Best guess: the humidity is too low, you're not watering often enough, or both. There's an outside chance that you're watering too much.

It would be easier to diagnose if you said how much light it's getting, how big it is, how long you've had it, what the humidity and temperature are like where it is, how often you water, etc.

I just aquired a bird nest fern about a month ago. the leaves are getting brown spots on them. It is in a shaded area of my carport. It gets lot of inderect light.

Ditto to what Mr. Subjunctive said.

I have 2 of these plants, one the species and one 'Osaka'(wavy leaved one). I have lost one 'Osaka' in the past. The one died, I feel, because I was watering the crown of the plant. A couple of different sources say that you shouldn't do this. BUT, the logic just isn't there. As these plants grow in the rainforests, rain collects in the crown and they don't die. Go figure. Anyway, the 'Osaka' is much more finicky with it's watering and humidity requirements than the species. It HATES to dry out and must have constant humidity. The species, Asplenium Nidus, also likes to stay moist, not wet, like a wrung out sponge. If it dries out too much, I'm rewarded with a tan leaf or two. :) I don't provide it with high humidity and it does fine.

I'm new to house plants, but i've killed one birds nest fern before and the second is thriving (this is how we get to be good at caring for a particular kind of plant it seems you have to kill one and learn from your mistakes).

What i've found is that it's easiest to water from UNDER the plant. What i mean is when the surface of the soil in the pot is dry (check it every other day folks you don't want it to get starved). Take it and set it in a shallow bowl of water mixed with the right amounts of liquid miracle grow houseplant food. Let it soak maybe 15-30minutes or until either all the water is absorbed or the surface of the soil is moist. If the soil is dry on the top and the water is all absorbed add more and check every so often. when the soil is thoroughly moist, remove the plant and drain for a few minutes (i stick it in the kitchen sink) and then return it to it's normal home. My 4 inch plastic pots sit inside glazed ceramic containers to dress them up and keep moisture from getting on the windowsill.

Watering from underneath avoids crown rot (which i understand to be a problem common to this plant), and it assures even moisture in the soil, i've noted it's hard to get the soil fully watered when watering from 'overhead' esp since i have a 4inch pot for my birdsnest fern.

Also i noticed in TOO HIGH lighting conditions the leaves get really really pale almost white even after just one day. When not watered enough the leaves get really dry and start getting brown spots at the edges. With crown rot i started loosing leaves rapidly and no new leaves would spring up out of the crown.

I can tell my plant is healthy the way i've been caring for it now (after a few months after bringing it home from the nursery) the fronds have gotten darker (they started almost yellow and are now darker)and i'm getting new buds poking through the crown.

My birdsnest fern is in a west facing window with a 6 foot porch overhang. It gets gentle light until the end of the day just before the sun sinks over the horizon. It doesn't seem to prefer bright light, nice 'understory' kind of filtered light seems to suit it well. (like what you'd get under a tree)

I've started watering all my houseplants from underneath (with exception of my orchid which gets misted). The african violets and my birdsnest ferns love being watered this way from my experience.

I've only had these about 6 months but for now it seems everything's going quite well.

As others said, more info about growing conditions should help pin down the problem. Also-- if you're new and getting frustrated with too many losses, I'd recommend telling the folks here what your growing conditions are and letting them recommend some plants that'd thrive where you want them.

Nerdgirl-- I like your statement about having to kill one of each plant in order to learn how to grow it correctly. Too true, it seems!

GH-- Hi! Just thought I'd throw something in about bird's nests & crown rot. You're right that on the surface it doesn't seem to make sense that they'd be so sensitive when they get overhead water all the time in habitat--- but, in habitat they get great air circulation, above and beyond what they can get indoors. I think that's the main difference.