Old observations - still useful?

Here’s a set of related general questions from a relative newbie. I’ve been taking wildlife photos for years, and I’m a reasonably good photographer. I recently joined iNaturalist, and posted photos from my yard going back maybe 7 years, photos from Africa from 2019 and also 2008. I assume that this has value as long as I have exact location and date information. The question is in several parts: (1) Am I right that these older photos have value? (2) I have older photos than these that in some cases have sufficient location/date data, some from other countries or other states. Should I post them?

Related question: if I see the same species over a long period of time, should I post ongoing observations? If so, how often?


yes, as long as you have the time and passion to do so.

observations can be valuable even if the dates and locations are not super precise.

yes, if you like. probably not every second, probably not every minute, probably not every hour. otherwise, use your best judgment.


Yes, old observations are indeed useful!

I have posted a couple of observations from the mid-2000s, and have come across observations dating to the 1970s and 80s and earlier!

if I see the same species over a long period of time, should I post ongoing observations? If so, how often?

You could post every day if you wanted to.


I recently posted some old photos of dragonflies that I took while on vacation in California 10 years ago. The person who identified them said they were new state records for latest flight dates for those species. I thought it was pretty cool that my old photos could contribute something about the biology of a species.

If you’re trying to figure out what to concentrate on, I would suggest looking for photos from places of seasons where that species has few or no observations. Or ones that document interactions with other species such as predators, food sources, diseases, pollinators, breeding period, etc.

As a conservation biologist, the new observations that are most useful to my work are the ones that fill in gaps in information instead of ones that repeat or overlap existing information.


Please post your older photos! They present important historical records. And post as many photos of the same thing as you want.


I was contacted by the county historical society a while back about some notebooks that they found with bird journals dating back to the 1890’s, I don’t know who the person was who wrote them, but I could kiss them. They had dates, locations, and in cases of rarities, good descriptions. I was able to make eBird entries for Evening Grosbeak (only county record at time of upload), and Greater Prairie Chicken. So yeah, you never know when someone may find your records.


Thanks, everyone. I’ll look at my old digital pix.


And if you have time to do old non-digital scans. That too.


and sketches from memory… and notes from journals (photo-less obs can have value too!)…

Seriously, anything which you yourself find interesting enough to post an observation of is bound to have someone else interested as well… either from a data point pure science perspective, or just from an amateur “learning about nature” point of view. I started on plants in iNat, and now I review ALL New Zealand spider observations, and I love seeing stuff I haven’t seen before. And it’s terrific to be able to practise my ID skills on stuff I HAVE seen before. And it’s just plain cool to see people caring enough to post them!

As long as you are happy to do so, your observations are very appreciated!


I’ll just echo all that has been said above. I’ve got a small moth collection from 1985, and have posted about half of them. Why not?
Right now we are in winter, and there isn’t a wide range of Life out and about. I still take pictures when I can. I’ve got lots of observations of Black Capped Chickadees and White Breasted Nuthatches!


Same for me, except it’s mostly Chestnut-backed Chickadees and Red-breasted Nuthatches!


The iNaturalist definition of “recent” is within the last 100 years. So anything later than 1921 will do. I will certainly be posting pictures taken on my travels as I come across them again.


The way I see it iNat has one principle raison d’être (to promote understanding of and learning about biodiversity) and a bunch of subsidiary benefits, one of which is having fun learning about…etc. I have a lot of fun rummaging through old photos and figuring out when and where they were taken. I’m still looking for a circa 1964 photo of me with a fish I caught in a little lake north of Thunder Bay that I know is in an album someplace and when I find it I will post it here, just because. If it keeps you engaged with the natural world and manages to put a smile on your face besides then it’s all on mission.


This may be leading this discussion on a different tangent, but what about posting observations of things you have already posted in a previous year? I am mostly interested in plants, and every season that rolls around presents some of the same plants to be observed. Is there value in one more photo of, say, Yellow Trillium? I suppose there is value in posting observations from different locations, to show range. Maybe more pictures of anything can “teach” the AI how to recognize them.

Personally, I wouldn’t. I’m okay with posting the same bird at different times because, well, it’s an animal. More is likely to have changed since I last photographed it. But plants… I wouldn’t post the same individual plant multiple times unless a lot had changed. Multiple observations of the same species are fine, although you should exercise good judgement - e.g. don’t just photograph every single dandelion in your yard and post them as separate observations. But others may disagree with me.

You may want to check out this topic for more opinions.

Yellow trillium? Another data point for distribution and time of blooming.


I just realized I posted a duplicate observation while sorting photos. Should I delete one? Identical date, photos, etc. Both tagged as Research Grade by someone else.

I’m having a difference of opinion with another iNaturalist member on a plant I observed. I hope it’s perennial, because then I will be able to observe it again next year and see if we can figure out what it is. Any goldenrod experts willing to look at my observations? I’d appreciate another opinion.

Yes, please delete one! Duplicates are useless and annoying, so either delete it or identify another organism in the photo (noticed @trh_blue doing that recently and it seems smart).


Yes. Post that Trillium again this year. For one thing, it’s still there; some day it may not be. Also, the date of flowering or fruit set may change as climate changes. That’s important data that people can mine from iNaturalist data.