As we prepare to launch Season 7 (yes! it’s coming soon! stay tuned!), I thought I’d share with you some things we’ve seen in seasons 1-6.
Snapshot Serengeti is over a year old now, but the camera survey itself has been going on since 2010; you guys have helped us process three years of pictures to date!
First, of the >1.2 million capture events you’ve looked through, about two-thirds were empty. That’s a lot of pictures of grass!
But about 330,000 photos are of the wildlife we’re trying to study. A *lot* of those photos are of wildebeest. From all the seasons so far, wildebeest made up just over 100,000 photos! That’s nearly a third of all non-empty images altogether.
We also get a lot of zebra and gazelle – both of which hang out with the wildebeest as they migrate across the study area. We also see a lot of buffalo, hartebeest, and warthog — all of which lions love to eat.
We also get a surprising number of photos of the large carnivores. Nearly 5,000 hyena photos! And over 4,000 lion photos! (Granted, for lions, many of those photos are of them just lyin’ around.)
Curious what else? Check out the full breakdown below…
I’m in the process of writing up some *really* cool camera trap results from Seasons 1-6, and plan to share them here next week (as soon as I make them pretty). It would never have been possible without your guys’ help. But in the meanwhile, this just aired again on TV, and thought you might enjoy a bit of a break! They talk about the camera traps a bit ~33 minutes in.
Okay, okay, it’s actually more like 2 months in the life of the camera, but I strung selected images together for site M08, Season 4, “roll 2.”
It’s actually pretty cool. It amazes me just how much information we get on even a single camera. We can see the migration moving through, the grass greening up, and even a spat between lions and hyenas!
My next task will be to string *all* of the images together for the season, but there are >2,000 of them, which my little computer couldn’t quite handle just yet.
As you all ready know Snapshot Serengeti’s thousands of camera-trap images are part of an ongoing study into predator interactions by Ali. There are few projects that use camera-traps as extensively as Snapshot Serengeti and of course Ali has her hands full analysing the bits relevant to her. The cameras work around the clock recording details of daily and nightly life in the Serengeti and do not discern between the stuff Ali does and doesn’t want. That’s why, Ali’s sanity aside, they are such perfect tools. Those same cameras providing Ali’s data could also be the basis of a future ecologist’s research.
One of the most striking asides for me is the case of the giraffe and the oxpeckers.
Oxpeckers are small birds that feed on ticks and other parasites that they glean from the bodies of large mammals. Most usually they are seen riding along on large mammals such as buffalo, wildebeest and giraffe whilst they search their hosts for ticks or open wounds. This in itself is not an unusual occurrence and most of you will have hit the bird /other button with these guys. Much more unusual are the shots of giraffe at night time with these birds using them as roosting spots. There are two species of oxpecker, the red-billed (Buphagus erythrorhynchus) and the yellow-billed (Buphagus africanus) both of which are found in the Serengeti.
According to research carried out by M. Stutterheim and K. Panagis that looked at the roosting habits of both species the red-billed oxpecker roosts in trees but the yellow-billed was often found roosting on their preferred host species. Apparently red-billed oxpeckers feed on a wide range of host species where as yellow-billed oxpeckers are much more picky preferring buffalo and giraffe. It is thought that the habit of roosting at night on their favourite host species is an adaptation to save the birds time looking for the right animal the following day. Given that buffalo and giraffe are prone to walking large distances this is probably very sensible.
From most of the images we have of oxpeckers on giraffe at night it is hard to tell which species they are but there are one or two where you can see the tell-tell yellow bill confirming that they are indeed yellow-billed oxpeckers. The images also show that the birds seem to prefer settling between the hind legs of the giraffe. This must be a nice warm spot in winter and keeps them safe from any nocturnal predators.
Perhaps the behaviour is not so unusual after all but rather little documented. Getting photographic evidence of birds at night on mobile roosts is obviously not easy. Looks like our camera-traps have excelled themselves again.
In processing Seasons 5 and 6, I recently stumbled upon a bunch of video files amongst the stills. You may recall that while we have our cameras set to take still images, every once in a while a camera gets accidentally switched to video mode. Then it takes 10-second (silent) clips. Most of these are “blanks” triggered by grass waving in the wind. But every once in a while, we get ten seconds of animal footage. Here are some from Season 5.
And, what do you think this is?
I’ve got to echo Margaret’s apology for our sporadic blog posts lately. Things have been a bit hectic for all of us — Dr (!!!) Margaret Kosmala is finishing up her dissertation revisions and moving on to an exciting post-doctoral position at Harvard, our latest addition, Meredith, is finishing up her first semester (finals! ah!), and I’m knee deep in analyses (and snow!).
So,\ please bear with us through the craziness and rest assured that we’ll pick up the blog posts again after the holidays. In the meanwhile, I’ll show you something that got me really excited last week. (Warning: this involves graphs, not cute pictures.)
Last week, I was summarizing some of the Snapshot Serengeti data to present to my committee members. (My committee is the group of faculty members that eventually decide whether my research warrants a PhD, so holding these meetings is always a little nerve-wracking.) As a quick summary, I made this graph of the total number of photographs of the top carnivores. Note that I’m currently only working with data from Seasons 1-3, since we’re having trouble with the timestamps from Seasons 4-6, so the numbers below are about half of what I’ll eventually be able to analyze.
The height of each bar represents the total number of pictures for each species. The color of the bar reflects whether or not a sighting is “unique” or “repeat.” Repeated sightings happen when an animal plops down in front of the camera for a period of time, and we get lots and lots of photos of it. This most likely happens when animals seek out shade to lie in. Notice that lions have wayyyy more repeated sightings percentage-wise than other species. This makes sense — while we do occasionally see cheetahs and hyenas conked out in front of a well-shaded camera, this is a much bigger issue for lions.
I also dived a little deeper into the temporal patterns of activity for each species. The next graph shows the number of unique camera trap captures of each species for every hour of the day. See the huge spike in lion photos from 10am-2pm? It’s weird, right? Lions, like the other carnivores, are mostly nocturnal….so why are there so many photos of them at midday? Well, these photos are almost always lions who have wandered over for a well-shaded naptime snoozing spot. While there are a fair number of cheetahs who seem to do this too, it doesn’t seem to be as big of a deal for hyenas or leopards.
Why is this so exciting? Well, recall how I’ve repeatedly lamented about the way shade biases camera trap captures of lions? Because lions are so drawn to nice, shady trees, we get these camera trap hotspots that don’t match up with our lion radio-collar data. The map below shows lion densities, with highest densities in green, and camera traps in circles. The bigger the circle, the more lions were seen there.
The “lion hotspots” in relatively low density lion areas have been driving me mad all year. These are nice, shady trees that lions are drawn to from up to several kilometers away, and I’ve been struggling to reconcile the lion radio-collar data with the camera trapping data.
What the graphs above suggest, though, is that there likely to be much less bias for hyenas and leopards. Lions are drawn to shade, because they are big and bulky and easily overheated. We see this in the data in the form of many repeated sightings (indicating that lions like to lie down in one spot for hours) and in the “naptime spike” in the timing of camera trap captures that suggest lions seeking out shade trees to go to. Although this remains a bit of an issue for cheetahs, what the graphs above suggest is that using camera traps to understand hyena and leopard activity will be much less biased and much more straightforward — ultimately, much easier than it is for lions. And this is really good news for me.
Last week I posted an animated GIF of hourly carnivore sightings. To clarify, the map showed patterns of temporal activity across all days over the last 3 years — so the map at 9am shows sites where lions, leopards, cheetahs, and hyenas like to be in general at that time of day (not on any one specific day).
These maps here actually show where the carnivores are on consecutive days and months (the dates are printed across the top). [For whatever reason, the embedded .GIFs hate me; click on the map to open in a new tab and see the animation!]
Keep in mind that in the early days (June-Sept 2010) we didn’t have a whole lot of cameras on the ground, and that the cameras were taken down from Nov 2010-Feb 2011 (so that’s why those maps are empty).
The day-by-day map is pretty sparse, and in fact looks pretty random. The take-home message for this is that lions, hyenas, cheetahs, and leopards are all *around*, but the chances of them walking past a camera on any given day are kinda low. I’m still trying to find a pattern in the monthly distributions below.
So this is what I’ve been staring at in my turkey-induced post-Thanksgiving coma. Could be worse!
Tomorrow is American Thanksgiving. Whether or not you celebrate Thanksgiving this week, I hope you’re able to spend time with family,
hang out with friends,
find some tasty food to eat,
get some rest,
and give thanks for the good things in life.
And a special thank you from us to you for all the work you’ve put in to classifying animals on Snapshot Serengeti.
Calling all camera trap captures!
BBC’s annual camera-trap ‘photo of the year’ contest is drawing a close – and we’re pretty sure Snapshot Serengeti has some winners. So we’re asking for your help to find them!
The contest has three relevant categories:
- Animal Portraits Images taken during the course of research that capture the character or spirit of the animal
- Animal Behaviour Images captured during the course of research that show interesting or unusual behaviour.
- New Discoveries Images that show something new to science, such as a species never before photographed in the wild or outside its known range, or behaviour never before recorded. The caption must make clear what the discovery is.
We can submit up to 12 photos across these three categories. Long-time Snapshot Serengeti moderator lucycawte has already pinpointed a couple of fantastic photos:
…but we’d like your help to find some more!
So send us the subject ID’s or urls of your all-time favorite Snapshot Serengeti pics (via comments here). One of them just might wind up front and center in the next issue of BBC Wildlife or make Snapshot Serengeti the proud winner of a monetary prize to keep the cameras clicking.
And speaking of Snapshot Serengeti funding, I wanted to take a minute to say thank you all who have supported our Save Snapshot Serengeti campaign so far. Yesterday we passed our 20% mark, and we’re marching forward! For everyone out there who loves looking at these incredible photos, please take a look at our campaign — we have some really fun perks that you might enjoy. And whether or not you’re able to make a donation, please help us spread news of the campaign by sharing our link: igg.me/at/serengeti – the more people we reach, the better our chances of bringing you these photos for years to come. Thank you for your support, your effort, and for being as addicted to Snapshot Serengeti as we are!
Every once in a while, a camera gets knocked off a tree and ends up pointing up into the tree where there are many grassy balls hanging from the branches. We have one of these cameras in Season 5, and it is taking pictures like this one:
What are those odd grassy balls? Why, they’re the nests of weaver birds. My Birds of East Africa book lists a dozen species of weavers in the Serengeti, and most of them have a yellow and black pattern. Here’s what some of these guys look like close up.
Several years ago, I watched through a Lion House window as a weaver bird build its nest from scratch. The bird started with just a branch, one with something of a knot at the end where a twig may have split off in the past. The weaver grabbed a long blade of grass and wrapped it around that knobby joint and tucked the blade under itself, as you might do if you were tying your shoe. Then it got another blade of grass and wove that through the loop it had created with the first blade, tucking it securely back under and through the loop a second time. It continued to add blades for the next twenty minutes or so, such that the grass formed two clumps, one sticking out of either side of the knot.
(Aside: the soundtrack is completely coincidental; field assistant John was cooking something in the kitchen while listening to music.)
Straddling the two clumps, with one talon hanging on to each, the weaver then took a long blade from one clump and wove its end back up into the other clump. The result was a loop. The bird pulled additional grass from one clump to the other and strengthened the loop. Bit by bit.
I watched for over a half-hour, but I had work to do, too. So I left the little weaver to its task, and checked in again that evening before the sun set. There it was, a hefty wreath of grass hanging from the end of a tree branch.
I checked again a couple days later. The weaver had been working on filling in grass around the sides to form the ball shape.
Three days later the ball shape was becoming apparent (and I finally decided to take pictures outdoors instead of through the window, so that they’re better in focus).
Aha! I caught a decent shot of the builder. My bird appears to be a Vitelline Masked Weaver male. (Although, my book also says that the top of the head ought to be rather chestnut color and this guy has maybe only a little bit of chestnut and rather brown markings on the back instead of black. Maybe it’s a young male?) These guys generally are found solitary or in pairs, which explains why I saw just one of them building a nest in a tree all alone. And their nests are “distinctive onion-shaped nests with an entrance hole at the bottom.” Looking good…
Five days later Mr. Vitelline’s work was looking very much like a nest.
Five days later was also my last day in the Serengeti, so I didn’t see further developments of this nest. But I suspect it was completed and became a comfortable abode for its industrious builder.