ground Squirrels are not known to take adult Burrowing Owls; rather, 
they have been documented foraging on road kill. They have also been 
known to take birds eggs and, although not specified (Walker's Mammals 
of the World, Vol. 2), it's likely that Burrowing Owl eggs might be a 
target. One South Bay biologist who specializes in Burrowing Owls feels 
that there might be a symbiotic relationship between the owls and the 
squirrels: the owls use burrows dug by the squirrels and, "in return", 
provide alarm alerts when potential predators are near.

The Birds of North America account for Burrowing owls notes that very 
little is known about their migration and wintering life. Some evidence 
suggests that birds from the northern range, including Northern 
California, migrate southward for winter. Also, while the data are not 
conclusive, birds from the Canadian range may migrate further south 
than those from the northern states, aka, "leap-frog" migration.

Les
---
Les Chibana
BirdNUTZ(tm) - Ornigasmic Birding
Palo Alto Baylands Birding Classes
em 
web 
ph 650-949-4335
fx 650-949-4137
snailmail: SR2 Box 335, La Honda CA 94020

On Apr 5, 2005, at 9:05 AM, Alan Howe wrote:

> Hi, all.
>   Speaking of the Berkeley Marina (Cesar Chavez Park)
> burrowing owl(s), I was out both Sunday and yesterday
> and the usual perch was empty. The place was crawling
> with ground squirrels, however. They wouldn't have
> driven the owls away, would they? They are certainly
> big enough to intimidate birds of that size.

[snip]

> Alan Howe
> North Oakland
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It's unlikely that ground squirrels would drive away Burrowing Owls.
In their far western range, Burrowing Owls depend on ground squirrels
to excavate the burrows that they use, since the owls do not dig
burrows. The squirrel's burrow systems is extensive and it is thought
that the small section appropriated by an owl is not a problem for a
squirrel. There has been evidence that Burrowing Owls have taken baby
ground squirrels for food, but this is apparently a rare occurrence.
Among their small mammal food selection, they are most likely to take
voles. Ground Squirrels are not known to take adult Burrowing Owls;
rather, they have been documented foraging on road kill. They have
also been known to take birds eggs and, although not specified
(Walker's Mammals of the World, Vol. 2), it's likely that Burrowing
Owl eggs might be a target. One South Bay biologist who specializes in
Burrowing Owls feels that there might be a symbiotic relationship
between the owls and the squirrels: the owls use burrows dug by the
squirrels and, "in return", provide alarm alerts when potential
predators are near. 


The Birds of North America account for Burrowing owls notes that very
little is known about their migration and wintering life. Some
evidence suggests that birds from the northern range, including
Northern California, migrate southward for winter. Also, while the
data are not conclusive, birds from the Canadian range may migrate
further south than those from the northern states, aka, "leap-frog"
migration. 



---

Les Chibana

BirdNUTZ(tm) - Ornigasmic Birding

Palo Alto Baylands Birding Classes

em <

web <

ph 650-949-4335

fx 650-949-4137

snailmail: SR2 Box 335, La Honda CA 94020


On Apr 5, 2005, at 9:05 AM, Alan Howe wrote:



  Speaking of the Berkeley Marina (Cesar Chavez Park)

burrowing owl(s), I was out both Sunday and yesterday

and the usual perch was empty. The place was crawling

with ground squirrels, however. They wouldn't have

driven the owls away, would they? They are certainly

big enough to intimidate birds of that size. 


[snip]



North Oakland
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