Why bird feet don’t freeze

Many people have bird feeders out and get enjoyment out of seeing birds in their back yard during the winter months.

If you pay attention you will have noticed that birds are well covered with a thick layers of warm feathers with the exception of their legs and feet, yet somehow these naked, spindly little legs and feet don’t freeze.

Birds actually have a nifty heat exchange system in their legs called Rete Mirabile which helps them prevent freezing. They share this system with some other animals such as fish and some mammals such as sloth and lorises.

In bird feet the arteries run really close to the veins causing warm blood heading from the body to the legs to warm the cooler blood flowing back to the body. This system reduces heat loss and is further enhanced by the arteries which relocate from a position closer to the skin during the summer more to the center of the leg during the colder winter month.

Bird lower legs and feet don’t contain muscles (just tendons). This causes the legs and feet to need very little energy allowing for reduced blood supply.

When it is really cold however even this system needs a little help and you will see birds sitting down with their feet tugged up into the downy feathers on their chest/belly to prevent their feet from freezing.

Canada Goose Sitting down to prevent cold feet

During severe cold spells we often receive calls from people who think waterfowl are frozen to the ice which most often is simply a case of a waterbird sitting on the ice using its feathers to keep its feet warm. They are often reluctant to move because exposing their naked feet to the cold can cause them to freeze, much like our fingers and toes.

 

Many healthy birds, particularly waterfowl spent a lot of time preening ensuring their plumage is perfectly oiled. The oil is produced by their uropygial gland which is located at the base of their tail. The oil repels water making it that the birds don’t get wet, but it also prevents them from freezing to the ice.

Waterfowl who are not healthy and therefore have neglected their plumage will often appear wet. These are birds who need help right away. In those causes don’t hesitate to contact you local SPCA, Humane Society, Animal Control or Authorized Wildlife Custodian.

Some of the birds of prey have adapted by growing feathers further down their legs and sometimes even feet reducing the exposed skin portion of the leg. This of course also helps reduce heat loss.

 

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A stranded Horned Grebe and Parrot food…

Today we received a Horned Grebe through one of the agencies we deal with regularly.

As many of you may know Grebes are unable to walk due to the placement of their feet. Those feet are ideal for diving, but on dry land Grebes are much like a fish out of water (unable to walk or to take flight). So, this time of year we regularly receive grebes who have mistakenly landed on dry land. This can be as result of them mistaking wet tarmac for water (it shimmers like water) or they simply get so tired looking for open water that they have to make an emergency landing.

Horned Grebes are listed as ‘Special Concern’ on the Species at Risk Ontario (SARO) list. Meaning that their numbers have dwindled low enough to receive extra protection by the Endangered Species Act (ESA)

What makes this Grebe so special (in a bad way) is that it was found by a concerned citizen who took it home and kept it for several days as she attempted to ‘help’ it. Not knowing much about this water bird she force fed it the same food she feeds her parrot…

She did finally turn it over to the agency who proceeded to transport it to me. However, instead of dealing with simply re-hydrating the bird and returning it to open water I am now dealing with a bird who has a severe gastro-intestenal upset with a bad case of diarrhea. Meaning that now the life of this SARO listed bird is on the line

Dealing with injured birds is not easy and you have to know what you are doing. To feed a dehydrated bird can have devastating results. Feeding a water bird who is a strict piscivore (fish eater) parrot food while dehydrated is even worse.

I know the lady who found it tried very hard to help this animal, but instead of helping she inadvertently made its condition worse.  I understand people try their best, but wild animals are not pets and should not be treated as such. It is imperative to the animal’s well being that it gets into the hands of a wildlife professional as soon as possible.

Not only is it in the wild animal’s best interest to get to a professional asap, it is also illegal to be in possession of wildlife without proper paperwork as per the Fish and Wildlife Conservation Act (FWCA). This Grebe as a migratory bird is protected under the federal Migratory Bird Conservation Act (MBCA) and because it is SARO listed it receives extra protection under the Endangered Species Act (ESA).

At Hobbitstee we have a great working relationship with many agencies such as Animal Controls, Humane Societies, SPCA’s and many vet clinics. If you are unable to locate an Authorized Wildlife Custodian near you. Please don’t hesitate to contact your locale animal agency.

I know many of you reading this have heard me say this over and over, but I am going to keep repeating this message until I stop receiving wildlife who have been fed the wrong food at the wrong time.

‘Please do not feed any injured or orphaned wildlife unless directed to do so by a wildlife professional’

Every situation is different and all though the internet can be a great tool there is a lot of incorrect information on there i.r. to wildlife. There is no one size fits all solution. At Hobbitstee we do not adhere to regular business hours. We take calls around the clock, 7 days a week and on holidays to make sure we help as many wild animals as we can. We are a non for profit charitable organization and as such we do not charge for our services. We do however appreciate donations.

This is the sick Grebe. Look at the placement of it's feet. These feet are made for diving, not walking
This is the sick Grebe. Look at the placement of it’s feet. These feet are made for diving, not walking