we have built a system this year for Arribada Initiative http://blog.arribada.org/ that is working closely with ZSL that implements the functions you require to a large extent. The Arribada FMP device is open source open hardware and you can find more details here: https://github.com/IRNAS/arribada-fmp
The device has the following features:
* Solar powered
* Built-in camera
* RockBlock Iridium modem
* WiFi and LoraWAN communications (not required in you application)
* Ultrasonic distance sensor (not required in you application)
We have built a version of this device for Arribada Penguin monitoring: https://github.com/IRNAS/arribada-pmp which captures images hourly on Antarctica of penguins and stores to the SD card, without the Iridium comunication.
Note that the cost of Iridium system may be prohibitively expensive, see http://www.rock7mobile.com/products-rockblock
2000 credits for 800GBP will give about 100MB of capacity, which can translate to about one photo per day if a compressed resolution is sufficient. A full HD image will for example be 2.4MB.
A more optimal method would be to take a photo several times a day, process them using OpenCV or other image processing library to determine if the image is interesting and then send it via Iridium. This can save some data as well as generate interesting photos. All of them can be stored to the SD card and retrieved at a later point.