First, some more bone-reference sites;
As Gary said, giraffes are easy to start with because they're so difficult to screw up, plus they're fairly slow-moving but easy to visually analyze. The things that are most likely to trip up newcomers are the spots. Please please please, don't try drawing the spots during your first sketches, or even your first hour. Our reaction to the resulting drawings is usually something like this
So, start loose.
Things to remember;
-the head is generally triangular, as are the ears, and is much thicker at the jaw than at the muzzle.
-the neck has a gesture, not just a curve. Think of it like the giraffe's head is a hand puppet.
-the neck doesn't merge smoothly with the torso and back; there is a raised ridge, sort of like they're hunchbacked.
-the body is bulky toward the front, and rises higher than the rear.
-the bottom halves of the legs are very thin, but the knees, elbows and ankles are all thick.
-there are two hooves on each foot.
The jaws are thick, but not as thick as in other animals. The skull actually continues behind the horns and creates a small protrusion just above where the neck dips down. The ears are stuck on to the very back of the skull, and always start to the rear of the horns, but around eye level. The lips are supple and expressive because they're used for foraging. There's a raised bone ridge just above the eyes, in the middle of the head, that changes slightly from giraffe to giraffe and increases with age.
When you do draw the spots, use them to define the contour of the head; placing them randomly and unintelligently will flatten the drawing and generally make it look like crap.
And, if you find it useful, I made a video of a giraffe skull fading in and out over a photo.
Giraffe Photo/Skull Transposition
More of Gary's drawings;
Partial Leg Study
Partial Leg Study 2
Three muscle-deconstructions similar to Natural History Museum pics
Three, three Giraffes, ah-ah-ah-ah-ah!
This is an excellent archive of high-resolution video clips of giraffes, and many other animals. I'll be referring to it often. I got the best results by selecting Quicktime-Broadband from the little window that says "select streaming format" beneath each clip.
Info on Giraffes from Wikipedia;
Gerenuks are a little harder to find reference for, but they're generally shorter giraffes, but they move much quicker and look much less awkward and bulky.
Our trip to the Natural History Museum was meant to introduce you to animal
drawing in the same way we approach life drawing; by understanding the forms
beneath the surface, and how they affect that shape with their movement. Of
course, in the field, we'll rarely get the opportunity to draw a motionless
animal in the same way we do with life drawing models, so animal drawing requires
a much more informed artist right from the start.
Nothing can make up for knowing what muscles and bones go where in these animals, and any similarities or visual cues you can pick up on will enable you to put more into your drawings regardless of how long you observed the pose you're drawing. In the case of the skeletons at the museum, we can identify bone structures by their similarities both to humans and to the modern animals they resemble, and from that, make informed "guesses" as to where and how their muscles were once arranged. As you become more informed, these "guesses" won't really be guesses at all.
Sloth skulls and a sabertooth cat;
Compare to this image of a sloth skull from http://www.boneclones.com:
The skull is generally bear-like (bear skull) so this is a good starting point for visualizing how the skull would have looked with skin covering it. Note also that we're not drawing bones; all those little nuances and cracks belong in your illustration or drawing & comp class. We're trying to get the gesture and form of the shape down quickly but clearly.
black = gesture, outline and skeleton
orange = muscle
blue = contour
We can already see, from the size and layout of the bones, that the animal is heavyset and well-muscled; the wide swath of scapula is clearly set up to anchor large tricep muscles that end at the protruding ulna. As you move farther down in the leg, the amount of muscle generally decreases in favor of more ligaments and tendons, which are thinner and create less mass over the underlying bone.
The same logic applies here. We can clearly see the similarities to a human leg, especially in the location of the calf muscle. The femur and humerus on many quadrupeds tend to be shorter than the tibia, because this maximizes the length of the stride for each extension of the femur or humerus, which anchor most of the muscle. Note also that the form becomes sharper and more angular around key points like the hips, knee and ankle, which have little or no muscle over them, and are easy to identify in the field.
We'll be working on giraffes at the zoo next week, so take the opportunity to get familiar with the form while you can. The muscle thins out dramatically over the length of the legs, and the joints protrude noticeably, giving you easy visual cues. The body is heavier toward the front - just visualize how this guy supports that head and neck with every movement, and how much weight is placed on the forelegs when he takes up a pose like this (many animals carry most of their weight on their front legs all the time). The weight creates bulges and overlapping skin folds all around the base of the neck, the chest, forelegs, meanwhile stretching and revealing the hollow behind the scapula.
Elephants can be very challenging because of the overwhelming amount of information. The best thing you can do here is to find those visual cues, as well as develop a familiarity with the animal's gesture and weight.
Ultimately, the reverse of our process with the bones; seeing the muscle and bone underneath the form, rather than visualizing it on top. Sharper curves in the form, such as over the scapula, hips, ulna and jaw, are clear indicators of the forms beneath. Stretches, such as in front of the femur, imply extension, and bulges imply compression.